Multicenter analysis of postoperative CT findings after percutaneous nephrolithotomy: Defining complication rates

Objectives To perform a multi-institutional study to characterize CT-detected complications after PNL. Computed tomography (CT) is commonly performed after percutaneous nephrolithotomy (PNL). One benefit of this imaging modality is the detection of procedure-related complications. Presently, the incidence of such complications is not well-defined. Patients and Methods PNL procedures performed at 5 stone referral centers between July 2007 and June 2008 were reviewed. All patients undergoing CT within 24 hours after surgery were selected for further analysis. All CT studies were reviewed by a staff radiologist. Results One-hundred ninety-seven patients satisfied the study inclusion criteria. A body mass index >30 was present in 27.5% of patients. Treated stone burden was staghorn in 70 (35.5%), >2 cm in 72 (36.5%), and <2 cm in 55 (28%). Six treated renal units (3%) were ectopic; 45.4% of calculi were predominantly lower pole. Thoracic complications encountered were atelectasis in 88 (44.7%), pleural effusion in 17 (8.6%), pneumothorax in 3 (1.5%), hemothorax in 2 (1%), and hydrothorax in 1 (0.5%). Renal complications were perinephric hematoma in 15 (7.6%), collecting system perforation in 4 (2%), subcapsular hematoma in 3 (1.5%), urinoma in 2 (1%), and pseudoaneurysm in 1 (0.5%). There was 1 trans-splenic nephrostomy without splenic hematoma. No injuries to hollow viscera were detected. Two patients (1%) were found to have ascites. Conclusions Major post-PNL complications detected by CT are uncommon, and when encountered, they are generally amenable to conservative management.