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

Current Perspectives on Endourological Ex Vivo Stone Interventions in Kidney Transplantation: A Systematic Review

OBJECTIVE

To conduct a systematic review (SR) of literature to assess the existing evidence concerning the success and complications of endourological ex vivo stone surgeries.

METHODS

Eligible studies for inclusion focused on investigating the success and/or complications related to endourological ex vivo surgeries in donors with nephrolithiasis. A SR was undertaken in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The search included databases of Web of Science, PubMed, and Scopus and only article in English were included. Studies published between 2002 and 2023 included in this SR.

RESULTS

After screening 1726 abstracts, this SR included 16 studies with a total of 209 patients. The mean stone size was 5.6 mm and majority of kidneys contained single stones, located in the lower calyx. After ex vivo endourological stone surgeries, the average stone-free rate was found to be 95.4%. The mean duration of ex vivo surgery was 17.3 minutes. Regarding intraoperative complications, two patients (1%) experienced mucosal injuries during pneumatic lithotripsy. As for postoperative complications, two patients (1%) experienced vascular complications. In terms of urological complications, hematuria was observed in 24 patients (11.5%), while one patient (0.5%) experienced clot formation in renal pelvis. Seven patients (3.3%) had urinary tract infections, and three patients (1.4%) developed urolithiasis during the follow-up. Additionally, one patient (0.5%) experienced complete occlusion of ureteroneocystostomy and required revision.

CONCLUSION

Given the advancements in current technology and techniques, endourological ex vivo stone surgeries are increasingly recognized as an effective and safe option for donors with nephrolithiasis.

TRIAL REGISTRATION

This systematic review was registered under the protocol registration number CRD42024538384/PROSPERO.

URS for de-novo urolithiasis after kidney transplantation: a systematic review of the literature

INTRODUCTION

There is a gap in the available literature and guidelines concerning the optimal approach for treating allograft stones, which currently include external shockwave lithotripsy, ureteroscopy and laser lithotripsy, or percutaneous nephrolithotomy. The objective of this systematic review was to evaluate the safety and effectiveness of URS as a treatment option for patients in this scenario.

EVIDENCE ACQUISITION

A comprehensive search of the literature was conducted until August 2023. Only original articles written in English were considered for inclusion. This review has been registered in PROSPERO (registration number CRD42023451154).

EVIDENCE SYNTHESIS

Eleven articles were included (122 patients). The mean age was 46.9±9.5 years, with a male-to-female ratio of 62:49. The preferred ureteral reimplantation technique was the Lich-Gregoire. The mean onset time was 48.24 months. Acute kidney injury, urinary tract infections and fever were the most frequent clinical presentations (18.3% each), followed by hematuria (10%). The mean stone size measured 9.84 mm (±2.42 mm). Flexible URS was preferred over semirigid URS. The stone-free rate stood at 83.35%, while the overall complication rate was 13.93%, with six (4.9%) major complications reported. Stones were mainly composed of calcium oxalate (42.6%) or uric acid (14.8%). Over an average follow-up period of 30.2 months, the recurrence rate was 2.46%. No significant changes in renal function or allograft loss were reported.

CONCLUSIONS

URS remains an efficient choice for addressing de-novo allograft urolithiasis, offering the advantage of treating urinary stones with a good SFR and a low incidence of complications. Procedures should be performed in an Endourology referral center.

Ureteroureterostomy With Near-Infrared Ray Catheter in a Kidney Transplant

Transplant ureteral stenosis (US) is a complication of kidney transplantation (KT) that sometimes adversely affects kidney function. Endoscopic treatment may be selected as the initial treatment; however, the recurrence rate is high. Ureteral reconstruction is necessary as a secondary treatment, but it is often difficult to identify the transplanted ureter due to reoperation; therefore, transplanted ureter and renal arteriovenous injury are intraoperative complications that should be noted. The Near-Infrared Ray Catheter (NIRC™) fluorescent ureteral catheter (NIRFUC) fluoresces by illuminating near-infrared rays, facilitating the identification of intraoperative ureteral locations. Herein, we report the case of a 34-year-old woman who developed US following KT. She underwent balloon dilation for transplant US, but the stenosis recurred; therefore, she underwent transplant ureteral auto-ureteral anastomosis. Although it was difficult to identify and detach the transplanted ureter owing to adhesions, the use of NIRFUC facilitated the identification of the ureter in the surgical field and enabled safe end-side anastomosis between the transplanted ureter and the autologous ureter. In conclusion, although there is no consensus on the best method for complex transplantation-related US cases, NIRFUC may be used to safely identify and perform surgeries on the ureter.

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.