Benefit of Systematic Segmentectomy of the Hepatocellular Carcinoma Revisiting the Dye Injection Method for Various Portal Vein Branches

Background: Systematic segmentectomy is useful in treating small hepatocellular carcinoma in the cirrhotic liver. However, accomplishment of an exact systematic segmentectomy still remains a challenging procedure because of the variable anatomy of portal branches. We evaluated the usefulness of the dye injection method for systematic segmentectomy, which focuses on the various patterns of portal vein (PV) branches feeding the tumor. Methods: From January 2001 to May 2011, systematic segmentectomy by the dye injection method was performed in 70 patients. We evaluated the efficiency of systematic segmentectomy by ultrasonogram-guided dye injection into the portal branches that feed the tumor-bearing segments. The type of tumor-feeding PV branch, perioperative outcome, and survival rates were analyzed retrospectively. Results: There were variations in the PV branches that fed the masses in 70 patients in whom the dye injection method for anatomical segmentectomy was tried. Forty masses (54.8%) were fed by a single main PV branch (type 1), 17 masses (23.3%) by a couple of PV branches (type 2), and 11 masses (15.1%) were supplied partially by single PV branch (type 3). In 5 patients (7.1%), masses were supplied by several small distributed PVs (type 4). For types 1 and 2, the tumor-bearing segments were resected anatomically with the help of staining; type 3 was partially stained and as the opposite side was not discrete, it was demarcated through counterstaining; and in type 4, dye injection could not be performed. Anatomical systematic segmentectomy was obtained in types 1 to 3; however, nonanatomical resection was inevitable for type 4. The 3- and 5-year overall survival rates were 80.5% and 67.2%, respectively, and the 3- and 5-year disease-free survival rates were 61.5% and 42.5%, respectively. The anatomical segmentectomy group showed better overall and disease-free survival than the nonanatomical group, even though it is not significant statistically. Conclusion: Systematic segmentectomy by the dye injection method overcomes the variation in PV tributaries in the segments and can be done according to the natural branching pattern of PVs.