Abstract
Small lung tumors with ground glass opacity (GGO) are often not palpable during surgery. Therefore, identifying and localizing these lesions is a major challenge in the field of general thoracic surgery. To date, a number of strategies for detecting such lesions have been reported, although each has advantages and disadvantages. Intraoperative ultrasound and the Endofinger are non-invasive tools for isolating small lung tumors, although the accuracy of these devices for identifying GGO lesions is controversial. Reported preoperative lung marking techniques using percutaneous CT-guided needle puncture include the placement of a hook wire and injection of dye or Lipiodol®. Although these techniques are relatively concise, the number of areas suitable for percutaneous needle puncture is anatomically limited, and there are concerns regarding complications, such as pneumothorax, apparatus dislodgement (especially the hook wire) and potentially fatal air embolism. Peribronchial marking techniques include the injection of dye, barium or Lipiodol. These strategies are considered to be relatively safe, although, if marking is conducted under CT guidance, the setup may be troublesome and excessive radiation exposure for the bronchoscopist is a problem. Recent advances in virtual bronchoscopy may overcome these limitations. We recently reported a novel strategy, termed virtual-assisted lung mapping (VAL-MAP), which is an extension of the bronchoscopic technique. In VAL-MAP, multiple markings are made on the lung surface by bronchoscopically injecting dye under fluoroscopy with the guidance of virtual bronchoscopy. These markings provide " geometric information" on the lung surface. Beyond the conventional concept of " lung marking", VAL-MAP is expected to play a role as an intraoperative navigation system in the field of general thoracic surgery by allowing the surgeon to set precise resection lines in patients undergoing lung wedge resection and/or complex segmentectomy.
