BACKGROUND: Anatomical hepatectomy aims to eliminate the spread of malignant tumor cells via portal vein systemically. An anatomical concept of the right anterior section (RAS) and preservation of the liver parenchyma within the RAS has been proposed. METHODS: We focused on the anatomical concept of the RAS based on portal perfusion and described surgical procedures to preserve the ventral or dorsal RAS using preoperative simulation. RESULTS: In 370 patients undergoing a preoperative simulation, the ramification of the tertiary portal branches of the RAS could be divided into three types including the cranio-caudal type; Couinaud's classification in 50% of patients, ventro-dorsal type in 26% of patients, and multiple type in 24% of patients. Then in 32 patients of the ventro-dorsal type, curative parenchyma-sparing hepatectomy of the RAS was performed, preserving the ventral and dorsal RAS in 14 and 18 patients, respectively. There were no differences in the postoperative complications and long-term survival compared with the results obtained after segment 5 or 8 resection (n = 33). CONCLUSION: Three-dimensional simulation revealed three types of portal vein ramification of the RAS. Parenchyma-preserving hepatectomy based on the precise portal ramification may contribute to safe and curative hepatectomy in selected cases with liver neoplasm involving the RAS.
BACKGROUND: Anatomical hepatectomy aims to eliminate the spread of malignant tumor cells via portal vein systemically. An anatomical concept of the right anterior section (RAS) and preservation of the liver parenchyma within the RAS has been proposed. METHODS: We focused on the anatomical concept of the RAS based on portal perfusion and described surgical procedures to preserve the ventral or dorsal RAS using preoperative simulation. RESULTS: In 370 patients undergoing a preoperative simulation, the ramification of the tertiary portal branches of the RAS could be divided into three types including the cranio-caudal type; Couinaud's classification in 50% of patients, ventro-dorsal type in 26% of patients, and multiple type in 24% of patients. Then in 32 patients of the ventro-dorsal type, curative parenchyma-sparing hepatectomy of the RAS was performed, preserving the ventral and dorsal RAS in 14 and 18 patients, respectively. There were no differences in the postoperative complications and long-term survival compared with the results obtained after segment 5 or 8 resection (n = 33). CONCLUSION: Three-dimensional simulation revealed three types of portal vein ramification of the RAS. Parenchyma-preserving hepatectomy based on the precise portal ramification may contribute to safe and curative hepatectomy in selected cases with liver neoplasm involving the RAS.