Association Between Preoperative Hydronephrosis and Perioperative Outcomes Among Patients Undergoing Percutaneous Nephrolithotomy: A Single-Center Prospective Cohort Study

Abstract

Background: Staghorn calculi are complicated renal stones that are frequently linked to hydronephrosis, a parameter that can have a major impact on the results of surgery. Percutaneous nephrolithotomy (PCNL) is widely recognized as the gold standard for treating large kidney stones and staghorn calculi. Data on the effect of preoperative hydronephrosis on PCNL perioperative outcomes is still limited.

Objective: This study aimed to investigate the association between preoperative hydronephrosis and perioperative outcomes among patients undergoing PCNL in a tertiary government hospital in Manila.

Methods: A single-center prospective cohort study was conducted, involving 90 patients diagnosed with staghorn calculi and scheduled for elective PCNL. Patients were categorized into two groups based on the presence or absence of moderate-to-severe hydronephrosis as determined by preoperative imaging. Perioperative outcomes, including total operative time, access time, lithotripsy time, and perioperative complications such as bleeding and sepsis, were evaluated. Data were analyzed using linear and logistic regression models to assess associations between hydronephrosis and perioperative outcomes.

Results: The presence of hydronephrosis was associated with a statistically significant reduction in access time (p = 0.036), likely due to the dilation of renal structures facilitating easier entry. However, hydronephrosis was linked to a borderline significant reduction in lithotripsy rate (p = 0.051), indicating potential challenges in stone fragmentation. No significant association was found between hydronephrosis and total operative time or perioperative complications, such as bleeding and sepsis.

Conclusion: While hydronephrosis may make kidney access and other technical aspects of PCNL easier, it may also make stone fragmentation more difficult. Larger stone size and stone location were significant predictors of longer operative times and slower lithotripsy rates, underscoring their critical role in surgical outcomes.