Preliminary study of perineural invasion in patients with hilar cholangiocarcinoma by computed tomography imaging

Objectives: To explore the characteristics of hepatic plexuses and celiac ganglia, and their relationships with hilar cholangiocarcinoma (HCCA) perineural invasion (PNI) by computed tomography (CT) imaging preliminarily.

Materials and methods: Sixty-five HCCA patients (55 with PNI) between December 2014 and February 2019 were included in this retrospective study. The CT values of hepatic plexuses in Region 1 (the fat tissue around proper hepatic artery), in Region 2 (the fat tissue around common hepatic artery), and in Region 3 (the fat tissue around celiac trunk), and the CT values and diameters of celiac ganglia were measured on the preoperative CT images. Mann-Whitney U test was used to compare the measurements between PNI group and Non-PNI group. ROC curve was performed to analyze the sensitivity, specificity and optimal threshold of the measurements in discriminating HCCA PNI.

Results: The CT values of hepatic plexuses in PNI group were significantly higher than those in Non-PNI group (all P < 0.05). The CT values of right celiac ganglia were significantly higher in PNI group than those in Non-PNI group (P = 0.007). There were no significant differences between two groups in other measurements (all P > 0.05). The CT values of hepatic plexuses in Region 1 showed the highest sensitivity (90.9%) and the CT values of right celiac ganglia demonstrated the highest specificity (80.0%).

Conclusions: The increases of CT values of hepatic plexuses around proper hepatic artery may be used as an indicator of PNI in patients with HCCA and may facilitate treatment planning in considering its early recurrence after surgery and poor prognosis.