Abstract
BACKGROUND: A right-sided ligamentum teres (RSLT) is a rare congenital anomaly in which the fetal umbilical vein is connected to the right paramedian trunk. RSLT creates difficulty in liver resection with respect to decision-making regarding the resection line, deviation of the vasculobiliary architecture. We report a case in which laparoscopic left lateral sectionectomy (LLLS) was performed to treat colorectal liver metastasis (CRLM) in a patient with RSLT. CASE PRESENTATION: A 63-year-old man with a past history of rectal cancer presented to our institution due to liver metastasis in the left lateral section from rectal cancer. In this patient, an RSLT was diagnosed and LLLS was planned. The lateral superior branch of the portal vein (P2) branched off behind the bifurcation of the portal vein and running separately from the common branch of the lateral inferior branch (P3) and left paramedian branch (P4) so that stapling could not be performed for liver resection. Frequent intraoperative ultrasonography (IOUS) was necessary to identify the root of P2 and P3. The resection line was distant from the falciform ligament and was carefully decided. The lateral superior branch of Glisson (G2) and lateral inferior branch of Glisson (G3) were separately resected. The patient had a favorable clinical course without any complications. CONCLUSIONS: The resection line of LLLS, which is distant from the falciform ligament, should be carefully identified using IOUS due to the deviation of the umbilical portion and falciform ligament. The recognition of portal vein and hepatic vein anomalies and clear identification of the lateral sectional branches are important to complete LLLS in patients with an RSLT.