The results of vascular and biliary variations in turks liver donors: comparison with others

Hepatic Hilum Variations and Their Clinical Considerations in the Liver: A Systematic Review and Meta-Analysis

Background: The liver has a region called the hepatic hilum (HH) where structures enter and exit: anteriorly, the left and right hepatic ducts; posteriorly, the portal vein; and between these, the left and right hepatic arteries. The objective of this review is to know how variants in structures of the hepatic hilum are associated with clinical alterations of the liver. Methods: The databases Medline, Scopus, Web of Science, Google Scholar, CINAHL, and LILACS were researched until January 2024. The methodological quality was evaluated with an assurance tool for anatomical studies (AQUA). The pooled prevalence was estimated using a random effects model. Results: A total of six studies met the selection criteria established in this study for meta-analysis. The prevalence of hepatic hilus variants was 9% (CI = 5% to 13%), and the heterogeneity was 83%. The other studies were analyzed descriptively and with their respective clinical considerations in the presence of the variant, such as the high incidence of the Michels type III variant; among the portal vein variants, the type III variant of the Cheng classification stands out and in biliary anatomy, and the IIIa variant stands out according to the Choi classification. Conclusions: This review allowed us to know in detail the anatomical variants of HH; the structure with which the greatest care should be taken is the hepatic artery because of the probability of metastatic processes due to increased blood distribution in the hepatic lobules. Finally, we believe that new anatomical and clinical studies are needed to improve our knowledge of the relationship between HH variants and liver alterations or surgeries.

Importance of Anatomical Variation of the Hepatic Artery for Complicated Liver and Pancreatic Surgeries: A Review Emphasizing Origin and Branching

Knowledge of anatomical variations of the hepatic artery from its origin to intrahepatic segmentation is of utmost importance for planning upper abdominal surgeries including liver transplantation, pancreatoduodenectomy, and biliary reconstruction. The origin and branching pattern of the hepatic artery was thoroughly described by the classification of Michels and Hiatt. Some rare variations of the hepatic artery were classified by Kobayashi and Koops. By the use of the multidetector computed tomography (MDCT) technique, the branching pattern of the hepatic artery can be visualized quite accurately. Unawareness of these arterial variations may lead to intraoperative injuries such as necrosis, abscess, and failure of the liver and pancreas. The origin and course of the aberrant hepatic arteries are crucial in the surgical planning of carcinoma of the head of the pancreas and hepatobiliary surgeries. In liver transplant surgeries, to minimize intraoperative bleeding complications and postoperative thrombosis, exact anatomy of the branching of the hepatic artery, its variations and intrahepatic course is of utmost importance. This review discusses variations in the anatomy of the hepatic artery from its origin to branching by the use of advanced imaging techniques and its effect on the liver, pancreatic, biliary and gastric surgeries.

Living liver donor hilar anatomical variations and impact of variant anatomy on transplant outcomes

Donor anatomy is an essential part of donor selection and operative planning in living donor liver transplantation. In this study, variations of hilar structures, and the effects of variant anatomy on donor and recipient outcomes were evaluated. Living donor liver transplantations in a single center between January 2013 and December 2020 were retrospectively reviewed. In total, 203 liver transplantations were analyzed. Type 1 arterial anatomy, type 1 portal vein anatomy and type 1 bile duct anatomy were observed in 144 (70.9%), 173 (85.2%), and 129 (63.5%) donors, respectively. Variant biliary anatomy was observed more frequent in donors with variant portal vein branching than in those with type 1 portal anatomy (60.0% vs 32.3%, P = .004). The overall survival rates calculated for each hilar structure were similar between recipients receiving grafts with type 1 anatomy and those receiving grafts with variant anatomy. When donors with variant anatomy and donors with type 1 anatomy were compared in terms of hilar structure, no significant difference was observed in the frequency of complications and the frequency of serious complications. Biliary variations are more common in individuals with variant portal vein anatomy. Donor anatomic variations are not risk factors for inferior results of recipient survival or donor morbidity.

Impact of Hepatic Artery Variations and Reconstructions on the Outcome of Orthotopic Liver Transplantation

BACKGROUND

Donor variational arteries often require complex reconstruction.

METHODS

We analysed the incidence of different variations, types of arterial reconstructions and their impact on post-operative results from 409 patients undergoing liver transplantation at Karolinska Institute between 2007 and 2015.

RESULTS

A total of 292 (71.4%) liver grafts had a standard hepatic artery (SHA), and 117 (28.6%) showed hepatic artery variants (HAV). 58% of HAV needed reconstruction. The main variations were variant left hepatic artery (45.3%) from the gastric artery; variant right hepatic artery (38.5%); and a triple combination of variant right and left hepatic artery and the proper hepatic artery from the common hepatic artery (12.8%); other 3.4%. Patients/graft survival and arterial complications were not different between SHA and HAV. Incidence of biliary stricture was numerically higher in left hepatic artery variants (p = 0.058) and in variants where no arterial reconstruction was performed (p = 0.001). Operation and arterial warm ischaemia time were longer in the HAV group. The need for intraoperative re-reconstruction was higher in the HAV group (p = 0.04). Intraoperative bleeding was larger after back-table reconstruction than with intraoperative reconstruction (p = 0.04).

CONCLUSION

No overall differences were found between the HAV and the SHA groups. Occurrence of a variant left hepatic artery and HAV with no reconstruction seems to increase the risk of biliary strictures.

Intrahepatic bile duct variation: MR cholangiography and implication in hepatobiliary surgery

Background

The aim of this study was to assess the prevalence of biliary anatomical variants using 3-T MR cholangiography (MRC) with its impact in reduction of the complication of hepatobiliary surgical techniques.

Results

MRC was applied to 120 subjects (24 potential liver donors and 96 volunteers) and the right posterior hepatic duct insertion was documented, and accordingly, the biliary variants were classified based on Huang classification (Huang et al, Transplant Proc 28: 1669–1670, 1996).

Biliary anatomic variants were divided based on Huang classification: Huang A1, 65.83% (n = 79); Huang A2, 11.67% (n = 14); Huang A3, 13.3% (n = 16); Huang A4, 7.5% (n = 9); and Huang A5, 1.67% (n = 2). The total frequency for A2, A3, A4, and A5 was 34.17% (n = 41). The distance between RPHD insertion and the junction of right and left hepatic ducts (L) was measured, and Huang A1 cases were then subtyped into S1 subtype (L > 1 cm) and S2 subtype (L ≤ 1 cm). We had 52 subjects with subtype S1 (43.33%) and 27 subjects with subtype S2 (22.5%).

Twenty-three subjects had bile duct exploration or intraoperative cholangiograms and showed Huang type A1 in 14 (60.87%), type A2 in 3 (13.05%), and type A3 in 6 (26.08%). Twenty-two (95.65%) had the same classification in MRC and intraoperative while only one case (4.35%) was considered as A2 at MRC but the intraoperative classification was Huang A3, which was attributed to the insertion of the RPHD insertion at the distal end of the left hepatic duct.

Conclusion

MRC is an accurate tool for biliary tract mapping before hepatobiliary surgery to provide excellent identification of biliary variants which can reduce the incidence of biliary complications.