Predictors of Postoperative Complications Following Percutaneous Nephrolithotomy: A Prospective Observational Study.

Original Article

Abstract

Background: Percutaneous nephrolithotomy (PCNL) is an established treatment for large and complex renal calculi. Despite advances in surgical and endourological techniques, postoperative complications such as fever, bleeding, urinary leakage, and urosepsis remain important causes of morbidity. Identification of factors associated with these complications may facilitate perioperative risk stratification and improve patient outcomes.

Objective: To determine the incidence of postoperative complications following PCNL and identify clinical, stone-related, and operative factors independently associated with postoperative morbidity.

Methods: This prospective observational study was conducted in the Department of General Surgery, Ziauddin Hospital, Karachi, Pakistan, from January 2025 to January 2026. We enrolled 100 consecutive adult patients undergoing elective PCNL using consecutive non-probability sampling. We recorded demographic characteristics, comorbidities, stone characteristics, laboratory findings, operative variables, and postoperative outcomes. Postoperative complications occurring within 30 days were classified using the Modified Clavien–Dindo Classification. Data were analyzed using IBM SPSS Statistics version 27.0. Continuous variables were expressed as mean ± standard deviation, while categorical variables were presented as frequencies and percentages. We used multivariable logistic regression to identify factors independently associated with postoperative complications. Adjusted odds ratios (AORs) with 95% confidence intervals (CIs) were reported, and a p-value <0.05 was considered statistically significant.

Results: Among 100 patients, 68 (68.0%) were male, and 32 (32.0%) were female, with a mean age of 46.8 ± 12.4 years. Postoperative complications occurred in 23 (23.0%) patients. Fever was the most frequent complication (11.0%), followed by bleeding requiring blood transfusion (7.0%), urinary leakage (3.0%), and urosepsis (2.0%). Patients with complications had significantly larger stones (3.1 ± 0.8 vs. 2.3 ± 0.7 cm; p=0.001) and longer operative duration (102.5 ± 21.6 vs. 81.4 ± 18.7 minutes; p<0.001). Diabetes mellitus, positive preoperative urine culture, multiple access tracts, and estimated blood loss >250 mL were also significantly associated with postoperative complications. Multivariable logistic regression identified diabetes mellitus (AOR=1.96; p=0.021), positive urine culture (AOR=2.15; p=0.018), stone size >3 cm (AOR=2.37; p=0.011), operative duration >90 minutes (AOR=2.84; p=0.002), multiple access tracts (AOR=2.09; p=0.008), and blood loss >250 mL (AOR=2.48; p=0.004) as independently associated factors.

Conclusion: Postoperative complications occurred in 23% of patients undergoing PCNL. Diabetes mellitus, positive preoperative urine culture, larger stone size, prolonged operative duration, multiple access tracts, and greater intraoperative blood loss were independently associated with postoperative complications. Early identification and optimization of high-risk patients, appropriate management of urinary infection, careful assessment of stone burden, and meticulous operative planning may help reduce postoperative morbidity.