Incidence of Hepatic Artery Variations in Liver Transplantation: Does It Really Influence Short- and Long-Term Results?

Donor hepatic artery reconstruction based on human embryology: A case report

BACKGROUND

Embryonic hepatic artery anatomy simplifies its identification during liver transplantation. Injuries to the donor hepatic artery can cause complications in this process. The hepatic artery's complex anatomy in adults makes this step challenging; however, during embryonic development, the artery and its branches have a simpler relationship. By restoring the embryonic hepatic artery anatomy, surgeons can reduce the risk of damage and increase the procedure's success rate. This approach can lead to improved patient outcomes and lower complication rates.

CASE SUMMARY

In this study, we report a case of donor liver preparation using a donor hepatic artery preparation based on human embryology. During the preparation of the hepatic artery, we restored the anatomy of the celiac trunk, superior mesenteric artery, and their branches to the state of the embryo at 5 wk. This allowed us to dissect the variant hepatic artery from the superior mesenteric artery and left gastric artery during the operation. After implanting the donor liver into the recipient, we observed normal blood flow in the donor hepatic artery, main hepatic artery, and variant hepatic artery, without any leakage.

CONCLUSION

Donor hepatic artery preparation based on human embryology can help reduce the incidence of donor hepatic artery injuries during liver transplantation.

Effect of accessory hepatic artery reconstruction on prognosis in orthotopic liver transplantation: a single center experience

BACKGROUND

In orthotopic liver transplantation (OLT), preserving an aberrant hepatic artery (AHA) can increase the number of arterial anastomoses and may lead to arterial-related complications. AHA includes accessory hepatic artery and replaced hepatic artery. Herein, the purpose of our research is to evaluate the requirement for accessory anastomosis in OLT.

METHODS

We retrospectively reviewed a total of 95 patients who underwent OLT in our hospital between April 2020 and December 2022. We found seven cases of donor livers with accessory HA. The method of arterial anastomosis and details of the diagnosis and treatment of complications were collated.

RESULTS

Among 95 consecutive patients with OLT, complications occurred in two of seven patients-patient 2 had an accessory right hepatic artery, while patient 5 had an accessory left hepatic artery. Patient 2 showed bile leakage leading to rupture and bleeding of the accessory HA anastomosis after OLT, and was treated with interventional coil embolization. In patient 5, hepatic artery thrombosis and accessory HA occlusion were treated with embolization and thrombolysis of the splenic artery and left gastric artery. During the intervention, we also found that the internal hepatic artery and accessory HA had communicating branches. After treatment, both patients remain healthy with no complications such as liver necrosis or liver abscess.

CONCLUSION

An AHA can be ligated when assessed as an accessory artery. This can reduce the incidence of arterial complications, contribute to the perioperative management of liver transplantation (LT) patients, and improve the prognosis of LT.

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.

Graft aberrant hepatic arteries in deceased donor liver transplantation: The "one liver, one artery" approach

In liver transplantation (LT), graft aberrant hepatic arteries (aHAs) frequently require complex arterial reconstructions, potentially increasing the risk of post-operative complications. However, intrahepatic hilar arterial shunts are physiologically present and may allow selective aHA ligation. Thus, we performed a retrospective study from a single-center cohort of 618 deceased donor LTs where a selective reconstruction policy of aHAs was prospectively applied. In the presence of any aHA, the vessel with the largest caliber was first reconstructed. In case of adequate bilobar arterial perfusion assessed on intraparenchymal Doppler ultrasound, the remnant vessel was ligated; otherwise, it was reconstructed. Consequently, outcomes of three patient groups were compared: the "no aHAs" group (n = 499), the "reconstructed aHA" group (n = 25), and the "ligated aHA" group (n = 94). Primary endpoint was rate of biliary complications. Only 38.4% of right aHAs and 3.1% of left aHAs were reconstructed. Rates of biliary complications in the no aHA, reconstructed aHA, and ligated aHA groups were 23.4%, 28%, and 20.2% (p = 0.667), respectively. The prevalence rates of primary non-function (p = 0.534), early allograft dysfunction (p = 0.832), and arterial complications (p = 0.271), as well as patient survival (p = 0.266) were comparable among the three groups. Retransplantation rates were 3.8%, 4%, and 5.3% (p = 0.685), respectively. In conclusion, a selective reconstruction policy of aHAs based on Doppler assessment of bilobar intraparenchymal arterial flow did not increase post-operative morbidity and avoided unnecessary and complex arterial reconstructions.

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.

Anatomic Variations of the Hepatic Artery in 5625 Patients

Purpose

To analyze the origin and anatomic course of the hepatic arteries by using digital subtraction angiography (DSA) and multidetector CT in a large study sample.

Materials and Methods

This retrospective study included 5625 patients who underwent liver CT and chemoembolization between January 2005 and December 2018 (mean age, 60 years ± 11 [range, 11-99 years]; 4464 males). The CT and DSA images were reviewed to evaluate the visceral arterial anatomy for variations in the celiac axis and hepatic arteries. Aberrant right hepatic arteries (aRHAs) and aberrant left hepatic arteries (aLHAs) were defined on the basis of their origin and anatomic course. Statistical analyses were performed to evaluate the association between aRHAs and aLHAs and the association between variations in the hepatic artery and celiac axis.

Results

Right hepatic arteries were categorized as being aRHAs (if originating from the proximal to middle common hepatic artery, gastroduodenal artery, superior mesenteric artery [SMA], celiac axis, aorta, splenic artery, or left gastric artery [LGA]) or as being aLHAs (if arising from the LGA, celiac axis, aorta, or SMA). The prevalence of aRHAs (15.63%; 879 of 5625) and the prevalence aLHAs (16.32%; 918 of 5625) were similar. Patients with an aRHA were more likely to have an aLHA than those without an aRHA (29.01% vs 13.97%; P < .001), and patients with an aLHA were more likely to have an aRHA than those without an aLHA (27.78% vs 13.26%; P < .001). There was no association between the hepatic arterial variations and celiac axis variations. A hypothetical anatomic model summarizing the observed variations was created.

Conclusion

A comprehensive list of hepatic arterial variations and a three-dimensional hypothetical model for the observed variations were described.Keywords: CT, Angiography, Liver, Anatomy, Arteries© RSNA, 2021 Supplemental material is available for this article. See also commentary by Sutphin and Kalva in this issue.

Pyogenic liver abscess in liver transplant recipient: A warning signal for the risk of recurrence and retransplantation

BACKGROUND

Pyogenic liver abscesses in liver transplant recipients (PLA-LTR) are a rare disease whose specificities compared with PLA in non-transplanted patients (PLA-C) are unknown.

METHODS

A retrospective case-control study was conducted in a French academic hospital from January 1, 2010, to December 31, 2014.

RESULTS

Among 176 patients diagnosed with PLA, 14 were LTR; each case was matched with 3 PLA-C controls by date of PLA diagnosis and pathophysiological mechanism of PLA. Median time from liver transplantation to PLA diagnosis was 34.5 months. Among 14 PLA-LTR, 8/14 (57.1%) had bacteremia and 10/14 (71.4%) had positive PLA cultures. Most commonly isolated bacteria were Enterobacteriaceae (9/14; 64.3%), Enterococcus spp. (4/14; 28.6%), and anaerobic bacteria (3/14; 21.4%). Clinical, radiological, and microbiological characteristics did not significantly differ between PLA-LTR and PLA-C but there was a tendency toward more diabetic patients and a less acute presentation. All but one PLA-LTR were associated with ischemic cholangitis, whereas this was a rare cause among PLA-C (13/14 vs 3/42, respectively, P < .001) among patients with PLA-LTR. In contrast, hepatobiliary neoplasia was rare in PLA-LTR but frequent in PLA-C (1/14 vs 24/42, P = .001). No significant difference was found between PLA-LTR and PLA-C in terms of duration of antibiotic therapy (6.5 and 6 weeks, respectively), PLA drainage rates (10/14 and 26/42, respectively), or mortality at 12 months after PLA diagnosis (2/14 and 5/42, respectively). Recurrence rates within the first year were observed in 6/14 patients (42.9%), and retransplantation was needed in 5/14 (35.7%).

CONCLUSIONS

Occurrence of PLA in LTR is a severe event leading to high risk of recurrence and retransplantation.

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.

Aberrant left gastric vein is associated with hepatic artery variations

OBJECTIVE

To investigate the imaging findings and hepatic artery variations encountered in patients with aberrant left gastric vein (ALGV).

METHODS

A retrospective database search between January 2014 and November 2018 was carried for ALGV. The course and types (1-3) of ALGV, the presence of associated liver lesions, and coexistence of hepatic artery variations were reviewed on CT images.

RESULTS

A total of 32 patients (22 men, 68.7%) with a mean age of 52.5 years (range 22-76 years) were found to have ALGV. The prevalence of ALGV was 0.073%. The most frequent type of ALGV was type 1 (n = 22, 68.7%), followed by type 3 (n = 7, 21.8%) and type 2 (n = 3, 9.3%). We noticed mild-to-severe parenchymal hyperdensity at the posterior aspect of segments II and III in patients with type 1 (n = 20/22) and type 2 (n = 2/3) ALGV consistent with fat sparing due to third inflow effect. Two out of seven patients with type 3 ALGV had main portal vein thrombosis; however, the presence of ALGV maintained left portal vein flow in these patients. Twelve (37.5%) patients had accompanying hepatic artery variation. Left hepatic and right hepatic artery variations were detected in 8 (25%) and 2 (6.25%) of the patients, respectively. In 2 patients, Michels type IV variation was detected.

CONCLUSION

Aberrant left gastric vein is associated with hepatic artery variations, which can be important for preoperative and pretransplant planning.

Vascular Anomalies of the Extrahepatic Artery as a Predictable Risk Factor for Complications After Liver Transplant

OBJECTIVES

Vascular variations of the extrahepatic artery occur in up to 50% of the population. Exact knowledge of any anomalies is of great significance in hepatobiliary surgery to avoid perioperative complications. In fact, in liver transplant, vascular complications are rare but have a major impact on graft function and survival. This study evaluated variations of the extrahepatic artery in donors and recipients as risk factors for vascular complications after liver transplant.

MATERIALS AND METHODS

From January 2010 until June 2015, 469 liver transplant procedures were performed at our institution. We included 323 patients in our retrospective analysis after exclusion of retransplants, split-livertransplants, and pediatric patients. We analyzed the impact of anatomic variations of recipients and donors on postoperative vascular complications and organ and patient survival.

RESULTS

Of total study recipients, 71.2% had a normal vascular supply according to Michel classification I. However, these patients developed significantly more vascular complications (25.65%) than those with vascular anomalies (15.05%), especially showing higher incidence of arterial stenosis (8.26% vs 2.15%). In contrast, vascular variations in donors and the need for a vascular reconstruction of the graft led to significantly higher mortality (26.76% vs 15.48%). An abnormality of the graft did not influence incidence of postoperative complications or graft survival.

CONCLUSIONS

Unexpectedly, recipients with variations of the hepatic artery and grafts with an abnormal arterial supply did not show higher rates of com-plications or mortality. Only vascular reconstruction of the graft before transplant raised the mortality of recipients.

Anatomical variations of the celiac trunk and hepatic arterial system: an analysis using multidetector computed tomography angiography

OBJECTIVE

To analyze the prevalence of anatomical variations of celiac arterial trunk (CAT) branches and hepatic arterial system (HAS), as well as the CAT diameter, length and distance to the superior mesenteric artery.

MATERIALS AND METHODS

Retrospective, cross-sectional and predominantly descriptive study based on the analysis of multidetector computed tomography images of 60 patients.

RESULTS

The celiac trunk anatomy was normal in 90% of cases. Hepatosplenic trunk was found in 8.3% of patients, and hepatogastric trunk in 1.7%. Variation of the HAS was observed in 21.7% of cases, including anomalous location of the right hepatic artery in 8.3% of cases, and of the left hepatic artery, in 5%. Also, cases of joint relocation of right and left hepatic arteries, and trifurcation of the proper hepatic artery were observed, respectively, in 3 (5%) and 2 (3.3%) patients. Mean length and caliber of the CAT were 2.3 cm and 0.8 cm, respectively. Mean distance between CAT and superior mesenteric artery was 1.2 cm (standard deviation = 4.08). A significant correlation was observed between CAT diameter and length, and CAT diameter and distance to superior mesenteric artery.

CONCLUSION

The pattern of CAT variations and diameter corroborate the majority of the literature data. However, this does not happen in relation to the HAS.