Investigating the Intersegmental Veins between S6 and S7 in Anatomical Resection

Abstract Background Hepatocellular carcinoma often metastasizes along the portal vein watershed, necessitating precise anatomical resection. Anatomic resection (AR) involving segments S6 and S7 aims to enhance oncological efficacy while preserving liver volume. The intersegmental veins (IVs) between these segments are potential anatomical landmarks that facilitate accurate resection plane determination. Methods Three-dimensional (3D) reconstruction technology was used to analyze the IVs between S6 and S7 in 164 patients who underwent contrast-enhanced computed tomography (CT). The IVs' occurrence rate, characteristics, spatial localization, and correlation with right hepatic veins (RHVs) diameters were examined. Results IVs were identified in 71.95% of patients, primarily connecting to RHVs. They often converged in the middle-lower portion of RHVs. The most clearly identifiable junctions between the IVs and RHVs occurred the midpoint of the horizontal planes of the second hepatic portal and the center of the gallbladder bed. Patients with larger RHV diameters were more likely to have IVs draining into RHVs (Type 1), while smaller RHV diameters correlated with IVs draining into inferior right hepatic veins (IRHVs) (Type 2). Conclusion The IVs between S6 and S7 are prevalent and feasible anatomical landmarks for AR. When RHVs and IRHVs coexist, the RHV diameter predicts the type of IVs present. Considering the IVs enhances precision in determining transection planes during AR of S6 and S7, potentially reducing blood loss and enhancing patient safety. Further research is needed to validate these findings and address limitations in sample size and hemodynamic variations.