Ultrasonographic evaluation of small nodules in the peripheral lung during video-assisted thoracic surgery (VATS).

OBJECTIVE We examined the possibility of intraoperative ultrasonography during video-assisted thoracic surgery (VATS) to localize and make a qualitative diagnosis of small peripheral pulmonary nodules. METHODS Ultrasonography during VATS and conventional thoractomy was performed on 25 and 18 nodules, respectively, all which were localized in the peripheral lung, were less than 30 mm in diameter and for which there was no definitive diagnosis. RESULTS All 25 nodules, including 10 invisible but palpable and three both invisible and non-palpable, could be localized by ultrasonography during VATS. If nodules were located less than 15 mm from the pleural surface, ultrasonography during VATS could detect nodules 10 mm or less in diameter. The rate of malignant tumors among 11 of 12 pulmonary nodules (91.6%) showing both heterogeneous and ill-defined patterns was significantly higher than 6 of 16 nodules (37.5%) showing both homogeneous and well-defined patterns on ultrasonography. CONCLUSIONS Our study suggested that ultrasonography during VATS is useful for the detection of peripheral pulmonary nodules, even when they are not identified on video images or palpation, and may enable a differential diagnosis between malignant and non-malignant lesions.