Benefits and Harms of Benign Prostatic Obstruction Treatments in Renal Transplanted Patients.

CONTEXT: In an increasingly ageing transplant population, timely management of benign prostatic obstruction (BPO) is key to preventing complications that result in graft dysfunction or compromise survival. OBJECTIVE: To evaluate benefits/harms of BPO treatments in transplant patients by reviewing current literature. EVIDENCE ACQUISITION: A computerised bibliographic search of Medline, Embase, and Cochrane databases was performed for studies reporting outcomes on BPO treatments in transplanted patients. EVIDENCE SYNTHESIS: A total of 5021 renal transplants (RTs) performed between 1990 and 2016 were evaluated. BPO incidence was 1.61 per 1000 population per year. Overall, 264 men underwent intervention. The mean age was 58.4 yr (27-73 yr). In all, 169 patients underwent surgery (n = 114 transurethral resection of the prostate [TURP]/n = 55 transurethral incision of the prostate [TUIP]) and 95 were treated with an un-named alpha-blocker (n = 46) or doxazosin (n = 49). There was no correlation between prostate volume and treatment modality (mean prostate size = 26 cc in the surgical group where reported and 48 cc in the medical group). The mean follow-up was 31.2 mo (2-192 mo). The time from RT to BPO treatment was reported in six studies (mean: 15.4 mo, range: 0-156 mo). The time on dialysis before RT was recorded in only three studies (mean: 47.3 mo, range: 0-288 mo). There was a mean improvement in creatinine after intervention from 2.17 to 1.77 mg/dl. A total of 157 men showed an improvement in the International Prostate Symptom Score (from 18.26 to 6.89), and there was a significant reduction in postvoid residual volume in 199 (mean fall 90.6 ml). Flow improved by a mean of 10 ml/s following intervention in 199 patients. Complications included acute urinary retention (4.1%), urinary tract infections (8.4%), bladder neck contracture (2.2%), and urethral strictures (6.9%). The mean reoperation rate was 1.4%. CONCLUSIONS: Current literature is heterogeneous and of low-level evidence. Despite this, alpha-blockers, TUIP, and TURP showed a beneficial increase in the peak urinary flow and reduced symptoms in transplants patients with BPO. Improvement in the mean graft creatinine was noted after intervention. Complications were under-reported. A multicentre comparative cohort study is needed to draw firm conclusions about the ideal treatment for BPO in RT patients. PATIENT SUMMARY: In this report, we looked at the outcomes for transplant patients undergoing medical or surgical management of benign prostatic obstruction. Although the literature was very heterogeneous, we found that medical management and surgery with transurethral resection/incision of the prostate are beneficial for improving urinary flow and bothersome symptoms. We conclude that further prospective studies are required for better clarity about timing and modality of intervention in transplant patients.

Machine learning models in predicting graft survival in kidney transplantation: meta-analysis.

BACKGROUND: The variations in outcome and frequent occurrence of kidney allograft failure continue to pose important clinical and research challenges despite recent advances in kidney transplantation. The aim of this systematic review was to examine the current application of machine learning models in kidney transplantation and perform a meta-analysis of these models in the prediction of graft survival. METHODS: This review was registered with the PROSPERO database (CRD42021247469) and all peer-reviewed original articles that reported machine learning model-based prediction of graft survival were included. Quality assessment was performed by the criteria defined by Qiao and risk-of-bias assessment was performed using the PROBAST tool. The diagnostic performance of the meta-analysis was assessed by a meta-analysis of the area under the receiver operating characteristic curve and a hierarchical summary receiver operating characteristic plot. RESULTS: A total of 31 studies met the inclusion criteria for the review and 27 studies were included in the meta-analysis. Twenty-nine different machine learning models were used to predict graft survival in the included studies. Nine studies compared the predictive performance of machine learning models with traditional regression methods. Five studies had a high risk of bias and three studies had an unclear risk of bias. The area under the hierarchical summary receiver operating characteristic curve was 0.82 and the summary sensitivity and specificity of machine learning-based models were 0.81 (95 per cent c.i. 0.76 to 0.86) and 0.81 (95 per cent c.i. 0.74 to 0.86) respectively for the overall model. The diagnostic odds ratio for the overall model was 18.24 (95 per cent c.i. 11.00 to 30.16) and 29.27 (95 per cent c.i. 13.22 to 44.46) based on the sensitivity analyses. CONCLUSION: Prediction models using machine learning methods may improve the prediction of outcomes after kidney transplantation by the integration of the vast amounts of non-linear data.

Evaluation of the Effectiveness of Interventions on Nephrolithiasis in Transplanted Kidney.

CONTEXT: De Novo nephrolithiasis in renal transplant can have severe consequences since renal transplantation involves a single functioning kidney with medical and anatomical specificities (heterotopic transplantation on iliac vessels, immunosuppressive treatments, and comorbidities). OBJECTIVE: To systematically review all available evidence on the prevalence of de novo nephrolithiasis in renal transplant, presentation, and stone characteristics, and to report in a meta-analysis the efficacy of stone treatments (extracorporeal shock wave lithotripsy [ESWL], medical treatment, percutaneous nephrolithotomy [PCNL], open surgery, and ureteroscopy). EVIDENCE ACQUISITION: Medline, Embase, and the Cochrane Library were searched up to November 2021 for all relevant publications reporting the management of de novo nephrolithiasis in renal allografts. The primary outcome was stone-free rate (SFR) at 3 mo. Secondary outcomes included prevalence, stone characteristics (size, density, and composition), symptoms on presentation, need for drainage, complications, and recurrence. Data were narratively synthesized in light of methodological and clinical heterogeneity, and a meta-analysis was performed for SFR. The risk of bias of each included study was assessed. EVIDENCE SYNTHESIS: We included 37 retrospective studies with 553 patients and 612 procedures; of the 612 procedures 20 were antegrade ureteroscopy, 154 retrograde ureteroscopy, 118 PCNL, 25 open surgery, 155 ESWL, and 140 surveillance/medical treatment. The prevalence of nephrolithiasis in renal transplant was 1.0%. The mean stone size on diagnosis was 11 mm (2-50). The overall SFR at 3 mo was 82%: 96% with open surgery, 95% with antegrade ureteroscopy, 86% with PCNL, 81% with retrograde ureteroscopy, and 75% with ESWL. CONCLUSIONS: De novo nephrolithiasis in renal transplant is an infrequent condition. A high SFR were obtained with an antegrade approach (ureteroscopy, PCNL, and open approach) that should be considered in renal transplant patients owing to the heterotopic position of the renal graft. The choice of technique was correlated with stone size: generally ureteroscopy and ESWL for stones 11-12 mm (mean stone size) versus PCNL and open surgery for 17-25 mm stones. PATIENT SUMMARY: De novo nephrolithiasis in renal transplants is an infrequent situation that can have severe consequences on the function of the renal graft. We evaluated the efficacy of each treatment and noted that antegrade approaches (open surgery, percutaneous nephrolithotomy, and antegrade ureteroscopy) were associated with the highest stone-free rate. As opposed to the management of nephrolithiasis in native kidney, an antegrade approach should be considered more in renal transplant patients.

European Association of Urology Guidelines on Renal Transplantation: Update 2018.

CONTEXT: The European Association of Urology (EAU) panel on renal transplantation (RT) has released an updated version of the RT guidelines. OBJECTIVE: To present the 2018 EAU guidelines on RT. EVIDENCE ACQUISITION: A broad and comprehensive scoping exercise was performed, encompassing all areas of RT guidelines published between January 1, 2007, and May 31, 2016. Databases covered by the search included Medline, Embase, and the Cochrane Libraries. Previous guidelines were updated, and levels of evidence and grades of recommendation were assigned. EVIDENCE SYNTHESIS: It is strongly recommended to offer pure or hand-assisted laparoscopic/retroperitoneoscopic surgery as the preferential technique for living donor nephrectomy. Decisions on the acceptance of a donor organ should not be based on histological findings alone since this might lead to an unnecessarily high rate of discarded grafts. For ureterovesical anastomosis, a Lich-Gregoir-like extravesical technique protected by a ureteral stent is the preferred technique for minimisation of urinary tract complications. It is also strongly recommended to perform initial rejection prophylaxis with a combination therapy comprising a calcineurin inhibitor (preferably tacrolimus), mycophenolate, steroids, and an induction agent (either basiliximab or anti-thymocyte globulin). The long version of the guidelines is available at the EAU website (http://uroweb.org/guidelines). CONCLUSIONS: These abridged EAU guidelines present updated information on the clinical and surgical management of RT for incorporation into clinical practice. PATIENT SUMMARY: The European Association of Urology has released the renal transplantation guidelines. The implementation of minimally invasive surgery for organ retrieval and the latest evidence on transplant surgery as well as on immunosuppressive regimens are key factors for minimisation of rejection and achievement of long-term graft survival.

The Risk of Tumour Recurrence in Patients Undergoing Renal Transplantation for End-stage Renal Disease after Previous Treatment for a Urological Cancer: A Systematic Review.

CONTEXT: Renal transplantation is the gold standard renal replacement therapy in end-stage renal disease owing to its superior survival and quality of life compared with dialysis. When the potential recipient has a history of cancer, the waiting period before renal transplantation is usually based on the Cincinnati Registry. OBJECTIVE: To systematically review all available evidence on the risk of cancer recurrence in end-stage renal disease patients with a history of urological cancer. EVIDENCE ACQUISITION: Medline, Embase, and the Cochrane Library were searched up to March 2017 for all relevant publications reporting oncologic outcomes of urological cancer in patients who subsequently received a transplantation or remained on dialysis. The primary outcome was time to tumour recurrence. Secondary outcomes included cancer-specific and overall survival. Data were narratively synthesised in light of methodological and clinical heterogeneity. The risk of bias of each included study was assessed. EVIDENCE SYNTHESIS: Thirty-two retrospective studies enrolling 2519 patients (1733 dialysed, 786 renal transplantation) were included. For renal cell carcinomas, the risks of recurrence, cancer-specific, and overall survival were similar between transplantation and dialysis. For prostate cancer, most of the tumours had favourable prognoses consistent with nomograms. Studies dealing with urothelial carcinomas (UCs) mainly included upper urinary tract UC in the context of aristolochic acid nephropathy, for which the risks of synchronous bilateral tumour and recurrence were high. Data on testicular cancer were scarce. CONCLUSIONS: Immunosuppression after renal transplantation does not affect the outcomes and natural history of low-risk renal cell carcinomas and prostate cancer. Therefore, the waiting time from successful treatment for these cancers to transplantation could be reduced. Except in the particular situation of aristolochic acid nephropathy, more studies are needed to standardise the waiting period after UC owing to the paucity of data. PATIENT SUMMARY: Renal transplantation does not appear to increase the risk of recurrence of renal carcinoma or the recurrence of low-risk prostate cancer compared with dialysis. More reliable evidence is required to recommend a standard waiting period especially for urothelial and testicular carcinomas.