Non-contrast computed tomography after percutaneous nephrolithotomy: Findings and clinical significance

Objective: To describe the post-percutaneous nephrolithotomy (PNL) non-contrast-enhanced computed tomography (NCCT) findings and assessed their clinical significance. NCCT evaluates stone clearance after PNL and also reveals procedure-related changes. Methods: One hundred consecutive patients who underwent PNL were evaluated by NCCT one day post-procedure. Two radiologists analyzed the type and severity of the NCCT findings, which were then statistically analyzed in relation to the patient's clinical course. Results: The patients' mean age was 54 years (range 18-82) and the mean maximal stone diameter was 37 mm (range 15-70). The median operative time was 110 minutes for an immediate stone-free rate of 83%, changing to 94% (P =.073) after a second-look PNL in 11 patients. The post-PNL NCCT findings were hydronephrosis (70%), atelectasis (54%), ipsilateral pleural effusion (52%), paracolic gutter fluid (44%), perinephric hematoma (40%), perinephric fluid (32%), ureteronephrosis (31%), renal swelling (23%), contralateral pleural effusion (22%), residual fragments (RFs) (17%), subcapsular hematoma (10%), and flank hematoma (6%). Univariate analysis revealed a significant association with clinical variables for all NCCT findings except for atelectasis, ureteronephrosis, contralateral pleural effusion, RFs, and flank hematoma. In multivariate analysis, only perinephric fluid (P =.007) and ipsilateral pleural effusion (P =.034) were associated with longer hospitalization, and perinephric fluid with longer recovery (P =.004). The complication rate was 12%, but none were linked with the radiological findings. Conclusion: This work describes the post-PNL NCCT findings and their clinical significance. Perinephric fluid and ipsilateral pleural effusion were found to independently predict longer hospitalization and recovery time.