Localization of pulmonary nodules before thoracoscopic surgery: value of percutaneous staining with methylene blue

Video-assisted thoracic surgery (VATS) is a new procedure that makes it possible to see the intrathoracic organs and to resect pulmonary nodules without thoracotomy. Preoperative localization of small nodules that may not be visible or palpable during VATS is desirable. Percutaneous placement of spring hookwires is widely used to localize pulmonary nodules before VATS; infrequently, the adjacent lung parenchyma is also stained with methylene blue. The purpose of this study was to evaluate the effectiveness of methylene blue staining of pulmonary nodules without placement of a hookwire.

Fifteen pulmonary nodules in 15 patients were localized preoperatively under CT guidance by using techniques identical to those for CT-guided fine-needle aspiration of pulmonary nodules. Approximately 0.3 ml of methylene blue dye was injected into the nodule with a 22-gauge Chiba needle to stain the nodule, the needle pathway, and the visceral pleura. In two patients, a hookwire also was placed. All patients had solitary nodules in which transbronchial or transthoracic biopsy had been unsuccessful. The mean nodule diameter was 16 mm (range, 8-33 mm), and the mean distance to the nearest pleural surface was 10 mm (range, 0-21 mm). The localization procedure required a mean of 32 min (range, 18-47 min).

All 15 nodules were stained successfully either in the center or within the margins; the two hookwires were found to be displaced. In three cases, pulmonary hemorrhage occurred as a complication of the percutaneous staining procedure: in one case, subsequent conversion to thoracotomy was necessary owing to pulmonary hemorrhage and additional pleural bleeding during VATS, which resulted from puncture with a trocar directly into the pleural adhesions. Anticipated complications, such as pneumothorax, occurred in five patients; one patient had pleuritic pain, but none required treatment. In one patient, conversion to thoracotomy was done so that an adenocarcinoma could be treated by means of a lobectomy. In two others, thoracotomy was done because of problems with technical devices.

Percutaneous staining of pulmonary nodules is an accurate technique for localizing nodules before VATS. The procedure is easily and safely performed, and it obviates wire-related complications, such as severe pleuritic pain.