Non-contrast Computed Tomography After Percutaneous Nephrolithotomy: Findings and Clinical Significance

Abstract

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. 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. 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. 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.