Prediction models for postoperative renal function after living donor nephrectomy: a systematic review.

INTRODUCTION: Living-donor nephrectomy (LDN) is the most valuable source of organs for kidney transplantation worldwide. The current preoperative evaluation of a potential living donor candidate does not take into account formal estimation of postoperative renal function decline after surgery using validated prediction models. The aim of this study was to summarize the available models to predict the mid- to long-term renal function following LDN, aiming to support both clinicians and patients during the decision-making process. EVIDENCE ACQUISITION: A systematic review of the English-language literature was conducted following the principles highlighted by the European Association of Urology (EAU) guidelines and following the PRISMA 2020 recommendations. The protocol was registered in PROSPERO on December 10, 2022 (registration ID: CRD42022380198). In the qualitative analysis we selected the models including only preoperative variables. EVIDENCE SYNTHESIS: After screening and eligibility assessment, six models from six studies met the inclusion criteria. All of them relied on retrospective patient cohorts. According to PROBAST, all studies were evaluated as high risk of bias. The models included different combinations of variables (ranging between two to four), including donor-/kidney-related factors, and preoperative laboratory tests. Donor age was the variable more often included in the models (83%), followed by history of hypertension (17%), Body Mass Index (33%), renal volume adjusted by body weight (33%) and body surface area (33%). There was significant heterogeneity in the model building strategy, the main outcome measures and the model's performance metrics. Three models were externally validated. CONCLUSIONS: Few models using preoperative variables have been developed and externally validated to predict renal function after LDN. As such, the evidence is premature to recommend their use in routine clinical practice. Future research should be focused on the development and validation of user-friendly, robust prediction models, relying on granular large multicenter datasets, to support clinicians and patients during the decision-making process.

BK Viremia and Viruria Does Not Depend on the Type of Double-J Stent Used During Kidney Transplantation.

OBJECTIVES: BK virus is a major cause of chronic renal allograft failure.Transplant ureteral stent use has been reported as a risk factorfor BK virus infection. Recently, the use of a new type of ureteral stent (Magnetic Black Star) was reported in kidney transplant recipients. The aim ofthis preliminary report was to compare BK virus viremia and viruria occurrence depending on the type of double-J stent (standard versus Magnetic Black Star). MATERIALS AND METHODS: We included all kidney transplants performed in our center from January to December 2022. Each case had double-J stent placement. Indwelling stents were either a 6- or 7-Fr standard double-J stent or a 6-Fr Magnetic Black Star double-J stent. The type of double-J stent was chosen according to the surgeon's preference. A standard BK virus screening protocol was followed during the study period, which consisted of routine polymerase chain reaction examination of plasma and urine samples during monthly follow-ups. RESULTS: We assessed 120 patients without missing data: 92 patients received standard double-J stents and 28 patients received Magnetic Black Star stents. Patients were mostly male in the standard group (70.7%) versus the Magnetic Black Star group (42.9%) (P = .01). ABO- and HLA-incompatible transplant rates were similar in both groups. BK viremia occurrence and BK viruria occurrence were similar between groups at 1 month, 3 months, and 6 months. CONCLUSIONS: This preliminary study showed no differences concerning BKvirus infection depending on the type of double-J stents used during kidney transplant.

Orthotopic Robot-assisted Kidney Transplantation: Surgical Technique and Preliminary Results.

BACKGROUND AND OBJECTIVE: Orthotopic kidney transplantation (KT) has been proposed as an option for patients ineligible for heterotopic KT. In this scenario, orthotopic robot-assisted KT (oRAKT) represents a novel, minimally invasive alternative to the open approach. Here we describe the largest oRAKT series of patients, with a focus on the surgical technique, perioperative surgical outcomes, and functional results. METHODS: We queried prospectively maintained databases from three referral centers to identify patients who underwent oRAKT and evaluated surgical and functional outcomes. KEY FINDINGS AND LIMITATIONS: Overall, 16 oRAKT procedures were performed between January 2020 and August 2023. These involved four donors after cardiovascular death, five donors after brain death, and seven living donors. All oRAKT procedures were carried out in the left renal fossa. The indication for oRAKT was extensive calcification of the external iliac vessels (100%), frequently associated with prior KT (31%). The median operative time was 295 min (interquartile range [IQR] 268-360) and the median rewarming time 48 min (IQR 40-54). Conversion to open surgery occurred in two cases (12%), and delayed graft function was observed in two cases (12%). Postoperative complications occurred in 11 patients (69%) and three (18%) experienced Clavien-Dindo grade >II complications. At median follow-up of 9 mo (IQR 7-17), 14 patients had a functioning graft and median creatinine of 1.49 mg/dl (IQR 1.36-1.72). CONCLUSIONS AND CLINICAL IMPLICATIONS: Although oRAKT is a challenging procedure, it represents a feasible option for individuals ineligible for heterotopic KT and yields favorable perioperative and mid-term functional outcomes. PATIENT SUMMARY: We evaluated outcomes of orthotopic robot-assisted kidney transplantation (KT), in which the native kidney is removed and the donor kidney is transplanted into its place, in patients who are not eligible for heterotopic KT, in which the native kidney is left in place and the donor kidney is transplanted into a new location. We found that robot-assisted surgery is a safe and feasible alternative to traditional open surgery for orthotopic KT.

Young urologists and kidney transplantation training: A survey designed by the French Transplantation Committee of the French Association of Urology (CTAFU) and the French Association of Urologists in training (AFUF).

OBJECTIVE: In France, kidney transplantations (KT) are mainly performed by urologist. Young urologists and residents are involved in this activity mostly performed in emergency. How do they feel about KT training? Is KT an attractive part of the urologist activity? METHODS: This survey has been designed in the form of a questionnaire by the French Committee of Kidney Transplantation (CTAFU) and the French Association of Urologists in training (AFUF). It has been sent by e-mail to all the AFUF members. Interest in KT and performance of the training were evaluated. RESULTS: In total, 126 members filed the form. Among the residents, 51.5% feel secure to perform KT at the end of their residency. KT is considered as an interesting surgery for 92.1% of the participants: 76.5% are willing to get involved in KT during their residency/fellowship. Among the participants, 44% are willing to continue a long-term involvement. Among the residents, 65.9% consider their practical training insufficient: 56.8% have been supervised for a KT performance during their residency and 86% declare a lack of practical training and had a patient-based learning. Among the residents, 92.1% declare an insufficient theorical training. Among the residents, 33.3% say the schedules of transplantation limit their interest in KT. Among the participants, 34.4% receive a transplant bonus in addition to the usual on-call salary. CONCLUSION: Young urologists wish to continue their involvement in KT activity, but improved theoretical and practical training are essential. In addition, the conditions under which this activity is performed and remunerated are a matter of concern.

Proposal of a standardized training curriculum for open and robot-assisted kidney transplantation.

Standardized training programs for open (OKT) and robot-assisted kidney transplantation (RAKT) remain unmet clinical needs. To fill this gap, we designed a modified Delphi Consensus aiming to propose the first structured surgical curricula for both OKT and RAKT, involving a multispecialty international panel of experts. Two web-based surveys were built drafting two separate series of statements (for OKT and RAKT, respectively). The two surveys were delivered to a panel of 63 experts (for OKT) and 21 experts (for RAKT), selected considering their experience, academic profile and involvement in international associations. Consensus was defined as ≥75% agreement between the responders. Overall, 25/63 (40%) and 14/21 (67%) participated in the first round of the Delphi Consensus for the development of the structured curriculum for OKT and RAKT, respectively. During the second round, the experts reached consensus on all statements, as well as on the domains composing the structure of the training pathway: 1) eligibility criteria for trainees and host centres; 2) theoretical training; 3) simulation; 4) real case observation; and 5) modular training in the operating theatre. To the best of our knowledge, this is the first proposal of a dedicated curriculum for OKT and RAKT grounded on insights from international experts of different specialties. Our proposed curriculum provides the foundation to standardize the education and training in KT across Europe and beyond.

Endourological Management of Ureteral Stricture in Patients with Renal Transplant: A Systematic Review of Literature.

Purpose: To analyze the utility and outcomes of available endourologic options to treat ureteral stricture after kidney transplantation (KT). Methods: A systematic review was carried out for all English language articles from 2000 to 2023 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) standards using EMBASE, MEDLINE, SCOPUS, Google scholar, and Cochrane library. The search term combination for the string was follows: [(Ureteral stricture) OR (ureter stenosis) OR (ureteral stenosis) OR (Stricture ureter) OR (Narrowing ureter) OR (Ureter restriction) OR (ureteral restriction) OR (ureteral narrowing) OR (ureteral obstruction) OR (ureter obstruction) OR (obstructing ureter) OR (obstructive ureter) OR (narrow ureter) OR (ureteral narrow)] AND [(kidney transplant) OR (transplanted kidney) OR (transplant) OR (transplantation)] AND [(management) OR (Robotic) OR (laser) OR (stent) OR (dilatation) OR (dilation) OR (endoscopic) OR (endourological) OR (Urologic) OR (laparoscopic) OR (surgery) OR (treatment)]. Case reports, review articles, animal and laboratory studies were excluded. Risk of bias assessment was conducted using the RoB 2 and ROBINS-I tools. Results: A total of 1102 relevant articles published from 2000 to 2023 were found. After screening of titles and abstracts, a total of 19 articles were included in our systematic review. Ureteral stent/nephrostomy placement, balloon dilatation (ureteroplasty) with or without laser was used as initial approaches whereas follow-up and success rate were analyzed among other parameters. Conclusions: The management of ureteral strictures after KT is challenging and selecting the most appropriate treatment is crucial for successful outcomes. Our review suggests that, an endourologic management is a safe option with good long-term outcomes, especially in short and early strictures.

Graft survival and postoperative complications following orthotopic renal transplantation.

The iliac fossa is the most commonly used site to place the graft in renal transplantation in adults. However, iliac fossa may not be used in various conditions. Thus, orthotopic renal transplantation becomes a viable alternative for these selected patients. Given the technically challenging surgery and limited number of patients, data on the long-term outcomes on this regard are scarce. This narrative review serves as an update on the clinical outcomes after orthotopic renal transplantation, focusing on overall recipient survival and renal graft survival, as well as postoperative complications. We found that studies to date showed a comparable survival rate in both recipients and renal grafts in the postoperative follow-up period after orthotopic renal transplantation with a lower complication rate compared to the published data on heterotopic renal transplantation. The results of our review may encourage transplant centers to reevaluate their policies to consider orthotopic renal transplantation as an alternative technique in cases where heterotopic kidney transplantation is not possible.

Psychological Impact of Living Kidney Donation: A Systematic Review by the EAU-YAU Kidney Transplant Working Group.

We performed a systematic literature review of the psychological impact on donors of living kidney donation. We conducted a literature review in PubMed/Medline according to PRISMA guidelines which included both qualitative (based on interviews) and quantitative studies (based on standardized questionnaire). There were 15 quantitative studies and 8 qualitative studies with 2,732 donors. Given that the methodologies of qualitative and quantitative studies are fundamentally different, we narratively synthetized results of studies according to four axes: quality of life, anxiety/depression, consequences of donation on the donor/recipient relationship, overall satisfaction and regret. The quantitative studies reported that donor quality of life remained unchanged or improved. Donor regret rates were very low and donor-recipient relationships also remained unchanged or improved. Qualitative studies reported more complex donation experiences: one can regret donation and still decide to recommend it as in a social desirability bias. In both study types, donor-recipient relationships were closer but qualitative studies reported that post-donation rebonding was required. The qualitative studies therefore highlighted the psychological complexity of donation for donors, showing that living donation impacts the donor's life whether it is successful or not. A better understanding of the impact of donation on donors could provide better care for donors.

Robot-Assisted Radical Prostatectomy in Renal Transplant Recipients: A Systematic Review.

Robot-assisted radical prostatectomy (RARP) has been shown to achieve excellent oncological outcomes with a low rate of complications in patients with prostate cancer. However, data on RARP in renal transplant recipients (RT) are dispersed. A literature search was conducted through April 2023 using PubMed/Medline, Embase and Web of Science databases. The primary aim was to evaluate the safety, oncologic and clinical outcomes of RARP in RT recipients. The secondary aim was to identify surgical technique modifications required to avoid iatrogenic damage to the transplanted kidney. A total of 18 studies comprising 186 patients met the inclusion criteria. Age at the time of treatment ranged 43-79 years. Biopsy results showed a high prevalence of low- and intermediate-risk disease. Operative time ranged between 108.3 and 400 mins, while estimated blood loss ranged from 30 to 630 mL. Length of hospital stay ranged from 3 to 6 days whereas duration of catheterization was between 5 and 18 days. Perioperative complication rate was 17.1%. Overall positive surgical margin rate was 24.19%, while biochemical recurrence was observed in 10.21% (19/186 patients). Modifications to the standard surgical technique were described in 13/18 studies. Modifications in port placement were described in 7/13 studies and performed in 19/88 (21.6%) patients. Surgical technique for the development of the Retzius space was reported in 13/18 studies. Data on lymphadenectomy were reported in 15/18 studies. Bilateral lymphadenectomy was described in 3/18 studies and performed in 4/89 (4.5%) patients; contralateral lymphadenectomy was reported in 7/18 studies and performed in 41/125 (32.8%) patients. RARP in RTRs can be considered relatively safe and feasible. Oncological results yielded significantly worse outcomes in terms of PSM and BCR rate compared to the data available in the published studies, with an overall complication rate highly variable among the studies included. On the other hand, low graft damage during the procedure was observed. Main criticisms came from different tumor screening protocols and scarce information about lymphadenectomy techniques and outcomes among the included studies.

Effect of Recipient Body Mass Index on Kidney Transplantation Outcomes: A Systematic Review and Meta-analysis by the Transplant Committee from the French Association of Urology.

CONTEXT: The impact of recipient obesity on kidney transplantation (KT) outcomes remains unclear. OBJECTIVE: The aim of this study was to perform a systematic review and meta-analysis to appraise all available evidence on the outcomes of KT in obese patients (body mass index [BMI] ≥30 kg/m2) versus nonobese patients (BMI <30 kg/m2). EVIDENCE ACQUISITION: A systematic review and meta-analysis was performed. Search was conducted in the MEDLINE OvidSP, Web of Science, Google Scholar, Embase, and Cochrane databases to identify all studies reporting the outcomes of KT in obese versus nonobese recipients. EVIDENCE SYNTHESIS: Fifty-two articles met the inclusion criteria. Delayed graft function and surgical complications were significantly higher in obese recipients (delayed graft function: relative risk [RR]: 1.44, 95% confidence interval [CI]: 1.32-1.57, p < 0.01; surgical complications: RR: 1.74, 95% CI: 1.36-2.22, p < 0.0001). Five-year patient survival (RR: 0.96, 95% CI: 0.92-1.00, p = 0.01), 10-yr patient survival (RR: 0.90, 95% CI: 0.84-0.97, p = 0.006), and 10-yr graft survival (RR: 0.87, 95% CI: 0.79-0.96, p = 0.01) were significantly inferior in the obese group. CONCLUSIONS: KT in obese recipients was associated with lower patient and graft survival, and higher delayed graft function, acute rejection, and medical and surgical complications than nonobese recipients. In the current situation of organ shortage and increasing prevalence of obesity, ways to optimize KT in this setting should be investigated. PATIENT SUMMARY: Compared with nonobese population, kidney transplantation in obese recipients has inferior patient and graft survival, and higher medical and surgical complications.

Effectiveness of endourological management of ureteral stenosis in kidney transplant patients: EAU-YAU kidney transplantation working group collaboration.

PURPOSE: Ureteral stenosis (US) in kidney transplant (KT) recipients is associated with poorer long-term graft survival. Surgical repair is the standard of care, and endoscopic treatment represents an alternative for stenosis < 3 cm. We aimed to determine the effectiveness and safety of endourological management of US in KT patients and predictors of failure. METHODS: A retrospective multicenter study was conducted in four European referral centers, including all KT patients with US managed endoscopically between 2009 and 2021. Clinical success was defined as the absence of upper urinary tract catheterization, surgical repair or transplantectomy during follow-up. RESULTS: A total of 44 patients were included. The median time to US onset was 3.5 months (IQR 1.9-10.8), the median length of stricture was 10 mm (IQR 7-20). Management of US involved balloon dilation and laser incision in 34 (79.1%) and 6 (13.9%) cases, respectively, while 2 (4.7%) received both. Clavien-Dindo complications were infrequent (10%); only one Clavien ≥ III complication was reported. Clinical success was 61% at last follow-up visit (median = 44.6 months). In the bivariate analysis, duckbill-shaped stenosis (vs. flat/concave) was associated with treatment success (RR = 0.39, p = 0.04, 95% CI 0.12-0.76), while late-onset stenosis (> 3 months post KT) with treatment failure (RR = 2.00, p = 0.02, 95% CI 1.01-3.95). CONCLUSIONS: Considering the acceptable long-term results and the safety of these procedures, we believe that the endoscopic treatment should be offered as a first-line therapy for selected KT patients with US. Those with a short and duckbill-shaped stenosis diagnosed within 3 months of KT seem to be the best candidates.

MHC Class I Masking to Prevent AMR in a Porcine Kidney Transplantation Model in Alloimmunized Recipients.

Presensitized patients awaiting a kidney transplant have a lower graft survival and a longer waiting time because of the limited number of potential donors and the higher risk of antibody-mediated rejection (AMR), particularly in the early posttransplant period, because of preformed donor-specific antibodies binding major histocompatibility complex (MHC) molecules expressed by the graft endothelium followed by the activation of the complement. Advances in kidney preservation techniques allow the development of ex vivo treatment of transplants. We hypothesized that masking MHC ex vivo before transplantation could help to prevent early AMR in presensitized recipients. We evaluated a strategy of MHC I masking by an antibody during ex vivo organ perfusion in a porcine model of kidney transplantation in alloimmunized recipients. Methods: Through the in vitro calcein-release assay and flow cytometry, we evaluated the protective effect of a monoclonal anti-swine leukocyte antigen class I antibody (clone JM1E3) against alloreactive IgG complement-dependent cytotoxicity toward donor endothelial cells. Kidneys perfused ex vivo with JM1E3 during hypothermic machine perfusion were transplanted to alloimmunized recipients. Results: In vitro incubation of endothelial cells with JM1E3 decreased alloreactive IgG cytotoxicity (mean complement-dependent cytotoxicity index [% of control condition] with 1 µg/mL 74.13% ± 35.26 [calcein assay] and 66.88% ± 33.46 [cytometry]), with high interindividual variability. After transplantation, acute AMR occurred in all recipients on day 1, with signs of complement activation (C5b-9 staining) as soon as 1 h after transplantation, despite effective JM1E3 binding on graft endothelium. Conclusions: Despite a partial protective effect of swine leukocyte antigen I masking with JM1E3 in vitro, ex vivo perfusion of the kidney with JM1E3 before transplantation was not sufficient alone at preventing or delaying AMR in highly sensitized recipients.

Impact of newly diagnosed prostate cancer at time of evaluation for renal transplantation.

Systematic screening for prostate cancer is widely recommended in candidates for renal transplant at the time of listing. There are concerns that overdiagnosis of low-risk prostate cancer may result in reducing access to transplant without demonstrated oncological benefits. The objective of the study was to assess the outcome of newly diagnosed prostate cancer in candidates for transplant at the time of listing, and its impact on transplant access and transplant outcomes according to treatment options. This retrospective study was conducted over 10 years in 12 French transplant centers. Patients included were candidates for renal transplant at the time of prostate cancer diagnosis. Demographical and clinical data regarding renal disease, prostate cancer, and transplant surgery were collected. The primary outcome of the study was the interval between prostate cancer diagnosis and active listing according to treatment options. Overall median time from prostate cancer diagnosis to active listing was 25.0 months [16.4-40.2], with statistically significant differences in median time between the radiotherapy and the active surveillance groups (p = .03). Prostate cancer treatment modalities had limited impact on access and outcome of renal transplantation. Active surveillance in low-risk patients does not seem to compromise access to renal transplantation, nor does it impact oncological outcomes.

Postoperative surgical complications after pediatric kidney transplantation in low weight recipients (<15 kg): a systematic review.

PURPOSE OF REVIEW: Kidney transplantation in low-weight recipients (<15 kg) is a challenging surgery with special characteristics. We proposed to perform a systematic review to determine the postoperative complication rate and the type of complications after kidney transplantation in low-weight recipients (<15 kg). The secondary objectives were to determine graft survival, functional outcomes, and patient survival after kidney transplantation in low-weight recipients. METHODS: A systematic review was performed according to preferred reporting items for systematic reviews and meta-analyses. Medline and Embase databases were searched to identify all studies reporting outcomes on kidney transplantation in low-weight recipients (<15 kg). RESULTS: A total of 1254 patients in 23 studies were included. The median postoperative complications rate was 20.0%, while 87.5% of those were major complications (Clavien ≥3). Further, urological and vascular complications rates were 6.3% (2.0-11.9) and 5.0% (3.0-10.0), whereas the rate of venous thrombosis ranged from 0 to 5.6%. Median 10-year graft and patient survival were 76 and 91.0%. SUMMARY: Kidney transplantation in low-weight recipients is a challenging procedure complicated by a high rate of morbidity. Finally, pediatric kidney transplantation should be performed in centers with expertise and multidisciplinary pediatric teams.