Protective strategy for the caudate lobe bile duct during left hemihepatectomy based on imaging data analysis.

Purpose: This study was performed to analyze the rule of confluence of the caudate lobe bile duct (CLD) into the left hepatic duct (LHD) and to discuss the protective strategy during left hemihepatectomy. Methods: MRI of 400 patients and T-tube angiography images of 100 patients were collected, and the imaging rules of the confluence of the CLD into the LHD were summarized. The clinical data of 33 patients who underwent left hemihepatectomy using the protective strategy were analyzed. Results: MRI and T-tube angiography images showed that the length from the confluence point of the CLD into the LHD to the confluence of the left and right hepatic ducts was 1.19 ± 0.40 cm and 1.26 ± 0.39 cm, respectively. The average angle between the longitudinal axis of the 2 bile ducts was 68.27° ± 22.59° and 66.58 ± 22.88°, respectively. Coronal and cross-sectional images showed that inflow from the foot side to the cranial side was noted in 79.8% and 82.0% of patients, respectively, and inflow from the dorsal to the ventral side was observed in 84.5% and 88.0%, respectively. Based on these imaging rules, the safe transection length and plane were summarized, and the CLD was effectively protected in 33 cases of left hemihepatectomy. Conclusion: In left hemihepatectomy, the LHD should be transected at least 1.5 cm away from the confluence of the left and right hepatic ducts, and the plane of transection should be oblique to the dorsal side at an angle of 45° with the LHD, these parameters represent an effective strategy to protect the CLD.