Precise anatomical resection of the ventral part of Segment VIII

INTRODUCTION: Anatomical resection of the ventral part of Segment VIII (S8vent) is demanding and there are no accurate methods to identify the demarcation line inside the liver. The current authors have proposed a method to solve the problem. PRESENTATION OF CASE: The tumor was located in the S8vent and was 4 cm in size. One tributary of the middle hepatic vein (MHV), designated V8i, was running between S8vent and the dorsal part of Segment VIII (S8dor). Another tributary of the MHV, designated V8-5i, was running between S8vent and the ventral part of S5 (S5vent). About 5 ml of indigo carmine dye was injected into the proximal part of P8vent. After the small tributary of V8-5i was exposed, it was followed all the way to the main trunk of the MHV. The portal pedicle of S8vent was then ligated and divided. Next, the V8i was gradually exposed from the distal MHV to its trunk. DISCUSSION: A recent study showed that the subsegmental border visualized between the ventral and dorsal region always coincided with the plane of V8i, so the subsegmental plane can be divided along with V8i by preserving the very small tributaries near the liver surface and following them to determine where they meet as they run into V8i. Also, the landmark vein of V8-5i in the transverse S8–S5 intersegmental plane was determined for the first time. CONCLUSION: Proposed here is a more accurate method of dividing the liver parenchyma along the intersegmental and intersubsegmental demarcation.