The effect of delayed graft function on graft and patient survival in kidney transplantation: an approach using competing events analysis

Understanding Delayed Graft Function to Improve Organ Utilization and Patient Outcomes: Report of a Scientific Workshop Sponsored by the National Kidney Foundation

Delayed graft function (DGF) is a common complication after kidney transplant. Despite extensive literature on the topic, the extant definition of DGF has not been conducive to advancing the scientific understanding of the influences and mechanisms contributing to its onset, duration, resolution, or long-term prognostic implications. In 2022, the National Kidney Foundation sponsored a multidisciplinary scientific workshop to comprehensively review the current state of knowledge about the diagnosis, therapy, and management of DGF and conducted a survey of relevant stakeholders on topics of clinical and regulatory interest. In this Special Report, we propose and defend a novel taxonomy for the clinical and research definitions of DGF, address key regulatory and clinical practice issues surrounding DGF, review the current state of therapies to reduce and/or attenuate DGF, offer considerations for clinical practice related to the outpatient management of DGF, and outline a prospective research and policy agenda.

HLA B eplet mismatches in the context of delayed graft function and low tacrolimus trough levels are risk factors influencing the generation of de novo donor-specific antibodies and acute rejection in the early stage after kidney transplantation

BACKGROUND

De novo donor-specific antibody (dnDSA) generation and acute rejection (AR) are the main factors affecting long-term graft survival. This study aims to investigate human leukocyte antigen (HLA) eplet mismatching (MM), delayed graft function (DGF), and tacrolimus (TAC) trough levels on the occurrence of dnDSA and AR in the early stages after kidney transplantation (KT).

METHODS

This retrospective study included 526 cases of deceased donation KT. The effects of DGF, HLA eplet MM, and TAC trough levels on dnDSA and AR occurrence were analyzed with logistic regression analysis.

RESULTS

Multivariate logistic regression analysis showed the independent risk factor of dnDSA generation was HLA B eplet MM (OR: 1.201, 95% CI: 1.007-1.431, P = 0.041). The independent risk factors of AR occurrence include DGF (OR: 4.045, 95% CI: 1.047-15.626, P = 0.043), HLA B eplet MM (OR: 1.090, 95% CI: 1.000-1.187, P = 0.050), and TAC trough levels at 12 months (OR: 0.750, 95% CI: 565-0.997, P = 0.048). HLA B eplet MM combined with DGF and TAC trough levels at 12 months increased the predictive value of dnDSA (AUC 0.735) and AR (AUC 0.730) occurrence. HLA B eplet MM > 9 and TAC trough levels below 5.95 ng/mL at 12 months could increase the risk of early AR occurrence.

CONCLUSIONS

HLA B eplet MM, DGF, and TAC trough levels at 12 months after KT could affect the occurrence of dnDSA and AR in the early stage of KT.

Contrast-Enhanced Ultrasonography Value for Early Prediction of Delayed Graft Function in Renal Transplantation Patients

OBJECTIVES

Delayed graft function (DGF) is a common early complication after kidney transplantation. The aim of the present study was to evaluate the value of contrast-enhanced ultrasonography (CEUS) in the early prediction of DGF after kidney transplantation.

METHODS

A total of 89 renal transplant recipients were retrospectively enrolled and divided into DGF group or normal graft function (NGF) group according to the allograft function. Conventional Doppler ultrasound and CEUS examination data on the first postoperative day were collected and analyzed.

RESULTS

The resistive indices of segmental and interlobar artery in the DGF group were significantly higher than those in the NGF group (0.71 ± 0.17 versus 0.63 ± 0.08, P = .006; 0.70 ± 0.16 versus 0.62 ± 0.08, P = .004, respectively). The patients experiencing DGF had significantly lower PI-c (14.7 dB ± 6.1 dB versus 18.5 dB ± 3.3 dB, P = .001) and smaller AUC-c (779.8 ± 375.8 dB·seconds versus 991.0 ± 211.7 dB·seconds, P = .003), as well as significantly lower PI-m (12.6 dB ± 5.9 dB versus 15.9 dB ± 3.9 dB, P = .006), shorter MTT-m (30.7 ± 9.4 seconds versus 36.3 ± 7.1 seconds, P = .01), and smaller AUC-m (P = .007). Multivariate analysis demonstrated that PI-c, AUC-c, and MTT-m were independent risk factors for DGF. The area under the receiver operating characteristic curve values of the combined predicted value (PI-c + MTT-m, PI-c + AUC-c + MTT-m) of DGF incidence were bigger than that of PI-c, AUC-c, or MTT-m.

CONCLUSIONS

CEUS parameters of the cortex and medulla have a good value for an early prediction of DGF after renal transplantation.

Baseline Characteristics and Representativeness of Participants in the BEST-Fluids Trial: A Randomized Trial of Balanced Crystalloid Solution Versus Saline in Deceased Donor Kidney Transplantation

Delayed graft function (DGF) is a major complication of deceased donor kidney transplantation. Saline (0.9% sodium chloride) is a commonly used intravenous fluid in transplantation but may increase the risk of DGF because of its high chloride content. Better Evidence for Selecting Transplant Fluids (BEST-Fluids), a pragmatic, registry-based, double-blind, randomized trial, sought to determine whether using a balanced low-chloride crystalloid solution (Plasma-Lyte 148) instead of saline would reduce DGF. We sought to evaluate the generalizability of the trial cohort by reporting the baseline characteristics and representativeness of the trial participants in detail.

METHODS

We compared the characteristics of BEST-Fluids participants with those of a contemporary cohort of deceased donor kidney transplant recipients in Australia and New Zealand using data from the Australia and New Zealand Dialysis and Transplant Registry. To explore potential international differences, we compared trial participants with a cohort of transplant recipients in the United States using data from the Scientific Registry of Transplant Recipients.

RESULTS

During the trial recruitment period, 2373 deceased donor kidney transplants were performed in Australia and New Zealand; 2178 were eligible' and 808 were enrolled in BEST-Fluids. Overall, trial participants and nonparticipants were similar at baseline. Trial participants had more coronary artery disease (standardized difference [d] = 0.09; P = 0.03), longer dialysis duration (d = 0.18, P < 0.001), and fewer hypertensive (d = -0.11, P = 0.03) and circulatory death (d = -0.14, P < 0.01) donors than nonparticipants. Most key characteristics were similar between trial participants and US recipients, with moderate differences (|d| ≥ 0.2; all P < 0.001) in kidney failure cause, diabetes, dialysis duration, ischemic time, and several donor risk predictors, likely reflecting underlying population differences.

CONCLUSIONS

BEST-Fluids participants had more comorbidities and received slightly fewer high-risk deceased donor kidneys but were otherwise representative of Australian and New Zealand transplant recipients and were generally similar to US recipients. The trial results should be broadly applicable to deceased donor kidney transplantation practice worldwide.

Investigation of Different Methods of Intraoperative Graft Perfusion Assessment during Kidney Transplantation for the Prediction of Delayed Graft Function: A Prospective Pilot Trial

Delayed graft function (DGF) after renal transplantation is a relevant clinical problem affecting long-term organ function. The early detection of patients at risk is crucial for postoperative monitoring and treatment algorithms. In this prospective cohort study, allograft perfusion was evaluated intraoperatively in 26 kidney recipients by visual and formal perfusion assessment, duplex sonography, and quantitative microperfusion assessment using O2C spectrometry and ICG fluorescence angiography. The O2C tissue spectrometry device provides a quantitative method of microperfusion assessment that can be employed during kidney transplantation as an easy-to-use and highly sensitive alternative to ICG fluorescence angiography. Intraoperative microvascular flow and velocity in the allograft cortex after reperfusion predicted DGF with a sensitivity of 100% and a specificity of 82%. Threshold values of 57 A.U. for microvascular flow and 13 A.U. for microvascular velocity were identified by an ROC analysis. This study, therefore, confirmed that impairment of microperfusion of the allograft cortex directly after reperfusion was a key indicator for the occurrence of DGF after kidney transplantation. Our results support the combined use of intraoperative duplex sonography, for macrovascular quality control, and quantitative microperfusion assessment, such as O2C spectrometry, for individual risk stratification to guide subsequent postoperative management.

Predictive value of the renal resistive index in the immediate postoperative period after kidney transplantation on short- and long-term graft and patient outcomes

INTRODUCTION

During the postoperative stay in the intensive care unit after kidney transplantation, the renal resistive index (RI) is routinely measured. An increased RI, measured months posttransplant, is associated with a higher mortality. We wanted to investigate the value of the RI immediately posttransplant in predicting both short- and long-term outcome.

METHODS

We performed a retrospective single-center study. The RI was collected <48 h posttransplant in patients undergoing kidney transplantations between 2005 and 2014. Short-term outcome was evaluated by delayed graft function (DGF). The long-term endpoints were kidney function and mortality at 30 days, 1 year and 5 years.

RESULTS

We included 478 recipients, 91.4% of whom reached the end of the 5-year follow-up. A higher RI < 48 h posttransplant was significantly associated with DGF. This association was particularly strong in patients receiving grafts from donors after brain death and expanded criteria donors. A higher RI also correlated with mortality and death with functioning graft but not with graft failure. After adjustment for confounders, we found an association between increased RI and DGF, but not with long-term kidney function or mortality.

CONCLUSION

The RI routinely measured <48 h posttransplant is an independent predictor of short-term kidney function.

Extracellular Vesicles From Kidney Allografts Express miR-218-5p and Alter Th17/Treg Ratios

Delayed graft function (DGF) in kidney transplantation is associated with ischemic injury and carries long term functional and immunological risks. Extracellular vesicles (EV) released from allografts may signal a degree of ischemic stress, and are thought to play an important role in the development of anti-donor immunity. Here, we show that kidney perfusate-derived extracellular vesicles (KP-EV) express donor-specific human leukocyte antigen. KP-EV from kidneys that experience DGF increase the T-helper 17 (Th17) to T-regulatory (Treg) ratio in third party peripheral blood mononuclear cells to a greater degree than those from kidneys with immediate function. We report miR-218-5p upregulation in KP-EV of kidney transplant recipients with DGF. Levels of miR-218-5p in KP-EV inversely correlated with recipient eGFR at multiple time points following transplantation. Additionally, the degree of increase in Th17/Treg ratio by KP-EV positively correlated with miR-218-5p expression in KP-EV samples. Taken together, these data provide evidence that KP-EV may contribute to modulating immune responses in transplant recipients. This could lead to novel intervention strategies to inhibit DGF in order to improve graft function and survival.

Age at Time of Kidney Transplantation as a Predictor for Mortality, Graft Loss and Self-Rated Health Status: Results From the Swiss Transplant Cohort Study

Introduction: The effect of age on health outcomes in kidney transplantation remains inconclusive. This study aimed to analyze the relationship between age at time of kidney transplantation with mortality, graft loss and self-rated health status in adult kidney transplant recipients.

Methods: This study used data from the Swiss Transplant Cohort Study and included prospective data of kidney transplant recipients between 2008 and 2017. Time-to-event analysis was performed using Cox’ regression analysis, and -in the case of graft loss- competing risk analysis. A random-intercept regression model was applied to analyse self-rated health status.

Results: We included 2,366 kidney transplant recipients. Age at transplantation linearly predicted mortality. It was also predictive for graft loss, though nonlinearly, showing that recipients aged between 35 and 55 years presented with the lowest risk of experiencing graft loss. No relationship of age with self-rated health status was detected.

Conclusion: Higher mortality in older recipients complies with data from the general population. The non-linear relationship between age and graft loss and the higher scored self-rated health status at all follow-up time-points compared to the pre-transplant status -regardless of age- highlight that age alone might not be an accurate measure for risk prediction and clinical decision making in kidney transplantation.

Repeated kidney re-transplantation in times of organ shortage - a critical review

PURPOSE OF REVIEW

Organ shortage forces those responsible to streamline allocation rules to provide a maximum of candidates with a graft and to optimize transplant outcome. Recently, repeated kidney re-transplantation was investigated in several studies with different analytic settings concerning the control group, the donors, parameters influencing outcome, and demographic characteristics. This review gives an overview on the candidates awaiting a repeated re-transplantation, summarizes the outcome, and comments on the relevance of these findings in the context of sustained organ shortage.

RECENT FINDINGS

Repeated kidney re-transplantation is technically and immunologically feasible and the recipients' survival is better compared to candidates remaining on dialysis or on the waiting-list. However, the outcome is mainly reported to be worse as compared to first or second kidney transplantation. Kidneys from living donors seem to have a favorable impact on outcome in this setting.

SUMMARY

The survival benefit of repeated re-transplantation recipients over patients on dialysis demands for continuation of this procedure. Comprehensive registries are essential to continuously optimize allocation. Governmental authorities are obliged to set the course to increase organ donation rather than forcing transplant decision makers to withhold a third or fourth graft from any candidate.

Kidney transplantation after rescue allocation-meticulous selection yields the chance for excellent outcome

BACKGROUND

The small number of organ donors forces transplant centres to consider potentially suboptimal kidneys for transplantation. Eurotransplant established an algorithm for rescue allocation (RA) of kidneys repeatedly declined or not allocated within 5 h after procurement. Data on the outcomes and benefits of RA are scarce to date.

METHODS

We conducted a retrospective 8-year analysis of transplant outcomes of RA offers based on our in-house criteria catalogue for acceptance and decline of organs and potential recipients.

RESULTS

RA donors and recipients were both older compared with standard allocation (SA). RA donors more frequently had a history of hypertension, diabetes or fulfilled expanded criteria donor key parameters. RA recipients had poorer human leucocyte antigen (HLA) matches and longer cold ischaemia times (CITs). However, waiting time was shorter and delayed graft function, primary non-function and biopsy-proven rejections were comparable to SA. Five-year graft and patient survival after RA were similar to SA. In multivariate models accounting for confounding factors, graft survival and mortality after RA and SA were comparable as well.

CONCLUSIONS

Facing relevant comorbidities and rapid deterioration with the risk of being removed from the waiting list, kidney transplantation after RA was identified to allow for earlier transplantation with excellent outcome. Data from this survey propose not to reject categorically organs from multimorbid donors with older age and a history of hypertension or diabetes to aim for the best possible HLA matching and to carefully calculate overall expected CIT.

Exploring the causes of the high incidence of delayed graft function after kidney transplantation in Brazil: a multicenter study

This retrospective multicenter (n = 18) cohort study evaluated the incidence, risk factors, and the impact of delayed graft function (DGF) on 1-year kidney transplant (KT) outcomes. Of 3992 deceased donor KT performed in 2014-2015, the incidence of DGF was 54%, ranging from 29.9% to 87.7% among centers. Risk factors (_{lower-bound-95%CI} OR _{upper-bound-95%CI} ) were male gender (_1.066 1.249_1.463 ), diabetic kidney disease (_1.053 1.296_1.595 ), time on dialysis (_1.005 1.007_1.009 ), retransplantation (_1.035 1.397_1.885 ), preformed anti-HLA antibodies (_1.011 1.383_1.892 ), HLA mismatches (_1.006 1.066_1.130 ), donor age (_1.011 1.017_1.023 ), donor final serum creatinine (sCr) (_1.239 1.317_1.399 ), cold ischemia time (CIT) (_1.031 1.043_1.056 ), machine perfusion (_0.401 0.542_0.733 ), and induction therapy with rabbit antithymocyte globulin (rATG) (_0.658 0.800_0.973 ). Duration of DGF > 4 days was associated with inferior renal function and DGF > 14 days with the higher incidences of acute rejection, graft loss, and death. In conclusion, the incidence and duration of DGF were high and associated with inferior graft outcomes. While late referral and poor donor maintenance account for the high overall incidence of DGF, variability in donor and recipient selection, organ preservation method, and type of induction agent may account for the wide variation observed among transplant centers.

Vasopressor selection during critical care management of brain dead organ donors and the effects on kidney graft function

BACKGROUND

Delayed graft function (DGF), the need for dialysis in the first week following kidney transplant, affects approximately one quarter of deceased-donor kidney transplant recipients. Donor demographics, donor serum creatinine, and graft cold ischemia time are associated with DGF. However, there is no consensus on the optimal management of hemodynamic instability in organ donors after brain death (DBDs). Our objective was to determine the relationship between vasopressor selection during donor management and the development of DGF.

METHODS

Prospective observational data, including demographic and critical care parameters, were collected for all DBDs managed by 17 organ procurement organizations from nine Organ Procurement and Transplantation Network Regions between 2012 and 2018. Recipient outcome data were linked with donor data through donor identification numbers. Donor critical care parameters, including type of vasopressor and doses, were recorded at three standardized time points during donor management. The analysis included only donors who received at least one vasopressor at all three time points. Vasopressor doses were converted to norepinephrine equivalent doses and analyzed as continuous variables. Univariate analyses were conducted to determine the association between donor variables and DGF. Results were adjusted for known predictors of DGF using binary logistic regression.

RESULTS

Complete data were available for 5,554 kidney transplant recipients and 2,985 DBDs. On univariate analysis, donor serum creatinine, donor age, donor subtype, kidney donor profile index, graft cold ischemia time, phenylephrine dose, and dopamine dose were associated with DGF. After multivariable analysis, increased donor serum creatinine, donor age, kidney donor profile index, graft cold ischemia time, and phenylephrine dose remained independent predictors of DGF.

CONCLUSION

Higher doses of phenylephrine were an independent predictor of DGF. With the exception of phenylephrine, the selection and dose of vasopressor during donor management did not predict the development of DGF.

LEVEL OF EVIDENCE

Prognostic study, Level III.

Perioperative hemoglobin decrement as an independent risk of poor early graft function in kidney transplantation

OBJECTIVE

Perioperative change of hemoglobin concentration (Hb) was associated with acute kidney injury in patients who underwent non-cardiac surgery, but has never been investigated in kidney transplant patients. This study aimed to observe the effects of perioperative Hb change on early graft function in kidney transplant recipients.

RESULTS

A total of 269 kidney transplant patients were enrolled, of whom 98 (36.4%) developed poor early graft function (PEGF), and 171 (63.6%) had immediate graft function. Comparing two groups, patients with PEGF had a greater decremental change of Hb (-1.60 [-2.38,-0.83] vs. -0.70 [-1.35,0.20] g/dL, respectively; p < 0.001). A Hb cut-point of -1.35 g/dL was obtained from ROC analysis. Multivariate analysis showed that perioperative Hb decrement greater than 1.35 g/dL was an independent risk of PEGF (adjusted OR of 2.52, 95% CI 1.11-5.72; p = 0.026). Subgroup analysis revealed deceased donor kidney transplant (DDKT; n = 126) (adjusted OR of 2.89, 95% CI 1.11-7.55; p = 0.029), but not living donor kidney transplantation (LDKT; n = 143) (adjusted OR of 1.68, 95% CI 0.23-12.15; p = 0.606), was influenced by the perioperative Hb decrement. In conclusion, this study suggests that decremental change in perioperative Hb greater than 1.35 g/dL may serve as a modifiable factor of PEGF in DDKT.

WITHDRAWN: Impact on Delayed Graft Function of the Renal Resistive Index in the Immediate Postoperative Period After Kidney Transplantation: A Cohort Analysis

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The impact of deceased donor maintenance on delayed kidney allograft function: A machine learning analysis

Background

This study evaluated the risk factors for delayed graft function (DGF) in a country where its incidence is high, detailing donor maintenance-related (DMR) variables and using machine learning (ML) methods beyond the traditional regression-based models.

Methods

A total of 443 brain dead deceased donor kidney transplants (KT) from two Brazilian centers were retrospectively analyzed and the following DMR were evaluated using predictive modeling: arterial blood gas pH, serum sodium, blood glucose, urine output, mean arterial pressure, vasopressors use, and reversed cardiac arrest.

Results

Most patients (95.7%) received kidneys from standard criteria donors. The incidence of DGF was 53%. In multivariable logistic regression analysis, DMR variables did not impact on DGF occurrence. In post-hoc analysis including only KT with cold ischemia time<21h (n = 220), urine output in 24h prior to recovery surgery (OR = 0.639, 95%CI 0.444–0.919) and serum sodium (OR = 1.030, 95%CI 1.052–1.379) were risk factors for DGF. Using elastic net regularized regression model and ML analysis (decision tree, neural network and support vector machine), urine output and other DMR variables emerged as DGF predictors: mean arterial pressure, ≥ 1 or high dose vasopressors and blood glucose.

Conclusions

Some DMR variables were associated with DGF, suggesting a potential impact of variables reflecting poor clinical and hemodynamic status on the incidence of DGF.

Intraoperative Fluid Restriction is Associated with Functional Delayed Graft Function in Living Donor Kidney Transplantation: A Retrospective Cohort Analysis

Background: In 2016 we observed a marked increase in functional delayed graft function (fDGF) in our living donor kidney transplantation (LDKT) recipients from 8.5% in 2014 and 8.8% in 2015 to 23.0% in 2016. This increase coincided with the introduction of a goal-directed fluid therapy (GDFT) protocol in our kidney transplant recipients. Hereupon, we changed our intraoperative fluid regimen to a fixed amount of 50 mL/kg body weight (BW) and questioned whether the intraoperative fluid regimen was related to this increase in fDGF. Methods: a retrospective cohort analysis of all donors and recipients in our LDKT program between January 2014–February 2017 (n = 275 pairs). Results: Univariate analysis detected various risk factors for fDGF. Dialysis dependent recipients were more likely to develop fDGF compared to pre-emptively transplanted patients (p < 0.001). Recipients developing fDGF received less intraoperative fluid (36 (25.9–50.0) mL/kg BW vs. 47 (37.3–55.6) mL/kg BW (p = 0.007)). The GDFT protocol resulted in a reduction of intraoperative fluid administration on average by 850 mL in total volume and 21% in mL/kg BW compared to our old protocol (p < 0.001). In the unadjusted analysis, a higher intraoperative fluid volume in mL/kg BW was associated with a lower risk for the developing fDGF (OR 0.967, CI (0.941–0.993)). After adjustment for the confounders, prior dialysis and the use of intraoperative noradrenaline, the relationship of fDGF with fluid volume was still apparent (OR 0.970, CI (0.943–0.998)). Conclusion: Implementation of a GDFT protocol led to reduced intraoperative fluid administration in the LDKT recipients. This intraoperative fluid restriction was associated with the development of fDGF.

The Impact of Therapeutic Hypothermia Used to Treat Anoxic Brain Injury After Cardiopulmonary Resuscitation on Organ Donation Outcomes

Therapeutic hypothermia (TH) is clinically used to improve neurologic outcomes in patients with anoxic brain injury after cardiopulmonary resuscitation (CPR). For patients that regress and become organ donors after neurologic determination of death (DNDDs), the impact of TH received before determination of death on organ donation outcomes remains unknown. A prospective observational study of all adult DNDDs that received CPR and had anoxia as a cause of death from March 2013 to December 2014 was conducted across 20 organ procurement organizations (OPOs) in the United States. Main outcome measures included organs transplanted per donor (OTPD), specific organ transplantation rates, and recipient graft outcomes. One thousand ninety eight DNDDs met inclusion criteria, with 46% having received TH before determination of death. DNDDs with hypothermia before death had a similar number of OTPD (2.74 vs. 2.69, p = 0.61) and similar transplantation rates of individual organs. With regards to recipients, there was significantly less delayed graft function (DGF) in kidney grafts from donors who received TH before death (24% vs. 30%, p = 0.02). After adjusting for donor, recipient, and graft related factors, the protective effect of TH on DGF persisted (OR 0.75, 95%CI [0.56-0.995], p = 0.046). TH before death in the donor is independently associated with a 25% decrease in DGF among kidney recipients. This should be considered a protective donor selection factor in guiding the decision to accept or reject an organ for transplantation.

Assessment of delayed graft function using susceptibility-weighted imaging in the early period after kidney transplantation: a feasibility study

PURPOSE

This study aimed to explore the feasibility of susceptibility-weighted imaging (SWI) for evaluating delayed graft function (DGF) during the early posttransplantation period.

METHODS

Sixty-nine recipients who accepted allograft renal transplantation underwent SWI during the second posttransplantation week. Renal allograft function was estimated via the glomerular filtration rate. Recipients with and without DGF were identified. For each transplanted kidney, the presence of abnormal signal intensity lesions (ASILs), excluding benign lesions, on SWI was assessed. Renal allograft function was compared between the recipients with and without ASILs. The correlation between ASILs and renal allograft function was tested by Spearman's rank correlation analysis.

RESULTS

Thirty-four recipients were diagnosed with DGF, while 35 recipients showed no DGF. In the DGF group, 16 recipients had low-intensity ASILs, primarily at the corticomedullary junction of transplanted kidneys on SWI, and no ASILs were found in 18 recipients. In the non-DGF group, none of the recipients showed ASILs on SWI. In the DGF group, the renal allograft function among the 16 recipients with low-intensity ASILs was significantly lower than that among the other 18 recipients (8.5 ± 4.2 vs. 19.7 ± 9.7 mL/min, P < 0.001). The presence of low-intensity ASILs on SWI showed a moderate negative correlation with renal allograft function in recipients with DGF (r = - 0.553, P = 0.001).

CONCLUSION

SWI can be used to evaluate DGF in the early post-kidney transplantation period.

Long-term effects of delayed graft function duration on function and survival of deceased donor kidney transplants

Introduction:

Delayed graft function (DGF) is a frequent complication after deceased donor kidney transplantation with an impact on the prognosis of the transplant. Despite this, long-term impact of DGF on graft function after deceased donor kidney transplantation has not been properly evaluated.

Objective:

The main objective of this study was to evaluate risk factors for DGF and the impact of its occurrence and length on graft survival and function.

Methods:

A retrospective cohort study was performed in 517 kidney transplant recipients who received a deceased donor organ between January 2008 and December 2013.

Results:

The incidence of DGF was 69.3% and it was independently associated with donor's final serum creatinine and age, cold ischemia time, use of antibody induction therapy and recipient's diabetes mellitus. The occurrence of DGF was also associated with a higher incidence of Banff ≥ 1A grade acute rejection (P = 0.017), lower graft function up to six years after transplantation and lower death-censored graft survival at 1 and 5 years (P < 0.05). DGF period longer than 14 days was associated with higher incidence of death-censored graft loss (P = 0.038) and poorer graft function (P < 0.001). No differences were found in patient survival.

Conclusions:

The occurrence of DGF has a long-lasting detrimental impact on graft function and survival and this impact is even more pronounced when DGF lasts longer than two weeks.

Renal Transplantation as a Platform for Teaching Residents Open Vascular Surgical Techniques: Effects on Early Graft Function

BACKGROUND

Over the past decade, increases in vascular fellowships and the use of endovascular technology have decreased the general surgery residents' exposure to open vascular surgery. We sought to elucidate whether renal transplant is a safe way to teach general surgery residents the essential tenants of vascular surgery without adversely affecting early patient outcomes.

METHODS

All solitary, adult deceased donor kidney transplants performed at the University of Wisconsin from 2011 through 2016 were identified and divided into a resident-assist (RA) and fellow-assist cohorts (FA). DGF, defined by the requirement of dialysis within 1 week of transplant, was the primary outcome. Early graft survival and postoperative complications were considered the secondary endpoints.

RESULTS

Of the 774 total cases, there were 228 (29.5%) in the RA cohort and 546 (70.5%) in the FA cohort. The RA and FA cohorts had comparable characteristics, except for a nonclinically significant difference in mean donor creatinine (0.96 vs 0.88mg/dL, p = 0.03). RA cases had a similar DGF rate compared to FA cases (25% vs 26%, p = 0.93). Additionally, there was no difference in 2-year graft survival (93.7% vs 95.5%, p = 0.38), nor the rates of graft thromboses (0.4% vs 0.7%, p = 0.65), incisional hernias (0.9% vs 1.8%, p = 0.35), and ureteral strictures (2.2% vs 1.6%, p = 0.55) between the 2 cohorts.

CONCLUSIONS

Resident involvement in renal transplantation has no effect on DGF and early allograft function. Though the procedural involvement of each resident in a case is variable, it seems to be a safe way to teach retroperitoneal vascular exposure and anastomotic techniques.

Delayed graft function is associated with an increased rate of renal allograft rejection: A retrospective single center analysis

INTRODUCTION

The association of delayed graft function (DGF) and biopsy proven acute rejection (BPAR) of renal allografts is controversial. Borderline rejections comprise a major portion of biopsy results but the significance of such histologic changes is debated. The present study explores the impact of DGF on BPAR with a special emphasis on discriminating the effects of borderline rejection.

METHODS

Single center analysis of 417 deceased donor kidney recipients (age>18; transplantation date 1/2008-2/2015). Patients with primary non-function were excluded. DGF was defined as the need for dialysis within the first week after transplantation. Acute rejection was defined according to Banff criteria. Cox proportional hazards models were used to examine the relationship of DGF with BPAR within the first year.

RESULTS

No graft loss was observed during the first year after transplantation. DGF significantly associated with BPAR in the first year, irrespective of whether borderline rejections were included (HR 1.71, 95%CI 1.16,2.53) or excluded (HR 1.79, 95%CI 1.13,2.84).

CONCLUSION

DGF is significantly associated with rejection-with or without borderline changes-within the first year.

Central venous pressure monitoring in living donor kidney recipients does not affect immediate graft function: A propensity score analysis

BACKGROUND

During kidney transplantation, intraoperative fluid management can affect post-transplant graft function. It is unclear whether or not central venous pressure (CVP) monitoring is required to guide fluid therapy during kidney transplantation.

METHODS

We compared post-transplant graft function in recipients of living donor kidney transplants between August 2006 and March 2009 based on the use or absence of intraoperative CVP monitoring. Graft function, assessed using the creatinine reduction ratio on postoperative day 2 (CCR2), was evaluated by multivariable linear regression analysis and in a propensity-matched cohort.

RESULTS

Two hundred and ninety patients were included in the analysis. Central venous pressure was monitored in 84 patients (29%). There was no difference in post-transplant graft function, as measured by CCR2, between patients with and without CVP monitoring in both unadjusted and multivariable-adjusted analyses. There were also no statistically significant differences in CCR2, delayed graft function, or 3-month renal function between those monitored with CVP and those without, in the propensity-matched cohort.

CONCLUSIONS

In this single-center analysis, immediate post-transplant renal function was not associated with the use of intraoperative CVP monitoring.

Two-year management after renal transplantation in 2013 in France: Input from the French national health system database

The objective of this study was to describe the management of patients undergoing renal transplantation in 2013 and over the following two years on the basis of healthcare consumption data. The National Health Insurance Information System was used to identify 1876 general scheme beneficiaries undergoing a first isolated renal transplantation (median age: 53 years; men 63%). Overall, 1.2% of patients died during the transplantation hospital stay (>65 years 3.3%) and 87% of patients had a functional graft at 2 years. Thirty-three percent of patients were readmitted to hospital for 1 day or longer during the first month, 73% the first year and 55% the second year. At least 10% of patients were hospitalised for antirejection treatment during the first quarter after renal transplantation, 16% the first year and 9% the second year. The first year, 32% of patients were hospitalised for renal disease (12% the second year), 14% were hospitalised for cardiovascular disease (9% the second year), 13% for infectious disease (5% the second year) and 2% for a malignant tumour (2% the second year). Almost 80% of patients consulted their general practitioner each year (almost 50% consulted every quarter). During the second year, 83% of patients were taking antihypertensives, 45% lipid-lowering drugs, 26% antidiabetic drugs, 77% tacrolimus, 18% ciclosporin, 88% mycophenolic acid and 69% corticosteroids. This study highlights the important contribution of healthcare consumption data to a better understanding of the modalities of management of renal transplant recipients in France, allowing improvement of this management in line with guidelines.

Prediction, prevention, and management of delayed graft function: where are we now?

Delayed graft function (DGF) remains a major barrier to improved outcomes after kidney transplantation. High-risk transplant recipients can be identified, but no definitive prediction model exists. Novel biomarkers to predict DGF in the first hours post-transplant, such as neutrophil gelatinase-associated lipocalin (NGAL), are under investigation. Donor management to minimize the profound physiological consequences of brain death is highly complex. A hormonal resuscitation package to manage the catecholamine "storm" that follows brain death is recommended. Donor pretreatment with dopamine prior to procurement lowers the rate of DGF. Hypothermic machine perfusion may offer a significant reduction in the rate of DGF vs simple cold storage, but costs need to be evaluated. Surgically, reducing warm ischemia time may be advantageous. Research into recipient preconditioning options has so far not generated clinically helpful interventions. Diagnostic criteria for DGF vary, but requirement for dialysis and/or persistent high serum creatinine is likely to remain key to diagnosis until current work on early biomarkers has progressed further. Management centers on close monitoring of graft (non)function and physiological parameters. With so many unanswered questions, substantial reductions in the toll of DGF in the near future seem unlikely but concentrated research on many levels offers long-term promise.

Survival Analysis in the Presence of Competing Risks: The Example of Waitlisted Kidney Transplant Candidates

Competing events (or risks) preclude the observation of an event of interest or alter the probability of the event's occurrence and are commonly encountered in transplant outcomes research. Transplantation, for example, is a competing event for death on the waiting list because receiving a transplant may significantly decrease the risk of long-term mortality. In a typical analysis of time-to-event data, competing events may be censored or incorporated into composite end points; however, the presence of competing events violates the assumption of "independent censoring," which is the basis of standard survival analysis techniques. The use of composite end points disregards the possibility that competing events may be related to the exposure in a way that is different from the other components of the composite. Using data from the Scientific Registry of Transplant Recipients, this paper reviews the principles of competing risks analysis; outlines approaches for analyzing data with competing events (cause-specific and subdistribution hazards models); compares the estimates obtained from standard survival analysis, which handle competing events as censoring events; discusses the appropriate settings in which each of the two approaches could be used; and contrasts their interpretation.

Delayed Graft Function in Kidney Transplantation

Context:

Although kidney transplantations are routinely performed at many centers in Turkey, the incidence and risk factors associated with delayed graft function (DGF) here have not yet been well defined.

Objective:

The aim of this study is to evaluate the incidence and risk factors of DGF and its impact on early graft function.

Design:

The medical charts of 154 adult patients who underwent deceased donor kidney transplantation between 2000 and 2014 in a single center were reviewed retrospectively.

Setting:

Delayed graft function-related risk factors for donors, recipients, and the transplant surgery itself were analyzed, and their relation with graft function was evaluated.

Main Outcomes Measures:

The median recipient age was 39 years. The median cold ischemia time (CIT) was 840 minutes (14 hours). The incidence of DGF and acute rejection were 57.8% and 8.4%, respectively. Higher serum creatinine levels at 3, 6, and 12 months were observed in patients with DGF compared to other patients without DGF ( P < .05). Patients with DGF had poor graft function (glomerular filtration rate ≤ 50) at 3 and 6 months ( P < .05), but these correlations were not seen at 12 months ( P = not significant).

Results:

This study showed that DGF was a common and serious problem associated with poor graft functions at 3, 6, and 12 months after transplantation. Extra effort to shorten CIT as an independent risk factor for DGF could have protective effect on graft functions.

Significance of HLA Antibody Detected by PRA-Bead Method in Kidney Transplant Outcomes

BACKGROUND

The impact of specific HLA antibodies on the allograft function in the Luminex era is not clearly known. This study aimed to investigate kidney transplantation outcomes in patients with different anti-HLA antibody status as detected by Luminex PRA.

METHODS

This retrospective study included 106 deceased-donor kidney transplantation (DDKT) patients divided into 3 groups by PRA status as detected by PRA-bead: (1) PRA = 0; (2) positive PRA but with negative antibody against donor's HLA antigens; and (3) positive PRA with positive anti-HLA antibody specificity against donor's HLA antigens.

RESULTS

There were 65, 23, and 18 patients in groups 1, 2, and 3, respectively. Early allograft rejections were highest in group 3 (22.2%) (P = .02). In multivariate analysis, delayed graft function was the only factor that was associated with allograft rejection (hazard ratio, 8.9; 95% confidence interval, 1.9-39.8; P = .004). Estimated glomerular filtration rates at 1 year of the 3 groups were 54.6, 55.8, and 60.0 mL/min (P = .71). One-year allograft failure and death were not different among the 3 groups. Expanded-criteria deceased donors were associated with both allograft failure (P = .003) and patient death (P = .02).

CONCLUSIONS

Anti-HLA antibody as detected by Luminex PRA was associated with early allograft rejection but not graft or patient survival. The effect of newer treatment modalities can improve the outcomes of PRA-positive patients to be similar to nonsensitized patients at 1 year.

Therapeutic Hypothermia in Deceased Organ Donors and Kidney-Graft Function

BACKGROUND

Delayed graft function, which is reported in up to 50% of kidney-transplant recipients, is associated with increased costs and diminished long-term graft function. The effect that targeted mild hypothermia in organ donors before organ recovery has on the rate of delayed graft function is unclear.

METHODS

We enrolled organ donors (after declaration of death according to neurologic criteria) from two large donation service areas and randomly assigned them to one of two targeted temperature ranges: 34 to 35°C (hypothermia) or 36.5 to 37.5°C (normothermia). Temperature protocols, which were initiated after authorization was obtained for the organ to be donated and for the donor's participation in the study, ended when organ donors left the intensive care unit for organ recovery in the operating room. The primary outcome was delayed graft function in the kidney recipients, which was defined as the requirement for dialysis during the first week after transplantation. Secondary outcomes were the rates of individual organs transplanted in each treatment group and the total number of organs transplanted from each donor.

RESULTS

The study was terminated early, on the recommendation of an independent data and safety monitoring board, after the interim analysis showed efficacy of hypothermia. At trial termination, 370 organ donors had been enrolled (180 in the hypothermia group and 190 in the normothermia group). A total of 572 patients received a kidney transplant (285 kidneys from donors in the hypothermia group and 287 kidneys from donors in the normothermia group). Delayed graft function developed in 79 recipients of kidneys from donors in the hypothermia group (28%) and in 112 recipients of kidneys from donors in the normothermia group (39%) (odds ratio, 0.62; 95% confidence interval, 0.43 to 0.92; P=0.02).

CONCLUSIONS

Mild hypothermia, as compared with normothermia, in organ donors after declaration of death according to neurologic criteria significantly reduced the rate of delayed graft function among recipients. (Funded by the Health Resources and Services Administration; ClinicalTrials.gov number, NCT01680744.).