Predictors of surgical complications of nephrectomy for urolithiasis

OBJECTIVES: Nephrectomy due to stone disease may be a challenging procedure owing to the presence of significant inflammation and infection, involving high complication rate. The objective of our study was to identify predictors for complications of nephrectomy for urolithiasis. PATIENTS AND METHODS: A retrospective review of 149 consecutive patients > 18y submitted to simple nephrectomy for urolithiasis from January 2006 to July 2012 was performed. Clinical data, computed tomography findings and pathology report were analyzed. Postoperative complications were categorized based on Clavien - Dindo classification. Logistic multivariate regression models assessed the predictors for surgical complications of nephrectomy for urolithiasis. RESULTS: Eighty-three (55.7%) patients were submitted to laparoscopic nephrectomy and 66 (44.2%) to open procedure. Conversion to open surgery was necessary in 19.2% (16 / 83). On univariable analysis, higher preoperative chronic kidney stage (p = 0.02), Charlson comorbidity index ≥ 2 (p = 0.04), higher ASA score (p = 0.001), urgency due to sepsis (p = 0.01), kidney size ≥ 12 cm (p = 0.006), renal and perirenal abscess (p = 0.004 and 0.002 respectively) and visceral adhesion (p = 0.04) were associated with Clavien - Dindo score > 1. On multivariate analysis, higher ASA score (p = 0.01), urgency due to sepsis (p = 0.03), kidney size ≥ 12 cm (p = 0.04) and preoperative abscess (p = 0.04) remained significantly associated with complications. End - stage renal disease with dialysis was needed post - operatively in 3.4% (5 / 144) of patients. CONCLUSIONS: We identified that higher ASA score, urgency due to sepsis, kidney size ≥ 12 cm and preoperative abscess were associated with Clavien - Dindo score > 1.