The arterial-ligation-alone method for identifying the intersegmental plane during thoracoscopic anatomic segmentectomy

Abstract

Background: Currently, methods for identifying the intersegmental plane during anatomical segmentectomy can be classified into 2 categories: the bronchial method and the vascular method. One of the vascular methods, the arterial-ligation-alone method, has not yet been validated or objectively evaluated in a large case series. We thus aimed to confirm that the arterial-ligation-alone method could effectively and accurately identify the intersegmental plane.

Methods: We retrospectively reviewed the records of 104 patients who were scheduled for thoracoscopic anatomic segmentectomy. Preoperative three-dimensional (3D) reconstruction was performed on all the affected lungs to distinguish the targeted segmental arteries, veins and bronchi. The procedure was as follows: first, based on the 3D reconstruction of the lung, the targeted segmental arteries were distinguished and ligated. Second, bilateral pulmonary ventilation was performed with pure oxygen. When the affected lung had completely inflated, contralateral pulmonary ventilation was performed. After waiting for some time, the first intersegmental plane could be obtained, and the time was recorded as T1, with an electric coagulation hook being used for marking. Thirdly, when the targeted segmental veins and bronchi had been ligated, the second intersegmental plane could be obtained by the inflation-deflation method as before, with the waiting time being recorded as T2. The differences between the 2 intersegmental planes were evaluated by 2 experienced chief thoracic surgeons.

Result: In a total of 99 (95.2%) patients, the intersegmental planes were successfully and accurately identified by the arterial-ligation-alone method. Ultimately, 85 (81.7%) patients underwent thoracoscopic anatomic segmentectomy. The results for evaluating the differences between the 2 planes were as follows: completely consistent (94 cases, 94.9%), basically consistent (5 cases, 5.1%), and discrepant (0 cases, 0%). The mean T1 was 13.6±2.7 minutes (range, 8-25 minutes), and the mean T2 was 13.0±2.6 minutes (range, 8-23 minutes), with P=0.100 (95% CI). For 99 patients, the mean nodule size was 1.1±0.34 cm. In the 85 patients who underwent segmentectomy, the mean margin width was 2.84±0.51 cm, the mean operative duration was 165.6±18.3 minutes, the mean operative hemorrhage was 52.1±20.2 mL, and the mean duration of chest tube drainage was 3.9±1.3 days. Postoperative complications related to operative procedures occurred in 2 cases.

Conclusions: The arterial-ligation-only method can effectively, accurately and inexpensively identify the intersegmental plane, and is especially suitable for the patients whose veins or bronchi are difficult to anatomize. Whether the target bronchus is ligated has no effect on the intersegmental plane.

Keywords: Lung cancer; ground glass nodule; inflation-deflation method; three-dimensional reconstruction (3D reconstruction).

Figure 1

Preoperative left lung three-dimensional reconstruction. (A) Different colors represent different segments of the lung; (B) the overall position of the left pulmonary artery, vein, bronchus, and nodules. The pink structure represents the bronchus, the red structures represent the arteries, and the blue structures represent the veins. S, segment.

Figure 2

RS8 anatomical segmentectomy was planned. (A) Preoperative right-lung three-dimensional reconstruction. Black solid lines represent the virtual intersegmental plane; (B) after the arterial-ligation-alone method, the expansion-collapse boundary between the excluded segment (pink) and the remaining lung (dark red) was shown. The solid blue line represents the first real intersegmental plan; (C) after the ligation of the targeted bronchi and veins, the expansion-collapse boundary was visible again. The solid yellow line represents the second real intersegmental plane. The solid black line represents the margin with the most obvious difference between the 2 intersegmental planes. *, star segment. D, distance; RS, right segment.

Figure 3

After the RS8 anatomic segmentectomy, the intersegmental vein remained intact. The solid green line represents the intersegmental vein. RS, right segment.

Video 1

The RS8 thoracoscopic anatomical segmentectomy using arterial-ligation-alone method to identify the intersegmental plane. The pink lung parenchyma demarcates the segment to be resected, the dark red lung parenchyma demarcates the lung to be left intact. The virtual, and first- and second-real intersegmental planes appeared, and their consistency was confirmed.