Positioning during PCNL for complex kidney stones may not impact the success rates

Brazil: In a new study led by Rodrigo Perrella, it was found that positioning in percutaneous nephrolithotomy (PCNL) for complicated kidney stones had no effect on success rates; hence, any posture may be appropriate. However, the supine posture (SUP) may be associated with a decreased risk of high-grade complications. The findings of this study were published in the Journal of Urology.

There is a dearth of high-quality evidence comparing supine to prone percutaneous nephrolithotomy for the treatment of complicated stones. The purpose of this study was to compare the results of supine (SUP) and prone (PRO) PCNL.

In this study, the CONSORT (Consolidated Standards for Reporting Trials) criteria were used to conduct a noninferior randomized controlled trial. Patients over the age of 18 with complicated stones met the inclusion criteria. SUP was conducted in the modified Barts flank-free posture. Except for the placement, all of the surgical factors were the same. The primary outcome was the difference in success rates between groups on the first postoperative day (POD1). The difference in the stone-free rate (SFR) on the 90th postoperative day was the secondary endpoint (final SFR). The non inferiority margin was set at 15%. The groups were compared in terms of demographic, operational, and safety characteristics. The statistical significance level was chosen at p 0.05.

The results of this study stated as follow:

1. In all, 112 individuals were randomized, and their demographics were comparable. POD1 success rates were comparable (SUP: 62.5% versus PRO: 57.1%).

2. The recorded difference (5.4%) was less than the preset limit.

3. The final SFRs were likewise comparable (SUP: 55.4% versus PRO: 50.0%).

4. SUP had a shorter operational time (meanSD 117.939.1 minutes vs 147.638.8 minutes, p 0.001), although PRO had a higher risk of Clavien 3 complications (14.3% vs 3.6%).

In conclusion, urologists should be aware that both procedures can be used to treat complicated stones. The surgical method should ultimately be determined by the surgeon's discretion and the placement of the stone.

Reference: Rodrigo Perrella, Fabio C. Vicentini, Eliane D. Paro, Fabio C. M. Torricelli, Giovani S. Marchini, Alexandre Danilovic, Carlos A. Batagello, Priscila K. V. Mota, Daniel B. Ferreira, David J. Cohen, Claudio B. Murta, Joaquim F. A. Claro, Guido Giusti, Manoj Monga, William C. Nahas, Miguel Srougi, and Eduardo Mazzucchi. Supine versus Prone Percutaneous Nephrolithotomy for Complex Stones: A Multicenter Randomized Controlled Trial. https://doi.org/10.1097/JU.0000000000002291