Hepatic arterial anastomosis in adult liver transplantation

Kai-Wun Chang ,Zhe Yang ,Shuo Wang a,,Shu-Sen Zheng

a Zhejiang University School of Medicine,Hangzhou 310 0 0 0,China

b Department of Hepatobiliary and Pancreatic Surgery,Department of Liver Transplantation,Shulan (Hangzhou) Hospital,Zhejiang Shuren University School of Medicine,Hangzhou 310022,China

c Division of Hepatobiliary Pancreatic Surgery,the First Affiliated Hospital,Zhejiang University School of Medicine,Hangzhou 310 0 03,China

d National Clinical Research Center of Infectious Diseases,Hangzhou 310 0 03,China

Hepatic arterial reconstruction remains a critically challenging technique in liver transplantation,as efficient graft and patient survival are dependent on strong and continuous arterial blood supply to the donor liver [1,2].Complex arterial reconstruction has been identified as a crucial risk factor for arterial thrombosis [1–5].Consequently,selecting the appropriate arterial reconstruction method to decrease hepatic artery thrombosis has garnered the attention of the surgical community.

The first case of a standard surgical technique employed in a patient with hepatic malignancy was reported in 1969 [6].Arterial reconstruction was performed through anastomosis of the donor’s celiac trunk to the recipient’s common hepatic artery.Over the past decade,significant advancements have been made in the field of hepatic arterial reconstruction.Several studies have reported favorable outcomes with aortohepatic anastomosis,with or without conduits [7–9],celiac trunk [10,11]or splenic artery [1,4,12]in liver recipients with unusable hepatic arteries due to complete thrombosis,intimal dissection,small size,or inadequate blood flow.Regarding the choice of arterial anastomosis sites,the surgeons either decide intraoperatively after evaluating the quality and blood flow of the recipient hepatic artery or make the decision preoperatively in case of known thrombosis.The surgeon also selects an alternative arterial site based on the surgeon’s judgment [10].

Splenic arterial anastomosis is utilized when hepatic arterial blood flow is insufficient or the velocity of intraoperative blood flow is less than 100 mL/min,as measured by ultrasonography [10,13].Most cases of end-to-end anastomosis are conducted between the splenic artery and the donor celiac trunk [12,14].This end-to-end technique has been proven very effective for hepatic inflow while demonstrating splenic and pancreatic safety [15].However,a few cases of end-to-side anastomosis between the recipient splenic artery and donor celiac trunk have also been reported [14–18].Although the numbers involved in this series are small,this technique was associated with a relatively high rate of postanastomotic intimal hyperplasia [15].Figueras et al.[19]reported the first case of splenic artery anastomosis in a patient diagnosed with sclerosing cholangitis secondary to hepatic ischemia caused by hepatic arterial thrombosis.The postoperative course was favorable,except for positive viremia for cytomegalovirus and leakage from the biliary anastomosis.Several studies have described the use of the splenic artery and found that the incidences of all arterial complications,including early hepatic arterial thrombosis,late hepatic arterial thrombosis,and hepatic arterial stenosis,were equal between the splenic artery and the standard surgical technique and considered splenic arterial reconstruction should be the first alternative after standard hepatic arterial reconstruction [1,2,10,11].

When the recipient’s hepatic artery is not accessible or has been used,or when the spleen needs to be removed,the celiac trunk can provide sufficient blood flow and will be used as the arterial source,reducing the need for further stripping.El-Hinnawi et al.[11]in 2013 reported their 9 cases with the use of the recipient’s celiac trunk as an alternative method for providing arterial inflow to the donor liver allograft in orthotopic liver transplantation without major postoperative complications.Recipient celiac trunk reconstruction has been described in many short reports [10,20,21],and these studies described no complications of the technique after a short-term follow-up.A previous study even found that the patent arterial flow was 100% with a follow-up of 6 to 15 months after using the technique [20].

In more complex cases,aortohepatic conduits have been placed between the infrarenal aorta and hepatic hilum,primarily through the antepancreatic route [22].Nikitin et al.[23]first reported the long-term follow-up (up to 20 years) of aortohepatic conduits,demonstrating that these conduits can be safely used in liver transplantation in consideration of long-term graft survival,patient survival,hepatic arterial complications,or biliary complications.Numerous studies have assessed the outcomes of using aortohepatic conduits [24–27].Although the use of arterial conduits is safe and effective,postoperative thrombosis and biliary complications should be closely monitored.

The reported postoperative mortality rates for various arterial reconstructions are highly variable,primarily due to the data being derived from case reports or small case series,and also due to the varying duration of follow-up.There may also be a significant reporting bias,particularly in reviews based on case reports,as there is a tendency to only report successful cases and not those who did not survive after undergoing such procedures for arterial inflow.In the context of liver transplantation in patients with hepatic arterial thrombosis,the following perioperative questions need to be addressed.How can non-complex hepatic arterial thrombosis be prevented from progressing to complex thrombosis? How can the inflow of thrombosis be prevented into the reconstructed hepatic artery after liver transplantation?

Most patients diagnosed with hepatic arterial thrombosis at the time of liver transplantation had already finished the initial evaluation.This highlights the importance of screening for hepatic arterial thrombosis in cirrhotic patients and potential liver transplant candidates,as well as administering anticoagulants to prevent progression to complex hepatic arterial thrombosis.The anticoagulant dose should be adjusted as the patient advances on the waiting list.In cases where anticoagulant use is contraindicated or hepatic arterial thrombosis progresses despite anticoagulant use,surgical recanalization,retransplantation and endovascular therapy such as catheter-directed thrombolysis may be attempted with the same objective [28–33],namely,to prevent thrombus progression and/or promote recanalization of the hepatic artery,allowing for standard hepatic artery reconstruction during transplantation.

Long-term low-molecular-weight heparin treatment has been proposed to prevent hepatic arterial thrombosis after liver transplantation,especially for patients with documented hypercoagulable states [34].Anticoagulation tends to complicate follow-up in post-liver transplantation patients,due to drug–drug interactions and interference with surgical or endoscopic interventions.Lerut et al.[35]previously pointed out that anticoagulation may not be necessary for all patients after liver transplantation,but may be reserved for those with complete thrombectomy during the transplant or with early development of post-liver transplantation hepatic arterial thrombosis.In patients with a hypercoagulable state or metabolic defect,anticoagulation may not be necessary after liver transplantation as the new liver will correct the situation.

In conclusion,the surgical outcomes of splenic artery,celiac trunk,and aortohepatic anastomosis are similar to those of standard hepatic arterial anastomosis.Therefore,the type of anastomosis depends on the circumstances at the time of liver transplantation.

Acknowledgments

None.

CRediTauthorshipcontributionstatement

Kai-WunChang:Data curation,Formal analysis,Writing -original draft.ZheYang:Conceptualization,Formal analysis,Funding acquisition,Resources,Writing -review &editing.ShuoWang:Formal analysis,Resources,Writing -review &editing.Shu-Sen Zheng:Conceptualization,Funding acquisition,Project administration,Supervision,Writing -review &editing.

Funding

This study was supported by grants from the Fundamental Research Funds for the Central Universities (2022ZFJH003),the Major Research Plan of the National Natural Science Foundation of China (92159202),the Research Project of Jinan Microecological Biomedicine Shandong Laboratory (JNL-2022016B),and Zhejiang Provincial Natural Science Foundation of China g(Y21H160259).

Ethicalapproval

Not needed.

Competinginterest

No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.