Sensitivity of chest fluoroscopy compared with chest CT and chest radiography for diagnosing hydropneumothorax in association with percutaneous nephrostolithotomy.

Objectives: Hydropneumothorax (HPTX) is recognized as a potential complication of percutaneous nephrostolithotomy (PCNL), particularly with supracostal access. Postoperative chest radiography (CXR) is routinely used to evaluate the chest after PCNL. We prospectively compared the sensitivity of intraoperative chest fluoroscopy with immediate postoperative portable CXR and postoperative day 1 chest computed tomography (CT) for the detection of pleural fluid.
Methods: A total of 89 consecutive patients (mean age 47.9 +/- 13.3 years; 100 renal units) undergoing PCNL were prospectively evaluated with intraoperative fluoroscopy at the conclusion of the procedure and then with anteroposterior CXR in the postanesthesia care unit and postoperative day 1 noncontrast, thin-cut CT of the kidneys and lung bases. CT imaging of the lung bases comprised the reference standard for detecting pleural fluid.
Results: A total of 104 percutaneous renal accesses in 100 renal units, 60 above and 44 below the 12th rib, were used. In 16 cases (16%), a second-stage procedure was performed to clear residual stone fragments detected on post-PCNL CT. HPTX was detected in 1, 8, and 38 cases by initial fluoroscopy, immediate postoperative CXR, and CT scan, respectively. Intervention was necessary in 7 patients. In 2 patients with fluoroscopic evidence of pleural fluid (1 at the initial PCNL and 1 during second-look flexible nephroscopy), intraoperative pleural drainage was performed percutaneously. In the other 5 patients, intervention was determined by the size of the HPTX on chest CT scan (n = 1) or the presence of symptoms (n = 4). In no case was intervention performed on the basis of the immediate postoperative CXR findings when intraoperative chest fluoroscopy was negative.
Conclusions: Intraoperative chest fluoroscopy during PCNL is sufficient to detect clinically significant HPTXs, and, therefore, routine postoperative CXRs are not necessary. However, a high index of suspicion based on clinical symptoms postoperatively should prompt chest imaging.