Dual kidney transplantation offers a safe and effective way to use kidneys from deceased donors older than 70 years

Dual Kidney Transplantation: Single-Center Experience

BACKGROUND

Dual and en bloc kidney transplantation are strategies used to mitigate the disparity between a reduced organ pool and an ever-increasing need for organ procurement. En bloc refers to the implantation of 2 kidneys from a pediatric donor, compensating for small renal mass, whereas dual expanded criteria donor (DECD) transplantation refers to older donors with grafts otherwise rejected for single transplant, including expanded. This study describes one center's experience with dual and en bloc transplantation.

METHODS

A retrospective cohort study of dual kidney transplants (en bloc and DECD) from 1990 through 2021. The analysis included demographic, clinical, and survival analysis.

RESULTS

Of 46 patients who underwent dual kidney transplantation, 17 (37 %) received en-bloc transplantation. The overall mean recipient age was 49.4 ± 13.9 years old, younger in the en-bloc subgroup (39.2 vs 59.8 years old, P < .01). The mean time on dialysis was 37 ± 25 months. Delayed graft function was present in 17.4 % and primary nonfunction in 6.4 %, all from the DECD group. The estimated glomerular filtration rates at 1 and 5 years were 76.7 ± 28.7 and 80.4 ± 24.8 mL/min/1.73 m2, lower in the DECD group (65.9 vs 88.7 mL/min/1.73 m2, P = 0.02). Eleven recipients lost their graft during the study period: 63.6% from death with a functioning graft, 27.3% due to chronic graft dysfunction (a mean of 76.3 months after transplantation), and 9.1% due to vascular complications. Subgroup comparison found no differences regarding cold ischemia time or length of hospitalization. Kaplan-Meier estimates, censored for death with a functioning graft, resulted in a mean graft survival of 21.3 ± 1.3 years, with survival rates of 93.5, 90.5, and 84.1% at 1, 5, and 10 years, respectively, without significant differences between subgroups.

CONCLUSIONS

Both DECD and en bloc strategies provide safe and effective options to further expand the use of otherwise rejected kidneys. Neither of the 2 techniques was superior to the other.

Disparities in Deceased Donor Kidney Offer Acceptance: A Survey of Canadian Transplant Nephrologists, General Surgeons and Urologists

Background

Significant variability in organ acceptance thresholds have been demonstrated across the United States, but data regarding the rate and rationale for kidney donor organ decline in Canada are lacking.

Objective

To examine decision making regarding deceased kidney donor acceptance and non-acceptance in a population of Canadian transplant professionals.

Design

A survey study of theoretical deceased donor kidney cases of increasing complexity.

Setting

Canadian transplant nephrologists, urologists, and surgeons making donor call decisions responding to an electronic survey between July 22 and October 4, 2022.

Participants

Invitations to participate were distributed to 179 Canadian transplant nephrologists, surgeons, and urologists through e-mail. Participants were identified by contacting each transplant program and requesting a list of physicians who take donor call.

Measurements

Survey respondents were asked whether they would accept or decline a given donor, assuming there was a suitable recipient. They were also asked to cite reasons for donor non-acceptance.

Methods

Donor scenario-specific acceptance rates (total acceptance divided by total number of respondents for a given scenario and overall) and reasons for decline were determined and presented as a percentage of the total cases declined.

Results

In all, 72 respondents from 7 provinces completed at least one question of the survey, with considerable variability between acceptance rates for centers; the most conservative center declined 60.9% of donor cases, whereas the most aggressive center declined only 28.1%, P-value < .001. There was an increased risk of non-acceptance with advancing age, donation after cardiac death, acute kidney injury, chronic kidney disease, and comorbidities.

Limitations

As with any survey, there is the potential for participation bias. In addition, this study examines donor characteristics in isolation, however, asks respondent to assume there is a suitable candidate available. In reality, whenever donor quality is considered, it should be considered in the context of the intended recipient.

Conclusion

In a survey of increasingly medically complex deceased kidney donor cases, there was significant variability in donor decline among Canadian transplant specialists. Given relatively high rates of donor decline and apparent heterogeneity in acceptance decisions, Canadian transplant specialists may benefit from additional education regarding the benefits achieved from even medically complex kidney donors for appropriate candidates relative to remaining on dialysis on the transplant waitlist.

Pre-Implantation Kidney Biopsies in Extended Criteria Donors: From On Call to Expert Pathologist, from Conventional Microscope to Digital Pathology

The number of patients awaiting a kidney transplant is constantly rising but lack of organs leads kidneys from extended criteria donors (ECD) to be used to increase the donor pool. Pre-transplant biopsies are routinely evaluated through the Karpinski-Remuzzi score but consensus on its correlation with graft survival is controversial. This study aims to test a new diagnostic model relying on digital pathology to evaluate pre-transplant biopsies and to correlate it with graft outcomes. Pre-transplant biopsies from 78 ECD utilized as single kidney transplantation were scanned, converted to whole-slide images (WSIs), and reassessed by two expert nephropathologists using the Remuzzi-Karpinski score. The correlation between graft survival at 36 months median follow-up and parameters assigned by either WSI or glass slide score (GSL) by on-call pathologists was evaluated, as well as the agreement between the GSL and the WSIs score. No relation was found between the GSL assessed by on-call pathologists and graft survival (P = 0.413). Conversely, the WSI score assigned by the two nephropathologists strongly correlated with graft loss probability, as confirmed by the ROC curves analysis (DeLong test P = 0.046). Digital pathology allows to share expertise in the transplant urgent setting, ensuring higher accuracy and favoring standardization of the process. Its employment may significantly increase the predictive capability of the pre-transplant biopsy evaluation for ECD, improving the quality of allocation and patient safety.

Clinical Phenotypes of Dual Kidney Transplant Recipients in the United States as Identified through Machine Learning Consensus Clustering

Background and Objectives: Our study aimed to cluster dual kidney transplant recipients using an unsupervised machine learning approach to characterize donors and recipients better and to compare the survival outcomes across these various clusters. Materials and Methods: We performed consensus cluster analysis based on recipient-, donor-, and transplant-related characteristics in 2821 dual kidney transplant recipients from 2010 to 2019 in the OPTN/UNOS database. We determined the important characteristics of each assigned cluster and compared the post-transplant outcomes between clusters. Results: Two clinically distinct clusters were identified by consensus cluster analysis. Cluster 1 patients was characterized by younger patients (mean recipient age 49 ± 13 years) who received dual kidney transplant from pediatric (mean donor age 3 ± 8 years) non-expanded criteria deceased donor (100% non-ECD). In contrast, Cluster 2 patients were characterized by older patients (mean recipient age 63 ± 9 years) who received dual kidney transplant from adult (mean donor age 59 ± 11 years) donor with high kidney donor profile index (KDPI) score (59% had KDPI ≥ 85). Cluster 1 had higher patient survival (98.0% vs. 94.6% at 1 year, and 92.1% vs. 76.3% at 5 years), and lower acute rejection (4.2% vs. 6.1% within 1 year), when compared to cluster 2. Death-censored graft survival was comparable between two groups (93.5% vs. 94.9% at 1 year, and 89.2% vs. 84.8% at 5 years). Conclusions: In summary, DKT in the United States remains uncommon. Two clusters, based on specific recipient and donor characteristics, were identified through an unsupervised machine learning approach. Despite varying differences in donor and recipient age between the two clusters, death-censored graft survival was excellent and comparable. Broader utilization of DKT from high KDPI kidneys and pediatric en bloc kidneys should be encouraged to better address the ongoing organ shortage.

Recommendations for Evaluation and Selection of Deceased Organ Donor: Position Statement of ISCCM

There is a wide gap between patients who need transplants and the organs that are available in India. Extending the standard donation criterion is certainly important to address the scarcity of organs for transplantation. Intensivists play a major role in the success of deceased donor organ transplants. Recommendations for deceased donor organ evaluation are not discussed in most intensive care guidelines. The purpose of this position statement is to establish current evidence-based recommendations for multiprofessional critical care staff in the evaluation, assessment, and selection of potential organ donors. These recommendations will give "real-world" criteria that are acceptable in the Indian context. The aim of this set of recommendations is to both increase the number and enhance the quality of transplantable organs.

How to cite this article

Zirpe KG, Tiwari AM, Pandit RA, Govil D, Mishra RC, Samavedam S, et al. Recommendations for Evaluation and Selection of Deceased Organ Donor: Position Statement of ISCCM. Indian J Crit Care Med 2022;26(S2):S43-S50.

The use of marginal kidneys in dual kidney transplantation to expand kidney graft utilization

PURPOSE OF REVIEW

The purpose of this review is to chronicle the history of dual kidney transplantation (DKT) and identify opportunities to improve utilization of marginal deceased donor (MDD) kidneys through DKT.

RECENT FINDINGS

The practice of DKT from adult MDDs dates back to the mid-1990s, at which time the primary indication was projected insufficient nephron mass from older donors. Multiple subsequent studies of short- and long-term success have been reported focusing on three major aspects: Identifying appropriate selection criteria/scoring systems based on pre- and postdonation factors; refining technical aspects; and analyzing longer-term outcomes. The number of adult DKTs performed in the United States has declined in the past decade and only about 60 are performed annually. For adult deceased donor kidneys meeting double allocation criteria, >60% are ultimately not transplanted. MDDs with limited renal functional capacity represent a large proportion of potential kidneys doomed to either discard or nonrecovery.

SUMMARY

DKT may reduce organ discard and optimize the use of kidneys from MDDs. New and innovative technologies targeting ex vivo organ assessment, repair, and regeneration may have a major impact on the decision whether or not to use recovered kidneys for single or DKT.

Ipsilateral dual kidney transplantation in an elderly patient with severe atherosclerosis: a case report

Dual Kidney Transplantation (DKT) has been developed to improve outcomes from transplantation based on extended criteria of donors (ECD) and demonstrated excellent short-term outcomes. We performed DKT at Samsung Medical Center in March 2021. The donor was a 74-year-old male with no history of known underlying diseases but died from traumatic subarachnoid hemorrhage. The recipient was a 72-year-old male who had been undergoing nephrological observation for 4 years prior to the kidney transplant. The patient had been on hemodialysis since July 2017 and had been suffering from type 2 diabetes since 2003. On non-contrast computed tomography, diffuse calcific atherosclerosis was observed in the abdominal aorta and left iliac artery. As a result, ipsilateral DKT was performed. Because of this diffuse calcific atherosclerosis, we planned ipsilateral DKT on the right side. Postoperative healing was uneventful without complications. In conclusion, DKT is an option for improving survival in the ECD pool, and ipsilateral DKT can be helpful option for preventing organ discard in ECDs.

Dual kidney transplants from adult marginal donors: Review and perspective

The practice of dual kidney transplantation (DKT) from adult marginal deceased donors (MDDs) dates back to the mid-1990s with initial pioneering experiences reported by the Stanford and Maryland groups, at which time the primary indication was estimated insufficient nephron mass from older donors. Multiple subsequent studies of short and long-term success have been reported focusing on three major aspects of DKT: Identifying appropriate selection criteria and developing scoring systems based on pre- and post-donation factors; refining technical aspects; and analyzing mid-term outcomes. The number of adult DKTs performed in the United States has declined in the past decade and only about 60 are performed annually. For adult deceased donor kidneys meeting double allocation criteria, >60% are ultimately not transplanted. Deceased donors with limited renal functional capacity represent a large proportion of potential kidneys doomed to either discard or non-recovery. However, DKT may reduce organ discard and optimize the use of kidneys from MDDs. In an attempt to promote utilization of MDD kidneys, the United Network for Organ Sharing introduced new allocation guidelines pursuant to DKT in 2019. The purpose of this review is to chronicle the history of DKT and identify opportunities to improve utilization of MDD kidneys through DKT. This article is protected by copyright. All rights reserved.

Staggered Dual Kidney Transplantation

We describe a case where a patient received a successful dual kidney transplantation in a staggered fashion. Two kidneys from a deceased donor were accepted for 2 separate primary intended recipients, however, due to unforeseen circumstances, both kidneys were eventually transplanted in a staggered fashion into an alternate single recipient. The intention behind this method was to enhance the patient's renal function and to prevent the wastage of a kidney. Despite the significantly prolonged cold ischemia times, the recipient has excellent dual graft function after 3 years. The positive outcome underpins the effectiveness of donor kidneys even with prolonged cold ischemia times outside established best practice guidelines. It also reinforces the effectiveness of dual kidney transplantation. Transplant professionals encounter complex situations occasionally where an established evidence-base or aids to decision-making are limited. This case reflects challenges in decision-making, patient counselling and consent, especially when the opportunity for the staggered dual kidney transplantation, with potential increased morbidity, came about as another recipient declined a usable kidney. It also highlights the widely differing risk appetites of different patients. Crucially, it optimised the donation process and procurement of 2 kidneys while preventing wastage. To our knowledge, this is the first report of a staggered dual kidney transplantation in a single recipient.

Quality Assessment of Donor Kidneys and the Tendency of Kidney Acceptance: A Single-Center Experience

PURPOSE

The increasing age of donors and the increasing tendency of comorbidities requires an extension in acceptance criteria. In this review, the tendency for acceptance and refusal was analyzed by examining reasons for declining donor kidneys at the kidney transplantation center in Debrecen. This analysis aimed to assess the quality of donor kidneys and indicate why two-thirds of donated organs were refused.

METHOD

Our center in Debrecen received 535 kidney offers (based on exclusion criteria) between November 2016 and August 2019, which were retrospectively analyzed. Donor kidneys were evaluated using expanded criteria donor, kidney donor profile index (KDPI), and kidney donor risk index criteria systems.

RESULTS

Thirty-five percent (n = 189) of the kidneys offered to the center in Debrecen had been approved in advance, and later 63% (n = 119) were transplanted. Using the KDPI system, 41% of donors had a KDPI above 85, of which 23% were accepted, while acceptance of kidneys with a KDPI of 0 to 35 was around 70%. When examining causes of donor kidney refusal, 90% of the organs had donor quality problems, 13% had logistical cause (long cold ischemic time, large age difference between donor and recipient), and 10.5% had immunologic cause. In 13% of cases, the refusal of donor organs was due to the coexistence of several problems.

CONCLUSION

Our data showed that high-risk donor organs were being refused in our center; however, they are being transplanted at a higher rate in other Eurotransplant centers. The decision to refuse or accept donor organs depends on several factors, including expected waiting time, patient's clinical characteristics, and quality of life.

Double Single-Side Kidney Transplants With Bench Vascular Reconstruction: A Further Challenge Beyond the Marginality Without Future Preclusions

BACKGROUND

Double kidney transplantation allows the use of marginal kidneys with a significant improvement in the recovery of renal function expected after transplantation, although with a greater anesthesiologic and surgical risk. One-sided positioning, more cautious in the event of functional exhaustion, can be complex due to vascular anomalies.

MATERIALS AND METHODS

We report the case of 2 double unilateral kidney transplants with vascular reconstructions. The first is a double kidney transplant from a 83-year-old donor. Both kidneys (score 5) had 2 arteries and the arterial patch was not usable. A cryopreserved arterial graft was used for the packaging of an arterial axis with which a single T-L anastomosis was performed; the 2 veins were also joined with the packaging of a single anastomosis. The second case is a double kidney transplant from a cadaveric donor performed on a recipient suffering from severe diffuse atheromasia. The right kidney had 2 arteries and the left kidney had 3 arteries (both score 5). The aortic patches and veins of the 2 kidneys were joined together and a single arterial and venous anastomosis was performed.

RESULTS

The course has been uneventful. In both cases there were no perioperative vascular complications.

CONCLUSIONS

The use of marginal organs is an increasingly common reality. Bench vascular reconstructions can further increase donation resources, safely enhancing the transplantation of already marginal organs that would otherwise not be usable and allowing the contralateral vascular axis to be kept intact.

Degree of Glomerulosclerosis in Procurement Kidney Biopsies from Marginal Donor Kidneys and Their Implications in Predicting Graft Outcomes

Background: This study aimed to assess the association between the percentage of glomerulosclerosis (GS) in procurement allograft biopsies from high-risk deceased donor and graft outcomes in kidney transplant recipients. Methods: The UNOS database was used to identify deceased-donor kidneys with a kidney donor profile index (KDPI) score > 85% from 2005 to 2014. Deceased donor kidneys were categorized based on the percentage of GS: 0-10%, 11-20%, >20% and no biopsy performed. The outcome included death-censored graft survival, patient survival, rate of delayed graft function, and 1-year acute rejection. Results: Of 22,006 kidneys, 91.2% were biopsied showing 0-10% GS (58.0%), 11-20% GS (13.5%), >20% GS (19.7%); 8.8% were not biopsied. The rate of kidney discard was 48.5%; 33.6% in 0-10% GS, 68.9% in 11-20% GS, and 77.4% in >20% GS. 49.8% of kidneys were discarded in those that were not biopsied. Death-censored graft survival at 5 years was 75.8% for 0-10% GS, 70.9% for >10% GS, and 74.8% for the no biopsy group. Among kidneys with >10% GS, there was no significant difference in death-censored graft survival between 11-20% GS and >20% GS. Recipients with >10% GS had an increased risk of graft failure (HR = 1.27, p < 0.001), compared with 0-10% GS. There was no significant difference in patient survival, acute rejection at 1-year, and delayed graft function between 0% and 10% GS and >10% GS. Conclusion: In >85% KDPI kidneys, our study suggested that discard rates increased with higher percentages of GS, and GS >10% is an independent prognostic factor for graft failure. Due to organ shortage, future studies are needed to identify strategies to use these marginal kidneys safely and improve outcomes.