A proposal for selecting appropriate intersegmental plane identification methods based on tumor characteristics in thoracoscopic segmentectomy.

Identifying the intersegmental plane (ISP) of the target segment is a key step in anatomical segmentectomy. Although multiple methods are available for ISP identification, the most appropriate approach for segmentectomy remains unclear. Traditionally, intersegmental veins or inflation-deflation lines have been used to demarcate the ISP. In the last decade, near-infrared fluorescence imaging combined with intravenous indocyanine green (ICG) injection has become widely used for ISP identification. More recently, an original method using the concave portion of the apical visceral pleura has been introduced as a simple ISP demarcation approach in patients undergoing anterior or apical segmentectomy. Small tumors indicated for segmentectomy have distinct computed tomography (CT) and intraoperative characteristics, such as ground-glass opacity, solid nodules, and features indicating whether the tumor location is detectable or undetectable during surgery. Thus, ISP identification methods should be selected according to these tumor characteristics. In sublobar resection, securing an adequate surgical margin is essential to avoid cancer recurrence. Specifically, determining whether the tumor location is detectable or undetectable during surgery is vital for ensuring an adequate surgical margin. Therefore, in segmentectomy for detectable tumors, approximate ISP identification can be achieved via the ICG method or simple demarcation of apical structures on the lung, because the distance from the tumor can be confirmed to ensure an adequate surgical margin. Conversely, segmentectomy for undetectable tumors requires more precise ISP identification using a combination of the ICG method, intersegmental vein demarcation, and inflation-deflation. In summary, the appropriate combination of intersegmental identification methods should be selected based on specific tumor characteristics.