A Comparison of Postoperative Urological Infection Rates Between Supine and Prone Positions During Percutaneous Nephrolithotomy

Objective: Urological infection is a significant complication following percutaneous
nephrolithotomy (PCNL), which can be performed in supine or prone positions, but
its impact on infection rates remains debated. This study compares postoperative uro-
logical infection rates between supine and prone PCNL and identifies associated risk
factors.

Methods: A retrospective study was conducted on 290 patients who underwent PCNL
between January 2014 and August 2023 in the Thammasat University Hospital. Patients
were allocated into 2 groups in a 1 : 2 ratio, with 87 patients in the supine group and
203 patients in the prone group. Statistical analysis included t-tests, Mann–Whitney U
tests, Fisher’s exact test, and logistic regression models.

Results: Postoperative infection rates were significantly lower in the supine group,
including fever (33.3% vs. 62.1%, P < .001), UTI (11.5% vs. 32.5%, P < .001), and sepsis
(6.9% vs. 17.2%, P = .021). Multivariable analysis identified positive preoperative urine
culture (RR 4.41, P < .001) and prone positioning (RR 4.38, P = 0.004) as independent
risk factors. The operative time was significantly shorter in the supine group (103.9 ±
42.6 vs. 116.3 ± 38.9 min, P = .016). Stone-free rates and blood loss were comparable,
whereas pleural complications were higher in the prone group (6.4% vs. 0%, P = .016).

Conclusion: Supine PCNL is associated with significantly lower postoperative infec-
tion rates, shorter operative times, and reduced pleural complications compared to
the prone position. These findings support supine PCNL as a safer and equally effective
alternative management for renal calculi.

Cite this article as: Batratanakij N, Liwrotsap!C, Tangpaitoon T. A comparison of postoperative urological infection rates between supine and prone positions during percutaneous nephrolithotomy. Urol Res
Pract. 2025;51(1):22-26.