Biliary architecture of livers exhibiting right-sided ligamentum teres: an indication for preoperative cholangiography prior to major hepatectomy

Laparoscopic Extended Left Lateral Sectionectomy for Hepatocellular Carcinoma in a Patient with Right-Sided Ligamentum Teres: A Case Report and Literature Review

Right-sided ligamentum teres (RSLT) is a rare anatomic variant in which the fetal umbilical vein connects to the right portal vein. Patients with RSLT frequently have hepatic vasculature and bile duct anomalies, which increase the risk of complications with hepatectomy. Most patients with RSLT undergo open hepatectomy. Herein, we describe a patient with RSLT and hepatocellular carcinoma who underwent laparoscopic hepatectomy. The patient was a 69-year-old man with hepatocellular carcinoma located in the left liver based on computed tomography (CT) and magnetic resonance imaging. Imaging also demonstrated RSLT. Three-dimensional CT analysis revealed independent right lateral type anomalies of the portal vein and bile duct. A laparoscopic extended left lateral sectionectomy was performed after careful surgical planning. Ultrasonography was used frequently during surgery to avoid damaging the right hepatic vasculature. The left lateral and partial left median sections were removed as planned. The patient's postoperative recovery was uneventful. Avoiding injury to the right hepatic vasculature is essential when performing left lobectomy, including left lateral sectionectomy, in patients with RSLT. Laparoscopic hepatectomy can be performed safely in patients with RSLT, provided that careful surgical planning is conducted using preoperative three-dimensional CT analysis and intraoperative ultrasonography.

Predicting portal venous anomalies by left-sided gallbladder or right-sided ligamentum teres hepatis: A large scale, propensity score-matched study

BACKGROUND

Right-sided ligamentum teres (RSLT) is often associated with portal venous anomalies (PVA) and is regarded as a concerning feature for hepatobiliary intervention. Most studies consider RSLT to be one of the causes of left-sided gallbladder (LGB), leading to the hypothesis that LGB must always be present with RSLT. However, some cases have shown that right-sided gallbladder (RGB) can also be present in livers with RSLT.

AIM

To highlight the rare variation that RSLT may not come with LGB and to determine whether ligamentum teres (LT) or gallbladder location is reliable to predict PVA.

METHODS

This study retrospectively assessed 8552 contrast-enhanced abdominal computed tomography examinations from 2018 to 2021 [4483 men, 4069 women; mean age, 59.5 ± 16.2 (SD) years]. We defined the surrogate outcome as major PVAs. The cases were divided into 4 subgroups according to gallbladder and LT locations. On one hand, we analyzed PVA prevalence by LT locations using gallbladder location as a controlled variable (n = 36). On the other hand, we controlled LT location and computed PVA prevalence by gallbladder locations (n = 34). Finally, we investigated LT location as an independent factor of PVA by using propensity score matching (PSM) and inverse probability of treatment weighting (IPTW).

RESULTS

We found 9 cases of RSLT present with RGB. Among the LGB cases, RSLT is associated with significantly higher PVA prevalence than typical LT [80.0% vs 18.2%, P = 0.001; OR = 18, 95% confidence interval (CI): 2.92-110.96]. When RSLT is present, we found no statistically significant difference in PVA prevalence for RGB and LGB cases (88.9 % vs 80.0%, P > 0.99). Both PSM and IPTW yielded balanced cohorts in demographics and gallbladder locations. The RSLT group had a significantly higher PVA prevalence after adjusted by PSM (77.3% vs 4.5%, P < 0.001; OR = 16.27, 95%CI: 2.25-117.53) and IPTW (82.5% vs 4.7%, P < 0.001).

CONCLUSION

RSLT doesn't consistently coexist with LGB. RSLT can predict PVA independently while the gallbladder location does not serve as a sufficient predictor.

Rare Portal Venous Anomaly in a Living Liver Donor: A Case Report

Knowledge of the anatomy of the portal system is essential for safe liver resection. We report a very rare anatomic anomaly of the portal system in a living liver donor. A 24-year-old female living liver donor was found to have anomalies of the portal system on preoperative contrast-enhanced computed tomography. The ventral branch of the right anterior segment arose from the transverse portion of the left portal vein. The gallbladder and round ligament were positioned normally. Intraoperative cholangiography for evaluation of biliary anatomy revealed very low confluence of the right and left hepatic ducts. All the bile ducts from the right lobe merged into the right hepatic duct. A right lobe graft was performed, including the ventral area of the right anterior segment. The portal branch of the ventral area of the right anterior segment could be transected extrahepatically. In the recipient operation, each of the right main portal branches, including the right posterior segment branch and the dorsal branch of the right anterior segment, and the ventral branch of the right anterior segment, were anastomosed to the right and left branches of the portal vein, respectively, of the recipient. The transected right hepatic duct of the graft was anastomosed with the recipient's common hepatic duct. Sixteen years after the liver transplant, the recipient continues to do well and has good portal flow.

Hepatic volume profiles in potential living liver donors with anomalous right-sided ligamentum teres

PURPOSE

In living liver donors with rare anatomical anomaly of right-sided ligamentum teres (RSLT), right or left hemiliver procurement is commonly contraindicated. The purpose of this study was to evaluate the hepatic volume profiles in potential donors with RSLT using semi-automated CT volumetry (CTV).

METHODS

Among 5535 potential donor candidates in our institution between April 2003 and May 2019, 23 cases of RSLT (0.4%) were included. Proportional liver volumes were measured using semi-automated CTV and compared with those of manual volumetry and intraoperative graft weights (seven surgical cases).

RESULTS

The mean percentage volume of the right posterior section was significantly larger than that of the left hemiliver (38.5 ± 8.4% vs. 23.3 ± 5.7%, P < 0.001). Particularly in independent right lateral type, the mean percentage volume of the right posterior section was about two times larger to that of the left hemiliver (41.5% ± 6.5% vs. 21.9% ± 4.4%, P < 0.001), whereas the volume proportions of these two parts were similar between the two parts in bifurcation and trifurcation types (P = 0.810 and 0.979, respectively). Semi-automated CTV of corresponding whole liver, right posterior section, right anterior section, and left hemiliver showed strong correlations with manual CTV (r = 0.989-0.998; P < 0.001). For the seven surgical cases, the graft weights estimated by semi-automated CTV showed a significant correlation with intraoperative graft weights (r = 0.972; P < 0.001).

CONCLUSION

In independent right lateral type of RSLT, the right posterior section tends to be significantly larger than left hemiliver, and may be an alternative option for graft in potential living liver donors with this rare anatomical anomaly.

Left hepatic trisectionectomy for perihilar cholangiocarcinoma with a right-sided round ligament: A case report

BACKGROUND

A right-sided round ligament (RSRL) is a rare, congenital anomaly of the intrahepatic portal vein, with a reported frequency of 0.2%-1.2%. For patients with perihilar cholangiocarcinoma associated with an RSRL, an accurate understanding of the vascular and biliary anatomy is indispensable.

CASE SUMMARY

We report a 70-year-old male with perihilar cholangiocarcinoma associated with an RSRL. After percutaneous transhepatic embolization of the left and anterior portal branches, we conducted a left trisectionectomy of the liver with extrahepatic bile duct resection and hepaticojejunostomy. The postoperative course was uneventful, and R0 resection was achieved. When the liver volume of each section was compared between 7 patients with an RSRL and 20 patients with normal portal vein anatomy, the posterior section in RSRL patients was significantly larger than that in patients with normal portal vein anatomy (median: 457 mL vs 306 mL, P = 0.031). In patients with perihilar cholangiocarcinoma associated with an RSRL, left trisectionectomy has several surgical advantages: (1) The posterior branch of the portal vein often ramifies independently, and the division of the portal vein is easily conducted; (2) A relatively large amount of remnant liver can be retained; and (3) The anatomy of the posterior branch of the Glissonian pedicle is similar to that in patients with normal anatomy.

CONCLUSION

In patients with an RSRL and perihilar cholangiocarcinoma that does not involve the posterior section, left trisectionectomy may be a favorable choice.

Four "fine" messages from four kinds of "fine" forgotten ligaments of the anterior abdominal wall: have you heard their voices?

On the posterior aspect of the anterior abdominal wall, there are four kinds of "fine" ligaments. They are: the round ligament of the liver, median umbilical ligament (UL), a pair of medial ULs, and a pair of lateral ULs. Four of them (the round ligament, median UL, and paired medial ULs) meet at the umbilicus because they originate from the contents of the umbilical cord. The round ligament of the liver originates from the umbilical vein, the medial ULs from the umbilical arteries, and the median UL from the urachus. These structures help radiologists identify right-sided round ligament (RSRL) (a rare, but surgically important normal variant), as well as to differentiate groin hernias. The ligaments can be involved in inflammation; moreover, tumors can arise from them. Unique symptoms such as umbilical discharge and/or location of pathologies relating to their embryology are important in diagnosing their pathologies. In this article, we comprehensively review the anatomy, embryology, and pathology of the "fine" abdominal ligaments and highlight representative cases with emphasis on clinical significance.

Laparoscopic left lateral sectionectomy for a patient with right-sided ligamentum teres

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.

Embryology, Anatomy, and Imaging of the Biliary Tree

"The anatomy of the biliary tree is notoriously variable. This variation is the bane of the hepatobiliary surgeon, to whom an understanding of biliary anatomic variation is key to the planning and safe conduct of liver surgery, from oncological resections to split-liver transplantation. The hepatic diverticulum, also termed "the liver bud," is the first semblance of the biliary system in the human embryo. A variety of techniques used in the mid twentieth century for imaging the biliary tree have since been abandoned in favor of more practical, safer, less invasive, and more sensitive and specific contemporary methods."

Is right-sided ligamentum teres hepatis always accompanied by left-sided gallbladder? Case reports and literature review

Right-sided ligamentum teres (RSLT) hepatis is a rare anatomical variant in which the fetal umbilical vein is connected to the right paramedian trunk of the portal vein. Despite its rarity, it is crucial for surgeons and intervention specialists because of its frequent association with intrahepatic vascular and biliary anomalies. Inattention to these anomalies before intervention, especially living-donor liver transplantation, can have life-threatening consequences. The relationship between gallbladder location and RSLT is still controversial, with RSLT regarded as one of the critical features of left-sided gallbladder in most studies. According to these hypotheses, once RSLT is present, left-sided gallbladder must be found as well. Here, we report three cases in which RSLT was associated with intrahepatic portal vein anomalies. In one case, the gallbladder was left-sided, but in the other two cases, it had a normal cholecystic axis to the right of the umbilical fissure. Therefore, the relationship between RSLT and gallbladder location may require redefinition, and surgeons should be aware of vascular anomalies once RSLT has been detected, even in the absence of left-sided gallbladder or biliary anomalies. TEACHING POINTS: • Right-sided ligamentum teres (RSLT) hepatis is a rare anatomical variant, which is frequently associated with intrahepatic vascular and biliary anomalies. Previous studies had discussed the vascular anomalies in livers with RSLT. • However, no predictable correlation exists between portal vein anomalies and anomalous biliary confluences in patients with RSLT. Moreover, we found that RSLT does not always coexist with left-sided gallbladder. • Unawareness of these vascular and biliary anomalies in liver with RSLT before intervention can have life-threatening consequences. • Thus, the vascular and biliary variations should be surveyed in multimodality imaging studies such as dynamic CT, 3D magnetic resonance cholangiopancreatography, or digital subtraction angiography once the RSLT is detected before intervention.

Hepatectomy for gallbladder-cancer with unclassified anomaly of right-sided ligamentum teres: A case report and review of the literature

Right-sided ligamentum teres (RSLT) is a congenital anomaly in which the right umbilical ligament becomes dominant and anomalous ramifications of the hepatic vessels and biliary system are present. A male patient in his 70s was diagnosed with advanced gallbladder cancer directly infiltrating the right hepatic duct (RHD), together with RSLT. Preoperative three-dimensional simulation of the liver based on multiple detector computed tomography images after cholangiography revealed ramifications of all segmental portal veins from the portal trunk and discordance of the arterial and biliary branching patterns of segment 8. Fusion analysis of the biliary architecture and segmental volumetry showed that the RHD drained segments 1r, 5, 6, and 7. We successfully performed a modified right-sided hepatectomy sparing segment 8 (i.e., resection of the RHD drainage territory), with negative surgical margins. This report is the first to describe major hepatectomy for advanced gallbladder cancer with RSLT.

Hepatectomy for Hilar Cholangiocarcinoma with Right-Sided Ligamentum Teres Using a Hepatectomy Simulation System

Right-sided ligamentum teres (RSLT) is a rare congenital anomaly often accompanied by variation of the hepatic vasculature. We herein report a surgical case of a hilar cholangiocarcinoma with RSLT in whom preoperative hepatectomy simulation proved useful for understanding the anatomical structure of the liver. A 78-year-old male with obstructive jaundice was referred to our department for further examination. The patient was suspected of having a hilar cholangiocarcinoma originating from the left hepatic bile duct by contrast-enhanced computed tomography (CT), and CT also showed right umbilical portion (RUP). Three-dimensional images of the hepatic vasculature and biliary system reconstructed using a hepatectomy simulation system suggested that all portal branches ramified from RUP were right paramedian branches, and three leftward portal branches from these ran parallel to the peripheral bile ducts confluent with the left hepatic bile duct, where the tumor was present. Hepatic resection of part of the ventral area of the right paramedian sector and left hemiliver was performed along the demarcation line drawn after clamping the portal branches; the ratio of estimated liver resection volume was 28.9%. After the operation, bile leakage occurred. However, the leakage was treated with percutaneous drainage alone, and the patient was discharged 77 days after the operation. The patient is doing well without any signs of recurrence 21 months after the operation. The vascular and biliary anatomy in patients with RSLT is complicated and should be evaluated in detail preoperatively using a hepatectomy simulation system.

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 (P_A-D) and the lateral segmental portal vein (P_LL), 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 (P_A) were evaluated for variations.

RESULTS

In all subjects, the diverging point of the P_A-D was constantly distal to that of the P_LL. 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 P_LL 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 P_A in eight subjects, whereas one predominant P_A-D branched from the P_A in six subjects.

CONCLUSIONS

Based on the diverging points of the P_A-D and P_LL, we proposed a three-step method for the detection and diagnosis of RSRL.