Non-heart-beating kidney transplantation: 6-year outcomes

Survival Benefit of Donation After Circulatory Death Kidney Transplantation in Children Compared With Remaining on the Waiting List for a Kidney Donated After Brain Death

BACKGROUND

Kidneys donated after circulatory death (DCD) are increasingly being used for transplantation in adults to alleviate organ shortage. Pediatric data on survival benefits of DCD transplantation compared with remaining on the waitlist for a kidney donated after brain death (DBD) offer are lacking.

METHODS

We used Scientific Registry of Transplant Recipients to identify 285 pediatric (<18 y) DCD kidney transplants performed between 1987 and 2017. Propensity score matching was used to create a comparison group of 1132 DBD transplants. We used sequential Cox analysis to evaluate survival benefit of DCD transplantation versus remaining on the waitlist and Cox regression to evaluate patient and graft survival.

RESULTS

DCD transplantation was associated with a higher incidence of delayed graft function (adjusted odds ratio: 3.0; P < 0.001). The risks of graft failure (adjusted hazard ratio [aHR], 0.89; P = 0.46) and death (aHR, 1.2; P = 0.67) were similar between DCD and DBD recipients. We found a significant survival benefit of DCD transplantation compared with remaining on the waitlist awaiting a DBD kidney (aHR, 0.44; P = 0.03).

CONCLUSIONS

Despite a higher incidence of delayed graft function, long-term patient and graft survival are similar between pediatric DCD and DBD kidney transplant recipients. DCD transplantation in children is associated with a survival benefit, despite pediatric priority for organ allocation, compared with remaining on the waitlist.

Advances in Kidney Preservation Techniques and Their Application in Clinical Practice

The use of cold preservation solutions to rapidly flush and cool the kidney followed by static cold storage in ice has been the standard kidney preservation technique for the last 50 y. Nonetheless, changing donor demographics that include organs from extended criteria donors and donation after circulatory death donors have led to the adoption of more diverse techniques of preservation. Comparison of hypothermic machine perfusion and static cold storage techniques for deceased donor kidneys has long been debated and is still contested by some. The recent modification of hypothermic machine perfusion techniques with the addition of oxygen or perfusion at subnormothermic or near-normothermic temperatures are promising strategies that are emerging in clinical practice. In addition, the use of normothermic regional perfusion to resuscitate abdominal organs of donation after circulatory death donors in situ before cold flushing is also increasingly being utilized. This review provides a synopsis of the different types of preservation techniques including their mechanistic effects and the outcome of their application in clinical practice for different types of donor kidney.

Perfusion of isolated rat kidney with Mesenchymal Stromal Cells/Extracellular Vesicles prevents ischaemic injury

Kidney donation after circulatory death (DCD) is a less than ideal option to meet organ shortages. Hypothermic machine perfusion (HMP) with Belzer solution (BS) improves the viability of DCD kidneys, although the graft clinical course remains critical. Mesenchymal stromal cells (MSC) promote tissue repair by releasing extracellular vesicles (EV). We evaluated whether delivering MSC-/MSC-derived EV during HMP protects rat DCD kidneys from ischaemic injury and investigated the underlying pathogenic mechanisms. Warm ischaemic isolated kidneys were cold-perfused (4 hrs) with BS, BS supplemented with MSC or EV. Renal damage was evaluated by histology and renal gene expression by microarray analysis, RT-PCR. Malondialdehyde, lactate, LDH, glucose and pyruvate were measured in the effluent fluid. MSC-/EV-treated kidneys showed significantly less global ischaemic damage. In the MSC/EV groups, there was up-regulation of three genes encoding enzymes known to improve cell energy metabolism and three genes encoding proteins involved in ion membrane transport. In the effluent fluid, lactate, LDH, MDA and glucose were significantly lower and pyruvate higher in MSC/EV kidneys as compared with BS, suggesting the larger use of energy substrates by MSC/EV kidneys. The addition of MSC/EV to BS during HMP protects the kidney from ischaemic injury by preserving the enzymatic machinery essential for cell viability and protects the kidney from reperfusion damage.

[Chronic kidney disease and kidney transplantation]

OBJECTIVES

To report epidemiology and characteristics of end-stage renal disease (ESRD) patients and renal transplant candidates, and to evaluate access to waiting list and results of renal transplantation.

MATERIAL AND METHODS

An exhaustive systematic review of the scientific literature was performed in the Medline database (http://www.ncbi.nlm.nih.gov) and Embase (http://www.embase.com) using different associations of the following keywords: "chronic kidney disease, epidemiology, kidney transplantation, cost, survival, graft, brain death, cardiac arrest, access, allocation". French legal documents have been reviewed using the government portal (http://www.legifrance.gouv.fr). Articles were selected according to methods, language of publication and relevance. The reference lists were used to identify additional historical studies of interest. Both prospective and retrospective series, in French and English, as well as review articles and recommendations were selected. In addition, French national transplant and health agencies (http://www.agence-biomedecine.fr and http://www.has-sante.fr) databases were screened using identical keywords. A total of 3234 articles, 6 official reports and 3 newspaper articles were identified; after careful selection 99 publications were eligible for our review.

RESULTS

The increasing prevalence of chronic kidney disease (CKD) leads to worsen organ shortage. Renal transplantation remains the best treatment option for ESRD, providing recipients with an increased survival and quality of life, at lower costs than other renal replacement therapies. The never-ending lengthening of the waiting list raises issues regarding treatment strategies and candidates' selection, and underlines the limits of organ sharing without additional source of kidneys available for transplantation.

CONCLUSION

Allocation policies aim to reduce medical or geographical disparities regarding enrollment on a waiting list or access to an allotransplant.

Late graft loss among pediatric recipients of DCD kidneys

BACKGROUND AND OBJECTIVES

Kidney transplantation from donors after cardiac death (DCD) provides similar graft survival to donors after brain death (DBD) in adult recipients. However, outcomes of DCD kidneys in pediatric recipients remain unclear, primarily because of limited sample sizes.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We identified 137 pediatric (<18 years old) recipients of DCD kidneys between 1994 and 2010 using Scientific Registry of Transplant Recipients data and compared outcomes with 6059 pediatric recipients of DBD kidneys during the same time period, accounting for donor, recipient, and transplant characteristics using time-varying Cox regression and matched controls. Long-term follow-up (4 years or beyond) was available for 31 DCD recipients.

RESULTS

Pediatric recipients of DCD kidneys experienced a significantly higher rate of delayed graft function (22.0% versus 12.3%; P = 0.001), although lower than reported delayed graft function rates of DCD grafts in adults. Although DCD and DBD graft survival was equal in the early postoperative period, graft loss among pediatric recipients of DCD kidneys exceeded their DBD counterparts starting 4 years after transplantation. This effect was statistically significant in a multivariate Cox model (hazard ratio = 2.03; 95% confidence interval, 1.21 to 3.39; P = 0.007) and matched-controls analysis (hazard ratio = 2.36; 95% confidence interval, 1.11 to 5.03; P = 0.03).

CONCLUSIONS

A significant increase in DCD graft loss starting 4 years after transplantation motivates a cautious approach to the use of DCD kidneys in children, in whom long-term graft survival is of utmost importance.

Extracorporeal support: improves donor renal graft function after cardiac death

Donors after cardiac death (DCD) could increase the organ pool. Data supports good long-term renal graft survival. However, DCDs are <10% of deceased donors in the United States, due to delayed graft function, and primary nonfunction. These complications are minimized by extracorporeal support after cardiac death (ECS-DCD). This study assesses immediate and acute renal function from different donor types. DCDs kidneys were recovered by conventional rapid recovery or by ECS, and transplanted into nephrectomized healthy swine. Warm ischemia of 10 and 30 min were evaluated. Swine living donors were controls (LVD). ECS-DCDs were treated with 90 min of perfusion until organ recovery. After procurement, kidneys were cold storage 4-6 h. Renal vascular resistance (RVR), urine output (UO), urine protein concentration (UrPr) and creatinine clearance (CrCl), were collected during 4 h posttransplantation. All grafts functioned with adequate renal blood flow for 4 h. RVR at 4 h posttransplant returned to baseline only in the LVD group (0.36 mmHg/mL/min +/- 0.03). RVR was higher in all DCDs (0.66 mmHg/mL/min +/- 0.13), without differences between them. UO was >50 mL/h in all DCDs, except in DCD-30 (6.8 mL/h +/- 1.7). DCD-30 had lower CrCl (0.9 mL/min +/- 0.2) and higher UrPr >200 mg/dL, compared to other DCDs >10 mL/min and <160 mg/dL, respectively. Normothermic ECS can resuscitate kidneys to transplantable status after 30 min of cardiac arrest/WI.

Kidney retrieval after sudden out of hospital refractory cardiac arrest: a cohort of uncontrolled non heart beating donors

Introduction

To counter the shortage of kidney grafts in France, a non heart beating donor (NHBD) program has recently been implemented. The aim of this study was to describe this pilot program for kidney retrieval from "uncontrolled" NHBD meaning those for whom attempts of resuscitation after a witnessed out-of-hospital cardiac arrest (CA) have failed (Maastricht 1 and 2), in a centre previously trained for retrieval from brain dead donors.

Methods

A prospective, monocentric, descriptive study concerning NHBD referred to our institution from February 2007 to June 2008. The protocol includes medical transport of refractory CA under mechanical ventilation and external cardiac massage, kidney protection by insertion of an intraaortic double-balloon catheter (DBC) with perfusion of a hypothermic solution, kidney retrieval and kidney preservation in a hypothermic pulsatile perfusion machine.

Results

122 potential NHBD were referred to our institution after a mean resuscitation attempt of 35 minutes (20–95). Regarding the contraindications, 63 were finally accepted and 56 had the DBC inserted. Organ retrieval was performed in 27 patients (43%) and 31 kidneys out of the 54 procured (57%) have been transplanted. Kidney transplantation exclusion was related to family refusal (n = 15), past medical history, time constraints, viral serology, high vascular ex vivo resistance of the graft and macroscopic abnormalities. The 31 kidneys exhibited an expected high delayed graft function rate (92%). Despite these initial results transplanted kidney had good creatinine clearance at six months (66 ± 24 ml/min) with a 89% graft survival rate at six months.

Conclusions

This study shows the feasibility and efficacy of an organ procurement program targeting NHBD allowing a 10% increase in the kidney transplantation rate over 17 months. With a six months follow-up period, the results of transplanted kidney function were excellent.

Early results of a controlled non-heart-beating kidney donor programme

BACKGROUND

We present our experience of a controlled non-heart beating donation (CNHBD) programme in a University Hospital.

METHODS

Data from all referrals for CNHBD between January 2005 and January 2008 were collected prospectively. Donor and recipient data were analysed and compared to other cadaveric and HBD transplants performed during the same period.

RESULTS

During the period, 79 donors were referred resulting in 35 proceeding to retrieval and 61 kidneys being successfully transplanted. The median time from withdrawal of therapy to asystole was 15 min (IQR 10.0-23.0). The median primary warm ischaemic time was 20 min (IQR 16.0-27.0). The mean cold ischaemia time was 16.6 +/- 4.21 h for CNHBD (16.6 +/- 5.91 for HBD) kidneys. Compared to HBD kidneys, CNHBD kidneys had more HLA mismatches and significantly more delayed graft function (44% versus 14%), and the mean time to halving of serum creatinine was significantly greater (12.8 versus 5 days). However, 1-year patient and graft survival (88% and 93%) were excellent and mean creatinine at 12 months for CNHB kidneys was not significantly different from HBD kidneys (141 mumol/l versus 131 mumol/l).

CONCLUSIONS

Structured implementation resulted in a successful CNHBD programme providing 61 successful renal transplants from 35 donors in 3 years-contributing to approximately 50% of the total number of cadaveric renal transplants during the period. At 12 months, CNHBD kidney graft function was equivalent to HBD organs.

Donor kidney disease and transplant outcome for kidneys donated after cardiac death

Background

Although outcomes of kidney transplants following donation after cardiac death (DCD) and donation after brainstem death (DBD) are similar, generally only optimal younger DCD donors are considered. This study examined the impact of pre-existing donor kidney disease on the outcome of DCD transplants.

Methods

This retrospective study compared the outcome of all DCD kidney transplants performed during 1996–2006 with contemporaneous kidney transplants from DBD donors. Implantation biopsies were scored for glomerular, tubular, parenchymal and vascular disease (global histology score). There were 104 DCD and 104 DBD kidney transplants.

Results

Delayed graft function (DGF) occurred more frequently in DCD than DBD kidneys (64·4 versus 28·8 per cent; P &lt; 0·001). Long-term graft outcome was similar. The only donor factor that influenced outcome was baseline kidney disease, which was similar in both groups, even though DCD donors were younger, with a higher predonation estimated glomerular filtration rate. The global histology score predicted DGF (odds ratio 1·85 per unit; P = 0·006) and graft failure (relative risk 1·55 per unit; P = 0·001), although there was no difference for DCD and DBD kidneys.

Conclusion

Transplant outcomes for DCD and DBD kidneys are comparable. Baseline donor kidney disease influences DGF and graft survival but the impact is no greater for DCD kidneys.

Urological complications and their impact on survival after kidney transplantation from deceased cardiac death donors

Urological complications after kidney transplantation may result in significant morbidity and mortality. However, the incidence of such complications after deceased cardiac death (DCD) donor kidney transplantation and their effect on survival is unknown. Purpose of this study was to estimate the incidence of urological complications after DCD kidney transplantation, and to estimate their impact on survival. Patient records of all 76 DCD kidney transplantations in the period 1997-2004 were reviewed for (urological) complications during the initial hospitalization until 30 days after discharge, and graft survival until the last hospital visit. Urological complications occurred in 32 patients (42.1%), with leakage and/or obstruction occurring in seven patients (9.2%). The latter seems to be comparable with the incidence reported in the literature for deceased heart-beating (DHB) transplantations (range 2.5-10%). Overall graft survival was 92% at 1 year and 88% at 3 years, comparable to the rates reported in the literature for kidneys from DHB donors, and was not affected by urological complications (chi(2) = 0.27, P = 0.61). Only a first warm-ischaemia time of 30 min or more reduced graft survival (chi(2) = 4.38, P < 0.05). We conclude that urological complications occur frequently after DCD kidney transplantation, but do not influence graft survival. The only risk factor for reduced graft survival in DCD transplant recipients was the first warm-ischaemia time.

Donor postextubation hypotension and age correlate with outcome after donation after cardiac death transplantation

BACKGROUND

Compared with standard donors, kidneys recovered from donors after cardiac death (DCD) exhibit higher rates of delayed graft function (DGF), and DCD livers demonstrate higher rates of biliary ischemia, graft loss, and worse patient survival. Current practice limits the use of these organs based on time from donor extubation to asystole, but data to support this is incomplete. We hypothesized that donor postextubation parameters, including duration and severity of hemodynamic instability or hypoxia might be a better predictor of subsequent graft function.

METHODS

We performed a retrospective examination of the New England Organ Bank DCD database, concentrating on donor factors including vital signs after withdrawal of support.

RESULTS

Prolonged, severe hypotension in the postextubation period was a better predictor of subsequent organ function that time from extubation to asystole. For DCD kidneys, this manifested as a trend toward increased DGF. For DCD livers, this manifested as increased rates of poor outcomes. Maximizing the predictive value of this test in the liver cohort suggested that greater than 15 min between the time when the donor systolic blood pressure drops below 50 mm Hg and flush correlates with increased rates of diffuse biliary ischemia, graft loss, or death. Donor age also correlated with worse outcome.

CONCLUSIONS

Time between profound instability and cold perfusion is a better predictor of outcome than time from extubation to asystole. If validated, this information could be used to predict DGF after DCD renal transplant and improve outcomes after DCD liver transplant.

[Cell energetic loading in experimental renal transplant with different periods of warm ischemia]

INTRODUCTION AND GOALS

Renal procurement after a period of heart st op demands a previous knowledge of ischemia-reperfusion injuries means. To study cell injury mechanisms an experimental study has been designed in pigs, with different rangres of warm ischemia (0-30-45 and 90 min). The main goal was to research on the basis of ischemic injury.

MATERIAL AND METHODS

Biochemical parameters (creatinine, urine output), energetic loading (ATP, ADP, AMP and global energetic loading) and pathological studies as long as survival analysis by 5th day were completed.

RESULTS

Animal survival and graft viability range from 100% at 5th day in control and 30 min warm ischemia groups to 60% in 90 min warm ischemia group. Creatinine levels rises at 1st, 3rd and 5th day, especially in those non-viable organs. ATP levels decrease after warm ischemia period, increases ADP and AMP levels after reperfusion in those viable organs.

CONCLUSIONS

Prolonged periods of warm ischemia do not result necessarily in non-viable kidneys. Viable organs recover nucleotide levels early. Study of energetic cell loading levels is a good way to get on better in the knowledge of injury mechanisms after ischemia-reperfusion.