Use of India ink during preoperative computed tomography localization of small peripheral undiagnosed pulmonary nodules for thoracoscopic resection.

Background: Computed tomography (CT) scans of the chest permit us to identify a large number of small peripheral, undefined pulmonary lesions that require a diagnosis. Broncoscopy results are generally negative in these cases, and needle aspiration results are often inconclusive owing to poor cytology and false-negative cases. Thoracoscopy is an ideal tool but allows us only to localize lesions that retract the visceral pleura. Our aim in this study was to establish a marking procedure for excising nodules of unknown etiology by injecting India ink on the surface of the lung.

Methods: Since January 2008, eight patients (six men, two women) who had been diagnosed as having a peripheral small pulmonary nodule of unknown etiology were selected for preoperative tattooing under CT guidance to facilitate thoracoscopic wedge resection.

Results: In six cases, thoracoscopy allowed diagnosis and definitive treatment of two benign peripheral nodules and four single metastases from colon carcinoma. In two patients who had been diagnosed to have a primitive non-small-cell lung cancer on frozen section following thoracoscopy, the surgical treatment was concluded with limited lateral thoracotomy and lobectomy with ilomediastinal node dissection.

Conclusions: Our experience suggests that this CT technique, which includes using India ink to label and localize peripheral small pulmonary nodules, is a safe, valid option for marking the lung, thereby facilitating subsequent thoracoscopic resection.