II. Dual Kidney Transplant
- What is the type of this study?
- What is the level of evidence this study provides?
- What are the indications of dual kidney transplantation?
- In your own words, summarise the outcome of this study!
- What is Remuzzi score and what is its implementations?
What is the type of this study?
Review article .
What is the level of evidence this study provides?
Level 5
What are the indications of dual kidney transplantation?
1-Donors older than 65 years old with at least 1 of the following risk factors : hypertension, type 2 diabetes mellitus, atherosclerotic disease, or death from a cardiovascular event.
2- Donors with eGFR between 30 -60 mL/min .
In your own words, summarise the outcome of this study!
Dual kidney transplantation increases the pool of potential donation and enables use of marginal kidney . It reduces the transplant waiting time . It was described for the first time in 1996 . The most common indication is; donors older than 65 years old with at least 1 of the following risk factors : hypertension, type 2 diabetes mellitus, atherosclerotic disease, or death from a cardiovascular event and those with eGFR between 30 -60 mL/min .Unilateral placement of both kidneys is the technique of choice .The result of graft and patient survival ,complication and quality of renal function provided by DKTs are comparable to SKTs. There is a high prevalence of vascular complications, mainly in form of graft thrombosis . Selection criteria for DKTs are still variable and center dependent. There is reluctance of many centers to perform DKTs because of lack of clear guidelines regarding allocation, which is usually left to the transplant clinicians to decide. More research should help to develop standardized criteria for DKT kidney allocation.
What is Remuzzi score and what is its implementations?
A scoring system based on pre transplant biopsy for selection of a kidney for DKT.
Kidneys with macroscopic major vascular abnormality or evidence of focal scarring were excluded.
Both kidneys were biopsied, and those with less than 25 glomeruli were excluded.
Dual kidney transplants were performed if a priori score was between 4 and 6 .
Pre transplant Biopsy Protocol
1-Glomerular Global Sclerosis:
0 None globally sclerosed
1 < 20% global glomerulosclerosis
2 20% – 50% global glomerulosclerosis
3 > 50% global glomerulosclerosis
2-Tubular Atrophy;
0 Absent
1 < 20% tubuli affected
2 20% – 50% tubuli affected
3 > 50% tubuli affected
3-Interstitial Fibrosis
0 Absent
1 < 20% of renal tissue replaced by fibrous connective tissue
2 20% – 50% renal tissue replaced by fibrous connective tissue
3 > 50% of renal tissue replaced by fibrous connective tissue
4- Arterial and arteriolar narrowing:
0 Absent
1 Increased wall thickness but to a degree that is less than the
diameter of the lumen
2 Wall thickness that is equal or slightly greater to the diameter of the lumen
3 Wall thickness that far exceeds the diameter of the lumen with
extreme luminal narrowing or occlusion Only biopsies with ≥ 25 glomerules considered for evaluation.
Kidneys with evidence of acute tubular necrosis are not considered for DK
1.Review article
2.Level of evidence : 5
3.Dual kidney transplantation done with marginal kidneys from expanded criteria donors , donor of cardiac death and pediatric donors
as marginal kidney may result in sub-optimal nephron mass to allow recipient to become dialysis independent so dual kidney transplantation is the treatment of choice
4.Rumuzzi score :scoring system based on pre-transplant biopsy for selection of a kidney for DKTs where brain dead donors ,older than 60 years , donors who were diabetes or donors with the presence of proteinuria less than 3 gm /24 hours were considered.Kidneys with macroscopic major vascular abnormality or evidence of focal scarring were excluded , both kidneys were biopsied , those with less than 25 glomeruli were excluded.
Dual kidney transplantation will be done if score between 4 to 6
5.Summarize the outcome :
Dual kidney transplant has increased the pool of potential organs by increasing use of marginal kidneys.
Ipsilateral placement of both grafts is widely accepted and performed.
Results of graft and patient survival, complications, and quality of renal function
provided by DKTs are comparable to single kidney transplant .
*Review article .
*Level 5 evidence .
*The indication of dual kidney transplant is using marginal kidneys to reduce waiting list for older patients.
*In summary: a review article to show the benefits and complications of dual kidney transplant ,main indication is to use marginal kidneys as in extended criteria donor with low nephron mass to get better result; selection of the kidney done by using biopsy for both kidneys and use one of glomerular sclerosis between 15 and 50% or eGFR between 60 and 30 ml/min. There are two surgical techniques Gibson incision ;one kidney in each side with longer operation time and anesthesia complications, second technique was unilateral placement of both kidneys ; for pediatric donor they ; en block kidney transplant with less complications .Graft and patient survival were excellent between 95 and 100%.
Remuzzi score depends on bilateral kidney biopsy, the biopsy should contain 25 glomeruli with exclusion of any scarred kidney or the one with vascular abnormalities, if sclerosis less than 15 % it use as single kidney transplant and if it is more than 50%;not used and use those between 15 and 50% for dual kidney transplant.
1-review article
2-level 3
3-indication of dual kidney transplantation
Donor with Extended criteria
Pediatric age group
2. Remuzzi and associates
-scoring based on pretransplant biopsy for selection a kidney (DKT)
Pretransplant Biopsy Protocol
Glomerular Global Sclerosis: Based on 3 sections (First, Middle and Last if available), the number of globally sclerosed glomeruli expressed as percentage
0 None globally sclerosed
1 50% global glomerulosclerosis
Tubular Atrophy
0 Absent
1 50% tubuli affected
Interstitial Fibrosis
0 Absent
1 50% of renal tissue replaced by fibrous connective tissue
Arterial and arteriolar narrowing: For the vascular lesions, if the changes are focal, the most severe lesion present gives the final grade
0 Absent
1 Increased wall thickness but to a degree that is less than the diameter of the lumen
2 Wall thickness that is equal or slightly greater to the diameter of the lumen
3 Wall thickness that far exceeds the diameter of the lumen with extreme luminal narrowing or occlusion
Only biopsies with ≥ 25 glomerules considered for evaluation. Kidneys with evidence of acute tubular necrosis are not considered for DKT
PS and Graft survival – 100% at 6 months
3.Study by Spanish group
-kidneys from dead donors with normal creat- DKT if donor older than 75 years
-donors from 60-74 years with GS of 15%-50%- DKT
-mean donor age 75 SD7
-Graft survival- 95%in 6 months
4.UNOS (2008)
1-review article
2-level 3
3-indication of dual kidney transplantation
DKT of marginal kidney better than kept in waiting list
marginal kidney :age>70
or between 60 up to 70 with HTN-DM-long ischemia time -<50%glomeruloscalerosis
we can say old doner for old recipient
marginal donor DKT for old person with lower immunological risk.
4-summary
* DKT in marginal kidney
* mostly use unilateral placment of both kidney
2-midline extra peritoneal approach
3-unilateral placement of both kidney
5-Remuzzi score
score use to determine suitable kidney for DKT
should biopsy >25 glomeruli
(score between 4&6 recommended)
Glomerular Global Sclerosis: the number of globally sclerosed glomeruli expressed as percentage. 0- None globally sclerosed
1- < 20% global glomerulosclerosis
2-20% – 50% global glomerulosclerosis
3- > 50% global glomerulosclerosis
Tubular Atrophy
0 Absent
1- < 20% tubuli affected
2- 20% – 50% tubuli affected
3- > 50% tubuli affected
Interstitial Fibrosis
0- Absent
1- < 20% of renal tissue replaced by fibrous connective tissue
2- 20% – 50% renal tissue replaced by fibrous connective tissue
3- > 50% of renal tissue replaced by fibrous connective tissue
Arterial and arteriolar narrowing
0- Absent
1- Increased wall thickness but to a degree that is less than the diameter of the lumen
2- Wall thickness that is equal or slightly greater to the diameter of the lumen
3- Wall thickness that far exceeds the diameter of the lumen with extreme luminal narrowing or occlusion
4.Summary ; Dual kidney transplant was introduced first in 1996 and since then there is increased use of this technique. Dual kidney transplantation allows utilization of the marginal kidneys and therefore reduces waiting time. Generally older recipients receive kidney from older donors. Surgical techniques includes; Bilateral Gibson incision( more tissue dissection), Midline extraperitoneal approach, Unilateral placement of both kidneys( less injure, and less time consuming), En block kidney transplantation. Shor-term survival within 6 months is excellent(6). UNOS data base showed similar death-censored graft survival in 48 months. Studies from Europe also demonstrated promising results specially in France(10), Ireland(24), and Spain(11). EBK in adults also showed encouraging results. Complications of DKT are ; Early graft thrombosis(11), ureteric stenosis/urinary fistula, myocardial infarction(10), more ICU admissions(24), Wandering Kidney. CONCLUSION ; DKT reduces the waitlist time and the outcome is comparable to single kidney transplantation. The complexity of the procedure and lack of experiences in many centres remain the major challenge for DKT.
5.Remuzzi and associates(4) developed a scoring system which depend on biopsy before before transplantation. They included DBD donor> 60 yrs, diabetic, non nephrotic range proteinuria. Kidneys with focal scarring were excluded. Marginal kidneys score between 4 and 6 were transplanted( Table 1 showed the scoring system). Most biopsies are superficial and therefore more glomerulosclerosis . This needs to be interpreted carefully
review atricle level five , expert opinion
address the daulkidney transplant outcome , surgical techinques , indication , selection criteria for donor and recipient
SUMMARY :
Daul tranplant have been used since 1996 with promising out come over years and improved surgical techeniqes
in 2003 the UNOS implemented the EDC expanded donor criteria as one of the solution to reduce waiting on dialysis due to increasing numbers of eldery ESRD waiting for RTX and expanding the pool of marginal donors
no clear cretieria for donors allocation but the use of older donor for older recipient is preferable based on local exprites opinions
EDC including the following
1- donor age > 60 years
2- donor age above 50s with Hypertesion
3-serum creatinine level of more than 1.97 mg/dL.
4-death due to cerbrovscaulr event
5- donation after cardiac death with long warm ischemic injury
between 2000-2005 the UNOS registray reveiwed the results of DKT of 525 recipients with the two or more of the following EDC:
1-Donor age above 60s years with baseline donor ccr above 65ml/min
2- increased creatinine by 2.5mg/dl
3-chronic hypertension or type 2 diabetes mellitus,
4-glomerulosclerosis score 15% and 50%,they found that Three-year graft survival was 79.8%.
DKT associated with more surgical complication like longer surgical time, more dissections , wound infections hernia ,and the complication rate vary due to different surgical techneqiues , in general DKT associated with more risk of graft and vascular thrombosis, DGF, wound related hernia , and ureteric stenosis urine leak . in pediatric Enblock kidney transplantaion also associated with higher surgical complication , higher rejection rate and hyperfilteration injuries
the transplantaion of single marginal kidney from EDC donor with cardiac death associated with reduced functional nephrom mass in addition to the subsequent effect of DGF, acute rejection , drug toxicity with CNi all can fruther compromized the remaining functional nephron mass overtime and affect the graft survival ,so using daul marginal donor transplantion can compensate for the mentioned effects.
in regards to the DKT we still lacking the evidnece from randomazid trails addressing the surgical feasiblity , standardized of the donor selction criteria adopopting pathological scoring for better selection and reduced rate of organ waisting
for better DKT out come prefered to consider better matching between recipent / donor age , BWT , choose recipent with low immunological risk ( no previous senisitization , less comorbids diseases
Remuzzi kidney biopsy glomerulosclerosis scoring adopted in 1999 and included in DKT donor selection creiteria with acceptable scoring abve 15 -50% with this scoring the data from single centre of DKT in donor age above 70s shows graft survival in first year above 90% also reduced the rate of oragn discard , its contain different domians with scoring rate from 0-3 including assesmnet of % of glomerulosclersis , scarring , tubular atrophy , intersitiatl fibrosis , and vascular changes , the adequte biopsy should contain 25 glomerlui and above with no ATN
Review article
Level 5 evidence
Dual Tx Indication?
To increase donor marginal pool in elderly specially those expected to have lower nephrons function after Tx . The transplant of a single marginal kidney (from
ECDs, donors with cardiac death, and pediatric
donors) may result in a suboptimal number of
functional nephrons to allow recipients to become
dialysis independent. Episodes of acute rejection,
medication toxicity (particularly from calcineurin
inhibitors), and effect of the recipient’s comorbidities
on the transplanted kidney will adversely affect these
limited functional nephrons
Summery of outcomes ?
Before this we should allocate suitable kidney for suitable recipients for dual kidney Tx .
●Many studies from 1999 to 2008 to allocate suitable kidney most of them depend on biopsy before tx but it has many complications so many centers
To avoid biopsy-based decisions, the estimated glomerular filtration rate (eGFR) in the donor as acriterion was used instead. Donors older than 65
years old with at least 1 of the following risk factors were considered:
1..hypertension,
2..type 2 diabetes mellitus, 3…atherosclerotic disease, or death from acardiovascular event
● Recipien Allocation.
most DKTs involve donors at age extremes, matching an older
donor with an older recipient is suggested.
Onereason is that the limitedfunctioning nephron mass would be enough for an elderly recipient with limited metabolic demands and the elderly would not require graft survival of greater than 20 years
based on their expected lifespan. In addition, lower
acute rejection rates in elderly recipients
Most authors have suggested DKTs to recipients with lower immuno –
logic risk (ie, recipients without previous transplant
and panel reactive antibody titer < 50%).4
In contrast, the encouraging results of DKTs with
excellent creatinine levels and lesser acute rejections
allow for greater consideration in younger recipients.
Younger candidates can more easily recover from the
longer operative time necessary for D
Authors recommend 👌
DKT is offered to patients 60 years or
older. Our group prefers offering DKTs to patients
with low immunological risk, who are less than 60
years old, and who have minimal comorbidities and
body mass index < 30 kg/m2.
Remuzzi system .
scoring system based on pretransplant biopsy for
selection of a kidney for DKT.
Pretransplant Biopsy Protocol
Glomerular Global Sclerosis: Based on 3 sections (First, Middle and Last if
available), the number of globally sclerosed glomeruli expressed as
percentage
0 None globally sclerosed
1 50% global glomerulosclerosis
Tubular Atrophy
0 Absent
1 50% tubuli affected
Interstitial Fibrosis
0 Absent
1 50% of renal tissue replaced by fibrous connective tissue
Arterial and arteriolar narrowing: For the vascular lesions, if the changes are
focal, the most severe lesion present gives the final grade
0 Absent
1 Increased wall thickness but to a degree that is less than the
diameter of the lumen
2 Wall thickness that is equal or slightly greater to the diameter of the
lumen
3 Wall thickness that far exceeds the diameter of the lumen with
extreme luminal narrowing or occlusion
Narative review
level 5 evidences
Dual kidney transplant
– Single marginal kidneys has been postulated might result in suboptimal number of functional nephrons which inadequate for dialysis independent
– Limited function might not enough to sustain insult of acute rejections, medication toxicities, comorbodities
– 2 marginal kidneys able to give more functioning nephrons
– Increasing nephrons mass by Tx 2 kidneys able to prevent deterioration in renal function
– Potential high risk surgery -longer surgical procedure, 2 folds increase risk in vascular and ureteric anastomoses
Kidneys that suitable for dual transplant
-no global consensus
1. Johnson and associates
-older than 60 years
-and /or long history of HTN or DM
-with CIT lesser than 30 min
-creat clearance – 80-40mls
– less than 40% GS without IF or arteriosclerosis on biopsy
Showed 100% PS and GS at 6 months
2. Remuzzi and associates
-scoring based on pretransplant biopsy for selection a kidney (DKT)
Pretransplant Biopsy Protocol
Glomerular Global Sclerosis: Based on 3 sections (First, Middle and Last if available), the number of globally sclerosed glomeruli expressed as percentage
0 None globally sclerosed
1 50% global glomerulosclerosis
Tubular Atrophy
0 Absent
1 50% tubuli affected
Interstitial Fibrosis
0 Absent
1 50% of renal tissue replaced by fibrous connective tissue
Arterial and arteriolar narrowing: For the vascular lesions, if the changes are focal, the most severe lesion present gives the final grade
0 Absent
1 Increased wall thickness but to a degree that is less than the diameter of the lumen
2 Wall thickness that is equal or slightly greater to the diameter of the lumen
3 Wall thickness that far exceeds the diameter of the lumen with extreme luminal narrowing or occlusion
Only biopsies with ≥ 25 glomerules considered for evaluation. Kidneys with evidence of acute tubular necrosis are not considered for DKT
PS and Graft survival – 100% at 6 months
3.Study by Spanish group
-kidneys from dead donors with normal creat- DKT if donor older than 75 years
-donors from 60-74 years with GS of 15%-50%- DKT
-mean donor age 75 SD7
-Graft survival- 95%in 6 months
4.UNOS (2008)
DKT criteria
-age greater than 60
-creat clearance >65
-increased serum creat->2.5mg/dl at retrieval
-chronic HTN or T2DM
-GS 15-50%
Histological findings that asso. Impaired allograft function
– 5 year survival -80% when no GS , 35% when GS>20%
eGFR
– Most used criterion
DKT
– Donor older than 65, with
– 1 of the following
o HTN
o T2DM
o Atherosclerotic disease
o Death from CVD
eGFR- >60-SKT
eGFR-7 with:
o HTN
o MI
o T2DM
o CVA – as cause of death
o Creat >1.97mg/dl
o Present of anatomical anomalies ( RAS/ PCKD)
Suitable recipient
– Suggested matching recipients with donor by age and size
– Limited functioning nephron mass – for elderly recipient who has limited metabolic demands and do not require GF >20 years
– Elderly require less CNI due to less AR- reduce the nephron insult
– RTR that lower risk -PRA 60 years but the study suggested for low immunological risk, <60 , and who had minimal comorbidities and BMI <30
Surgical technique
1. Bilateral Gibson incision and Tx 1 kidney to each side
– Single midline incision – shorter operative time and dissection and fewer hernia as complication vs bilateral Gibson insidious
–
2. Unilateral placement of 2 kidneys
-RK paced superiorly with RA anastomoses onto Common Iliac artery
-RV into IVC
-clamps released to allow anastomoses of LK vascular pedicle to external iliac vessels
-both ureters spatulated and joined each other’s
-reduced trauma from surgical procedure and contra lateral side for future TX
-Graft survival similar to BL side and shorter time for operation
Larger studies – unilateral DKT had shorter operative time 206min SD 35 min with 95%
at the R side -outcome similar to SKT
Graft and Patient survival
Lee associates- suggested older donor for older RTR
-similar PS and graft survival at 1 year ( 98% and 89% in DKT vs 97% and 90% in SKT)
-2 years survival not significant different among DKT and SKT
UNOS 2007
-DKTs from ECD – similar DCGS 70%
-inferior to SCD- 80%
PS and graft survival in general similar to SKT
Quality if DKT function is important as low long it will keep functioning and patient independent of dialysis
Complications
– Higher due to technical difficulties, loaner op timing, lower kidney quality
– Early renal graft thrombosis – concern in DKT
– UTI incidence is higher
– Post op RTR of DKd – higher risk of developing MI
– mono lateral placement reduces length of surgical procedure and hosp stay
Review article
Level 5
Using of extended criteria donation to compensate the shortage of donated kidneys, but sometimes the available kidneys do not functioning well to keep the patients dialysis independent which usually occurs in both elderly & pediatric kidney & cardiac death donor. Due to immunosuppressive toxicities & patient co morbidities the function of marginal kidney will be in sufficient to keep the patient well. For this reason the dual kidney transplantation idea start ( offer 2 marginal kidneys to patient that can keep him with out dialysis).
First DKT done in USA in 1996. Most transplantation center ddi not offer DKT to their patients due to prolonged surgical operation which carry high rate of complications. Usually DKD use the kidneys which rejected for single kidney transplant, depending on creatinine clearance (80-40 ml/min) & degree of glomerulosclerosis ( by renal biopsy). UNOS criteria for DKT include:
The DKT offered for patient age more than 60 years & who have low immunological risk ( minimal co morbidities, BMI<30). there are different surgical techniques used for DKT as:
Graft & patients survival was good after one year (70%) compared to single kidney transplant. But en block procedure associated with increased risk of graft loss. DKT had many complications including:
Remuzzi score used to evaluate the donated kidneys & classified it to SKT , DKT or rejected depending on renal biopsy of both kidneys. the score calculate the degree of tubular atrophy, interstitial fibrosis, vascular wall thickening & glomerulosclerosis. The renal biopsy should contain at least 25 glomeruli during histological examination.
Donation from elderly donors may result in early graft dysfunction due to poor nephron mass. The concept of dual kidney transplant has come into the clinical picture from 1999. Although RCT do not exists, many centers have published their experiences of DKT
The following criteria are used by the United Kingdom Kidney advisory group
Age>70 years, Hypertension, Type 2 Diabetes Mellitus, with history of CVA, MI, serum creatinine > 1.97mg% at retrieval, presence of any anatomical abnormalities like RAS, PCD, Small kidneys
Many centers use renal biopsy to decide on the glomerular/IFTA/vascular lesions score. Some centers use both clinical and biopsy score to decide about the DKT. In the Italian study group, Ekser and associates, used pre transplantation protocol biopsy of the donor and looked into glomerular, interstitial fibrosis, tubular atrophy and vascular lesions. Those with score of 4 to 6 were taken for DKT,but those with score more than were not accepted.
Pediatric Enblock kidney transplants were done from pediatric donors and also had good graft outcomes
4.Outcomes of DKT:
UNOS – Death censored graft survival 70% with dual kidney transplants as compared to Standard criteria donor the survival was 80% at 5 years.
European – At 3 years, comparable graft and patient survival between SKT and DKT in patients between 60 to 69 years and more than 70 years donor were identified.
2 large analysis of UNOS database published in 2008 and 2014 – overall graft and patient survival was comparable at 3 and 5 years. Interestingly DKT group had lower incidence of Delayed graft function as compared to SKT group. This was probably due to shorter cold ischemia times in DKT as compared to SKT where the kidneys will have to be transported across centers. Pediatric enblock kidney transplants had a slightly higher loss of graft as compared to SKT from ECD and SCD. This is due to higher rate of surgical complications with pediatric en block transplants and more sensitivity to rejection and hyperfiltration injury in the long term
5.
REmuzzi and associates in 1999, used a pretransplant scoring system in renal biopsy for the selection of DKT. Brain dead donors more than 60 years, donors who are diabetic, donors with proteinuria < 3gms in 24 hours were considered. Macroscopic abnormalities of kidneys with evidence of focal scarring were excluded. Those kidneys with less than 25 glomeruli were excluded. Those kidneys with ATN were excluded
A composite score with 4 parts. Each part has a score from 0 to 4.
glomerular global sclerosis:
0-none
1-<20% global glomerulosclerosis
2-20-50% of global glomerulosclerosis
3->50% global glomerulosclerosis
Tubular atrophy
0- none
1-<20% tubular atrophy
2- 20-50% tubular atrophy
3->50% tubular atrophy
Interstitial Fibrosis
0 – absent
1- <20%
2-20-50%
3->50%
Vascular lesions:
0 – absent
1- mild increase in the wall thickness
2-moderate increase in wall thickenss
3- severe wall thickening causing narrowing of vessels
score of 4 to 6 is accepted for transplant from DKT .With the above scoring system survival of 100% was reported by 6 months
This review article.
Level of evidence V.
Transplant is treatment of choice for ESRd patients. Limited donor pools lead to. Expand
of criteria by accepting ECD,transplant from extreme if age and double kidney and
donation after cardiac death.
Donation from single marginal kidney may result in suboptimal nephron ,with rejection
infection and transplant drug further affect this SKT.
So the DKT an increase of nephron mass I.e 2 marginal to one recipient , more or many
functioning nephron would be available.
There’s no guideline or controlled studies compare to SKT and practice is center specific .
DKT is surgery demanding due to multiple vasculature and double urter connection.
Which kidney vis suitable?
Kidney from donor older than 60years.
Long history of HTN or DM.
Cold ischemia less than 30hours.
Kidney with creatinine clearance 40-80ml/min ,with kidney shows less than
40%Glomerulosclerosis
With less severe IF or arteriolosclerosis. On biopsy.
Brain dead donor.
Proteinuria less than 3gram.
Remuzzi suggest scoring system based on pretransplant biopsy for election of DKT.
This include global sclerosis percent.
Tubular atrophy percent
And interstitial percent.
DKT performed if score between 4_6.
Spanish study include brain death donor more than 75year with normal serum
creatinine, and between 60_74 if glomerulosclerosis is less of 15_50% at biopsy.
GFR criteria to select DKT is guess by many center musing Cockcroft and Gault criteria.
Donor with eGFR more 60ml/min considered for SKT., discarded if less than 30ml and
between 30 to 60ml/mln is indicated for DKG.
Uk kidney advisory board suggest kidney rom door 70 or older can be used for DKT if
none or more is present:
HTN
T2DM.
MI
CVA
Creatinine more 1.97mg/dl.
Presence of any anatomical anomaly Or polycystic kidney.
Who is suitable recipient?
Most suggest match recipient age and size. recipient, with low immunization risk I.e. no
history of transplantation and PRA less than50%.
Less than 60years.
Minimal comorbidity and body mass index less than 30kg/m2.
DKT has both good patient and graft survival.
Unilateral placement of DK reduce surgical risk .
Remuzzi and associates suggested a scoring system based on pretransplant biopsy for
selection of a kidney for DKT. Brain dead donors
older than 60 years, donors who were diabetic, or
donors with presence of proteinuria of less than three grams/24 hours were considered. Kidneys with macroscopic major vascular abnormality or evidence of focal scarring were excluded. Both kidneys were biopsied, and those with less than 25 glomeruli were excluded. Dual kidney transplants were performed if a priori score was between 4 and 6
1- review articles.
2-Level of evidence v.
3- Indication of Dual Kidney Transplantation donors older age 60 years Or older than 50 with a history of hypertension had cause of death due to cerebrovascular events, or
-have serum creatinine level at retrieval of more than 1.97 mg/dL.
Remixing and associates suggested a scoring system based on pretransplant biopsy for selection of a kidney for DKT.
– Brain dead donors older than 60 years, donors who were diabetic, or donors with presence of proteinuria of less than three grams/24 hours were considered. Kidneys with macroscopic major vascular abnormality or evidence of focal scarring (ie, chronic pyelonephritis) were excluded. Both kidneys were biopsied, and those with less than 25 glomeruli were excluded. Dual kidney transplants were performed if a priori score was between 4 and 6 .
4- Renal transplantation is ttt of choice with ESRD patients, with increasing numbers waiting for kidney transplantation making us for search broad options within transplantation.
Extended criteria donors include donors older
than 60 years or those who are older than 50 with a history of hypertension, had cause of death due to cerebrovascular events, or have serum creatinine level at retrieval of more than 1.97 mg/dL.2 Donation after cardiac death also has been accepted worldwide as source of organs despite organs regarded as marginal due to association with warm ischemic injury. The transplant of a single marginal kidney (from ECDs, donors with cardiac death, and pediatric donors) may result in a suboptimal number of functional nephrons to allow recipients to become
dialysis independent. The first adult dual kidney transplant (DKT) was in the United States in 1996 by Johnson and assoiates.Two decades earlier, dual kidneys from pediatric donors had been transplanted into adults. Moreover, 54% of the kidneys from donors > 65 years old in the United States and 12% in Europe are discarded. These limitations clearly indicate the need to expand DKT practice. Remuzzi and associates4 suggested a scoring system based on pretransplant biopsy for selection of a kidney for DKT. Brain dead donors older than 60 years, donors who were diabetic, or donors with presence of proteinuria of less than three grams/24 hours were considered. Kidneys with macroscopic major vascular abnormality or evidence of focal scarring (ie, chronic pyelonephritis) were excluded. Both kidneys were biopsied, and those with less than 25 glomeruli were excluded. Dual kidney transplants were performed To avoid biopsy-based decisions, the estimated glomerular filtration rate (eGFR) in the donor as a criterion was used instead. Donors older than 65 years old with at least 1 of the following risk factors were considered: hypertension, type 2 diabetes mellitus, atherosclerotic disease, or death from a
cardiovascular event. Depending on maximal eGFR calculated with use of the Cockcroft and Gault formula, donors with eGFR > 60 mL/min were considered for SKT. Kidneys were discarded when eGFR was < 30 mL/min, and eGFR between these results was an indicator for DKT. with donors by age and size. Because most DKTs involve donors at age extremes, matching an older donor with an older recipient is suggested.
addition, lower acute rejection rates in elderly recipients as a result of antiproliferative agents with lower dose levels nephrotoxic calcineurin inhibitors would reduce long-term nephron insult.To reduce possible injury to limited nephron mass, most authors have suggested DKTs to recipients with lower immunologic risk ( recipients without previous transplant and panel reactive antibody titer )
Many factors affect graft function, including
donor factors, donation circumstances, cold ischemia time, and perioperative events
Monolateral placement of both kidneys reduces length of the surgical procedure and hospital stay.
ipsilateral placement reduced dissection time and made lymphocele risk similar to that for SKT procedures.
References:
1. Bunnapradist S, Gritsch HA, Peng A, Jordan SC, Cho YW. Dual kidneys from marginal adult donors as a source for cadaveric renal transplantation in the United States. J Am Soc Nephrol. 2003;14(4):
1031-1036.
2. Allen J, Hudson A. Dual kidney transplantation. Kidney Advisory Group. 2011;16(11):1-9.
3. Navarro AP, Sohrabi S, Reddy M, Carter N, Ahmed A, Talbot D. Dual transplantation of marginal kidneys from nonheart beating
donors selected using machine perfusion viability criteria. J Urol. 2008;179(6):2305-2309; discussion 2309.
4. Remuzzi G, Grinyo J, Ruggenenti P, et al. Early experience with dual kidney transplantation in adults using expanded donor criteria.
Double Kidney Transplant Group (DKG). J Am Soc Nephrol. 1999;10(12):2591-2598.
5. Codreanu I, Cravedi P, Remuzzi G, Ruggenenti P. Dual kidney transplantation. Tx Med. 2004;16:13-18.
1. This is a review article.
2. Its level of evidence is 5.
3. Nowadays with the growing demand of donated kidney, using marginal kidney is considered. Dual marginal kidney transplantation such as Extended Donor Criteria (EDC) or pediatric donors is a solution to increase nephron mass in these kidneys and improve their outcome. There is no absolute indication for using these kidneys; however, there are some suggestions based on researches. Remuzzi score between 4-6 was suggested for this purpose. In Spanish study, in deceased donors above 75 years old and normal creatinine or between 60-74 years old with 15-50% glomerulosclerosis duel kidney transplantation (DKT) was performed. In UNOS database study besides above mentioned criteria, donors with diabetes mellitus, hypertension or rising creatinine were considered for DKT. Other criteria for donors (based on age, clinical and pathologic variables) or recipients and different surgical methods were used for DKT. In Newcastle study glutathion transferase concentration and flow rate of perfusate were measured as a criteria. In UNOS registry, en block kidney transplant (EBK) was an option for pediatric donors less than five years old. Usually recipients of these kidneys have older age and low immunologic risk. Different surgical method such as Gibson’s or midline incision, unilateral kidneys placement and modified Eskar are performed. Graft and patient survival of DKT and EBK are improving. Slightly more surgical complications like wound healing problems, thrombosis or ureteral stenosis are reported.
4. Remuzzi score is a histologic scoring system used to determine the outcome of marginal kidneys of older donors that uses four variables. Its variables are glomerular global sclerosis, tubular atrophy, interstitial nephritis and arterial or arteriolar narrowing to decide which kidney is considered for single or dual transplantation. Scores equal or less than three shows good outcome and are considered for single kidney transplantation. Whereas scores between 4-6 indicates less favorable outcome and are better to use them as dual kidney transplantation. Scores above 7 has the worst outcome and these kidney should be discarded. Total score is 12 and shows the most horrible outcome.
References:
1. Vathsala, A., Haroon, S., Goh, A., & Tiong, H. (2014). Donor Remuzzi Score Coorelates Better With Renal Function Than Kidney Donor Risk Index in an Asian Deceased Donor Population. Transplantation, 98.
2. Remuzzi, G., Cravedi, P., Perna, A., Dimitrov, B. D., Turturro, M., Locatelli, G., Rigotti, P., Baldan, N., Beatini, M., Valente, U., Scalamogna, M., & Ruggenenti, P. (2006). Long-Term Outcome of Renal Transplantation from Older Donors. New England Journal of Medicine, 354(4).
Dual kidney transplantation is still an area of disagreement. Concern about donor criteria and to whom can be offered. In addition, to the best surgical approach. Many centers have no experience in this procedure.
Transplanting ECD kidney donor means suboptimal function nephrons that will not be able to stand the recipient’s comorbidities effects, medication toxicity, episodes of acute rejection. So, dual kidney transplantation has been adopted.
It is an idea to use marginal kidneys that may be discarded from SKT and to increase the function, two kidneys transplanted, as this will increase the nephron mass.
Pre-transplant Kidney biopsy in many studies, is used in the selection criteria, while in other it replaced by e-GFR.
Remuzzi Score: 1999
Scoring system based on pretransplant biopsy for selection of the kidney for DKT
Brain dead donor, older than 60, donor with DM, and donor with proteinuria < 3g/24 hrs were considered. DKT was performed if prior score was between 4-6
So far. There is no global consensus as to which donor kidney is best. And because most of the DKTS include older donor, giving these graft to older recipient is suggestion.
The operation associated with many complications like renal graft thrombosis, urinary tract fistula, ureteric stenosis, long postoperative ICU admission, and wound infection.
This study is a narrative review article
Level V evidence (expert opinion)
indications of dual kidney transplantation:
The indications are based on the hypothesis that 2 donor kidney placed in one recipient can provide a better outcome. when a single marginal kidney from ECD, DCD, pediatric donor may result in suboptimal nephron number to keep the patient dialysis independent and prevent progressive deterioration of the graft function.
Remuzzi score and what is its implementations:
Remuzzi et al 1999 suggested a pre-transplant kidney biopsy scoring system to guide in selection of a donor for DKT.
Before Biopsy:
Inclusion criteria:
Age: DBD donor aged more than 60 years
Comorbidities: history of diabetes or 24 hour urine protein less than 3 gram
Exclusion criteria :
Major vascular abnormalities
Focal scarring
After Biopsy of both kidneys:
< 25 glomeruli: Kidneys excluded
25 glomeruli or More with no ATN with a priori score
0-3: single kidney transplantation done
4-6: DKT
>6: kidneys discarded
This score included glomerular sclerosis, tubular atrophy, interstitial fibrosis and arterial or arteriolar parameters, each point scores from 0 to 3 in that score with a total score of 12).
Summary of the Article:
Renal transplantation is the standard good practice for ESRD patients. The use of kidneys from ECD has resulted in increase of the pool of available kidneys from transplantation. However, transplanting a single marginal kidney may result in suboptimal functioning nephrons to become dialysis independent. Accordingly, DCT (transplantation of two kidneys from a marginal deceased donor in one recipient) has been proposed despite its technical difficulties and high vascular complications.
Until now, there is no global consensus about which kidney is more suitable as DKT rather than SKT (no randomized prospective studies comparing both)being a non-routinely performed procedure with variation in the practice, protocols and absence of clear guide lines and allocation polices
This paper provided a literature about the different programs that performed DKT starting from Johnson and his associates in 1996 focusing on the selection criteria for donors, who is the best recipient, surgical techniques done and the outcome regarding patient and graft survival.
o commonest selection Criteria of deceased donor selection:
Age: variable between >60 to >75 years in elderly and < in pediatrics.
Comorbidities: history of Hypertension, diabetics, myocardial infarction, cerebrovascular events as a cause of death, proteinuria < 3 grams
Renal function: elevated terminal creatinine (>1.97 mg/dl), some centers preferred to go for a pre transplant renal biopsy to assess glomerulosclerosis and IFTA (usually from 15-50% are selected for DCT) and Remuzzi et al suggested a pre-transplant biopsy selection criteria. Others prefer to depend on the (eGFR) that ranged between and 30- 60 ml/min.in some studies and 40-80 ml/min in other studies
Other selection criteria:
cold ischemia time < 30 (suggested by Johnson et al)
Kidneys with anatomic abnormalities (RAS, polycystic small kidneys, kidneys with multiple cysts) used by united kidney advisory group and Sheffield kidney institute
Use of hypothermic machine perfusion(Newcastle team)
o Best Recipient for DKT:
Age: matched with the donor
co-morbidities: the minimal comorbidities the better outcome
Weight: BMI less than 30 in adults or body weight less than 80 kilograms in en block kidney transplant
Immunologic risk: no previous transplant or PRA less than 50%
o Surgical technique and complications:
Midline extra-peritoneal approach is the preferable and commonly used than bilateral Gibson incision. Unilateral placement of both kidneys with the RT higher that the LT was described by Mason and Hefty and modified by Ekser has a shorter operative time and hospital stay. En block kidney (EBK) transplantation is performed in case of pediatric donors.
DKT surgical complications are higher than SKT due to technical difficulty and long operative time , they include wound dehiscence, early graft thrombosis, urinary track complications like ureteric stenosis and fistulas(placing both kidneys on one side reduces these complications).EBK is associated with vascular complications due to smaller blood vessels.
o Outcome regarding patient and graft survival:
Most of the groups have shown similar patient and graft survival to SKT. Similarly, primary non function and DGF rates in DKT are comparable to SKT. The use of pediatric EBK resulted in similar outcomes despite high surgical complications.
Dear All
I acknowledge your replies, well done
It’s a review article with level of evidence 5
Summary
Using marginal kidney with dual kidney transplant DKT was more useful to decrease waitlist, DKT from extreme age (old age and pediatric) was performed to help the recipient to obtain more nephron mass which will prolong graft survival while single marginal kidney may give suboptimal nephrons.
Many centres adapted DKT with variable factors and surgical approaches.
Most patients receiving DKT are old age group so special precautions should be taken in consideration regarding the operation like time of operation ,total anasthesia and vascular anastomosis which obtained with better result by doing single midline incision and single anastomosis of both renal vessels and this help to reduce vascular complications and operation time .
The main cause of DKT is to keep the patient away from dialysis as long as possible so DKT quality is important and it’s important to keep DKT functioning which is affected by alot of factors like donor factors ,age ,donation circumstances and intraoperative factors like time of cold ischemia.
Alot of difficulties or complications facing the most centres that adapted DKT for example: technical difficulties,wound dehiscence and infection ,graft thrombosis ,urinary tract complications like fistula and uretric stenosis ,higher risk of developing MI and ICU admission rate and renal artery stenosis.
In addition in case of pediatric donor there will be more difficulties intraoperative (surgical) because of small vessel size ,less nephron mass and hyper filtration injury that may cause hypertrophy and proteinuria .
Indications :
This is depend on the centre that perform the operation because each center has it’s own criteria some of these are:
Recipient should be chosen carefully according to strict factors like both of them(donor and recipient)should be almost same age and size with acceptable cross match, low immunological risk (PRA Less than 50%),old age group but it could be done to young patient, body weight less than80kg to decrease operative complications.
And the chosen kidney depends on transplant centre and there is no selection criteria, but in 1999 Remuzzi scoring is adapted with including and excluding criteria to choose the kidneys before transplantation ,biopsy must taken from the prepared kidneys and if the score between 4 to 6 the operation can be done with 100% graft survival for 6 months post op.
Including criteria for the donor brain death ,age > 60years old ,diabetes and presence of proteinuria less than 3 gram in a day.
Excluding criteria :acute tubular necrosis,pyelonephritis ,macroscopic major vascular abnormalities and the sample of the biopsy less than 25 glomeruli .
The sample should be examined for the presence of glomerular global sclerosis ,tubular atrophy, interstitial fibrosis and arterial or arteriolar narrowing.
*Review article .
*Level 5 evidence .
*The indication of dual kidney transplant is to use marginal kidneys to reduce the waiting list for older patients.
*In summary this a review article to show the benefits and complications of dual kidney transplant,the main indication is to use marginal kidneys as in extended criteria donor with low nephron mass to get the better result; the selection of the kidney done by using biopsy for both kidneys and use the one of glomerular sclerosis between 15 and 50% or eGFR between 60 and 30 ml/min.There’s two surgical techniques Gibson incision ;one kidney in each side but it had longer operation time and Anathesia complications,the second technique was unilateral placed of both kidneys ; for paediatric donor they did en block kidney transplant with less complications.The graft and patient survival were excellent between 95 and 100%.
*The Remuzzi score depend on bilateral kidney biopsy, the biopsy should contain 25 glomerlui , with exclusion of any scared kidney or the one with vascular abnormalities, so if the sclerosis less than 15 % it use as single kidney transplant and if it’s more than 50% they discard it and use those between 15 and 50% for dual kidney transplant.
1- This is a review article
2- Level of evidence 5
3- DKT indicated from suboptimal kidney donors as extremes of age , ECD or deceased donor from cardiac causes) to marginal recipient as elderly recipient or recipient with expected short life expectancy aiming at achieving optimal number of nephrons to avoid dialysis
4-Dual kidney transplantation refers to transplanting both kidneys from a marginal donor to marginal recipient as elderly recipient or recipient with expected short life expectancy aiming at achieving optimal number of nephrons to avoid dialysis . The advantage of this process includes expanding donor pool and making best benefit from these donors.
The main complications with this procedure are surgical as vascular and ureter anastomosis complications .Remuzzi score is used to determine suitablility of the kidneys for DKT if their score is 4-6. Short and long term graft and patient outcomes were favorable in many studies as the study by Gepll J et al.
1- Gill J, Cho YW, Danovitch GM, et al. Outcomes of dual adult kidney transplants in the United States: an analysis of the OPTN/UNOS database. Transplantation. 2008;85(1):62-68.
5- Remuzzi score is pretransplantation biopsy scoring system to assess siutability of kidneys for DKT through taking biopsies from both kidney and examine for number of glomeruli , global glomerular Sclerosis, tubular Atrophy, Interstitial Fibrosis and arterial and arteriolar narrowing) .kidneys are suitable for DKT if their score is 4-6
-/–This is a review study with level 5 of evidence
—Dual kidney transplantation though there is no consensus and different centers dah different protocols maybe favored for patients who are not suitable or could not find matched donor especially those at extremes (either as recipients or donors). The theory of enough nephron mass, instead of wasting of deceased donors dual kidneys may be utilized.
—- Remuuzi score is the score used for evaluation of pretransplant deceased kidneys. It helps in selecting suitable kidneys eligible to be transplanted as dual kidneys. Glomerular sclerosis, tubular atrophy, interstitial fibrosis, and arteriolar narrowing (4 parameters are scored from 0-3). Although controversial because of biopsy being taken from peripheral tissues that may have more glomerular sclerosis misleading and reflecting the real percentage.
—–In this review many centers had different protocols but all studies had a favorable outcome. Although all are not talking about longer outcomes the first 2-3 years’ results are acceptable. Taking into consideration the surgical techniques and age and body mass matching well extend the pool of kidneys for transplantation. Either relying on biopsy or eGFR had acceptable results.
This is a review article and its level of evidence is 5.
Author’s in this article reviewed the their current experience with dual kidney transplantation.
Based on the fact that Renal transplant is the treatment of choice for patients with end-stage renal disease and due to long waiting list and the shortage of organs available for donation the use of kidneys from donors from age extremes (pediatric or elderly) appears to be a life saving option.
In late 2003, the United Network for Organ Sharing (UNOS) implemented the use of kidneys from extended criteria donors (ECDs).
Extended criteria donors include :
1 donors older than 60 years.
2 donors older than 50 with a history of hypertension, cerebrovascular disease was the cause of death.
3 donors have serum creatinine level at retrieval of more than 1.97 mg/dL.
Donation after cardiac death also has been accepted worldwide as source of organs despite organs regarded as marginal due to association with warm ischemic injury.
The idea of number of functioning nephrons (nephron mass) in the marginal kidney and how much benefit the recipient could have highlighted that giving 2 marginal kidneys will provide the patient with more functioning nephrons and better kidney function.
centers perform DKTs using different organ selection criteria and techniques. There is no enough studies to compare single marginal kidney transplantation with dual kidney transplantation.
several authors have reported acceptable results even with kidneys considered unacceptable by others.
Dual kidney transplant carries a higher risk of surgical complications because of the longer surgical procedure and the 2-fold risk associated with double vascular and ureteric anastomoses.
Remuzzi and associates suggested a scoring system based on pretransplant biopsy for selection of a kidney for DKT.
Brain dead donors older than 60 years, donors who were diabetic, or donors with presence of proteinuria of less than 3 grams/day were considered.
Kidneys with macroscopic major vascular abnormality or evidence of focal scarring (ie, chronic pyelonephritis) were excluded.
kidneys were biopsied, and those with less than 25 glomeruli were excluded. Dual kidney transplants were performed if a priori score was between 4 and 6 ,and kideys with 7or more were excluded.
Spanish group also included kidneys with
less than 15% glomerulosclerosis.
Five-year survival was 80% when protocol biopsy showed no glomerulosclerosis and dropped to 35% when sclerosis was > 20% in donated kidneys.
Some authors also have reported higher delayed graft function (80%) with sclerosis > 20%.
Biopsy may overestimate the percentage of
glomerulosclerosis so eGFR of donor as a criterion was used instead.
Donors > 65 years old with at least 1 of the following risk factors were considered: hypertension, type 2 diabetes mellitus, atherosclerotic disease, or death from a cardiovascular event. Depending on maximal eGFR calculated with use of the Cockcroft and Gault formula, donors with eGFR > 60 mL/min were considered for SKT. Kidneys were discarded when eGFR was < 30 mL/min, and eGFR between these results was an indicator for DKT.
No standard criteria for recipient selection age and size matching is accepted by some centrs .
Surgical techniques are different also but the common is Unilateral placement of both kidneys with the right kidney above the left one.
In pediatric due to surgical complications as vessels are small En block kidney transplant using pediatric donor aorta and the inferior vena cava can theoretically reduce that risk.
Complications with DKT are higher due to technical difficulties, with longer operative time and lower kidney qualit.
Graft and patient survival, complications, and quality of renal function provided by DKTs are comparable to SKTs.
Better to add references that support your data. From the paper itself or to add supportively updated references
Review article , expert opinion ( level of evidence 5)
Dual kidney transplantation is done to allow the use of kidney with suboptimal criteria , that otherwise will be discarded, so we can increase the donor pool.
Some centers uses dual kidney transplantation when the donor kidney is not fit in single kidney tansplantation.
Other centers uses dual kidney transplantation with certain criteria like :
So in general , kidneys that did not fit in single kidney transplantation , we can consider dual kidney transplantation provided that it’s expected to support the life of the patient being transplanted.
Remuzzi scoring is a score using the pretransplantation biopsy to allow classification of donor kidneys to make decisions , which kidney goes for single transplantation, and which goes for dual kidney transplantation. the score depends on 4 variables ( global glomerulosclerosis %, interstitial fibrosis, tubular atrophy, vascular changes)
A score of 0-3 , the kidney goes for single kidney transplantation.
A score of 4-6 , the kidney goes for dual donor transplantation.
A score > 7 , the kidney are discarded .
The recipient of dual kidney transplantation is also a source of debate . one strategy is to use old for old. Since older patients had lower immunological risk , and lower life expectancy so it would be useful to use these marginal kidneys .
Also low immunological risk patients fits better for dual kidney transplantation, since it had lower nephron mass and every effort should be done to reduce damage to it.
The outcome of dual kidney transplantation is encouraging , with the patient and graft outcome nearly equal of single kidney transplantation.
References?
This is a review article of level 5 evidence
there no allocation criteria for the selection of DKT but most of the centers that implement DKTs agree on older age above 60 years , brain dead or cardiac death due to warm ischemia time , ischemia time 30-40 min, GFR 80-40 , and normal in others ,
co-omorbidities as HTN or diabetes , renal biopsy is done for assessing the glomerulosclerosis , glomeruli , presence of nephritis :Presence of severe interstitial nephritis is excluded by some centers , Moreover selection of the donor is also important for the DKTs , usually older age recipients with low immunological risk PRA less than 50% , and no previous Tx are selected
The outcome of this study implement the idea and the importance of DKTs as a salvage way for decreasing the waiting list and using more of the ECD grafts with nearly comparable results as single good graft thus the importance of doing more research and control studies in order to reach the proper decision and to form proper allocative guidelines for the DKTs .
Remuzzi is the first one to perform a scoring system for DKTs , depending on renal biopsy ; glomerulosclerosis , tubular atrophy , interstitial fibrosis , arterial and arteriolar narrowing .
Dual Kidney Transplant
1. What is the type of this study? Systematic review
2. What is the level of evidence this study provides? A1
Elderly patients (60 years and older) who have minimal comorbidities , who might have a history of hypertension or type 2 diabetes mellitus. body mass index < 30 kg/m2 and low immunologic risk (without previous transplant and PRA titer < 50%)
4. What is Remuzzi score and what is its implementations?
A score used to evaluate a transplanted kidney from CKD donor or donation after cardiac death (DCD) donors for possibility of SKT Vs DKT. Remuzzi scores of 0-3 can be transplanted singly
5. In your own words, summarise the outcome of this study!
Dual kidney transplant has provided wide opportunity for organ transplantation by increasing use of marginal kidneys from ECD, extreme of age and after cardiac death (DCD) donors.
No clear guidelines are available for proper allocation which is usually left to the transplant clinicians to decide.
standard criteria donors
The transplantation of marginal kidneys from extended criteria donors (ECDs). Or donation after cardiac death with cold ischemia time less than 30 hours.
Donors were considered for DKT if any 2 of the following criteria present:
· age greater than 60 years, creatinine clearance greater than 65 mL/min,
· rising serum creatinine greater than 2.5 mg/dL
· chronic hypertension or type 2 diabetes mellitus,
· cerebrovascular event as cause of death
· presence of any anatomic anomaly (renal artery stenosis, polycystic, small kidneys)
· glomerulosclerosis on biopsy between 15% and 50%.
Pretransplantation evaluation of the graft is based on Renal biopsy scoring system as follows
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Pediatric donors were considered for pediatric recipients mostly but may be considered for adults based on promising outcomes.
Candidate recipient
matching recipients with donors by age and size is a golden standard for the following reasons; the limited functioning nephron mass would be satisfying for an elderly recipient with limited metabolic needs . the target graft survival in elderly is not greater than 20 years based on their lifespan expectency. On the other hand elderly are exposed to lower acute rejection rates due to the use of antiproliferative agents with lower dose levels of nephrotoxic calcineurin inhibitors .
Surgical approach
the original technique in DKT was described by Johnson and associates included bilateral Gibson incision and transplanting 1 kidney to each side. This method required more tissue dissection and a longer operative time.
A second technique was described by Haider and associates through A midline infraumbilical extraperitoneal approach to minimize dissection and operative time. With less potential of wound infection . This method can be converted easily to an intraperitoneal approach, Exp Clin Transplant Ahmed Hassan, Ahmed Halawa/Experimental and Clinical Transplantation (2015) 6: 500-509 but was associated with higher ileus and bowel complications, mobile grafts, and is more difficult to biopsy.
Unilateral placement of both kidneys was described by Mason and Hefty in 1998. The right kidney placed superiorly with renal artery anastomosed into the common iliac artery and renal vein into the inferior vena cava. both ureters were joined to each other and anastomosed to the bladder with ureteric double J stent. the contralateral side remained untouched for possible future transplant
modification was described in Ekser and associates the renal vein was extended using the donor’s inferior vena cava patch. It was anastomosed to the external iliac vein instead of the inferior vena cava. anastomosed the transplant ureters through 2 separate extravesical ureteroneocystostomies on ureteric stents. The upper kidney ureter was placed lateral to the lower kidney ureter. Many surgeons now prefer this technique for DKT due to Less intraoperative time and no dissection of the inferior vena cava .
Outcome, patient survival, graft survival, graft functioning
Results of graft survival , patient survival, and quality of graft function provided by DKTs are controversial yet comparable to SKTs. As shown in the timetable:
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Complications
Complications with DKT due to technical difficulties, with longer intra operative and anesthetic time , high admission rates to intensive care unit and lower kidney quality
Early renal graft thrombosis
Urinary tract complications ,especially urinary tract fistulas, ureteric stenosis
Postoperatively, recipients of DKT have a higher risk of developing myocardial infarctions compared to SKT candidates.
Pediatric kidneys have higher risk of surgical complications, especially vascular as a result of small vessel size
Review article
level of evidence: V
Dual kidney transplant
used to increase donor pool by using marginal kidneys
It provide more functioning nephrons to produce sufficient renal function from ECD instead of discarding them
It has comparable results to SKT
Criteria for selection of recipients:
elderly (60 years or more) who have low BMI and low basal metabolic rate
DKT will match their needs and graft survival will match their life expectancy
patients with low immunological risks.
Criteria for selection of donor:
ECD: donors aged >60 years or 50-59 years with 2 risk factors (HTN, death due to cerebrovascular accidents or terminal creatinine >1.5mg/dl
In 2008 UNOS used kidney biopsy and other factors to select donors (if 2 of the following were present) :
A study used eGFR to decide either DKT or SKT in donors aged >65 yeras with one risk factor (HTN, DM, atherosclerosis or death due to cardiovascular events),
kidney donor predictive index is used to predict risk of graft failure from deceased donor, (KDPI <2.2 the kidney is used for SKT)
UK advisory group considered donors >70 years and have one risk factor (HTN, type II DM, cerebrovascular event, creatinine >1.97mgdl or kidneys with anatomical anomaly)
pediatric donor <5years, with brain death using en block kidney transplant
Surgical techniques
Bilateral Gibson incision: long time, more vascular anastomosis & tissue dissection
mid line extraperitoneal approach: more bowel complications
unilateral placement of both kidneys
unilateral extraperitoneal dual kidney transplant: the most preferable technique
Complications
More frequent as DKT includes double vascular and ureteric anastomosis leading to ureteric stenosis, renal vessel thrombosis and more risk of postoperative myocardial infarction due to prolonged surgery in elderly.
Graft & patient survival
review of UNOS reported that recipients of DKT from ECD had graft survival of 70% while recipients of SKT had 80%
other report showed no significant difference in patient & graft survival at one year between DKT and SKT.
Remuzzi scoring
used for selection of kidney suitable for DKT according to pre transplant biopsy
kidneys with focal scarring, vascular abnormalities or biopsy with <25 glomeruli are excluded
biopsy is assessed according to glomerular global sclerosis, tubular atrophy, interstitial fibrosis and arterial narrowing
DKT done if score 4-6
Outcome of the given study
Dual kidney transplant or DKT is a way to make use of expanded criteria donors for elderly Renal transplant recipients in order to lower the pressure and load of transplant waiting lists in a suitable manner.
Complications of DKT are higher due to technical difficulties, contributed by longer operative time frames and lower quality of kidneys donated. Wound dehiscence rate was 5% for midline extraperitoneal bilateral placement of kidneys.
Early renal graft thrombosis is a cause for concern. Bilateral thrombosis is a very significant possibility which needs to be weighed and considered prior to proceeding for surgery. However, if there is single kidney thrombosis, renal function can be preserved in the other kidney thus facilitating acceptable rates of patient survival compared to remaining on the waitlist or dialysis.
UTI can occur at a higher rate in DKT.
Ipsilateral placement of both grafts is done in DKT and graft survival as well as patient survival, renal function parameters, all are comparable with single kidney transplant procedures.
Remuzzi score and its implementation :
Remuzzi scoring is based on pretransplant biopsy for selecting kidney for dual kidney transplantation. Brain dead donors older than 60, diabetics, donors with proteinuria less than 3 g per 24 hours was considered.
Exclusion criteria
kidneys with macroscopic major vascular abnormality or evidence of focal scarring – chronic pyelonephritis.
Kidneys were biopsied and those with less than 25 gloemruli were excluded.
The scoring system was based predominantly on glomerular sclerosis, tubular atrophy, interstitial fibrosis, arterial and arteriolar narrowing.
Implementation based on the Remuzzi scoring system was done by the considering the higher glomeruloscleorsis percentage among the kidneys biopsied. Kidneys with less than 15% glomerulosclerosis were transplanted separately while kidneys with more than 50% glomerulosclerosis were discarded. Mean donors were between the ages of 70 and 85.
Dear All
Please see Prof Ala question above about the outcome of dual kidney transplantation
This is a review article with level of evidence 5.
Indications of dual kidney transplantation :
Dual kidney transplantation gives a safe way to use kidneys from deceased donors above 70 years of age. It basically offers a way to use kidneys from ECDs or expanded criteria donors. These include donors above the age of 60, with at least 2 or 3 criteria such as cerebrovascular cause of death, hypertension, or renal insufficiency with serum creatinine above 1.5 mg/dL.
Survival rates of dual kidney transplant grafts is found to be compatible with those of single kidney transplant grafts. Comparable graft survival and graft function is seen despite donors being older, with higher serum creatinine levels, diabetics, higher KDPI and KDRI scores. However, this means that inappropriate use of unacceptable kidneys needs to be curtailed and this whole process regulated in order to improve DKT outcomes.
References :
This is a literature review
Level of evidence is V
Trying to overcome donor shortage ,and to decrease waiting lists , the idea of transplanting tow marginal grafts instead of one in a single recipient , have been introduced
The idea is instead of transplanting single kidney with limited no.of functioning nephrons , is to transplant double the no. of nephrons and this is suspected to increase graft and patient survival .
DKT is suitable for elderly who don’t require long duration of graft survival, also for less immunogenic patients, whose low immunological risks may allow for low doses of the nephrotoxic CNIs
Summary:
DkTs have increased the pool of donors , which is best offered for elderly as regards shorter life spans and less immunogenicity .
Results are encouraging and similar to single kidney transplants, to the extent that they are being tried in younger recipients .
No clear guidelines controlling allocation and each center have his own selection criteria ,which makes the physicians reluctant in using this approach .
Best surgical technique involves implanting both kidneys on one side , decreasing operative time and will have only single wound
Some suggested implanting pediatric grafts enblock but it was associated with surgical complications
Common complications with DKTs include graft thrombosis
Remuzzi score is a pre transplant scoring system, used to select donors for DKTs , was 1st described in 1999
It depend on 4 parameters ,% of GS , tubular atrophy ,interstitial fibrosis and arterial narrowing
Kidneys with score 4-6 are suitable for DKTs
Biopsies less 25 glomeruli are discarded
You all mentioned indications for DKT; what about the outcomes?
Outcome regarding patient, graft survival and DGF is the same when compared to single kidney transplantation, but with more incidence of CAN, higher incidence of wound dehiscence, post operative complications especially vascular thrombosis and ureteric complications when compared to single kidney transplantation .
The long-term outcome of double kidney transplantation from expanded criteria donors (ECD) was compared to the outcome of single kidney transplantation from standard criteria donor (SCD) in a study published by Tan JC, et al. 2004 (1).
The patient and graft survival were comparable in the two groups after 8 years of follow up, and they documented that the use of double kidney transplantation from ECD has provided an advantage to their patients in the form of decreasing the time spent while they were on the waiting list.
It is also worth mentioning that all the expanded criteria donor organs used in this study were those that were refused by all other local transplant centres (1).
References:
Tan JC, Alfrey EJ, Dafoe DC, et al. Dual-kidney transplantation with organs from expanded criteria donors: a long-term follow-up. Transplantation. 2004;78(5):692.
The reference is 2004 !!
Dear Dr Alaa,
You are right, Sir. I should have added more recent references.
There were some retrospective studies and review articles that documented the acceptable outcome of double kidney transplantation from ECD. They also stressed on the value of this approach in lowering the waiting time before transplantation (1,2,3).
References:
1) Robert J Stratta, Alan C Farney, Giuseppe Orlando, et al. Dual kidney transplants from adult marginal donors successfully expand the limited deceased donor organ pool. Clin Transplant. 2016 Apr;30(4):380-92.
2) Amarpali Brar, Ernie Yap, Angelika Gruessner, et al. Trends and outcomes in dual kidney transplantation- A narrative review. Transplant Rev (Orlando). 2019 Jul; 33(3):154-160.
3) B Tanriover, S Mohan, D J Cohen, et al. Kidneys at higher risk of discard: expanding the role of dual kidney transplantation. Am J Transplant. 2014 Feb;14(2):404-15.
most studies to date showed that DKTs has similar graft survival and delayed graft function rates when compared to single kidney transplants (SKTs). DKT is technically feasible with outcomes that are comparable to expanded criteria donor kidneys (ECD)
Trends and outcomes in dual kidney transplantation- A narrative review
Amarpali Brar a,⁎, Ernie Yap a, Angelika Gruessner a, Rainer Gruessner a, Rahul M. Jindal b, Robert Nee c,Moin Sattar a, Moro O. Salifua
Transplantation Reviews 33 (2019) 154–160
II. Dual Kidney Transplant
Narrative review article
Level V evidence (expert opinion)
Is answered in the summary
Dual Kidney transplantation was performed for the first time in 1996 in the USA by Jonson and associates.
The main target of DKT is to increase the nephron mass of ECD.
There is no randomized controlled trial comparing DKT to single kidney transplantation. DKT carries more surgical risks, that is why many centers are reluctant and lack of experience for DKT.
There is no clear guidelines and allocation policies for DKT.
There is no clear guideline for selection criteria of which kidney to be used for DKT.
Selection Criteria by Johnson et al.:
1- Donor age >60 years.
2- Long history of HTN or DM.
3- Cold ischaemia time less than 30 hours.
4- Cr Clearance levels between 80-40 ml/min.
5- Renal biopsy showing less than 40% glowerulosclerisis without severe IF or arteriolosclerosis.
6- Kidneys being rejected as a single kidney transplant by other units.
Selection Criteria for DKT by Remuzzi et al:
1- Remuzzi scoring system based on pre-transplant biopsy, DKT was performed if score between 4-6..
2- DBD older than 60 years.
3- Donors with DM, or albuminuria of less than 3 gm/day.
Exclusion criteria:
1- Biopsy showing: macroscopic vascular abnormality or evidence of focal scarring (like chronic pyelonephritis).
2- Those with less than 25 glomeruli were excluded.
3- GS more than 50% in kidney biopsy.
Spanish group selection criteria:
1- DBD with normal serum creatinine levels.
2- Donors older than 75 years.
3- Donors aged 60-74 years with GS of 15% to 50% at biopsy.
UNOS data base selection criteria: (2 of the following to be present)
1- Age> 60 years.
2- Cr Clearance > 65 ml/min.
3- Rising serum Cr >2.5 mg/dl at retrieval.
4- Chronic HTN, or DM II.
5- GS on biopsy between 15-50%.
Selection Criteria By Snanoudj et al without Biospy:
1- Donors age>65 years, and at least one of the following.
2- HTN.
3- DM II.
4- Atherosclerotic disease.
5- Death from a CVA.
6- e-GFR >30 ml/min to <60 ml/min (e-GFR < 30 ml/min were excluded).
Selection criteria by UK-KAG:
1- Donors age> 70 years if one of the following factors are present.
2- HTN.
3- MI.
4- DM II.
5- CVA as a cause of death
6- Serum Cr >1.97mg/dl at retrieval.
7- Presence of any anatomic anomaly (RAS, Polycystic, small kidneys.
There are different surgical Techniques:
1- The original technique included bilateral Gibson incision and transplanting 1 kidney to each side. It required more tissue dissection and longer operative time.
2- A midline extraperitoneal approach via infra-umbilical incision was described to minimize dissection and operative time.
3- Unilateral placement of both kidneys was described by Mason and Hefty in 1998.The right kidney was placed superiorly with renal artery anastomosed into the CIA and renal vein into the IVC.
4- A modification was described in Ekser and associates where the right kidney was placed superiorly, but the renal vein was extended using the donor’s IVC patch. It was anastomosed to the EIV instead of the IVC. The group also anastomosed the transplant ureters through 2 separate extravesical ureteroneocystostomies on ureteric stents.
5- Pediatric kidneys have higher risk of surgical complications, especially vascular as a result of small vessel size. En block kidney transplant using pediatric donor aorta and the IVC can theoretically reduce that risk.
Graft and patient survival
· The earliest report of DKT documented 100% graft and patient survival in 9 DKTs within 6 months follow up.
· A suggested strategy is an older donor for older recipient.
· The 2007 review of the UNOS database from 2000 until 2005 followed 625 recipients of DKT for 48 months. Recipients of DKTs from ECDs had similar death-censored graft survival, which reached 70%. During the same follow-up, recipients of kidneys from standard criteria donors had better survival of 80%.9
· Similarly, reports on pediatric kidneys transplanted into adults as EBK have shown encouraging results.
Complications:
1- Technical difficulties, longer operative time.
2- Local wound dehiscence.
3- Early graft thrombosis because of long vascular pedicle.
4- Urinary tract complications like urinary tract fistulas requiring surgery, Urine leak.
5- Higher incidence of MI in DKT recipients is mostly attributed to long procedure and anesthesia time.
6- Higher ITU admission, and longer hospital stay.
7- Lymphocele risk with ipsilateral placement is similar to that for SKT procedures.
8- EBK complications rate is higher versus SKT.
9- Renal artery stenosis occurred as a late complication in 2 recipients of EBK.
10-an interesting radiologic finding rather than a true complication is a “wandering kidney”.
What is Remuzzi score and what is its implementations?
The Remuzzi Score, initially proposed for the allocation of SKT vs DKT, is based on a semiquantitative assessment of glomeruloscelrosis, tubular atrophy,interstitial fibrosis, and arterial/arteriolar narrowing.
Using a histologic grade range from 0 to 12.
Remuzzi et al were able to obtain results following DKT using organs with more severe chronic histologic changes comparable to standard single kidney transplants.
G + TA + IF + A (0-12)
CURRENT PRACTICE IN CAMBRIDGE WITH REMUZZI SCORE (CAMBRIDGE MOD) ≤4 Single transplant
5-6 Dual transplant*
≥7 Discard
* “good 5s” with minimal (<5%) glomerular sclerosis, tubular atrophy and interstitial fibrosis
Do you accept a 72-year-old recipient who is hypertensive on 2 agents, diabetic and has asthma for a dual kidney transplant?
Yes I would accept DKT.
Literature review
level 5 evidence
Dual kidney transplant refer to transplantation of two kidneys from a marginal donor in one recipient that s theoretically may increase graft survival.
Technically operation is difficult and time consuming, associated with higher incidence of wound dehiscence, and associated with more post operative complications especially vascular thrombosis and ureteric complications when compared to single kidney transplantation .
The best approach is through midline infraumblical incision and the 2 kidney are put at one site in the extraperitoneal region this is to reduce operation time.
Outcome regarding patient, graft survival and DGF is the same when compared to single kidney transplantation, but with more incidence of CAN.
Donor kidneys play important rule in the decision for dual kidney transplantation, 3 parameters should be fulfilled in a donor kidney in order to decide DKT.
1- GFR
⦁ if GFR > 60 ml / min single kidney transplantation is selected
⦁ if GFR < 30 ml / min this donor is excluded
⦁ if GFR is between 30-60 this donor can be a candidate for dual kidney transplantation
2- Donor kidney should be a marginal kidney taken from the following type of patients :
3- Donor renal biopsy
addressing 4 parameters including assessment of glomerulosclerosis, interstitial fibrosis, tubular atrophy and arterial/arteriolar narrowing.
⦁ A score of 0-3 proceed to single kidney transplant
⦁ A score of 4-6 proceed for dual kidney transplant
⦁ A score of 7 or more discard these kidneys
Recipient also play an important rule in the decision for dual kidney transplantation, elderly may be better candidates for DKT due to the following :
Well structured answer Dr Sherif
This is a review article
Evidence Level 5
Dual kidney transplant carries a potentially higher risk of surgical complications because of the longer surgical procedure and the 2-fold risk associated with double vascular and ureteric anastomoses
Most of recipient are above 60 years ( low rate of acute rejection, low metabolic rate, no need for long graft survival and low nephron mass is adequate for them)
Donor kidneys should be biopsied, the percent of GS together with donor age and preexisting comorbidities are the factors determining the decision of DKT, and it differs from one center to another or from one surgeon to another, as there is no unified criteria for DKT
n 1999, Remuzzi and associates 4 suggested a scoring system based on pretransplant biopsy for selection of a kidney for DKT.
1-Brain dead donors older than 60 years.
2-donors who were diabetic.
3-donors with presence of proteinuria of less than three grams/24 hours were considered.
4-Kidneys with macroscopic major vascular abnormality or evidence of focal scarring (ie, chronic pyelonephritis) were excluded.
ramuzzi score sytem
0-3 —–> For Single Kidney Transplant (SKT)
4-6 —–>For Dual Kidney Transplant (DKT)
> 7 —–> Should be discarded
1) What is the type of this study?
Review article
2) What is the level of evidence this study provides?
Level 5
3) What are the indications of dual kidney transplantation?
There is no consensus on the indications/ criteria for dual kidney transplantation (DKT).
DKT has been performed in cases with donor age more than 60 years, with marginal kidneys.
The different criteria used by different groups for DKT include: donor with
a) characteristics: age more than 60 years, history of diabetes or hypertension, prolonged warm ischemia time
b) creatinine clearance: between 30-60 ml/min, Serum Creatinine > 1.97 mg/dl
c) renal anatomic abnormalities (small sized, polycystic kidney, renal artery stenosis)
d) renal biopsy: glomerulosclerosis 15 to 50% without severe interstitial fibrosis or arteriosclerosis.
The common criteria is a kidney not fitting in the standard criteria donor bracket.
4) In your own words, summarise the outcome of this study!
Dual kidney transplantation (DKT) is the procedure of transplanting both kidneys from a donor in a single recipient.
Need: It is a way to increase the “nephron mass” transplanted in a recipient when the available kidneys do not fit the definition of a standard criteria donor. Using DKT helps in utilising marginal kidneys and thereby reducing waiting list for kidney transplant.
Criteria for DKT: There are no for guidelines for DKT, but a common feature in all DKT programs is utilization of marginal kidneys. Different groups have used different criteria. Majority of the groups used elderly kidneys (>60 years age), with reduced creatinine clearance (30-60 ml/min) and elevated terminal creatinine (>1.97 mg/dl) or renal anatomical abnormalities. Most of the groups performed pre-transplant kidney biopsy to assess histological parameters and kidneys with glomerulosclerosis more than 50% were not utilised for DKT. Non-heart beating donors have also been used for DKT.
Candidate recipient for DKT: The ideal DKT recipient would be age-matched with the donor, having lower immunologic risk (PRA less than 50%, first transplant), minimal co-morbidities, BMI less than 30 or body weight less than 80 kilograms.
Surgical technique: DKT has been performed using different techniques by different groups including bilateral Gibson incision (but leads to increased operating time), or midline incision (decreases dissection and surgical time). Other groups performed unilateral transplant with usually transplanting right kidney superior to left kidney. (advantage being reduced surgical time) En block kidney (EBK) transplantation is performed in case of paediatric donors.
Results: Factors affecting graft function include donor factors, donation circumstances, cold ischemia time and peri-operative event. DGF rates in DKT are similar to single kidney transplant with ECD kidneys. Most of the groups have shown patient and graft survival similar to single kidney transplant. UNOS data on EBK shows better graft survival at 1, 3 and 5 years. Complications in DKT are usually due to technical difficulties in surgery and associated increased surgical time. Common complications include wound dehiscence, graft thrombosis, ureteric stenosis, urinary leak etc.
5) What is Remuzzi score and what is its implementations?
Remuzzi score is a pre-transplant kidney biopsy score to guide in selection of a donor for DKT. It was given by Remuzzi et al in 1999.
If a brain dead donor is aged more than 60 years, has history of diabetes or 24 hour urine protein less than 3 gram, then pre-transplant kidney biopsy is done and 4 parameters are assessed, namely, glomerular global sclerosis, interstitial fibrosis, tubular atrophy and arterial and arteriolar narrowing.
All parameters are scored 0 to 3 (maximum score 12)
If score 0-3: single kidney transplantation done
If score 4-6: DKT
If score >6: kidneys discarded
Reference:
Remuzzi G, Grinyo J, Ruggenenti P, et al. Early experience with dual kidney transplantation in adults using expanded donor criteria. Double Kidney Transplant Group (DKG). J Am Soc Nephrol 1999;10:2591-2598.
I like your structured answer Amit
1- Review article.
2- level of evidence is 5
3- Indications of dual kidney transplntations are still debatable, however the following is suggested :
a- matching with ages and sizes of both reciepients & donors
b- recepients with lower immunologic rsiks e.g PRA less than 50 %
c- recipients aged 60 years or more.
d- receipients aged less than 60 years plus the following : 1- low immunologic risk.
2- BMI less than 30
3- minimal comorbidities.
4- Breif summary :
due to the great demand for potential kidney donors and also the favourable outcome of kidney transplatation for the expanding ESRD populations, many trials have been suggested for managing these pts. of these trials, dual kidney transplantation was suggested. it simply means transplanting 2 weak or marginal kidneys to a suitable donor for a sum of reasonable function for a limited period of time for some specific receipients. it was successfully done in elderly pts. however, the indications and related criteria are still lacking. further studies are still awaited for more evaluation of this program.
5- Remuzzi score is a scoring system for evaluation of possible kidneys that are considered for dual transplantation.it is based on biospy findings. it was chosen for specific donors who are : a- brain dead and aged more than 60 years.
b- diabetic pts.
c- pts with proteinuria of less than 3 g/day.
some exclusions were applied as those with focal scarring or major vascular abnormalities.
review article
level V evidence
indications of dual kidney transplant
1) age >70 years with normal serum creatinine and biopsy score 4-6
2)age 50-69 years with any one of the following
eGFR between 30 to <60 ml/min
rising serum creatinine greater than 1.5 mg/dL at retrieval
chronic hypertension
type 2 diabetes mellitus
h/o myocardial infarction
presence of any anatomic anomaly,multiple cysts
prolonged warm ischemia time
death due to cerebrovascular cause
all the above to undergo pre implantation biopsy and those having biopsy score between 4-6 as proposed by Remuzzi be considered for dual kidney transplant .
suitable recipients
1) 60 years or older ,have low immunological risk, minimal comorbidities,BMI<30kg/m2
outcome of the study
1)By increasing the use of marginal kidneys in dual kidney transplants, the pool of potential organs has grown.
2)DKTs produce equivalent results to SKT in terms of graft survival and patient mortality, complications, and renal function quality.
3)Despite the higher surgical risk, using pediatric kidneys in adult recipients via an en block method has yielded equally promising results despite the higher rate of complication.
4)indications of dual kidney transplant
1) age >70 years with normal serum creatinine and biopsy score 4-6
2)age 50-69 years with any one of the following
eGFR between 30 to <60 ml/min
rising serum creatinine greater than 1.5 mg/dL at retrieval
chronic hypertension
type 2 diabetes mellitus
h/o myocardial infarction
presence of any anatomic anomaly,multiple cysts
prolonged warm ischemia time
death due to cerebrovascular cause
5)suitable recipients
1) 60 years or older ,have low immunological risk, minimal comorbidities,BMI<30kg/m2
6)From 2000 to 2005, an analysis of the UNOS database monitored 625 DKT recipients for 48 months. DKT recipients from ECDs shared comparable characteristics.The survival rate of death-censored grafts was 70%.Donors who met the standard criteria fared better in terms of survival with 80% rate.
For the selection of a kidney for DKT, Remuzzi and colleagues proposed a grading system based on pretransplant biopsies.Biopsies were taken from both kidneys, and those with fewer than 25 glomeruli were ruled out. If the a priori score was between 4-6, dual kidney transplants were conducted.
1-A review article
2-level of evidence 5
3-The indications of dual kidney transplantation
Donors aged 70 years or older with 1 or more of the following clinical risk factors were present:
history of hypertension, myocardial infarction, type 2 diabetes mellitus, cerebrovascular event as the cause of death, serum creatinine level of > 1.97 mg/dL at retrieval,
presence of any anatomic anomaly (renal artery stenosis, polycystic, small kidneys). Kidneys with prolonged warm ischemia time, small kidneys, eGFR < 60 mL/min.
Donor with glomerulosclerosis up to 50%
performed DKTs in recipients with a mean age of 60 ± 5 years old with low immunological risk.
4-The usage of marginal kidneys has increased and waiting times have decreased in recent decades because of dual kidney transplantation.
In many facilities, unilateral implantation of both kidneys is the preferred method. Surgeons have used an en block pediatric dual transplant and numerous vascular reconstruction procedures for dual kidneys to allow for a single artery and venous anastomosis and decrease problems.
Although vascular problems are more common in dual kidney transplants, particularly graft thrombosis, the overall complication rate is equivalent to a single kidney transplant. Kidney survival and function are promising, and outcomes are comparable to those obtained with a single kidney transplant using conventional criteria.
Despite the fact that the procedure is well-established in many locations, there are no set rules.
By expanding the use of marginal kidneys in dual kidney transplants, the pool of possible organs has grown. Ipsilateral graft implantation is commonly approved and practised.
DKTs produce equivalent results in terms of graft and patient mortality, complications, and renal function quality.
Furthermore, despite the increased surgical complication rate, the use of adolescent kidneys in adult patients using an en block method has shown equally favourable results. The major debate is whether DKT or SKT is better for DKT. DKT selection criteria are still a little ad hoc and centre-dependent.
5-Remuzzi and colleagues4 proposed a score method for selecting a kidney for DKT based on pretransplant biopsies.
Braindead donors over 60 years old, diabetic donors, and donors with proteinuria of fewer than three grams per 24 hours were all considered.
Biopsies were taken from both kidneys, and those with less than 25 glomeruli were ruled out. If the a priori score was between 4 and 6, dual kidney transplants were conducted.
In the 24 DKTs reported in the study, patient and graft survival was 100% at 6 months.
This article is a narrative review study. Level 5
Dual kidney transplantation can be performed in patients who may be waiting listed for a long-time and don’t have access to SCD. It is a way to increase donor pool despite some more complications such as more renal vein thrombosis in this setting.
Dual kidney transplantation (DKT) can be performed when a marginal kidneys (pediatric donors, from ECD and DCD) are not appropriate for single kidney donation because of suboptimal nephron number for making recipients dialysis independent.
The rationale for DKT is to increase the available nephron mass of one recipient.
Remuzzi scoring system is a system for suggestion of donors for dual kidney transplantation (DKT) among brain death donors older than 60 years, who are diabetic or have proteinuria more than 3 grams /day depending on biopsy findings of biopsy samples with at least 25 glomeruli.
Scoring is based upon the percent of globally sclerosed glomeruli, tubular atrophy, interstitial fibrosis and atrial or arteriolar narrowing.
DKT was suggested for a priori score between 4 and 6.
Kidneys from donors older than 70 years with history of hypertension or type 2 DM, 30<eGFR<60 ml/min, kidneys with multiple cysts and prolonged warm ischemic time can be considered for DKT.
For DKT, it is suggested to math donor and recipient age and size. Older recipients may be more acceptable for DKT owing to limited metabolic demand, lower life expectancy, lower acute rejection and their need for lower dose level of CNIs. However DKT can be appropriate for patients less than 60 years old with low immunological risk and minimal comorbidities and BMI<30 Kg/m2.
DKT and SKT are comparable in terms of graft and patient survival according to different studies.
It is a Review Article
Level of evidence 5
The transplant of a single marginal kidney (from ECDs, donors with cardiac death, and pediatric donors) may result in a suboptimal number of functional nephrons to allow recipients to become dialysis independent. Episodes of acute rejection, medication toxicity (particularly from calcineurin inhibitors), and effect of the recipient’s comorbidities on the transplanted kidney will adversely affect these limited functional nephrons.The concept of trans- planting both donor kidneys into 1 recipient as dual renal transplant has been adopted to increase available “nephron mass.”
The first adult dual kidney transplant (DKT) was in the United States in 1996 by Johnson and assoiate
Two decades earlier, dual kidneys from pediatric donors had been transplanted into adults.
Although no randomized prospective studies comparing the results of DKT to single transplant have been published, several authors have reported acceptable results even with kidneys considered unacceptable by others.
Dual kidney transplant carries a potentially higher risk of surgical complications because of the longer surgical procedure and the 2-fold risk associated with double vascular and ureteric anastomoses. As a result, many centers remain reluctant and lack experience with DKT.
There is so far no global consensus as to which donor kidney is best for DKT, with one reason being that DKTs are not routinely performed in many transplant centers. In addition, the variations in practice and protocols between different surgeons and centers have led to differences in kidney selection criteria
In 1999, Remuzzi and associates4 suggested a scoring system based on pretransplant biopsy for selection of a kidney for DKT
Pediatric donors were first considered for pediatric recipients. Because of increased surgical complications, inadequate nephron mass, relative sensitivity regarding rejection, and risk of hyperfiltration injury, pediatric SKT remains controversial
who is a suitable recipient?
Similarly, there is debate about the best candidate for DKTs. Many authors suggested matching recipients with donors by age and size. Because most DKTs involve donors at age extremes, matching an older donor with an older recipient is suggested. One reason is that the limited functioning nephron mass would be enough for an elderly recipient with limited metabolic demands and the elderly would not require graft survival of greater than 20 years based on their expected lifespan. In addition, lower acute rejection rates in elderly recipients as a result of antiproliferative agents with lower dose levels of
nephrotoxic calcineurin inhibitors would reduce long-term nephron insult.To reduce possible injury to limited nephron mass, most authors have suggested DKTs to recipients with lower immuno- logic risk (ie, recipients without previous transplant and panel reactive antibody titer < 50%).
In contrast, the encouraging results of DKTs with excellent creatinine levels and lesser acute rejections allow for greater consideration in younger recipients. Younger candidates can more easily recover from the longer operative time necessary for DKTs. To support this approach, Andres and associates performed DKTs in recipients with mean age of 60 ± 5 years old from donors with mean age 75 ± 7 years.11
Hobart and associates failed to show a difference in recipient or graft survival to support using age or weight as variables to guide selection in his 33 pediatric EBK into adult recipients,7 although it has been suggested that candidates of pediatric EBK should weigh less than 80 kg.
In general, DKT is offered to patients 60 years or older. Our group prefers offering DKTs to patients with low immunological risk, who are less than 60 years old, and who have minimal comorbidities and body mass index < 30 kg/m2.
Surgical technique
Johnson and associates6 described the first DKT; the original technique included bilateral Gibson incision and transplanting 1 kidney to each side. This method required more tissue dissection and a longer operative time. Because most recipients are 55 years or older, reduction of total anesthetic, a shorter operative time, and less vascular anastomoses are desirable.
A midline extraperitoneal approach was described to minimize dissection and operative time. Through midline infraumbilical incision, blunt dissection of extraperitoneal space bilaterally to expose iliac vessels. Because the left iliac vein is in a deeper anatomic position, the left kidney with its longer renal vein was placed on the left side. Drains were placed bilaterally. Haider and associates described this technique in 2007.16 The single midline incision has the advantage of a shorter operative time and dissection and fewer hernia complications in comparison to a bilateral Gibson incision. In addition, a potential wound infection would be far away from the graft. This method can be converted
nephrotoxic calcineurin inhibitors would reduce long-term nephron insult.To reduce possible injury to limited nephron mass, most authors have suggested DKTs to recipients with lower immuno- logic risk (ie, recipients without previous transplant and panel reactive antibody titer < 50%).
In general, DKT is offered to patients 60 years or older. Our group prefers offering DKTs to patients with low immunological risk, who are less than 60 years old, and who have minimal comorbidities and body mass index < 30 kg/m2.
Graft and patient survival
The earliest report of DKT documented 100% graft and patient survival in 9 DKTs.
Complications
Complications with DKT are perceived to be higher due to technical difficulties, with longer operative time and lower kidney quality.
Urinary tract complications also have been reported to be slightly higher, especially urinary tract fistulas requiring surgery (17%; P = .06), although no significant difference in overall surgical complications was shown.
Remuzzi score is pretransplant biopsy scoring system developed in 1999 aiming for assessment of the donor Kidneya whether suitable for dual or single Kidney transplantation.
It requires biopsy with at least 25 glomerules for evaluation.
this is a review article with level 5 of evidence
Renal transplant remains the treatment of choice for patients with ESRD. For this purpose, ECD was established to recruit more and more marginal kidneys and the use of kidneys from donors from extreme ages. The transplant of a single marginal kidney from ECDs may cause delayed graft function and may not to allow recipients to become dialysis independent. DKT is an option to rapidly transplant elderly patients with double the nephron mass.
Historically, dual kidney transplants were offered to elderly recipients from elderly deceased donors to overcome the longtime dialysis while on the waiting list. This practice was followed by many centers however no clear inclusion or exclusion criteria for this practice and it is center-based and center-oriented.
The expanded donor criteria enabled the allocation of low quality kidneys to older recipients and this was associated with delayed graft function.
The first adult dual kidney transplant (DKT) was in the United States in 1996 by Johnson and associates and since that time DKT became familiar in many centers worldwide.
So far no global consensus on the selection of donor kidney for DKT, with one reason being that DKTs are not routinely performed in many transplant centers.
In 1999, Remuzzi and associates suggested a scoring system based on pre-transplant biopsy for selection of a kidney for DKT based on extant of glomerular sclerosis, tubular atrophy, interstitial fibrosis and vascular damage.
But who is the selected recipient for DKT? it is still not clear who is the best candidate for DKTs. Many authors suggested matching recipients with donors based on the age. Because most DKTs involve donors at age extremes, matching an older donor with an older recipient is suggested. His means that marginal kidneys from elderly donor are given to elderly recipient.
The first report of DKT document high successful graft and survival reaching 100%. This was also observed in many later reports including UNOS and European reports.
Complications with DKT are perceived to be higher due to technical difficulties, with longer operative time and lower kidney quality. Complications in the post-operative period include wound dehiscence rate, Early renal graft thrombosis, Urinary tract complications, especially urinary tract fistulas requiring surgery and incidence of vascular thrombosis
Dear All
Thank you for your input, really enjoyed it. Let us dissect it further
Do you accept a 72-year-old recipient who is hypertensive on 2 agents, diabetic and has asthma for a dual kidney transplant?
yes, i think should be accepted
No.
The recipient is having co-morbidities which will have increased risk of surgical complications like vascular thrombosis, wound dehiscence (due to hypertension and diabetes). Prolonged surgery time and anaesthesia will not be good in an asthmatic patient.
if GFR is between 30-60 and if Remuzzi biopsy score < 7 yes we can accept for elderly recipient
Dear All
Any more replies to my question above?
Just to give you a clue, it is a major operation with a higher complication rate especially in the presence of comorbidities (age, hypertension, DM and asthma).
I am sorry i did not notice that these criteria are for recipient, no with these comorbidities it is better to take standered deceased donor or living donor kidney with good HLA matching especially in DR to avoid the complications of over immunosuppression provided asthma is controlled and no problem regarding anasthesia
after thorough preoperative evaluation and balancing benefit versus risk and in case of extreme welling of recipient may be tried !!!
In this scenario, I will evaluate each point in his history in detail:
– Being 72 years old alone is not a contra-indication anymore, as we addressed during our study this week (the acceptable general condition is more important than the chronological age).
– Both diabetes and hypertension can lead to vascular complications (e.g. atherosclerosis and coronary artery disease). In addition, an unhealthy vascular tree carries the risk of vascular thrombosis post-operative, especially with complex vascular anastomosis.
– Being asthmatic needs a meticulous evaluation of his pulmonary functions by a specialized pulmonologist. Many asthmatic patients with mild to moderate disease and well preserved pulmonary function were transplanted without complications.
In conclusion, if the patient is clinically fit for transplantation, I will list him on the waiting list. I suggest providing him with en block double ECD kidneys (where the donated kidneys will be provided with the aorta and inferior vena cava). This kidney offer will provide a single, wide lumen vascular anastomosis that may be anastomosed with the main vessels of the recipients as in the attached picture; thus, I will partially overcome the point of the poor vascular tree.
I believe decision would be based upon expected life span , as for this patient if the underlying comorbids are controlled with no major cardiovascular or cerebrovascular complications. I believe the patient would benifit from DKT
Type of this study:
Review Article
Level of evidence this study :
Level 5
Indications of dual kidney transplantation:
Donors were considered for DKT if any 2 of the following criteria present:
Some centers include the followings within the indications:
Summary:
The first adult dual kidney transplant (DKT) was in the United States in 1996 by Johnson and assoiates.
Dual kidney transplant carries a potentially higher risk of surgical complications because of the longer surgical procedure and the 2-fold risk associated with double vascular and ureteric anastomoses.
Remuzzi and associates4 suggested a scoring system based on pretransplant biopsy for selection of a kidney for DKT to minimize DKT with insufficient function which is extremely unwelcomed.
In a review of UNOS database published on 2008, five hundred twenty-five DKTs were performed from 2000 to 2005. Donors were considered for DKT if any 2 of the following criteria present: age greater than 60 years, creatinine clearance greater than 65 mL/min, rising serum creatinine greater than 2.5 mg/dL at retrieval, chronic hypertension or type 2 diabetes mellitus, and glomerulosclerosis on biopsy between 15% and 50%.
Depending on maximal eGFR calculated with use of the Cockcroft and Gault formula, donors with eGFR > 60 mL/min were considered for SKT. Kidneys were discarded when eGFR was < 30 mL/min, and eGFR between these results was an indicator for DKT.
Many authors suggested matching recipients with donors by age and size. Because most DKTs involve donors at age extremes, matching an older donor with an older recipient is suggested. One reason is that the limited functioning nephron mass would be enough for an elderly recipient with limited metabolic demands and the elderly would not require graft survival of greater than 20 years based on their expected lifespan.
A midline extraperitoneal approach was described to minimize dissection and operative time rather than bilateral Gibson incision; the original technique described by Johnson and associates 6 in the first DKT.The goal of techniques that permit single arterial and venous anastomosis is to reduce vascular complications. Nghiem and associates26 described such a technique in their series of 12 patients, with a single venous thrombosis observed due to twist of 1 of the dual kidneys.Some authors have reported no surgical complications with vascular reconstruction of both kidneys.
Complications with DKT are perceived to be higher due to technical difficulties, with longer operative time and lower kidney quality. Complications that are encountered are;thrombosis(One patient had bilateral thrombosis), Urinary tract complications also have been reported to be slightly higher, especially urinary tract fistulas requiring surgery, In a French report, 11% of recipients had ureteric stenosis.
Remuzzi score and what is its implementations:
In 1999, Remuzzi and associates 4 suggested a scoring system based on pretransplant biopsy for selection of a kidney for DKT.
Both kidneys were biopsied, and those with less than 25 glomeruli were excluded. Dual kidney transplants were performed if a priori score was between 4 and 6 .
Remuzzi Score interpretation :
0-3 —–> For Single Kidney Transplant (SKT)
4-6 —–>For Dual Kidney Transplant (DKT)
> 7 —–> Should be discarded.
review article
level of evidence 5
DKT is indicated when transplanting single marginal kidney from ECD, DCD, pediatric donor may result in suboptimal nephron number to keep the patient dialysis independent.
Remuzzi and associates suggested a scoring system based on pre-transplant biopsy to select kidneys for DKT.
donor criteria considered include: DBD more that 60 year old, diabetic, proteinuria less than 3 gm/24hr.
exclusion criteria: kidneys with major vascular abnormality, evidence of focal scarring.
both kidneys are biopsied and those with less than 25 glomeruli excluded.
DKT was done if the score was between 4&6.
scoring system:
0 no sclerosis
1 < 20% global sclerosis
2 20-50% sclerosis
3 > 50% global sclerosis
2. tubular atrophy
0 no tubular atrophy
1 < 20% tubuli affected
2 20-50% tubuli affected
3 > 50% tubuli affected
3. interstitial fibrosis
0 absent
1 < 20%
2 20-50%
3 > 50%
arterial and arteriolar narrowing
0 absent
1 increased thickness but to a degree that is less than a diameter of the lumen
2 wall thickness that is equal or slightly greater than the diameter of the lumen
3 wall thickness that exceed the diameter of the lumen with extreme luminal narrowing or occlusion.
DKT resulted in increased use of marginal kidneys and thereby increasing donor pool.
the suitable recipient is less than 60 years old, low immunological risk, have minimal comorbidities, BMI less than 30.
surgical technique is the midline extraperitoneal approach. ipsilateral placement of both organs is widely accepted and performed.
graft and patient survival were good according to the early reports.
higher complications rate due to technical difficulties, long operative time and low quality kidney. early graft thrombosis is of concern, urinary tract complications such as fistula has been reported.
the use of pediatric kidney by an en block method resulted in similar outcomes despite high surgical complications.
Well done Huda
1. It is a review article
2. level of evidence 5
3. donors were considered for DKT if any 2 of the following criteria were present (according to UNOS data-based 2008):
-Age greater than 60
– Creatinine clearance greater than 65 ml/min
-Serumcreatinine˃2.5mg/dl
-Chronic HTN or type2 DM.
-Glomerulosclerosis on biopsy between 15%-50%.
In another large Italian study (2003-2009):)depend on donor age and clinical and histologic findings and to avoid biopsy they used eGFR
4. DKT has transplanted both kidneys from a donor into the recipient to increase nephron mass in case of using marginal kidney(From EDC, a donor with cardiac death, and pediatric donors).DKT is wasting of organs pool if a single kidney can keep patient dialysis independent. Kideny can be selected according to Remuzzi score or according to donor age and clinical and histological findings and eGFR. It is commonly offered for patients 60 years old or older with low immunologic risk and minimal comorbidities.
both kidneys commonly placed unilateral, extraperitoneal placement of both kidneys was preferred by many surgeons.DKT is associated with better patient and graft survival in many studies.
DKT has a lot of complications due to lower kidney quality, longer operative time, and technical difficulties. due to technical .complications are wound dehiscence, vascular thrombosis, urinary tract fistulas, ureteric stenosis, high risk for myocardial infarction.
5. Remuzzi score: it is a scoring system based on pretransplant biopsy for the selection kidney for DKT.Braindead donors older than60years, diabetic donors, donors with the presence of proteinuria˂3g/day were considered. Kidneys with a macroscopic major vascular abnormality or evidence of focal scaring were excluded. biopsy should contain at least 25 glomeruli.
Components of the system: glomerular global sclerosis, tubular atrophy, interstitial fibrosis, and arterial and arteriolar narrowing. In the 24DKT study, patient and graft survival was 100% at 6months.
1. This is a review article.
2. Level of evidence V
3. Dual kidney transplantation is used when there is a need to increase the count of functioning nephron. Usually this will be needed if one kidney is having glomeruloslreosis, from elderly donor, from patients with comorbidties e.g diabetic, hypertensive or CVA patients.
4.
Due to the mismatch between kidney supply and demand, the proven better survival with transplantation over being on maintatnce dialysis, and not to waste kidneys that do not meet the criteria of single kidney donations, dual kidney was proposed.
Although it is more surgical and monitoring demanding, it still has good survival with 100% survival on some studies over 6 months follow up period.
Dual kidney transplantation still lack universal guidelines as a result of being not widely adapted in all transplantation centers.
4.
Remuzzi pretransplant score is a biopsy based scoring system to classifies kidneys based on sclerosis , IFTA and presence of vascular defects. Then based on that score, kidneys with score 4-6 were used for DKT.
Dear All
I agree, there is no consensus regarding the selection criteria for dual kidney transplantation.
Imagine yourself as a policymaker
What are your selection criteria for donors who should transplant their both kidneys as dual and selection criteria for recipients who would receive dual kidneys?
selective criteria of donors including age , comorbidities, cold ischemic time and creatinine clearance , and pretransplant biopsy which should be assessed based on scoring system involve tubular atrophy, interstitial fibrosis, vascular changes, and glomerulosclerosis…each item from 0-3
as regard recipient , age is important factor old age for old age
Muhammad Abdul Mabood Khalil, Jackson Tan,Taqi F. Toufeeq Khan, Muhammad Ashhad Ullah Khalil, Rabeea Azmat.Dual Kidney Transplantation: A Review of Past and Prospect for Future. Int Sch Res Notices. 2017.
Ideal Donor for DKT:
1) Age more than 60 year with co-morbidities (Diabetes or Hypertension)
2) Serum creatinine >1.97 mg/dl or eGFR 30-60
3) Abnormal renal anatomy (multiple cysts, small kidneys)
4) Non heart beating donor
5) Pediatric donor (<5 year age)
Ideal recipient for DKT:
1) Age-matched with the donor, if elderly,
2) Having lower immunologic risk (PRA less than 50%, first transplant),
3) Minimal co-morbidities, especially without atherosclerosis (due to technical difficulties in vascular anastomosis)
4) BMI less than 30 or body weight less than 80 kilograms (to prevent post-operative surgical complications like wound dehiscence)
Well done Amit
Donors were considered for DKT if any 2 of the following criteria present:
· age greater than 60 years, creatinine clearance greater than 65 mL/min,
· rising serum creatinine greater than 2.5 mg/dL
· chronic hypertension or type 2 diabetes mellitus,
· cerebrovascular event as cause of death
· presence of any anatomic anomaly (renal artery stenosis, polycystic, small kidneys)
· glomerulosclerosis on biopsy between 15% and 50%.
candidate recepient:
Elderly patients (60 years and older) who have minimal comorbidities , who might have a history of hypertension or type 2 diabetes mellitus. body mass index < 30 kg/m2 and low immunologic risk (without previous transplant and PRA titer < 50%)
1- This is a review article
2- Evidence Level 5 is provided by this study
3- DKT is indicated to less immunogenic recipients ,those who are tranplanation naiive , with PRA titer<50% , and elderly recipients as they wont require graft survival of more than 20 years ,meanwhile it’s encouraging results in the forum of less acute rejections is making it considerable for younger recipients as they has better recovery from long operative periods needed ,so it can be offered to recipients less than 60 years old, with low BMI and less comorbidities .
4- Due to increasing demands of renal grafts and to increase the donation pool, reduce waiting lists DKT was established as well as ECD kidneys .
At the time being ,different centers have variable criteria for organ selection and surgical technique.
DKT surgery being a longer procedure than standard SKT surgery makes the recipient more liable to surgical complications as post surgical vascular thrombosis ,and urteric complications.
Since DKT is not established on wide bases there is no specific criteria for donor selection.
Some studies tried to demonstrate some criteria as selecting donors aged above 60 years with hypertension or diabetes ,having cold ischemia time less than 30 hours as well as those rejected kidneys for a SKT ,they noticed acceptable patient and graft survival rates
This concept was established as a trial to increase the nephron mass available for the recipient especially those receiving ECD kidenys.
Implanting the 2 kidneys unilateral is the usual technique in many centers.
Some surgeons had adopted En block pediatric dual transplant to reduce complications, but it showed increased occurrence of vascular complications.
It was suggested that donors can include those above 70 y with serum creatinine above 1.97 mg/dl , with hypertension ,MI,DM type2 ,cerebrovascular event or any anatomic anomaly and those with prolonged warm ischemic time particularly for older recipients.
5-Remuzzi scoring system was developped according to the graft biopsy taken pretransplantation , which must have 25 glomeruli for evaluation , it included categorising the degree of
-global glomerular sclerosis ,
-tubulat atrophy ,
– interstital fibrosis ,
-arterial and areteriolar narrowing
Proceeding with DKT occurred if the score is between 4-6
1. It is a Review Article
2. Level of evidence 5
———————–
3. Indication of DKT
☆ Age :
• Above 70 years
• or 60-69 years with
history of comorbidites such hypertension, T2 DM, atherosclerosis diseases (as myocardial infarction).
death related to cerebrovascular events.
after cardiac death.
☆ Kidney:
• small sized
• with multiple cysts (polycytic)
• renal artery stenosis
• prolonged ischemia time
☆ Kidney function:
• eGFR 30- 60 ( creatinine clearance 1.97 mg/dl at retrieval ( > 2.5 mg/dl as reported by UNOS in 2008)
• proteinuria less than 3 grams/ 24 hours.
☆ Kidney biopsy
There are 4 scoring systems to assess the quality of donor Kidney:
The Maryland Aggregate Pathology Index (MAPI), Banff, Leuven, and Remuzzi.
Remuzzi score of 4-6 is considered for DKT.
——————-
4. Summary
☆ Dual kidney transplant
• Definition: transplantation of both Kidneys of deceased donor into one recipient
• significance: DKT using marginal kidneys is considered important source and large pool for donation instead of discarding them.
• Indications of DKT (DKT or SKT): depends on many factors as mentioned above. No guideline has been established till now.
• Optimal recipient: controversial
Most of recipient are above 60 years ( low rate of acute rejection, low metabolic rate, no need for long graft survival and low nephron mass is adequate for them)
Some consider same age and size (weight) between donor and recipient, but other disagree depending on good results of transplantation of pediatric EBK to adult recipient.
Sheffield Kidney Institute offer DKT for patients with least history of chronic diseases, low risk of immunological complications, younger than 60 years and BMI less than 30.
• Results: patient and graft survival from DKT , as well as delayed graft dysfunction, is the same as the SKT.
• Surgical procedure
First DKT was done 1996 by Johson and his colleges (bilateral placement of kidneys through Gibson incision)
Preferred approach: unilateral placement of kidneys by midline infraumblical incision through extraperitoneal approach.
• En block kidney transplantation (EBKT) is transplant of both Kidneys ,with aorta and IVC, from deceased pediatric donor into one recipient.
EBKT has outstanding results but with more surgical complications.
• Disadvantages of DKT (vs SKT): more surgical complications especially vascular,more difficult technique, needs high surgical skills.
• Guideline: still no consensus.
——————–
5. Remuzzi score is pretransplant biopsy scoring system developed in 1999 aiming for assessment of the donor Kidneya whether suitable for dual or single Kidney transplantation.
It requires biopsy with at least 25 glomerules for evaluation.
It depends on 4 different parameters which are glomerular sclerosis, interstitial fibrosis, tubular atrophy, and arterial/arteriolar narrowing.
Interpretation of its score
0-3 —–> SKT
4-6 —–> DKT
> 7 —–> disregarded/ discarded.
Remuzzi reported 100% survival rate of patient and graft at 6 months in his 24 DKT.
literature review
level 5 evidence
Dual kidney transplant is transplantation or two donor kidneys in one recipient of course after brain death in order to increase nephron mass and this will affect positively graft survival and will decrease progression to CAN chronic allograft nephropathy.
In spite of that hypothesis, but still many centers disagree DKT because of many surgical complications related to longer time of operation consumed in ureteral and vascular anastomosis in comparison to single kidney transplant , in addition to any complication which could happen.
Donor kidneys should be biopsied, the percent of GS together with donor age and preexisting comorbidities are the factors determining the decision of DKT, and it differs from one center to another or from one surgeon to another, as there is no unified criteria for DKT.
There are some limitations of donor kidney biopsy, some surgeon refused needle biopsy because of risk of bleeding and its complications, also biopsy might be taken from the surface which mislead the percent of GS , and also reading of the biopsy may differ from one pathologist to another.
To avoid misleading of biopsy , eGFR is used, GFR 60 ml/min or more is determinant for single kidney transplantation in addition to other factors (Deceased donor), and GFR less than 30 ml/min is excluded, so GFR 30-60 ml/min may be included in DKT.
Candidate for DKT, some said old age recipient is better because his life expectancy and also low immunological risk and decrease his body metabolism will add to the success of DKT , and some said younger age recipient will recover faster from long time of operation period.
Its incision will be midline infraumbalical, with extraperitoneal approach is preferred to decrease operative time and complications.
Remuzzi score is the biopsy scoring system pretransplant.
Dear All
I’m waiting for your replies
This study is a review article , Level V evidence (expert opinion)
indications of dual kidney transplantation:
considered DKT if any 2 of the following are present:
-age more than 60 years
-creatinine clearance between 80 and 40 mL/min
-rising serum creatinine more than 2.5 mg/dL at retrieval
-chronic HTN or type 2 DM
-glomerulosclerosis between 15% and 50% by biopsy
To avoid renal biopsy in decision:
Age of donor more than 65 years old plus 1 of the following risk factors :
– HTN
-Type 2 DM
– atherosclerotic disease
– cardiovascular event is the cause of death
– eGFR calculated by Cockcroft and Gault formula between 30-60 mL/min .
Remuzzi score and what is its implementations:
It is based on biopsy in pre transplant for selection of a kidney for DKT
Brain dead donors with age older than 60 years.
History of diabetes
proteinuria of less than 3 grams/24 hours
Biopsy must contain > 25 glomeruli with no ATN with score 4-6( score depending on glomerular sclerosis, tubular atrophy, interstitial fibrosis and arterial or arteriolar parameters)
It excluded :
macroscopic major vascular abnormality
evidence of focal scarring.
Summary of the Article:
Transplantation is best treatment for ESRD patients. As there is more patients in waiting list, so ECD to increase the pool of donors .
The use of single marginal donor may result in decrease in numbers of functioning nephrons ,so
transplanting both donor kidneys (dual transplant ) into 1 recipient to increase the available nephron mass.
which kidney is suitable for dual transplant?
There is no global consensus to select which kidneys best for DKT .
considered DKT if any 2 of the following are present:
-age more than 60 years
-creatinine clearance between 80 and 40 mL/min
-rising serum creatinine more than 2.5 mg/dL at retrieval
-chronic HTN or type 2 DM
-glomerulosclerosis between 15% and 50% by biopsy
To avoid renal biopsy in decision as biopsy may be misleading in view of elliptical biopsy:
Age of donor more than 65 years old plus 1 of the following risk factors :
– HTN
-Type 2 DM
– atherosclerotic disease
– cardiovascular event is the cause of death
– eGFR calculated by Cockcroft and Gault formula between 30-60 mL/min .
who is a suitable recipient?
patients with age less than 60 years and low immunological risk (PRA titer < 50%)
With minimal comorbidities and BMI < 30 kg/m2.
Surgical technique and complications:
-Bilateral Gibson incision with transplanting 1 kidney to each side.
Disadvantages:more tissue dissection and a longer operative time and 2nd transplant will be difficult.
-A midline extraperitoneal approach: need shorter operative time and dissection with fewer hernia complications also wound infection will be away from the graft but still 2nd transplant will be difficult.
-Unilateral placement of both kidneys : has advantages of reduced trauma from the surgical procedure and operative time. Also the other side remained not used for possible future transplant.