The shortage of organs has pushed transplant surgeons to accept liver grafts with extended criteria, but severe vascular abnormalities may still discourage the use of otherwise acceptable organs. We report herein the case of a liver graft with a 64-mm aneurysm of the proper hepatic artery extended to the origin of the right and left hepatic branches. The graft was deemed unsuitable for transplant by all other centers in the region. However, liver function tests were normal, and there was no evidence of compromised arterial supply. At back table, we resected the aneurysm and anastomosed the right and left hepatic arteries to a vascular graft obtained from the distal tract of the donor’s superior mesenteric artery. After portal reperfusion, we anastomosed the mesenteric graft to the recipient’s hepatic artery at the origin of the gastroduodenal artery. The postoperative course and the subsequent 6-month follow-up were uneventful. In conclusion, the presence of a hepatic artery aneurysm should not be an absolute contraindication to the use of a liver graft. The present case emphasizes the possibility to utilize an organ that would have been otherwise discarded.

Key words : Extended criteria donors, Liver transplantation, Vascular abnormalities

Introduction

Liver transplant is the most effective treatment for end-stage liver disease and hepatocellular carcinoma, but the shortage of transplantable organs still restrains its clinical application. To increase the number of available organs, many centers now accept liver grafts from donors with extended criteria. Although historically associated with poorer outcomes, these grafts can be used safely and effectively after careful selection and matching with the appropriate recipient.¹ However, severe arterial abnormalities in the donor may still discourage the use of otherwise acceptable organs.^2,3 We report herein the case of a liver graft with an aneurysm of the proper hepatic artery, which was successfully transplanted after back-table reconstruction.

Case Report

A 74-year-old male donor who was pronounced brain dead due to subarachnoid hemorrhage was offered to our center for liver transplant. Liver function tests were normal, with aspartate transaminase of 40 IU/L, alanine transaminase of 38 IU/L, and total bilirubin of 0.75 mg/dL. However, computerized tomography scans demonstrated a proper hepatic artery aneurysm of 64 × 49 mm in diameter, which extended to the origin of the right and left hepatic arteries; the common hepatic artery arose from the superior mesenteric artery (Figure 1).

Although the graft was deemed unsuitable for transplant by all other centers in the region, we decided to proceed with surgical exploration. Before cold perfusion, we dissected the aneurysm from the other hilar elements and followed the hepatic artery behind the pancreas up to its mesenteric origin (Figure 2A). At back table and under loupe magnification, we resected the aneurysm and reconstructed the left and right hepatic arteries on a vascular graft obtained from the donor’s distal tract of the superior mesenteric artery (Figure 2B). All collaterals of the mesenteric graft were accurately ligated, apart from the ileocolic bifurcation, which was used for the anastomosis.

The recipient was a 49-year-old man with hepatitis C virus-related cirrhosis and a laboratory Model of End-Stage Liver Disease score of 29. Liver transplant was performed using the piggy-back technique without venovenous bypass. For arte­rialization, we anastomosed the mesenteric graft to the recipient’s hepatic artery at the origin of the gastroduodenal artery. Total cold ischemia time was 472 minutes. After arterial reperfusion, the artery was assessed for pulse and thrill, and Doppler ultraso­nography confirmed a valid intrahepatic arterial flow. Alanine amino­transferase level peaked at 2145 IU/L at 12 hours after transplant, which was then followed by a constant downward trend and normalization within week 3 posttransplant. No arterial filling defects were detected on postoperative computed tomography scan (Figure 3).

The patient was put on aspirin as standard management in our center in cases of multiple arterial anastomoses. The postoperative course was uneventful, and no complications were observed after a total follow-up of 6 months.

Discussion

The imbalance between the increasing number of patients on wait lists and the scarcity of donors has led many transplant centers to accept liver grafts from donors with extended criteria.¹ Furthermore, the increase in life expectancy over the past decades has simultaneously increased deceased donor age, with older donors at risk of age-related diseases, such as atherosclerosis.^2,4 Vascular diseases and abnormalities in the donor may still discourage the use of otherwise acceptable grafts. In fact, the hepatic artery anastomosis is one of the major technical challenges in liver transplant, as graft recovery and viability of the biliary tree heavily depend on the arterial blood flow.

In our present case, despite the finding of a hepatic artery aneurysm, we judged the liver graft suitable for transplant because there was no evidence of compromised arterial supply or graft dysfunction. The aneurysm extension to the origin of the right and left hepatic arteries implied reconstruction on an appropriate vascular graft. We chose the distal tract of the superior mesenteric artery because the ileocolic artery had favorable anatomy for reconstruction and a diameter similar to the right and left hepatic arteries. We preferred back-table reconstruction to reconstruction after portal reperfusion because this second option would have considerably increased warm ischemia time. Moreover, in this way, we were able to assess the arterial reconstruction before implantation. Given the need for back-table recon­struction, coordination between procurement and recipient teams helped keep total cold ischemia time to less than 8 hours, as this has been shown to improve transplant outcomes, especially with older donors.⁵

Few other reports of liver donors with hepatic artery aneurysms exist in the literature, and data are scarce on the long-term outcomes of these grafts.⁶ Liver grafts with arterial variations requiring reconstruction with more than one anastomosis have been traditionally associated with a higher com­plication rate.⁷ However, recent research has shown that these grafts can be used safely with a rigorous technique of reconstruction.⁸ Therefore, it is likely that the same rule applies to other vascular abnormalities such as arterial aneurysms.

Conclusions

The presence of a hepatic artery aneurysm should not be an absolute contraindication to the use of a liver graft. Although liver grafts with vascular abnormalities and complex reconstructions may be associated with an increased risk of complications, the present case emphasizes the possibility to utilize an organ that would have been otherwise discarded.

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