How to identify intersegmental planes in performing sublobar anatomical resections.

Pulmonary segmentectomy is a common surgical procedure in thoracic surgery nowadays. Though this technique helps preventing postoperative pulmonary function loss, potential challenges are the management of air leaks and the difficulty of palpating ground-glass components during surgery, as well as how to deal with the intersegmental planes. Several techniques have been proposed for the identification and treatment of the intersegmental planes during sublobar anatomical resections: this review focuses on preoperative planning and workup and intraoperative strategies. Three-dimensional computed tomography bronchography and angiography (3D-CTBA), virtual-assisted mapping (VAL-MAP) using bronchoscopy multi-spot dye marking and three-dimensional computed tomography (3D-CT) are preoperative tools that may facilitate the planning of operation. Inflation-deflation techniques, infrared-fluorescence-enhanced method combined with bronchial and intravenous injection of indocyanine green (ICG) and near-infrared fluorescence (NIF) mapping with ICG have been described as intraoperative strategies to identify the intersegmental plane. The treatment and section of the intersegmental planes is mainly accomplished by stapler and electrocautery or energy devices. The use of staplers reduces postoperative air leaks, bleeding risks and operative time but seems to reduce preserved lung volume, compromising adjacent lung expansion; in addition, higher costs and sometimes non-adequate oncological margins, being a non-anatomical technique have been described. The electrocautery and energy devices allow for a more anatomical and precise dissection maintaining safe oncological margins, with a better lung expansion and so an increased postoperative lung function. Time consuming procedure and frequent requirement of aero-haemostatic tools to treat air and blood leaks are the main drawbacks. In conclusion, there are several methods to identify and treat the intersegmental planes but there are no significant differences between the different tools, therefore the use of one technique rather than another depends overall on surgeon's preference and the location of the segment.