KDIGO Clinical Practice Guideline on the Evaluation and Care of Living Kidney Donors

Mediators of Socioeconomic Inequity in Living-donor Kidney Transplantation: Results From a UK Multicenter Case-Control Study

Supplemental Digital Content is available in the text.

There is evidence of socioeconomic inequity in access to living-donor kidney transplantation, but limited evidence as to why. We investigated possible mediators of the inequity.

Risk stratification for early bacteremia after living donor liver transplantation: a retrospective observational cohort study

BACKGROUND

This study investigated perioperative clinical risk factors for early post-transplant bacteremia in patients undergoing living donor liver transplantation (LDLT). Additionally, postoperative outcomes were compared between patients with and without early post-transplant bacteremia.

METHODS

Clinical data of 610 adult patients who underwent elective LDLT between January 2009 and December 2018 at Seoul St. Mary's Hospital were retrospectively collected. The exclusion criteria included overt signs of infection within 1 month before surgery. A total of 596 adult patients were enrolled in this study. Based on the occurrence of a systemic bacterial infection after surgery, patients were classified into non-infected and infected groups.

RESULTS

The incidence of bacteremia at 1 month after LDLT was 9.7% (57 patients) and Enterococcus faecium (31.6%) was the most commonly cultured bacterium in the blood samples. Univariate analysis showed that preoperative psoas muscle index (PMI), model for end-stage disease score, utility of continuous renal replacement therapy (CRRT), ascites, C-reactive protein to albumin ratio, neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio, and sodium level, as well as intraoperative post-reperfusion syndrome, mean central venous pressure, requirement for packed red blood cells and fresh frozen plasma, hourly fluid infusion and urine output, and short-term postoperative early allograft dysfunction (EAD) were associated with the risk of early post-transplant bacteremia. Multivariate analysis revealed that PMI, the CRRT requirement, the NLR, and EAD were independently associated with the risk of early post-transplant bacteremia (area under the curve: 0.707; 95% confidence interval: 0.667-0.745; p < 0.001). The overall survival rate was better in the non-infected patient group. Among patients with bacteremia, anti-bacterial treatment was unable to resolve infection in 34 patients, resulting in an increased risk of patient mortality. Among the factors included in the model, EAD was significantly correlated with non-resolving infection.

CONCLUSIONS

We propose a prognostic model to identify patients at high risk for a bloodstream bacterial infection; furthermore, our findings support the notion that skeletal muscle depletion, CRRT requirement, systemic inflammatory response, and delayed liver graft function are associated with a pathogenic vulnerability in cirrhotic patients who undergo LDLT.

ICES: Data, Discovery, Better Health

ICES was founded in 1992 to study the health care system and promote effective, efficient and equitable health care. Over 27 years later, the goal remains largely unchanged, though the institute has grown in size and impact. Created as an independent not-for-profit research institute and given what was, at the time, unprecedented access to administrative health data records for the population of Ontario, ICES’ initial focus was to better understand the delivery of hospital services and translate its findings into better health care and policy. From modest beginnings with a handful of researchers located in a few hospital offices, ICES has grown to encompass a community of almost 500 scientists and staff across a network of seven physical sites in Ontario. The original focus on hospital-based services has expanded significantly and now includes research and analysis of community-based health services, health policy, Indigenous health, social determinants of health, and data science.

APOL1 Long-term Kidney Transplantation Outcomes Network (APOLLO): Design and Rationale

INTRODUCTION

Much of the higher risk for end-stage kidney disease (ESKD) in African American individuals relates to ancestry-specific variation in the apolipoprotein L1 gene (APOL1). Relative to kidneys from European American deceased-donors, kidneys from African American deceased-donors have shorter allograft survival and African American living-kidney donors more often develop ESKD. The National Institutes of Health (NIH)-sponsored APOL1 Long-term Kidney Transplantation Outcomes Network (APOLLO) is prospectively assessing kidney allograft survival from donors with recent African ancestry based on donor and recipient APOL1 genotypes.

METHODS

APOLLO will evaluate outcomes from 2614 deceased kidney donor-recipient pairs, as well as additional living-kidney donor-recipient pairs and unpaired deceased-donor kidneys.

RESULTS

The United Network for Organ Sharing (UNOS), Association of Organ Procurement Organizations, American Society of Transplantation, American Society for Histocompatibility and Immunogenetics, and nearly all U.S. kidney transplant programs, organ procurement organizations (OPOs), and histocompatibility laboratories are participating in this observational study. APOLLO employs a central institutional review board (cIRB) and maintains voluntary partnerships with OPOs and histocompatibility laboratories. A Community Advisory Council composed of African American individuals with a personal or family history of kidney disease has advised the NIH Project Office and Steering Committee since inception. UNOS is providing data for outcome analyses.

CONCLUSION

This article describes unique aspects of the protocol, design, and performance of APOLLO. Results will guide use of APOL1 genotypic data to improve the assessment of quality in deceased-donor kidneys and could increase numbers of transplanted kidneys, reduce rates of discard, and improve the safety of living-kidney donation.

Robotic assisted nephrectomy for living kidney donation (RANLD) with use of multiple locking clips or ligatures for renal vascular closure

Background

Robotic assisted nephrectomy for living donation (RANLD) is a rapid emerging surgical technique competing for supremacy with totally laparoscopic and laparoscopic hand assisted techniques. Opinions about the safety of specific techniques of vascular closure in minimally invasive living kidney donation are heterogeneous and may be different for laparoscopic and robotic assisted surgical techniques.

Methods

We retrospectively analyzed perioperative and short-term outcomes of our first (n=40) RANLD performed with the da Vinci Si surgical platform. Vascular closure of renal vessels was performed by either double clipping or a combination of clips and non-transfixing suture ligatures.

Results

RANLD almost quintupled in our center for the observed time period. A total of n=21 (52.5%) left and n=19 (47.5%) right kidneys were procured. Renal vessel sealing with two locking clips was performed in 18 cases (45%) Both, clips and non-transfixing ligatures were used in 22 cases (55%). Mean donor age was 53.075±11.68 years (range, 28–70). The average total operative time was 150.75±27.30 min. Right donor nephrectomy (139±22 min) was performed significantly faster than left (160.95±27.93 min, P=0.01). Warm ischemia time was similar for both vascular sealing techniques and did not differ between left and right nephrectomies. No conversion was necessary. Clavien-Dindo Grade ≤IIIb complications occurred in (n=5) 12.5%. Grade IV and V complications did not develop. In particular no hemorrhage occurred using multiple locking clips or suture ligatures for renal vascular closure. Mortality was 0%. Thirteen kidneys (32.5%) were transplanted across the AB0 barrier.

Conclusions

RANLD is an emerging minimally invasive surgical technique which facilitates excellent perioperative and short-term outcomes also when using multiple locking clips or suture ligatures for renal vascular closure.

Framework for establishing integrated kidney care programs in low- and middle-income countries

Secular increases in the burden of kidney failure is a major challenge for health systems worldwide, especially in low- and middle-income countries (LMICs) due to growing demand for expensive kidney replacement therapies. In LMICs with limited resources, the priority of providing kidney replacement therapies must be weighed against the prevention and treatment of chronic kidney disease, other kidney disorders such as acute kidney injury, and other noncommunicable diseases, as well as other urgent public health needs. Kidney failure is potentially preventable-not just through primary prevention of risk factors for kidney disease such as hypertension and diabetes, but also by timely management of established chronic kidney disease. Among people with established or incipient kidney failure, there are 3 key treatment strategies-conservative care, kidney transplantation, and dialysis-each of which has its own benefits. Joining up preventive care for people with or at risk for milder forms of chronic kidney disease with all 3 therapies for kidney failure (and developing synergistic links between the different treatment options) is termed "integrated kidney care" and has potential benefits for patients, families, and providers. In addition, because integrated kidney care implicitly considers resource use, it should facilitate a more sustainable approach to managing kidney failure than providing one or more of its components separately. There is currently no agreed framework that LMIC governments can use to establish and/or scale up programs to prevent and treat kidney failure or join up these programs to provide integrated kidney care. This review presents a suggested framework for establishing integrated kidney care programs, focusing on the anticipated needs of policy makers in LMICs.

A randomized, controlled, behavioral intervention to promote walking after abdominal organ transplantation: results from the LIFT study

Kidney transplant recipients (KTRs) and liver transplant recipients (LTRs) have significant post-transplant weight gain and low physical activity. We conducted a home-based, remotely monitored intervention using wearable accelerometer devices to promote post-transplant physical activity. We randomized 61 KTRs and 66 LTRs within 24 months of transplant to: (i) control, (ii) accelerometer or (iii) intervention: accelerometer paired with financial incentives and health engagement questions to increase steps by 15% from baseline every 2 weeks. The primary outcome was weight change. A co-primary outcome for the two accelerometer arms was steps. Participants were recruited at a median of 9.5 [3-17] months post-transplant. At 3 months, there were no significant differences in weight change across the three arms. The intervention arm was more likely to achieve ≥7000 steps compared to control with device (OR 1.99, 95% CI: 1.03-3.87); effect remained significant after adjusting for demographics, allograft, time from transplant and baseline weight. Adherence to target step goals was 74% in the intervention arm, 84% of health engagement questions were answered correctly. A pilot study with financial incentives and health engagement questions was feasible and led KTRs and LTRs to walk more, but did not affect weight. A definitive trial is warranted.

Survival in Living Kidney Donors: An Australian and New Zealand Cohort Study Using Data Linkage

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Background.

Living kidney donors are a highly selected healthy population expected to have high survival postdonation, but mortality studies are limited. Our study aimed to compare mortality in living kidney donors with the general population in Australia and New Zealand, hypothesizing that donor survival would exceed average survival.

Methods.

All living kidney donors in Australia, 2004–2013, and New Zealand, 2004–2012, from the Australian and New Zealand Living Kidney Donor Registry were included. We ascertained primary cause of death from data linkage with national death registers. Standardized mortality ratios and relative survival were estimated, matching on age, sex, calendar year, and country.

Results.

Among 3253 living kidney donors, there were 32 deaths over 20 331 person-years, with median follow-up 6.2 years [interquartile range: 3.9–8.4]. Only 25 donors had diabetes-fasting blood sugar level predonation, of which 3 had impaired glucose tolerance. At discharge, the median creatinine was 108 µmol/L and estimated glomerular filtration rate was 58 mL/min/1.72 m². Four deaths occurred in the first year: 2 from immediate complications of donation, and 2 from unrelated accidental causes. The leading cause of death was cancer (n = 16). The crude mortality rate was 157 (95% confidence interval [CI], 111-222)/100 000 person-y, and the standardized mortality ratio was 0.33 (95% CI, 0.24-0.47). The 5-year cumulative relative survival was 1.019 (95% CI, 1.014-1.021), confirming that the survival probability in living kidney donors was 2% higher relative to the general population.

Conclusions.

As expected, mortality in living kidney donors was substantially lower than the general population and is reassuring for potential donor counseling. The Living Donor Registry only captured a third of the deaths, highlighting the benefit of data linkage to national death registries in the long-term follow-up of living kidney donors.

Determinants of the intercept and slope of glomerular filtration rate in recipients of a live donor kidney transplant

Background

Donor kidney function is considered a critical determinant of allograft survival after live donor (LD) kidney transplantation, but its independent impact on the evolution of graft function is less well defined. The objective of this study was to dissect the relative contribution of LD kidney function to baseline estimated glomerular filtration rate (eGFR) of recipients and its decline.

Methods

In this study 91 LD kidney transplantations performed between 2007 and 2015 were included. The eGFR of donated kidneys (eGFR-dk) was calculated from total LD eGFR (eGFR-dt) based on the results of isotope nephrography. Recipient eGFR (eGFR-r) determined 6‑monthly until 36 months posttransplantation served as dependent variable in mixed linear models estimating changes in baseline allograft function (intercept) and eGFR‑r slope. Models were adjusted either for eGFR-dk or eGFR-dt, in addition to other potential confounders.

Results

Overall, unadjusted mean eGFR‑r at baseline (6 months) and its annual decline in allograft function were 56.5 mL/min/1.73 m² and −0.2 mL/min/1.73 m², respectively. In multivariate analysis, eGFR-dk impacted on baseline eGFR‑r (0.6 mL/min/1.73 m² mean estimated increase per unit; P = 0.02) but not on its slope. In the eGFR-dt-adjusted model, a marginal effect was observed for LD age (P = 0.05). Both models identified antibody-mediated rejection (ABMR) as the strongest risk factor of accelerated loss of allograft function (eGFR‑r slope: approximately −6 mL/min/1.73 m² per year; P ≤ 0.02).

Conclusion

Donor-related characteristics, most prominently the function of donated kidneys and LD age, were predictive of eGFR at baseline. The ABMR was identified as the cardinal cause of progressive deterioration of allograft function.

Living donor program crisis management plans: Current landscape and talking point recommendations

Although minimized by expert evaluation, operative technique, and postoperative care, the extremely low risk of perioperative mortality following living kidney or liver donation will never be eliminated. Furthermore, anticipation of poor donor outcome may simultaneously be a source of anxiety for physicians and programs and also be a circumstance for which they are unprepared. We conducted a national survey of US transplant surgeons to understand experiences with and systemic preparedness for the event of a living donor death. Respondents represented 87 unique transplant programs (71 kidney and 16 liver donor programs). Perioperative deaths were rare, as expected. Although most respondents (N = 57, 64% of total respondents; 88% of liver programs) reported being moderately to extremely concerned about a future living donor death at their institution, only 30 (33% of total program respondents) had a written plan available in the case of such an event; 63% of programs would find guidance and recommendations useful. To help address this gap, the American Society of Transplantation Live Donor Community of Practice (AST LDCOP) developed Living Donor Crisis Management Plan Talking Points suitable to guide crisis plan development at transplant programs.

Differences in national and international guidelines regarding use of kidney stone formers as living kidney donors

PURPOSE OF REVIEW

Traditionally, nephrolithiasis was considered a relative contraindication to kidney donation because of a risk of recurrent stones in donors and adverse stone-related outcomes in recipients. However, the scarcity of organs has driven the transplant community to re-examine and broaden selection criteria for living donors with stones. In this review, we summarize and contrast the guidelines published by various prominent national and international societies on this topic.

RECENT FINDINGS

Although recent iterations of living donor guidelines are less stringent with respect to nephrolithiasis than those published in the 1990s, there is little consensus among national and international transplant society guidelines regarding selection criteria for potential kidney donors with nephrolithiasis.

SUMMARY

The lack of evidence-based guidelines deters transplant centers from implementing selection criteria to accept donors with nephrolithiasis and discourages studies of outcomes in donors with nephrolithiasis and their recipients. In addition to drawing attention to the disparities in prevailing guidelines, we put forth several questions that must be answered before generalizable criteria for selection of donor with nephrolithiasis can be developed.

Arterial Hypertension as a Risk Factor for Reduced Glomerular Filtration Rate after Living Kidney Donation

Living kidney donation represents the optimal renal replacement therapy, but recent data suggest an increased long-term renal risk for the donor. Here, we evaluated the risk for reduced estimated glomerular filtration rate (eGFR), death, and major cardiovascular events such as nonfatal myocardial infarction or cerebrovascular event including TIA (transient ischemic attack) and stroke in 225 donors, who underwent pre-donation examinations and live donor nephrectomy between 1985 and 2014 at our center. The median follow-up time was 8.7 years (1.0–29.1). In multivariate analysis, age and arterial hypertension at baseline were significantly associated with a higher risk of adverse renal outcomes, such as (1) eGFR <60 mL/min/1.73 m² (age per year: HR (hazard ratio) 1.05, 95% confidence interval (CI) 1.03–1.08, hypertension: HR 2.25, 95% CI 1.22–3.98), (2) eGFR <60 mL/min/1.73 m² and a decrease of ≥40% from baseline (age: HR 1.08, 95% CI 1.03–1.13, hypertension: HR 4.22, 95% CI 1.72–10.36), and (3) eGFR <45 mL/min/1.73 m² (age: HR 1.12, 95% CI 1.05–1.20, hypertension: HR 5.06, 95% CI 1.49–17.22). In addition, eGFR at time of donation (per mL/min/1.73 m²) was associated with a lower risk of (1) eGFR <60 mL/min/1.73 m² (HR 0.98, 95% CI 0.97–1.00) and (2) eGFR <45 mL/min/1.73 m² (HR 0.95, 95% CI 0.90–1.00). Age was the only significant predictor for death or major cardiovascular event (HR 1.08, 95% CI 1.01–1.16). In conclusion, arterial hypertension, lower eGFR, and age at the time of donation are strong predictors for adverse renal outcomes in living kidney donors.

Renal Function Assessment Gap in Clinical Practice: An Awkward Truth

INTRODUCTION

An accurate assessment of renal function is needed in the majority of clinical settings. Unfortunately, the most used estimated glomerular filtration rate (eGFR) formulas are affected by significant errors in comparison to gold standards methods of measured GFR (mGFR).

OBJECTIVE

The objective of the study is to determine the extent of the error of eGFR formulas compared to the mGFR in different specific clinical settings.

METHODS

A total retrospectively consecutive cohort of 1,320 patients (pts) enrolled in 2 different European Hospitals (Center 1: 470 pts; Center 2: 850 pts) was collected in order to compare the most common eGFR formulas used by physicians with the most widespread mGFR methods in daily clinical practice (Iohexol Plasma Clearance -Center 1 [mGFR-iox] and Renal Scintigraphy -Center 2 [mGFR-scnt]). The study cohort was composed by urological, oncological, and nephrological pts. The agreement between eGFR and mGFR was evaluated using bias (as median of difference), precision (as interquartile range of difference) accuracy (as P30), and total deviation index.

RESULTS

The most accurate eGFR formula in the comparison with gold standard method (Iohexol plasma clearance) in Center 1 was represented by s-creatinine and cystatin C combined Chronic Kidney Disease-Epidemiology Collaboration-cr-cy, even though the P30 is reduced (84%) under the threshold of 60 mL/min/1.73 m2. Similar results were found in Center 2, with a wider discrepancy between mGFR-scnt and eGFR formulas due to the minor accuracy of the nuclear tool in respect to the mGFR-iox.

CONCLUSIONS

The loss of accuracy observed for the formulas at lower values of GFR suggests the mandatory use of gold standards methods as Iohexol Plasma Clearance to assess the correct status of renal function for critical cases. The center 2 showed lower levels of agreement between mGFR and eGFR suggesting that the errors are partially accounted for the Renal Scintigraphy technique too. In particular, we suggest the use of mGFR-iox in oncological urological and nephrological pts with an eGFR lower than 60 mL/min/1.73 m2.

Predicting donor, recipient and graft survival in living donor kidney transplantation to inform pretransplant counselling: the donor and recipient linked iPREDICTLIVING tool - a retrospective study

Although separate prediction models for donors and recipients were previously published, we identified a need to predict outcomes of donor/recipient simultaneously, as they are clearly not independent of each other. We used characteristics from transplantations performed at the Oslo University Hospital from 1854 live donors and from 837 recipients of a live donor kidney transplant to derive Cox models for predicting donor mortality up to 20 years, and recipient death, and graft loss up to 10 years. The models were developed using the multivariable fractional polynomials algorithm optimizing Akaike’s information criterion, and optimism‐corrected performance was assessed. Age, year of donation, smoking status, cholesterol and creatinine were selected to predict donor mortality (C‐statistic of 0.81). Linear predictors for donor mortality served as summary of donor prognosis in recipient models. Age, sex, year of transplantation, dialysis vintage, primary renal disease, cerebrovascular disease, peripheral vascular disease and HLA mismatch were selected to predict recipient mortality (C‐statistic of 0.77). Age, dialysis vintage, linear predictor of donor mortality, HLA mismatch, peripheral vascular disease and heart disease were selected to predict graft loss (C‐statistic of 0.66). Our prediction models inform decision‐making at the time of transplant counselling and are implemented as online calculators.

Living donor hand-assisted laparoscopic nephrectomy in a healthy individual with situs inversus totalis: no need to turn down the donor

A 70-year-old healthy male individual offered to undergo a living donor hand-assisted laparoscopic nephrectomy to enable kidney transplantation for a close relative. As required for all living transplant donor candidates, extensive screening was performed to exclude potential contraindications for donation. Tests revealed a situs inversus totalis, meaning a complete transposition of the thoracic and abdominal organs in the sagittal plane. As other contraindications for living kidney donation were absent, the feasibility of this procedure was determined multidisciplinary. A successful donation procedure was performed without surgical complications for the donor and good short-term transplant outcomes. In line with current developments that have resulted in more liberal criteria for potential living kidney donors, major anatomical deviations should not automatically be a contraindication. With multidisciplinary efforts and thorough surgical preparation at a high-volume transplant centre, this procedure is feasible and safe.

Cytomegalovirus Viremia after Living and Deceased Donation in Kidney Transplantation

Despite screening, effective anti-viral drugs and risk-balanced prophylaxis, cytomegalovirus (CMV) remains a major cause of morbidity in transplant patients. The objective of this study was to retrospectively analyze the risk factors associated with CMV viremia after kidney transplantation in a large European cohort with standardized valganciclovir prophylaxis in the present era. A special focus was placed on the comparison of living and postmortal donation. We conducted a longitudinal observational study involving 723 adult patients with a total of 3292 patient-years who were transplanted at our center between 2007 and 2015. Valganciclovir prophylaxis was administered over 100 days for CMV+ donors (D) or recipients (R), over 200 days for D+/R−, and none in D−/R−. A CMV+ donor, rejection episodes, and deceased donor transplantation were identified to be associated with increased incidences of CMV viremia. Although we did not find a reduced overall survival rate for patients with CMV viremia, it was associated with worse graft function. Since we observed a relevant number of CMV infections despite prescribing valganciclovir prophylaxis, a pre-emptive strategy in patients with (suspected) adherence restrictions could be favored. Our data can help transplant physicians educate their patients about their individual CMV risk and choose the most appropriate CMV treatment approach.

Metabolic Surgery to Treat Obesity in Diabetic Kidney Disease, Chronic Kidney Disease, and End-Stage Kidney Disease; What Are the Unanswered Questions?

Obesity is a major factor in contemporary clinical practice in nephrology. Obesity accelerates the progression of both diabetic and non-diabetic chronic kidney disease and, in renal transplantation, both recipient and donor obesity increase the risk of allograft complications. Obesity is thus a major driver of renal disease progression and a barrier to deceased and living donor kidney transplantation. Large observational studies have highlighted that metabolic surgery reduces the incidence of albuminuria, slows chronic kidney disease progression, and reduces the incidence of end-stage kidney disease over extended follow-up in people with and without type 2 diabetes. The surgical treatment of obesity and its metabolic sequelae has therefore the potential to improve management of diabetic and non-diabetic chronic kidney disease and aid in the slowing of renal decline toward end-stage kidney disease. In the context of patients with end-stage kidney disease, although complications of metabolic surgery are higher, absolute event rates are low and it remains a safe intervention in this population. Pre-transplant metabolic surgery increases access to kidney transplantation in people with obesity and end-stage kidney disease. Metabolic surgery also improves management of metabolic complications post-kidney transplantation, including new-onset diabetes. Procedure selection may be critical to mitigate the risks of oxalate nephropathy and disruption to immunosuppressant pharmacokinetics. Metabolic surgery may also have a role in the treatment of donor obesity, which could increase the living kidney donor pool with potential downstream impact on kidney paired exchange programmes. The present paper provides a comprehensive coverage of the literature concerning renal outcomes in clinical studies of metabolic surgery and integrates findings from relevant mechanistic pre-clinical studies. In so doing the key unanswered questions for the field are brought to the fore for discussion.

Beliefs of UK Transplant Recipients about Living Kidney Donation and Transplantation: Findings from a Multicentre Questionnaire-Based Case-Control Study

Differing beliefs about the acceptability of living-donor kidney transplants (LDKTs) have been proposed as explaining age, ethnic and socioeconomic disparities in their uptake. We investigated whether certain patient groups hold beliefs incompatible with LDKTs. This questionnaire-based case-control study was based at 14 hospitals in the United Kingdom. Participants were adults transplanted between 1 April 2013 and 31 March 2017. LDKT recipients were compared to deceased-donor kidney transplant (DDKT) recipients. Beliefs were determined by the direction and strength of agreement with ten statements. Multivariable logistic regression was used to investigate the association between beliefs and LDKT versus DDKT. Sex, age, ethnicity, religion, and education were investigated as predictors of beliefs. A total of 1240 questionnaires were returned (40% response). DDKT and LDKT recipients responded in the same direction for 9/10 statements. A greater strength of agreement with statements concerning the 'positive psychosocial effects' of living kidney donation predicted having an LDKT over a DDKT. Older age, Black, Asian and Minority Ethnic (BAME) group ethnicity, and having a religion other than Christianity were associated with greater degree of uncertainty regarding a number of statements, but there was no evidence that individuals in these groups hold strong beliefs against living kidney donation and transplantation. Interventions should address uncertainty, to increase LDKT activity in these groups.

[Robot-assisted kidney transplantation]

BACKGROUND

Robot-assisted surgery has become widely adopted in urology due to advantages in comparison with laparoscopic or open approaches. Robot-assisted living kidney transplantation is one of the most challenging procedures in urology regarding technical, but also psychological and ethical aspects, and is currently routinely performed in two German departments.

OBJECTIVES

The goal was to analyze and compare current evidence and experiences of robot-assisted living kidney transplantation in Europe and in Germany.

MATERIALS AND METHODS

A systematic search was performed to identify relevant publications. They were compared with latest results from two German academic centers (Halle and Homburg/Saar).

RESULTS

In 2015, robot-assisted living kidney transplantation was performed for the first time in Europe. Since then, 8 academic centers have established this procedure. Until today, more than 180 robot-assisted kidney transplantations have been performed. Short- and mid-term results have proven to be excellent with low complication rates. Apart from 3 transplant losses because of arterial thrombosis and 5 surgical re-explorations due to hematoma, no other noteworthy complications occurred. There was only 1 lymphocele. The median blood loss was 150 ml and kidney function after 1 year was unchanged in comparison with postoperative day 30.

CONCLUSIONS

Robot-assisted living kidney transplantation is not inferior to the open approach. Even superiority is not unlikely because problematic situations such as obese patients or complex vascular anatomy can be handled safely. In particular, the development of lymphocele and wound healing disorders appear to be significantly decreased compared to conventional surgery.

In Vitro and In Vivo Renoprotective Effects of Telbivudine in Chronic Hepatitis B Patients Receiving Nucleotide Analogue

AIM

Renal toxicity of adefovir disoproxil (ADV) and tenofovir disoproxil fumarate (TDF) is a significant concern in chronic hepatitis B (CHB) patients. Early observational clinical data suggested that telbivudine (LdT) might have renoprotective effects.

METHODS

In this prospective study, consecutive CHB patients on combined lamivudine (LAM) + ADV/TDF were switched to LdT + ADV/TDF at recruitment and were followed up for 24 months. Estimated glomerular filtration rate (eGFR) was calculated with the modification of diet in renal disease equation. The effects of LdT on cell viability and expression of kidney injury or apoptotic biomarkers were investigated in cultured renal tubular epithelial cell line HK-2.

RESULTS

Thirty-one patients (median age 55 years, 90.3% male) were recruited (54.8% TDF: 45.2% ADV). Serum HBV DNA was undetectable at all time points. Median eGFR was 70.2 (IQR 62.6-77.9) and 81.5 (IQR 63.6-99.1) mL/min/1.73 m² at baseline and 24 months, respectively (p < 0.001). Downstaging of chronic kidney disease was observed in eight (25.8%) patients and was more common in ADV-treated compared to TDF-treated patients (7/8 vs. 1/17, p = 0.011; OR 16, 95% CI 1.643-155.766, p = 0.017). In vitro data showed that adding LdT to ADV or TDF was associated with improved cell viability and lower expression of injury and apoptotic biomarkers compared with ADV or TDF alone. Treatment was prematurely discontinued in four(12.9%) patients due to myalgia.

CONCLUSIONS

Clinical and in vitro data suggest that LdT has renoprotective effects in patients on long-term ADV/TDF treatment. LdT may be considered as an adjuvant therapy in this special group of patients with renal impairment (NCT03778567).

Donor-Recipient Relationship and Risk of ESKD in Live Kidney Donors of Varied Racial Groups

RATIONALE & OBJECTIVE

Risk factors for kidney failure are the basis of live kidney donor candidate evaluation. We quantified risk for end-stage kidney disease (ESKD) by the biological relationship of the donor to the recipient, a risk factor that is not addressed by current clinical practice guidelines.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

A cohort of 143,750 US kidney donors between 1987 and 2017.

EXPOSURE

Biological relationship of donor and recipient.

OUTCOME

ESKD. Donors' records were linked to national dialysis and transplantation registries to ascertain development of the outcome.

ANALYTIC APPROACH

Donors were observed over a median of 12 (interquartile range, 6-18; maximum, 30) years. Survival analysis methods that account for the competing risk for death were used.

RESULTS

Risk for ESKD varied by orders of magnitude across donor-recipient relationship categories. For Asian donors, risks compared with unrelated donors were 259.4-fold greater for identical twins (95% CI, 19.5-3445.6), 4.7-fold greater for full siblings (95% CI, 0.5-41.0), 3.5-fold greater for offspring (95% CI, 0.6-39.5), 1.0 for parents, and 1.0 for half-sibling or other biological relatives. For black donors, risks were 22.5-fold greater for identical twin donors (95% CI, 4.7-107.0), 4.1-fold for full siblings (95% CI, 2.1-7.8), 2.7-fold for offspring (95% CI, 1.4-5.4), 3.1-fold for parents (95% CI, 1.4-6.8), and 1.3-fold for half-sibling or other biological relatives (95% CI, 0.5-3.3). For white donors, risks were 3.5-fold greater for identical twin donors (95% CI, 0.5-25.3), 2.0-fold for full siblings (95% CI, 1.4-2.8), 1.4-fold for offspring (95% CI, 0.9-2.3), 2.9-fold for parents (95% CI, 2.0-4.1), and 0.8-fold for half-sibling or other biological relatives (95% CI, 0.3-1.6).

LIMITATIONS

Insufficient sample size in some race and relationship groups. Absence of data for family history of kidney disease for donors biologically unrelated to their recipients.

CONCLUSIONS

Marked differences in risk for ESKD across types of donor-recipient relationship were observed for Asian, black, and white donors. These findings warrant further validation with more robust data to better inform clinical practice guidelines.

Preoperative Comorbidities and Outcomes of Medically Complex Living Kidney Donors

Introduction

Recent reports have described an increased risk of renal disease in living kidney donors compared with the general population. However, these reports do not detail the outcomes of medically complex living donors (MCLDs) with preoperative comorbidities (PCs), such as hypertension, dyslipidemia, glucose intolerance, and obesity. Analysis of living donors with end-stage renal disease (ESRD) has shown that these PCs may contribute significantly to the development of ESRD. We aimed to evaluate the effect of PCs on postoperative renal function and mortality in MCLDs.

Methods

Between January 2008 and December 2016, 807 living-donor kidney transplants were performed in our unit. Of these, 802 donors completed postoperative follow-up of >5 months. Donors were stratified into 4 groups based on the number of PCs present: healthy living donors (HLDs) with no PCs (n = 214) or MCLDs with 1 PC (n = 302), 2 PCs (n = 196), or 3 PCs (n = 90) (denoted MCLD [PC 1], MCLD [PC 2], or MCLD [PC 3], respectively). We compared pathology observation data from baseline biopsy, postoperative estimated glomerular filtration rate (eGFR), postoperative urinary protein concentration, and mortality between HLD and MCLD groups.

Results

Interstitial fibrosis, tubular atrophy, glomerulosclerosis, and arteriolosclerosis were more frequent in MCLDs (PC 3) than in HLDs. No significant differences were identified between HLDs and MCLDs in terms of postoperative eGFR and short-term mortality. Overt proteinuria and ESRD were not observed.

Conclusions

Appropriate postdonation management of MCLDs with PCs may result in similar outcomes as for HLDs.

A donor risk index for graft loss in pediatric living donor kidney transplantation

Pediatric kidney transplant candidates often have multiple potential living donors (LDs); no evidence-based tool exists to compare potential LDs, or to decide between marginal LDs and deceased donor (DD) kidney transplantation (KT). We developed a pediatric living kidney donor profile index (P-LKDPI) on the same scale as the DD KDPI by using Cox regression to model the risk of all-cause graft loss as a function of living donor characteristics and DD KDPI. HLA-B mismatch (adjusted hazard ratio [aHR] per mismatch = 1.04 1.271.55 ), HLA-DR mismatch (aHR per mismatch = 1.02 1.231.49 ), ABO incompatibility (aHR = 1.20 3.268.81 ), donor systolic blood pressure (aHR per 10 mm Hg = 1.01 1.071.18 ), and donor estimated GFR (eGFR; aHR per 10 mL/min/1.73 m2 = 0.88 0.940.99 ) were associated with graft loss after LDKT. Median (interquartile range [IQR]) P-LKDPI was -25 (-56 to 12). 68% of donors had P-LKDPI <0 (less risk than any DD kidney) and 25% of donors had P-LKDPI >14 (more risk than median DD kidney among pediatric KT recipients during the study period). Strata of LDKT recipients of kidneys with higher P-LKDPI had a higher cumulative incidence of graft loss (39% at 10 years for P-LDKPI ≥20, 28% for 20> P-LKDPI ≥-20, 23% for -20 > P-LKDPI ≥-60, 19% for P-LKDPI <-60 [log rank P < .001]). The P-LKDPI can aid in organ selection for pediatric KT recipients by allowing comparison of potential LD and DD kidneys.

Associations of obesity with antidiabetic medication use after living kidney donation: An analysis of linked national registry and pharmacy fill records

We examined a novel linkage of national US donor registry data with records from a pharmacy claims warehouse (2007-2016) to examine associations (adjusted hazard ratio, LCL aHRUCL ) of post-donation fills of antidiabetic medications (ADM, insulin or non-insulin agents) with body mass index (BMI) at donation and other demographic and clinical factors. In 28 515 living kidney donors (LKDs), incidence of ADM use at 9 years rose in a graded manner with higher baseline BMI: underweight, 0.9%; normal weight, 2.1%; overweight, 3.5%; obese, 8.5%. Obesity was associated with higher risk of ADM use compared with normal BMI (aHR, 3.36 4.596.27 ). Metformin was the most commonly used ADM and was filled more often by obese than by normal weight donors (9-year incidence, 6.87% vs 1.85%, aHR, 3.55 5.007.04 ). Insulin use was uncommon and did not differ significantly by BMI. Among a subgroup with BMI data at the 1-year post-donation anniversary (n = 19 528), compared with stable BMI, BMI increase >0.5 kg/m2 by year 1 was associated with increased risk of subsequent ADM use (aHR, 1.03 1.482.14, P = .04). While this study did not assess the impact of donation on the development of obesity, these data support that among LKD, obesity is a strong correlate of ADM use.

Can Split Renal Volume Assessment by Computed Tomography Replace Nuclear Split Renal Function in Living Kidney Donor Evaluations? A Systematic Review and Meta-Analysis

Background:

As part of their living kidney donor assessment, all living donor candidates complete a computed tomography (CT) angiogram, but some also receive a nuclear renogram for split renal function (SRF%).

Objective:

We considered whether split renal volume (SRV%) assessed by CT can predict SRF%.

Design:

Systematic review and meta-analysis.

Setting:

Living donor candidates undergoing evaluation as potential living kidney donors.

Patients:

Living donor candidates who received both a nuclear renogram for split function and CT for SRV as part of their living donor work-up.

Measurements:

Split renal volume from CT scans and SRF from nuclear renography.

Methods:

We performed a systematic review and meta-analysis of the literature, abstracting data and digitizing plots where possible. We searched Medline, EMBASE, and the Cochrane Library. We added data from donor candidates assessed in London, Ontario from 2013 to 2016. We used fixed and random-effects models to pool Fisher’s z-transformed Pearson’s correlation coefficient (r). We conducted random-effects meta-regression on digitized and aggregate data. Studies were restricted to living kidney donors or living donor candidates.

Results:

After pooling 19 studies (n = 1479), we obtained a pooled correlation of r = 0.74 (95% confidence interval [CI] = 0.61-0.82). By linear regression using individual-level data, we observed a 0.76% (95% CI = 0.71-0.81) increase in SRF% for every 1% increase in SRV%. Split renal volume had a specificity of 88% for discriminating SRF at a threshold that could influence the decision of which kidney is to be removed (between-kidney difference ≥10%). Predonation SRV and SRF both moderately predicted kidney function 6 to 12 months after donation: r = 0.75 for SRV and r = 0.73 for SRF; Δr = 0.05 (–0.02, 0.13).

Limitations:

Most studies were retrospective and measured SRV and SRF only on selected living donor candidates. Efficiency gains in removing the SRF from the evaluation will depend on the transplant program.

Conclusion:

Split renal volume has the potential to replace SRF for some candidates. However, it is uncertain whether it can do so reliably and routinely across different transplant centers. The impact on clinical decision-making needs to be assessed in well-designed prospective studies.

Trial registration:

The digitized data are registered with Mendeley Data (doi10.17632/dyn2bfgxxj.2).

Blood Pressure and Living Kidney Donors: A Clinical Perspective

Elevated blood pressure (BP), or “hypertension,” has been one of the main exclusion criteria for living kidney donation, as it is a risk factor for renal and cardiovascular disease. The effect of elevated BP in living kidney donors is not well studied or understood. The most current living kidney donation guidelines state that donors with a BP >140/90 mm Hg with 1–2 antihypertensive medications or evidence of end-organ damage should be excluded from living kidney donation. Yet, the definitions of “hypertension” have changed with the release of the American Heart Association (AHA)/American College of Cardiology (ACC) clinical practice guidelines suggesting that 120–129 mm Hg is elevated BP and Stage 1 hypertension is 130 mm Hg. However, the kidney function (in terms of estimated GFR) of “hypertensive” living kidney donors does not fare significantly worse postdonation compared with that of “normotensive” donors. In addition, even though living kidney donation itself is not considered to be a risk factor for developing hypertension, there exist certain risk factors (African American or Hispanic descent, obesity, age) that may increase the risk of living kidney donors developing elevated BP postdonation. The choice of BP targets and medications needs to be carefully individualized. In general, a BP <130/80 mm Hg is needed, along with lifestyle modifications.

The changing landscape of live kidney donation in the United States from 2005 to 2017

The number of live kidney donors has declined since 2005. This decline parallels the evolving knowledge of risk for biologically related, black, and younger donors. To responsibly promote donation, we sought to identify declining low-risk donor subgroups that might serve as targets for future interventions. We analyzed a national registry of 77 427 donors and quantified the change in number of donors per 5-year increment from 2005 to 2017 using Poisson regression stratified by donor-recipient relationship and race/ethnicity. Among related donors aged <35, 35 to 49, and ≥50 years, white donors declined by 21%, 29%, and 3%; black donors declined by 30%, 31%, and 12%; Hispanic donors aged <35 and 35 to 49 years declined by 18% and 15%, and those aged ≥50 increased by 10%. Conversely, among unrelated donors aged <35, 35 to 49, and ≥50 years, white donors increased by 12%, 4%, and 24%; black donors aged <35 and 35 to 49 years did not change but those aged ≥50 years increased by 34%; Hispanic donors increased by 16%, 21%, and 46%. Unlike unrelated donors, related donors were less likely to donate in recent years across race/ethnicity. Although this decline might be understandable for related younger donors, it is less understandable for lower-risk related older donors (≥50 years). Biologically related older individuals are potential targets for interventions to promote donation.

Development and validation of a new prediction model for graft function using preoperative marginal factors in living-donor kidney transplantation

BACKGROUND

Recently, living-donor kidney transplantation from marginal donors has been increasing. However, a simple prediction model for graft function including preoperative marginal factors is limited. Here, we developed and validated a new prediction model for graft function using preoperative marginal factors in living-donor kidney transplantation.

METHODS

We retrospectively investigated 343 patients who underwent living-donor kidney transplantation at Kyushu University Hospital (derivation cohort). Low graft function was defined as an estimated glomerular filtration rate of < 45 mL/min/1.73 m² at 1 year. A prediction model was developed using a multivariable logistic regression model, and verified using data from 232 patients who underwent living-donor kidney transplantation at Tokyo Women's Medical University Hospital (validation cohort).

RESULTS

In the derivation cohort, 89 patients (25.9%) had low graft function at 1 year. Donor age, donor-estimated glomerular filtration rate, donor hypertension, and donor/recipient body weight ratio were selected as predictive factors. This model demonstrated modest discrimination (c-statistic = 0.77) and calibration (Hosmer-Lemeshow test, P = 0.83). Furthermore, this model demonstrated good discrimination (c-statistic = 0.76) and calibration (Hosmer-Lemeshow test, P = 0.54) in the validation cohort. Furthermore, donor age, donor-estimated glomerular filtration rate, and donor hypertension were strongly associated with glomerulosclerosis and atherosclerotic vascular changes in the "zero-time" biopsy.

CONCLUSIONS

This model using four pre-operative variables will be a simple, but useful guide to estimate graft function at 1 year after kidney transplantation, especially in marginal donors, in the clinical setting.

The experiences and impact of being deemed ineligible for living kidney donation: Semi-structured interview study

AIM

We aimed to describe the impact and experience of being deemed ineligible as a living kidney donor.

METHODS

Semi-structured interviews were conducted with 27 ineligible donor candidates. Transcripts were analysed thematically.

RESULTS

Seven themes were identified: deriving health and relationship benefits in the process (strengthening emotional connection, identifying problematic health conditions); devastating loss and disappointment (harbouring guilt over personal failings, shattering confidence and hope, undermining relationships with extended family and friends, disrupting home dynamics); constrained within a rigid system (denied autonomy, resorting to other avenues); acknowledging as matter of fact (accepting the clinical decision, reassured by preventing a poor outcome); reluctant to relinquish the donor identity (unable to fulfil family duty, having the donor role stolen, holding onto other opportunities to donate); uncertainty in unpredictability, inconsistency and ambiguities (frustrated by inefficiencies, questioning clinician motivation, suspended donor status, unfairness in changeable eligibility criteria, unresolved concerns and questions of own health); and abandoned in despair (lacking practical support to meet eligibility criteria, ill prepared for rejection, dismissed and discarded by the system).

CONCLUSION

Being deemed unsuitable for donation took an emotional toll on ineligible donor candidates who felt immense guilt for 'failing' the potential recipient. Ineligible donor candidates were frustrated and angry with the perceived lack of support from clinicians and rigidity of the evaluation process. Informing potential donors of available services, including psychological support, communicating the decision sensitively and with sufficient time, and full disclosure of their health status, may contribute to improved adjustment following the ineligibility decision.

Perioperative Complications During Living Donor Nephrectomy: Results From a Multicenter Cohort Study

BACKGROUND

While living kidney donation is considered safe in healthy individuals, perioperative complications can occur due to several factors.

OBJECTIVE

We explored associations between the incidence of perioperative complications and donor characteristics, surgical technique, and surgeon's experience in a large contemporary cohort of living kidney donors.

DESIGN

Living kidney donors enrolled prospectively in a multicenter cohort study with some data collected retrospectively after enrollment was complete (eg, surgeon characteristics).

SETTING

Living kidney donor centers in Canada (n = 12) and Australia (n = 5).

PATIENTS

Living kidney donors who donated between 2004 and 2014 and the surgeons who performed the living kidney donor nephrectomies.

MEASUREMENTS

Operative and hospital discharge medical notes were collected prospectively, with data on perioperative (intraoperative and postoperative) information abstracted from notes after enrollment was complete. Complications were graded using the Clavien-Dindo system and further classified into minor and major. In 2016, surgeons who performed the nephrectomies were invited to fill an online survey on their training and experience.

METHODS

Multivariable logistic regression models with generalized estimating equations were used to compare perioperative complication rates between different groups of donors. The effect of surgeon characteristics on the complication rate was explored using a similar approach. Poisson regression was used to test rates of overall perioperative complications between high- and low-volume centers.

RESULTS

Of the 1421 living kidney donor candidates, 1042 individuals proceeded with donation, where 134 (13% [95% confidence interval (CI): 11%-15%]) experienced 142 perioperative complications (55 intraoperative; 87 postoperative). The most common intraoperative complication was organ injury and the most common postoperative complication was ileus. No donors died in the perioperative period. Most complications were minor (90% of 142 complications [95% CI: 86%-96%]); however, 12 donors (1% of 1042 [95% CI: 1%-2%]) experienced a major complication. No statistically significant differences were observed between donor groups and the rate of complications. A total of 43 of 48 eligible surgeons (90%) completed the online survey. Perioperative complication rates did not vary significantly by surgeon characteristics or by high- versus low-volume centers.

LIMITATIONS

Operative and discharge reporting is not standardized and varies among surgeons. It is possible that some complications were missed. The online survey for surgeons was completed retrospectively, was based on self-report, and has not been validated. We had adequate statistical power only to detect large effects for factors associated with a higher risk of perioperative complications.

CONCLUSIONS

This study confirms the safety of living kidney donation as evidenced by the low rate of major perioperative complications. We did not identify any donor or surgeon characteristics associated with a higher risk of perioperative complications.

TRIAL REGISTRATIONS

NCT00319579: A Prospective Study of Living Kidney Donation (https://clinicaltrials.gov/ct2/show/NCT00319579)NCT00936078: Living Kidney Donor Study (https://clinicaltrials.gov/ct2/show/NCT00936078).

Current Management of Patients With Acquired Solitary Kidney

Persons with acquired solitary kidney, including those who have had a unilateral nephrectomy for living kidney donation, renal malignancies, or trauma, have decreased renal mass that leads to increased intraglomerular pressure and glomerular hyperfiltration. These physiologic adaptations of solitary kidney may exacerbate other preexisting and genetic conditions that could create a predisposition to or worsen glomerular pathologies, leading to unfavorable renal outcomes. Hence, these persons may benefit from special care and lifestyle modifications, including nutritional interventions. There is a lack of consensus and evidence for proper surveillance and management after nephrectomy, and misconceptions in both directions of having a “normal” versus “abnormal” kidney status may cause confusion among patients and healthcare providers pertaining to long-term kidney health monitoring and management. We have reviewed available data on the impact of lifestyle modifications, particularly nutritional measures, and pharmacologic interventions, on short- and long-term outcomes after nephrectomy. We recommend avoidance of excessively high dietary protein intake (>1 g/kg per day) and high dietary sodium intake (>4 grams/d), adequate dietary fiber intake from plant-based foods, a target body mass index of <30 kg/m² (in non-athletes and non-bodybuilders), and judicious management of risk factors of progressive chronic kidney disease (CKD), and future studies should help to better determine optimal care practices for these persons.

Risk of ESKD in Older Live Kidney Donors with Hypertension

BACKGROUND AND OBJECTIVES

Hypertension in older kidney donor candidates is viewed as safe. However, hypertension guidelines have evolved and long-term outcomes have not been explored. We sought to quantify the 15-year risk of ESKD and mortality in older donors (≥50 years old) with versus those without hypertension.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A United States cohort of 24,533 older donors from 1999 to 2016, including 2265 with predonation hypertension, were linked to Centers for Medicare and Medicaid Services data and the Social Security Death Master File to ascertain ESKD development and mortality. The exposure of interest was predonation hypertension. From 2004 to 2016, hypertension was defined as documented predonation use of antihypertensive therapy, regardless of systolic BP or diastolic BP; from 1999 to 2003, when there was no documentation of antihypertensive therapy, hypertension was defined as predonation systolic BP ≥140 or diastolic BP ≥90 mm Hg.

RESULTS

Older donors were 82% white, 6% black, 7% Hispanic, and 3% Asian. The median follow-up was 7.1 years (interquartile range, 3.4-11.1; maximum, 18). There were 24 ESKD and 252 death events during the study period. The 15-year risk of ESKD was 0.8% (95% confidence interval [95% CI], 0.4 to 1.6) for donors with hypertension (mean systolic BP, 138 mm Hg) versus 0.2% (95% CI, 0.1 to 0.4) for donors without hypertension (mean systolic BP, 123 mm Hg; adjusted hazard ratio, 3.04; 95% CI, 1.28 to 7.22; P=0.01). When predonation antihypertensive therapy was available, the risk of ESKD was 6.21-fold higher (95% CI, 1.20 to 32.17; P=0.03) for donors using antihypertensive therapy (mean systolic BP, 132 mm Hg) versus those not using antihypertensive therapy (mean systolic BP, 124 mm Hg). There was no significant association between donor hypertension and 15-year mortality (hazard ratio, 1.18; 95% CI, 0.84 to 1.66; P=0.34).

CONCLUSIONS

Compared with older donors without hypertension, older donors with hypertension had higher risk of ESKD, but not mortality, for 15 years postdonation. However, the absolute risk of ESKD was small.

Analysis of pre- and intraoperative clinical for successful operating room extubation after living donor liver transplantation: a retrospective observational cohort study

BACKGROUND

Early extubation after liver transplantation is safe and accelerates patient recovery. Patients with end-stage liver disease undergo sarcopenic changes, and sarcopenia is associated with postoperative morbidity and mortality. We investigated the impact of core muscle mass on the feasibility of immediate extubation in the operating room (OR) after living donor liver transplantation (LDLT).

METHODS

A total of 295 male adult LDLT patients were retrospectively reviewed between January 2011 and December 2017. In total, 40 patients were excluded due to emergency surgery or severe encephalopathy. A total of 255 male LDLT patients were analyzed in this study. According to the OR extubation criteria, the study population was classified into immediate and conventional extubation groups (39.6 vs. 60.4%). Psoas muscle area was estimated using abdominal computed tomography and normalized by height squared (psoas muscle index [PMI]).

RESULTS

There were no significant differences in OR extubation rates among the five attending transplant anesthesiologists. The preoperative PMI correlated with respiratory performance. The preoperative PMI was higher in the immediate extubation group than in the conventional extubation group. Potentially significant perioperative factors in the univariate analysis were entered into a multivariate analysis, in which preoperative PMI and intraoperative factors (i.e., continuous renal replacement therapy, significant post-reperfusion syndrome, and fresh frozen plasma transfusion) were associated with OR extubation. The duration of ventilator support and length of intensive care unit stay were shorter in the immediate extubation group than in the conventional extubation group, and the incidence of pneumonia and early allograft dysfunction were also lower in the immediate extubation group.

CONCLUSIONS

Our study could improve the accuracy of predictions concerning immediate post-transplant extubation in the OR by introducing preoperative PMI into predictive models for patients who underwent elective LDLT.

Clinicians' attitudes and approaches to evaluating the potential living kidney donor-recipient relationship: An interview study

AIM

Careful assessment of the potential donor-recipient relationship is recommended by guidelines to prevent undue coercion, and to ensure realistic expectations and genuine motivations. However, relationships are complex, nuanced and value-laden, and can be challenging to evaluate in living kidney donation. We aimed to describe the attitudes and approaches of transplant clinicians towards assessing the relationship between potential living kidney donors and their recipients.

METHODS

Semi-structured interviews were conducted with 54 transplant clinicians (nephrologists, surgeons, coordinators, social workers, psychiatrists and psychologists) from 32 transplant centres across nine countries including Australia, United States, Canada and New Zealand. Transcripts were analyzed thematically.

RESULTS

Four themes were identified: protecting against vulnerability and premature decisions (ensuring genuine motivation, uncovering precarious dynamics and pre-empting conflict, shared accountability, relying on specialty psychosocial expertise, trusting intimate bonds, tempering emotional impulsivity); safeguarding against coercion (discerning power imbalance, justified inquiry, awareness of impression management); minimizing potential threat to relationships (preserving the bond, giving equitable attention to donors and recipients, ensuring realistic expectations); and ambiguities in making judgments (adjudicating appropriateness and authenticity of relationships, questioning professional intervening, uncertainties in subjective and emotional assessments).

CONCLUSIONS

Clinicians felt ethically compelled to minimize the risk of undue coercion and to protect donors and recipients when evaluating the donor-recipient relationship. However, disentangling voluntariness and altruism from potential undisclosed pressures to enact societal and family duty, making decisions within this complex, multi-stakeholder context, and avoiding the imposition of undue paternalism and donor autonomy, were challenging. Multidisciplinary expertise and practical strategies for managing uncertainties are required.

Expanding deceased donor kidney transplantation: medical risk, infectious risk, hepatitis C virus, and HIV

PURPOSE OF REVIEW

Due to the organ shortage, which prevents over 90 000 individuals in the United States from receiving life-saving transplants, the transplant community has begun to critically reevaluate whether organ sources that were previously considered too risky provide a survival benefit to waitlist candidates.

RECENT FINDINGS

Organs that many providers were previously unwilling to use for transplantation, including kidneys with a high Kidney Donor Profile Index or from increased risk donors who have risk factors for window period hepatitis C virus (HCV) and HIV infection, have been shown to provide a survival benefit to transplant waitlist candidates compared with remaining on dialysis. The development of direct-acting antivirals to cure HCV infection has enabled prospective trials on the transplantation of organs from HCV-infected donors into HCV-negative recipients, with promising preliminary results. Changes in legislation through the HIV Organ Policy Equity Act have legalized transplantations from HIV-positive deceased donors to HIV-positive recipients for the first time in the United States.

SUMMARY

Critical reexamination of deceased donor organs that were previously discarded has resulted in greater utilization of these organs, an increased number of deceased donor transplants, and the provision of life-saving treatment to more transplant waitlist candidates.

Obesity and long-term mortality risk among living kidney donors

BACKGROUND

Body mass index of living kidney donors has increased substantially. Determining candidacy for live kidney donation among obese individuals is challenging because many donation-related risks among this subgroup remain unquantified, including even basic postdonation mortality.

METHODS

We used data from the Scientific Registry of Transplant Recipients linked to data from the Centers for Medicare and Medicaid Services to study long-term mortality risk associated with being obese at the time of kidney donation among 119,769 live kidney donors (1987-2013). Donors were followed for a maximum of 20 years (interquartile range 6.0-16.0). Cox proportional hazards estimated the risk of postdonation mortality by obesity status at donation. Multiple imputation accounted for missing obesity data.

RESULTS

Obese (body mass index ≥ 30) living kidney donors were more likely male, African American, and had higher blood pressure. The estimated risk of mortality 20 years after donation was 304.3/10,000 for obese and 208.9/10,000 for nonobese living kidney donors. Adjusting for age, sex, race/ethnicity, blood pressure, baseline estimated glomerular filtration rate, relationship to recipient, smoking, and year of donation, obese living kidney donors had a 30% increased risk of long-term mortality compared with their nonobese counterparts (adjusted hazard ratio: 1.32, 95% CI: 1.09-1.60, P = .006). The impact of obesity on mortality risk did not differ significantly by sex, race or ethnicity, biologic relationship, baseline estimated glomerular filtration rate, or among donors who did and did not develop postdonation kidney failure.

CONCLUSION

These findings may help to inform selection criteria and discussions with obese persons considering living kidney donation.

Changes in Body Weight Before and After Kidney Donation

Background:

Living kidney donors remain at low risk of end-stage kidney disease (ESKD), but the risk for obese and overweight donors is increased. The Kidney Disease Improving Global Outcomes (KDIGO) clinical guideline recommends that overweight and obese patients pursue weight loss before donation and maintain a healthy post-donation weight.

Objective:

To determine the trajectory of weight changes before and after living kidney donation.

Design:

Retrospective cohort study.

Setting:

The Living Kidney Donor program in the Champlain Local Health Integration Network at The Ottawa Hospital in Ottawa, Canada.

Patients:

The study included 151 living kidney donors who donated between January 2009 and December 2017.

Measurements:

Date of kidney donation, relationship to the transplant recipient, and cause of ESKD in the transplant recipient were documented. Demographic data, markers of glycemic control, and weights at the time of clinic visits were recorded.

Methods:

The analysis included use of paired Student’s t tests to compare mean differences in weight at kidney donation relative to the time of initial assessment and at last follow-up.

Results:

The median (interquartile range [IQR]) follow-up was 392 (362, 1096) days post-donation. Among donors with normal body mass index (BMI; 18.5-24.9 kg/m²), weight loss occurred before donation (62.8 ± 3.1 kg to 61.5 kg ± 2.9 kg; mean difference 1.1 ± 2.7 kg, P < .01) and did not change significantly post-donation. Among overweight/obese donors (BMI ≥25 kg/m²), weight did not change significantly pre-donation, but increased significantly post-donation (86.0 ± 2.1 kg to 88.8 ± 2.7 kg; mean difference 2.3 ± 0.9 kg, P < .0001).

Limitations:

The single-center design of the study limits generalizability.

Conclusions:

Donors with normal BMI experienced significant weight loss before donation and maintained healthy body weight post-donation. Conversely, donors with BMI ≥25 kg/m² at donation experienced significant weight gain over 1-year post-donation. Our findings suggest the need for enhanced weight control efforts among obese and overweight kidney donors to reduce the risk of ESKD.

Vascular Reconstructions in Living Unrelated Kidney Transplant Using Donor Ovarian Vein and Recipient Inferior Epigastric Artery with Simultaneous Enucleation of a Complex Cyst

Increasing the organ donor pool and solving the recipient demands continue to be one of the challenges in transplantation. We report our experience in transplanting a living donor kidney requiring complex vascular reconstructions and an enucleation of complex cyst. A 57-year-old male patient underwent a living unrelated kidney transplant. The living donor kidney was procured through a laparoscopic hand-assisted right donor nephrectomy. After vascular stapling, the kidney had a short upper pole arterial branch, a short renal vein (3 mm), and a complex upper pole cyst. The renal vein was elongated using the donor ovarian vein and the short upper pole artery was extended using the recipient inferior epigastric artery and anastomosed to the main renal artery. The renal allograft vessels were anastomosed end-to-side to the external iliac vessels. The complex cyst was removed performing an enucleation with a rim of normal tissue and reconstruction of the calyceal system. This case represents three different surgical reconstructions in order to make the organ available for transplantation. In some circumstances, complex vascular reconstruction of living donor kidney with removal of complex cyst represents a strategy to expand the donor pool.

Living kidney donor and recipient perspectives on their relationship: longitudinal semi-structured interviews

BACKGROUND AND OBJECTIVES

Many donors and recipients report an improved bond posttransplantation; however, unexpected conflicts and tension may also occur. Insights into the lived experiences of the donor-recipient relationship can inform strategies for interventions and support. We aimed to describe donor and recipient expectations and experiences of their relationship before and after living kidney donor transplantation.

DESIGN, SETTING AND PARTICIPANTS

Semistructured interviews were conducted with 16 donor-recipient pairs before the transplant and 11-14 months post-transplant. Transcripts were analysed thematically.

RESULTS

We identified seven themes (with respective subthemes): donation as enacting familial responsibility for care; analytical decision making to mitigate regret (avoiding anticipated regret and maintaining control, removing emotional impulsivity); strengthened interpersonal ties (gaining a deeper appreciation among family members, stronger empathy for each other, improving social participation); instability of relational impacts (anger and aggression threatening dynamics, unanticipated stress and emotional lability, triggering familial tension); renegotiating social roles (unexpected continuation of caregiving responsibilities, inability to relinquish the caregiving role, disappointment with unfulfilled renewal of intimacy, dissatisfaction over discrepant energy levels); guilt over unmet expectations and inevitability of the gift relationship (vague and transient indebtedness, expectation of reciprocity, transferring kidney ownership).

CONCLUSIONS

Donor-recipient relationships may be improved through increased empathy, appreciation, and ability to participate in life together; however, unfulfilled expectations and behavioural and emotional changes in recipients (a side effect related to immunosuppression) remain unresolved consequences of living kidney donor transplantation. Education and counselling to help donors and recipients adjust to potential changes in relationship dynamics may help protect and foster relational stability postdonation.

Diagnostic Performance of Blood Pressure Measurement Modalities in Living Kidney Donor Candidates

BACKGROUND AND OBJECTIVES

Precise BP measurement to exclude hypertension is critical in evaluating potential living kidney donors. Ambulatory BP monitoring is considered the gold standard method for diagnosing hypertension, but it is cumbersome to perform. We sought to determine whether lower BP cutoffs using office and automated BP would reduce the rate of missed hypertension in potential living donors.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We measured BP in 578 prospective donors using three modalities: (1) single office BP, (2) office automated BP (average of five consecutive automated readings separated by 1 minute), and (3) ambulatory BP. Daytime ambulatory BP was considered the gold standard for diagnosing hypertension. We assessed both the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC-7) and the American College of Cardiology/American Heart Association (ACC/AHA) definitions of hypertension in the cohort. Empirical thresholds of office BP and automated BP for the detection of ambulatory BP-diagnosed hypertension were derived using Youden index, which maximizes the sum of sensitivity and specificity and gives equal weight to false positive and false negative values.

RESULTS

Hypertension was diagnosed in 90 (16%) prospective donors by JNC-7 criteria and 198 (34%) prospective donors by ACC/AHA criteria. Masked hypertension was found in 3% of the total cohort by JNC-7 using the combination of office or automated BP, and it was seen in 24% by ACC/AHA guidelines. Using Youden index, cutoffs were derived for both office and automated BP using JNC-7 (<123/82 and <120/78 mm Hg) and ACC/AHA (<119/79 and <116/76 mm Hg) definitions. Using these lower cutoffs, the sensitivity for detecting hypertension improved from 79% to 87% for JNC-7 and from 32% to 87% by ACC/AHA definition, with negative predictive values of 95% and 87%, respectively. Missed (masked) hypertension was reduced to 2% and 4% of the entire cohort by JNC-7and ACC/AHA, respectively.

CONCLUSIONS

The prevalence of hypertension was higher in living donor candidates using ACC/AHA compared JNC-7 definitions. Lower BP cutoffs in the clinic improved sensitivity and led to a low overall prevalence of missed hypertension in prospective living kidney donors.

Impact of errors of creatinine and cystatin C equations in the selection of living kidney donors

Background

Reliable determination of glomerular filtration rate (GFR) is crucial in the evaluation of living kidney donors. Although some guidelines recommend the use of measured GFR (mGFR), many centres still rely on estimated GFR (eGFR) obtained through equations or 24-h creatinine clearance. However, eGFR is neither accurate nor precise in reflecting real renal function. We analysed the impact of eGFR errors on evaluation and decision making regarding potential donors.

Methods

We evaluated 103 consecutive living donors who underwent mGFR via iohexol plasma clearance and eGFR by 51 creatinine- and/or cystatin C-based equations. The cut-off for living donation in our centre is GFR > 80 mL/min for donors >35 years of age or 90 mL/min for those <35 years of age. We analysed the misclassification of donors based on the cut-off for donation-based eGFR.

Results

Ninety-three subjects (90.3%) had mGFR values above (donors) and 10 [9.7% (95% confidence interval 5.4-17)] below (non-donors) the cut-off. In non-donors, most of the equations gave eGFR values above the cut-off, so donation would have been allowed based on eGFR. All non-donors were female with reduced weight, height and body surface. In donors, up to 32 cases showed eGFR below the cut-off, while mGFR was actually higher. Therefore an important number of donors would not have donated based on eGFR alone.

Conclusion

The misclassification of donors around the cut-off for donation is very common with eGFR, making eGFR unreliable for the evaluation of living kidney donors. Whenever possible, mGFR should be implemented in this setting.

Healthcare Costs for the Evaluation, Surgery, and Follow-Up Care of Living Kidney Donors

BACKGROUND

The healthcare costs to evaluate, perform surgery, and follow a living kidney donor for the year after donation are poorly described.

METHODS

We obtained information on the healthcare costs of 1099 living kidney donors between April 1, 2004, and March 31, 2014, from Ontario, Canada, using comprehensive healthcare administrative databases. We estimated the cost of 3 periods of the living donation process: the predonation evaluation period (start of evaluation until the day before donation), perioperative period (day of donation until 30-days postdonation), and 1 year of follow-up period (after perioperative period until 1 year postdonation). We analyzed data for donors and healthy matched nondonor controls using regression-based methods to estimate the incremental cost of living donation. Costs are presented from the perspective of the Canadian healthcare payer (2017 CAD $).

RESULTS

The incremental healthcare costs (compared with controls) for the evaluation, perioperative, and follow-up periods were CAD $3596 (95% confidence interval [CI], CAD $3350-$3842), CAD $11 694 (95% CI, CAD $11 415-CAD $11 973), and $1011 (95% CI, CAD $793-CAD $1230), respectively, totalling CAD $16 290 (95% CI, CAD $15 814-CAD $16 767). The evaluation cost was higher if the intended recipient started dialysis partway through the donor evaluation (CAD $886; 95% CI, CAD $19, CAD $1752). The perioperative cost varied across transplant centers (P < 0.0001).

CONCLUSIONS

Although substantial costs of living donor care are related to the nephrectomy procedure, comprehensive assessment of costs must also include the evaluation and follow-up periods. These estimates are informative for planning future work to support and expand living donation and transplantation, and directing efforts to improve the cost efficiency of living donor care.

Risks of Living Kidney Donation: Current State of Knowledge on Outcomes Important to Donors

In the past decade, there have been increasing efforts to better define and quantify the short- and long-term risks of living kidney donation. Recent studies have expanded upon the previous literature by focusing on outcomes that are important to potential and previous donors, applying unique databases and/or registries to follow large cohorts of donors for longer periods of time, and comparing outcomes with healthy nondonor controls to estimate attributable risks of donation. Leading outcomes important to living kidney donors include kidney health, surgical risks, and psychosocial effects of donation. Recent data support that living donors may experience a small increased risk of severe CKD and ESKD compared with healthy nondonors. For most donors, the 15-year risk of kidney failure is <1%, but for certain populations, such as young, black men, this risk may be higher. New risk prediction tools that combine the effects of demographic and health factors, and innovations in genetic risk markers are improving kidney risk stratification. Minor perioperative complications occur in 10%-20% of donor nephrectomy cases, but major complications occur in <3%, and the risk of perioperative death is <0.03%. Generally, living kidney donors have similar or improved psychosocial outcomes, such as quality of life, after donation compared with before donation and compared with nondonors. Although the donation process should be financially neutral, living kidney donors may experience out-of-pocket expenses and lost wages that may or may not be completely covered through regional or national reimbursement programs, and may face difficulties arranging subsequent life and health insurance. Living kidney donors should be fully informed of the perioperative and long-term risks before making their decision to donate. Follow-up care allows for preventative care measures to mitigate risk and ongoing surveillance and reporting of donor outcomes to inform prior and future living kidney donors.

A National Survey of Transplant Surgeons and Nephrologists on Implementing Apolipoprotein L1 (APOL1) Genetic Testing Into Clinical Practice

INTRODUCTION

There is debate over whether Apolipoprotein L1 (APOL1) gene risk variants contribute to African American (AA) live donors' (LD) increased risk of kidney failure. Little is known about factors influencing physicians' integration of APOL1 genetic testing of AA LDs into donor evaluation.

DESIGN

We conducted a cross-sectional survey, informed by Roger's Diffusion of Innovations theory, among nephrology and surgeon members of the American Society of Nephrology, American Society of Transplantation, and American Society of Transplant Surgeons about their practices of and attitudes about APOL1 genetic testing of AA potential LDs. Descriptive statistics and bivariate analyses were performed.

RESULTS

Of 383 completed surveys, most physicians believed that APOL1 testing can help AA LDs make more informed donation decisions (87%), and the addition of APOL1 testing offers better clinical information about AA LD's eligibility for donation than existing evaluation approaches (74%). Among respondents who evaluate LDs (n = 345), 63% would definitely or probably begin or continue using APOL1 testing in the next year, however, few use APOL1 testing routinely (4%) or on a case-by-case basis (14%). Most did not know the right clinical scenario to order APOL1 testing (59%), but would use educational materials to counsel AA LDs about APOL1 testing (97%).

DISCUSSION

Although physicians were highly supportive of APOL1 genetic testing for AA LDs, few physicians use APOL1 testing. As more physicians intend to use APOL1 testing, an ethical framework and clinical decision support are needed presently to assist clinicians in clarifying the proper indication of APOL1 genetic testing.

Assessment of renal function in living kidney donors before and after nephrectomy: A Japanese prospective, observational cohort study

OBJECTIVE

To investigate the utility of estimated glomerular filtration rate for assessing kidney function in living kidney donors before and after nephrectomy.

METHODS

A total of 101 donors underwent inulin clearance measurements before and 1 year after nephrectomy. The mean of three inulin clearance values was used as the measured glomerular filtration rate. Estimated glomerular filtration rate based on serum creatinine and cystatin C levels was calculated using the Japanese estimated glomerular filtration rate equation, Chronic Kidney Disease Epidemiology Collaboration formula and new full age spectrum equation. Age-adjusted chronic kidney disease was defined as glomerular filtration rate <75 mL/min/1.73m² for donors aged <40 years, <60 mL/min/1.73m² for donors aged 40-65 years and <45 mL/min/1.73m² for donors aged >65 years.

RESULTS

The postoperative measured glomerular filtration rate <60 mL/min/1.73m² and age-adjusted chronic kidney disease rate were 36.0% and 27.0%, respectively. In younger donors (aged <50 years), postoperative measured glomerular filtration rate <60 mL/min/1.73m² and age-adjusted chronic kidney disease rates were 5.3% and 26.3%, respectively. In older donors (aged >70 years), postoperative measured glomerular filtration rate <60 mL/min/1.73m² and age-adjusted chronic kidney disease rates were 75.0% and 33.3%, respectively. Donor age and measured glomerular filtration rate were significant predictors of postoperative measured glomerular filtration rate. The Japanese estimated glomerular filtration rate equation based on creatinine and cystatin C showed the strongest correlation with measured glomerular filtration rate. However, the Japanese estimated glomerular filtration rate equation based on creatinine overestimated the prevalence of measured glomerular filtration rate <60 mL/min/1.73m² , whereas the Japanese estimated glomerular filtration rate based on cystatin C underestimated it.

CONCLUSIONS

Aged donors might have an increased risk of lower glomerular filtration rate after donor nephrectomy; post-surgery, long-term monitoring of renal function is recommended. Measurement of glomerular filtration rate should be carried out for donors, especially pre-surgery. A more precise glomerular filtration rate equation is required in the future.

Initiating Maintenance Dialysis Before Living Kidney Donor Transplantation When a Donor Candidate Evaluation Is Well Underway

BACKGROUND

Preemptive kidney transplants result in better outcomes and patient experiences than transplantation after dialysis onset. It is unknown how often a person initiates maintenance dialysis before living kidney donor transplantation when their donor candidate evaluation is well underway.

METHODS

Using healthcare databases, we retrospectively studied 478 living donor kidney transplants from 2004 to 2014 across 5 transplant centers in Ontario, Canada, where the recipients were not receiving dialysis when their donor's evaluation was well underway. We also explored some factors associated with a higher likelihood of dialysis initiation before transplant.

RESULTS

A total of 167 (35%) of 478 persons with kidney failure initiated dialysis in a median of 9.7 months (25th-75th percentile, 5.4-18.7 months) after their donor candidate began their evaluation and received dialysis for a median of 8.8 months (3.6-16.9 months) before kidney transplantation. The total cohort's dialysis cost was CAD $8.1 million, and 44 (26%) of 167 recipients initiated their dialysis urgently in hospital. The median total donor evaluation time (time from evaluation start to donation) was 10.6 months (6.4-21.6 months) for preemptive transplants and 22.4 months (13.1-38.7 months) for donors whose recipients started dialysis before transplant. Recipients were more likely to start dialysis if their donor was female, nonwhite, lived in a lower-income neighborhood, and if the transplant center received the recipient referral later.

CONCLUSION

One third of persons initiated dialysis before receiving their living kidney donor transplant, despite their donor's evaluation being well underway. Future studies should consider whether some of these events can be prevented by addressing inappropriate delays to improve patient outcomes and reduce healthcare costs.