# Successful Left Trisectionectomy for Intrahepatic Cholangiocarcinoma in a Patient with a Right-Sided Round Ligament: A Case Report

## TL;DR

A rare case of successful liver surgery for cholangiocarcinoma in a patient with a right-sided round ligament is reported, highlighting the importance of understanding anatomical anomalies.

## Contribution

This case report presents a successful left trisectionectomy in a patient with a rare anatomical anomaly and intrahepatic cholangiocarcinoma.

## Key findings

- A 3-D CT of the portal vein helped visualize the vascular anomalies associated with the right-sided round ligament.
- Left trisectionectomy with extrahepatic bile-duct resection was successfully performed, and the patient showed no recurrence three months post-surgery.

## Abstract

A right-sided round ligament (RSRL) is a rare congenital anomaly characterized by the umbilical vein being connected to the right paramedian trunk. As it is associated with intrahepatic vascular anomalies, it poses special difficulties in hepatic resection, and an accurate understanding of those anomalies is indispensable.

An 80-year-old man visited a health clinic with the chief complaint of jaundice. Hyperbilirubinemia and impaired liver function were detected upon laboratory examination. Therefore, the patient was referred to our hospital for further examination and treatment. Contrast-enhanced computed tomography (CT) demonstrated dilatation of the intrahepatic bile ducts and the presence of a hypovascular tumor of 30 mm in size in the left lateral segment of the liver. The anterior branch of the portal vein (PV) formed a right-sided umbilical portion of the PV and was connected to the round ligament. This anomaly is known as an RSRL. The round ligament was located to the right of the gallbladder. Three-dimensional (3-D) CT of the PV clearly illustrated the independent ramification of the posterior branch and the subsequent bifurcation of the anterior branch and the left PV. Endoscopic, nasogastric biliary drainage was performed to treat the patient for obstructive jaundice, and endoscopic retrograde cholangiopancreatography demonstrated severe stenosis of the hilar bile duct. Biopsies of the stenotic bile ducts were suggestive of adenocarcinoma. The root of the posterior branch of the bile duct was intact from the cancer. The preoperative diagnosis was intrahepatic cholangiocarcinoma (T4N0M0, stage III B), according to the American Joint Committee on Cancer Staging System, 8th edition. Left trisectionectomy with extrahepatic bile-duct resection and hepaticojejunostomy was performed. The histological diagnosis of the tumor was intrahepatic cholangiocarcinoma (large duct type, 5.5 × 4.5 cm). The final pathological stage was T4N1M0, stage 3B. Three months after surgery, the patient was doing well without recurrence.

The anatomy of patients with an RSRL should be evaluated in detail before surgery, especially when curative hepatic resection is performed for intrahepatic or perihilar cholangiocarcinoma.