Successful left hepatic trisectionectomy after portal vein embolization for colon cancer liver metastasis in a patient with right-sided ligamentum teres.

Right-sided ligamentum teres (RSLT) is a rare congenital anomaly in which the fetal umbilical vein is connected to the right paramedian trunk of the portal vein. An 80-year-old woman underwent curative sigmoidectomy for sigmoid cancer 3 years prior to presentation. After 1 year, small solitary liver metastasis was noted in segment 4. Because the patient experienced recurrence of the same lesion after chemotherapy and radiofrequency ablation, she was referred to our hospital. CT revealed an anomaly of the liver with RSLT, classified as an independent posterior branch type. The tumor in the left paramedian section was located in the right umbilical portion (RUP), and BDTT was advanced to the common bile duct. Because the estimated future remnant liver volume was 35.2%, transileocecal portal vein embolization (PVE) for the portal branches from the RUP increased it to 43.5% in 3 weeks. Left trisectionectomy with extrahepatic bile duct resection and hepaticojejunostomy were performed. The patient was discharged on postoperative day 75. We successfully performed a left trisectionectomy after PVE in a patient with RSLT. Understanding the vascular and biliary anomalies of patients with RSLT is essential. When the future remnant liver is small, PVE can be considered for safe hepatectomy.