Impact of ureteroscopy on renal function in solitary kidneys: a systematic review

This study aimed to assess ureteroscopy's impact on renal function in patients with a solitary kidney (SK), where nephron preservation is paramount. With the rising prevalence of SKs due to congenital anomalies or acquired conditions, understanding the safety profile of ureteroscopy, particularly its effects on renal function, seems essential.

A literature search following PRISMA guidelines was conducted to identify reports published until May 2024. Eligible studies were included if they focused on ureteroscopy in SK patients and reported renal function outcomes. Data extraction and bias assessment were performed using standardized protocols as Joanna Briggs Institute's checklist for non-randomized studies. Renal function changes (eGFR or serum creatinine), complications, and follow-up data were analyzed. Outcomes included acute kidney injury (AKI) and persistent renal function deterioration, as defined by the Collège-Français-des-Enseignants-d'Urologie (CFEU) criteria.

15 studies were included, involving 615 patients. The renal function remained stable in ten (67%) of them, with no significant AKI reported beyond one-month post-procedure. Two studies(13%) reported improved renal function, while three(20%) observed trends toward improvement. The mean stone size ranged from 6 to 37.5 mm, with an operative time of 50-117 min. Complications were reported in 22% of patients, predominantly low-grade(Clavien I-II). Severe complications were rare(0.3% and 2%, respectively). The mean follow-up period was 7.5 months.

Ureteroscopy appears to be a viable and safe option for SK patients, presenting minimal risk of long-term renal deterioration. However, only short-term and heterogenous data are available. Future research with standardized methodologies and long-term evaluations are required to validate these findings.