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

Laparoscopic cholecystectomy and common bile duct exploration for gallstone and common bile duct stone in a patient with a left-sided gallbladder: a case report

Left-sided gallbladder is a rare finding that is mostly discovered incidentally during surgery and is often associated with anatomic anomalies. We herein report a case in which laparoscopic cholecystectomy and common bile duct exploration were achieved for an 89-year-old female patient with left-sided gallbladder. Surgery was carried out using our usual trocar position. Calot triangle was covered by the body of the gallbladder and could not be detected. We dissected the gallbladder from the fundus towards the neck. The cystic duct joined the common bile duct from the right side, and common bile duct exploration was performed routinely without perioperative comorbidities. Although the preoperative diagnosis rate is low and the risk of intraoperative bile duct injuries in patients with left-sided gallbladder is high, laparoscopic cholecystectomy and common bile duct exploration can be safely performed by understanding the location and bifurcation of the cystic duct.

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.

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.

Role of CT Imaging With Three-Dimensional Maximum Intensity Projection Reconstruction in the Evaluation of Portal Vein Variants at a Tertiary Care Hospital

INTRODUCTION

Portal vein (PV) is the principal blood vessel transporting blood from the alimentary tract and spleen to the liver. The aim of this study is to determine the prevalence of PV anatomical variations in our population using multidetector CT with maximum intensity projection (MIP) technique at a tertiary care hospital.

METHODS

This cross-sectional study was prospectively conducted from November 2018 to June 2019 in the Department of Radiology at a tertiary care hospital in Karachi. After informed consent, all the patients with no known hepatic pathology undergoing routine abdomen CT were included in this study. Patients with previous hepatic resection surgeries, undiagnosed large hepatic tumors/metastasis, and those with PV thrombosis were excluded.

RESULTS

A total of 500 patients (256 males and 244 females) were included in the study; the mean age of female patients was relatively higher as compared to the male patients (53.80 ± 18.44 vs. 44.15 ± 19.94 years; p = 0.000). Standard PV anatomy (type 1) was found in 438 patients (87.6%). Trifurcation (type 2) occurred in 18 patients (3.6%). Right posterior portal vein as the first branch of main PV (type 3) was found in 22 patients (4.4%). A separate branch of the right portal vein (RPV) to segment VII (type 4) and separate branch of the RPV to segment VI (type 5) were found in 6 (1.2%) and 16 (3.2%) patients, respectively.

CONCLUSION

Our study displayed a relatively higher frequency of standard PV anatomy (type 1) compared to previous studies. We highlight the role of MIP in the analysis of hepatic venous anatomy with its utility demonstrating improved detection of variations.

Analysis of right-sided ligamentum teres: The novel anatomical findings and classification

BACKGROUND

The true anatomy of right-sided ligamentum teres (RSLT) has not been fully explained for a century. This study aimed to clarify the exact anatomy of RSLT.

METHODS

The computed tomography data of 17 651 surgical patients were observed and 76 patients with RSLT, were classified into the bilateral ligamentum teres (LT) group (type A) and three RSLT groups, (B) bifurcation type, (C) trifurcation type, and (D) independent posterior branch type.

RESULTS

Type A had double LT that connected to both the right and left sides of the umbilical portion (UP). Types B-D had a P3 + 4 rather than a left UP. Type D was anatomically different from types A-C. Upon comparing types A-C and type D, type D had a significantly smaller volume of segments 3 + 4 (P < .001), and the UP was more often on the left side. The position of the gallbladder fundus in type D was more commonly observed on the right side of the LT compared with that observed in the other types (P = .007).

CONCLUSIONS

The change in the volume of segments 3 + 4 and the extent of the RSLT shift create a false perception that the gallbladder changes the position.

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.

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.