Endobronchial valves are a potential alternative to lung volume reduction surgery for advanced emphysema. The greatest improvements in pulmonary function are seen in patients with complete pulmonary fissures, as determined by computed tomography (CT). However, the accuracy of CT to predict completeness of pulmonary fissures has not been compared with the reference standard of direct observation during thoracic surgery.

To determine the accuracy of CT scans to predict completeness of pulmonary fissures.

We conducted a double-blind, prospective trial in which completeness of pulmonary fissures was evaluated by direct observation during thoracic surgery. Preoperative CT scans were independently reviewed by two dedicated thoracic radiologists and completeness of the fissures was recorded and compared with intraoperative findings.

The fissures of 46 patients were evaluated. The positive predictive value of CT scan to detect a complete fissure was 100% for the right major fissure and 75% for the left fissure, but only 33% for the right minor fissure. CT scans had a negative predictive value of 29% in evaluation of the right major fissure.

CT scans overestimate completeness of the right minor fissure and underestimate completeness of the right major fissure. These findings may have implications for the use of CT scans to select patients for endobronchial valve insertion.