Intersegmental veins between segments 5 and 8 as a landmark along the intersegmental planes during laparoscopic anatomical segmentectomy for hepatocellular carcinoma.

Laparoscopic anatomical hepatectomy (LAH) of segments 5 and 8 (LAHSg5/Sg8) for hepatocellular carcinoma (HCC) remains one of the most challenging procedures due to the difficulty in exposing the main vascular structure. The aim of our study was to investigate the anatomical characteristics of inter-SVs based on the three-dimensional (3D) visualization technology exploring its safety and feasibility during LAHSg5/Sg8. A total of 110 patients who underwent LAHSg5/Sg8 in our center between January 2019 and August 2022 were enrolled and analyzed retrospectively. During the operation, the inter-SVs of the first 10 patients were observed. Subsequently, 100 patients were included based on the previous intraoperative understanding. The anatomical parameters of inter-SVs and the perioperative outcomes were recorded and evaluated. The safety and short-term efficacy of LAHSg5/Sg8 were assessed. All the patients underwent preoperative 3D processing software analysis. Of the included patients, 74.6% had inter-SVs in Sg5/Sg8, which could be classified into three types: trunk type, double branch type and multi branch type, accounting for 35.4%, 22.2% and 17.0%, respectively. The concordance between pre-operation and intra-operation in terms of portal vein territory of Sg5/Sg8 was 82 ± 31%. The inlet point diameter was 3.3 ± 1.0 mm. The distance between the inter-SVs in Sg5/Sg8 and P8, point "B" were 17.7 ± 6.2 mm, 6.1 ± 17 mm, respectively. The confluence of inter-SVs in Sg5/Sg8 at "point B" and below accounted for 10.2%. Preoperative 3D reconstruction and personalized surgical planning based on individual anatomical variations are crucial for successful LAHSg5/Sg8. Inter-SVs between Sg5/Sg8 as a landmark along the ISP during LAHS for HCC may be safe and feasible.