Trans-Inferior-Pulmonary-Ligament Single-Direction Thoracoscopic RS9 Segmentectomy: Application of Stem-Branch Method...

Video-assisted thoracoscopic segmentectomy has become a safe and effective surgical approach for stage IA non-small cell lung cancer.1^,2 Therein, thoracoscopic segmentectomy for the lateral basal segment (S9) is the most technically challenging anatomical segmentectomy.3^-6 Because the target vessels and bronchus are commonly variable and deeply located in the lung parenchyma, it is difficult to expose and correctly identify them through either an interlobar fissure approach or a posterior approach. Meanwhile, tailoring the intersegmental plane is another challenge that is encountered in a VATS S9 segmentectomy.

In this multimedia article, we present a thoracoscopic right S9 segmentectomy following the single-direction strategy through an inferior pulmonary ligament approach, using a novel method named stem-branch to track the target segmental branches along the stem (video).7 The positional relations of the basal segmental vessels and bronchi were preliminarily identified mainly through the high-resolution computed tomography (HRCT). The surgery was initiated through an inferior pulmonary ligament approach. The stems of the basal segmental vein and bronchus were first dissected, followed by dissection of their branches. Then, the target branches were tracked and identified according to the positional relations known via HRCT. Lung parenchyma between S10 and S7 should be divided to facilitate dissection and identification of the basal segmental venous and bronchus branches. After the target vein, bronchus and artery was transected in sequence. The method of inflation-deflation was used to identify the intersegmental plane. Then, stapler-based, three-dimensional tailoring was performed.

The operative time was 1.5 h with an estimated blood loss of 30 ml. The chest tube was removed on postoperative Day 3. The patient was discharged on postoperative Day 4 without any complication. The final pathological finding was minimally invasive adenocarcinoma (pTmiN0M0). The chest X-ray on postoperative Day 1 and HRCT scan on postoperative Month 4 revealed that the residual right lung expended well.

We identified the stem of the basal segmental bronchus, the number of its branches, and the relative locations of them according the preoperative HRCT. During the surgery, we started with dissection of the inferior pulmonary ligament. From the inferior view, the basal bronchus and its branches are located behind the veins. Division of the lung parenchyma between S10 and S7 would facilitate dissection and identification of the basal segmental venous branches during S9 segmentectomy. Because we already know the positional relations of the stem and its branches, the target segmental bronchus can easily be tracked. For the segmental veins, we should follow the principles of reserving uncertain veins, especially the intersegmental veins. The segmental arteries, which are usually accompanied by the segmental bronchus, could be found after transection of the bronchus. Stapling was started from the peripheral and thin parts of the lung and continued, reaching the segmental hilum and thick parts of the lung step-by-step during the intersegmental plane tailoring. For such a complex curved border, tailoring with the stapler alone was not affecting the expansion of the residual lung and causing atelectasis.

Thoracoscopic segmentectomy for S9 can be performed successfully through the inferior pulmonary ligament approach by using the method of stem-branch for tracking anatomy based on HRCT and method of complete stapler-based tailoring for the intersegmental plane management.