Portal vein-based subsegmental classification of liver segment four for parenchyma-sparing laparoscopic resection: A retrospective study

Figure 8 Type III classification: Scattered Glissonean inflow without dominant trunk anatomy in segment 4. A and B: Axial contrast-enhanced computed tomography images from a representative type III case, showing multiple small Glissonean branches entering segment 4 (S4) from varying directions, with no discernible cranial-caudal or left-right segmentation pattern; C: Three-dimensional portal vein reconstruction revealing a disorganized inflow configuration, composed of scattered pedicles and intermediate branches supplying overlapping territories within S4; D: Schematic diagram illustrating the non-converging, diffuse vascular distribution in type III, which lacks structured segmentation and requires intraoperative fluorescence guidance for accurate subsegmental resection. IB: Intermediate branch; G4: Glissonean pedicles of segment 4.