Spatial anatomy of the round ligament, gallbladder, and intrahepatic vessels in patients with right-sided round ligament of the liver.

PURPOSE: To analyze the vascular structure of the liver in patients with a right-sided round ligament. METHODS: We reviewed 16 patients with a right-sided round ligament and 3 polysplenia and situs inversus patients with a left-sided round ligament who underwent multidetector row CT with contrast media. The patient population consisted of 13 men and 6 women (mean 62 years). We analyzed the axial and volume-rendered images for the location of the round ligament, gallbladder, portal veins, hepatic veins, and hepatic artery. The following imaging findings for the patients with polysplenia and situs inversus were horizontally reversed. RESULTS: The prevalence of a right-sided round ligament with and without polysplenia was 75 and 0.11 %, respectively. The gallbladder was located to the right, below, and left of the round ligament in 27.7, 38.8 and 33.3 %, respectively. Independent branching of the right posterior portal vein was noted in 57.8 %. PV4 was difficult to identify in 36.8 %. The middle hepatic vein was located to the left of the round ligament. Two branching patterns for the lateral and medial branches of the right anterior hepatic artery were noted: the common (44.4 %) and separated types (55.5 %). Both of the right anterior hepatic artery and portal vein ramified into two segments; the lateral segment with many branches and the medial segment with a few branches. CONCLUSIONS: The right-sided round ligament divided the right anterior section into the lateral and medial segments based on the portal vein and hepatic artery anatomy.

Portal vein branching order helps in the recognition of anomalous right-sided round ligament: common features and variations in portal vein anatomy.

PURPOSE: This study aimed to evaluate the common features and variations of portal vein anatomy in right-sided round ligament (RSRL), which can help propose a method to detect and diagnose this anomaly. METHODS: In this retrospective study of 14 patients with RSRL, the branching order of the portal tree was analyzed, with special focus on the relationship between the dorsal branch of the right anterior segmental portal vein (PA-D) and the lateral segmental portal vein (PLL), to determine the common features. The configuration of the portal vein from the main portal trunk to the right umbilical portion (RUP), the inclination of the RUP, and the number and thickness of the ramifications branching from the right anterior segmental portal vein (PA) were evaluated for variations. RESULTS: In all subjects, the diverging point of the PA-D was constantly distal to that of the PLL. The portal vein configuration was I- and Z-shaped in nine and five subjects, respectively. The RUP was tilted to the right in all subjects. In Z-shaped subjects, the portal trunk between the branching point of the right posterior segmental portal vein and that of the PLL was tilted to the left in one subject and was almost parallel to the vertical plane in four subjects. Multiple ramifications were radially distributed from the PA in eight subjects, whereas one predominant PA-D branched from the PA in six subjects. CONCLUSIONS: Based on the diverging points of the PA-D and PLL, we proposed a three-step method for the detection and diagnosis of RSRL.