Detection of perfusion areas of the gallbladder vein on computed tomography during arterial portography (CTAP) - The background for dual S(4a) · S⁵ hepatic subsegmentectomy in advanced gallbladder carcinoma

Background/Aims: It has been speculated that the veins of the gallbladder join the intrahepatic portal veins supplying the Couinaud's S(4a)-S⁵. This has been the theoretical ground for the resection of these 2 hepatic subsegments in advanced gallbladder carcinoma. However, no consensus has been reached on this concept. Methodology: The current study describes the non-neoplastic perfusion defects in connection with the gallbladder bed in 100 consecutive hepatic CTAP (computed tomographies during arterial portography). The suitability of S(4a) and S⁵ subsegmentectomies of the liver for advanced gall-bladder carcinoma was also investigated by examining CTAP images of the branches of the portal vein involved in the perfusion defect. Results: Two types of gallbladder venous perfusion were observed: 1) sphenoid distribution from the gallbladder bed into the P(4d) (37%), P⁵ (52%) and P⁶ (3%), and 2) perfusion into the P⁴ (9%) or directly into the middle hepatic vein (9%) after communicating with the hepatic hilum at the dorsal side of S⁴. Conclusions: These results support liver resection at S4a and S5 as the surgical approach for cases of advanced gallbladder carcinoma.