Is Lower Pole Access Safer for Ultrasound-Guided Supine Percutaneous Nephrolithotomy?

INTRODUCTION Ultrasound (US) guided supine percutaneous nephrolithotomy (PCNL) is increasingly being adopted. The aim of this study is to assess the safety and efficacy of lower versus non-lower pole access in supine US-guided PCNL.

METHODS This study is a retrospective cohort analysis of 228 patients who underwent single access US-guided supine PCNL between March 2023 and June 2024 and were categorized into lower (n=162), interpolar (n=42) and upper pole (n=21) access categories. Baseline demographics, stone characteristics and intraoperative details were analyzed and compared between the groups. Safety outcomes, including 30-day postoperative total and major complications (based on Clavien-Dindo classification), as well as pain scores, were compared between lower pole access (LPa) and non-LPa access.

RESULTS Baseline clinical and stone characteristics were comparable between the groups. Non-LPa was more frequently performed on the right side (p=0.04), above 12th rib (p<0.001), into a posterior calyx (p=0.004), and more often followed by stent placement (p=0.01). Major complications occurred in 14% of the patients with upper pole access compared to 2% with LPa (p=0.03) and 5% with interpolar. Additionally, the LPa group had lower rates of total complications compared to upper pole and interpolar (11% vs 19% and 22% respectively, p=0.05). There were two visceral injuries in the interpolar group. VAS pain scores at the recovery room were not different between the groups.

CONCLUSION When performing US-guided supine PCNL, LPa has a superior safety profile, resulting in fewer major and total complications compared to non-LPa.