Supine versus Prone Percutaneous Nephrolithotomy for Complex Stones: A Multicenter Randomized Controlled Trial

Area of Science:

• Urology
• Nephrology
• Surgical Innovation

Background:

• Percutaneous nephrolithotomy (PCNL) is a key procedure for complex kidney stones.
• Evidence comparing supine (SUP) and prone (PRO) PCNL positions for complex stones is limited.
• Optimizing PCNL outcomes requires evaluating positional variations.

Purpose of the Study:

• To compare the efficacy and safety of supine versus prone positioning during PCNL for complex kidney stones.
• To assess the noninferiority of supine PCNL compared to prone PCNL regarding stone-free rates.
• To evaluate operative time and complication rates between the two positions.

Main Methods:

• A noninferior randomized controlled trial adhering to CONSORT criteria.
• Inclusion of adult patients (over 18) with complex kidney stones.
• Comparison of supine (Barts flank-free modified position) and prone PCNL, keeping other surgical parameters identical.
• Primary outcome: success rate on postoperative day 1; Secondary outcome: final stone-free rate (SFR) at 90 days.
• Noninferiority margin of 15% and statistical significance set at p <0.05.

Main Results:

• 112 patients were randomized with comparable demographics.
• Similar success rates on postoperative day 1 (SUP: 62.5% vs. PRO: 57.1%, p=0.563).
• Similar final stone-free rates at 90 days (SUP: 55.4% vs. PRO: 50.0%, p=0.571).
• Supine PCNL demonstrated significantly shorter operative times (117.9 min vs. 147.6 min, p <0.001).
• Prone PCNL showed a higher rate of Clavien ≥3 complications (14.3% vs. 3.6%, p=0.045).

Conclusions:

• Neither supine nor prone positioning significantly impacts success rates for PCNL in complex kidney stones.
• Both supine and prone PCNL positions are viable options for treating complex kidney stones.
• Supine PCNL may be associated with a lower incidence of high-grade complications and reduced operative time.