The role of arterial conduits for revascularisation in adult orthotopic liver transplantation

How to Handle Arterial Conduits in Liver Transplantation? Evidence From the First Multicenter Risk Analysis

OBJECTIVE

The aims of the present study were to identify independent risk factors for conduit occlusion, compare outcomes of different AC placement sites, and investigate whether postoperative platelet antiaggregation is protective.

BACKGROUND

Arterial conduits (AC) in liver transplantation (LT) offer an effective rescue option when regular arterial graft revascularization is not feasible. However, the role of the conduit placement site and postoperative antiaggregation is insufficiently answered in the literature.

STUDY DESIGN

This is an international, multicenter cohort study of adult deceased donor LT requiring AC. The study included 14 LT centers and covered the period from January 2007 to December 2016. Primary endpoint was arterial occlusion/patency. Secondary endpoints included intra- and perioperative outcomes and graft and patient survival.

RESULTS

The cohort was composed of 565 LT. Infrarenal aortic placement was performed in 77% of ACs whereas supraceliac placement in 20%. Early occlusion (≤30 days) occurred in 8% of cases. Primary patency was equivalent for supraceliac, infrarenal, and iliac conduits. Multivariate analysis identified donor age >40 years, coronary artery bypass, and no aspirin after LT as independent risk factors for early occlusion. Postoperative antiaggregation regimen differed among centers and was given in 49% of cases. Graft survival was significantly superior for patients receiving aggregation inhibitors after LT.

CONCLUSION

When AC is required for rescue graft revascularization, the conduit placement site seems to be negligible and should follow the surgeon's preference. In this high-risk group, the study supports the concept of postoperative antiaggregation in LT requiring AC.

Infrarenal versus supraceliac aorto-hepatic arterial revascularisation in adult liver transplantation: multicentre retrospective study

When the standard arterial reconstruction is not feasible during liver transplantation (LT), aorto-hepatic arterial reconstruction (AHAR) can be the only solution to save the graft. AHAR can be performed on the infrarenal (IR) or supraceliac (SC) tract of the aorta, but the possible effect on outcome of selecting SC versus IR reconstruction is still unclear. One hundred and twenty consecutive patients who underwent liver transplantation with AHAR in six European centres between January 2003 and December 2018 were retrospectively analysed to ascertain whether the incidence of hepatic artery thrombosis (HAT) was influenced by the type of AHAR (IR-AHAR vs. SC-AHAR). In 56/120 (46.6%) cases, an IR anastomosis was performed, always using an interposition arterial conduit. In the other 64/120 (53.4%) cases, an SC anastomosis was performed; an arterial conduit was used in 45/64 (70.3%) cases. Incidence of early (≤ 30 days) HAT was in 6.2% (4/64) in the SC-AHAR and 10.7% (6/56) IR-AHAR group (p = 0.512) whilst incidence of late HAT was significantly lower in the SC-AHAR group (4.7% (3/64) vs 19.6% (11/56) - p = 0.024). IR-AHAR was the only independent risk factor for HAT (exp[B] = 3.915; 95% CI 1.400-10.951; p = 0.009). When AHAR is necessary at liver transplantation, the use of the supraceliac aorta significantly reduces the incidence of hepatic artery thrombosis and should therefore be recommended whenever possible.

Liver Transplantation

The field of liver transplantation has changed since the MELD scoring system became the most widely used donor allocation tool. Due to the MELD-based allocation system, sicker patients with higher MELD scores are being transplanted. Persistent organ donor shortages remain a challenging issue, and as a result, the wait-list mortality is a persistent problem for most of the regions. This chapter focuses on deceased donor and live donor liver transplantation in patients with complications of portal hypertension. Special attention will also be placed on donor-recipient matching, perioperative management of transplant patients, and the impact of hepatic hemodynamics on transplantation.

Aortic conduit aneurysm and enteric fistula formation in a post-liver transplant patient: A potential causative role for cytomegalovirus?

Hepatic arterial aortic conduits can be used as an alternative means of revascularizing the donor liver when the native recipient hepatic artery (HA) cannot be used. Cytomegalovirus (CMV) is a common Herpesviridae infection in patients who have undergone solid organ transplants. It can be asymptomatic but may cause fever and invasive disease affecting any organ system. Here we describe the first case in the literature of an aortic conduit aneurysm and concurrent CMV viremia following liver transplantation. We speculate on a causative role for CMV in the development of the aneurysm.

A systematic review and meta-analysis of rescue revascularization with arterial conduits in liver transplantation

Although aortohepatic conduits (AHCs) provide an effective technique for arterialization in liver transplantation (LT) when the native recipient artery is unusable, various publications report higher occlusion rates and impaired outcome compared to conventional anastomoses. This systematic review and meta-analysis investigates the published evidence of outcome and risk of AHCs in LT using bibliographic databases and following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Primary and secondary outcome were artery occlusion as well as graft and patient survival. Twenty-three retrospective studies were identified with a total of 22 113 patients with LT, of whom 1900 patients (9%) received an AHC. An AHC was used in 33% of retransplantations. Early artery occlusion occurred in 7% (3%-16%) of patients with AHCs, compared to 2% (1%-3%) without conduit (OR 3.70; 1.63-8.38; P = .001). The retransplantation rate after occlusion was not significantly different in both groups (OR 1.46; 0.67-3.18; P = .35). Graft (HR 1.38; 1.17-1.63; P < .001) and patient (HR 1.57; 1.12-2.20; P = .009) survival was significantly lower in the AHC compared to the nonconduit group. In contrast, graft survival in retransplantations was comparable (HR 1.00; 0.82-1.22; P = .986). Although AHCs provide an important rescue option, when regular revascularization is not feasible during LT, transplant surgeons should be alert of the potential risk of inferior outcome.

Vascular and Biliary Complications Following Deceased Donor Liver Transplantation: A Meta-analysis

OBJECTIVE

To assess biliary and vascular complications after liver transplantations (LTs) sourced from deceased donors.

METHODS

This study reviewed potentially relevant English-language articles gathered from PubMed and Medline published from 2012 to 2017. One additional study was carried out using our institution's database for articles published from 2013 to 2017. Biliary and vascular complications from adult patients receiving their first deceased-donor LT were included. This meta-analysis was performed using Review Manager version 5.2 (Cochrane Collaboration, Copenhagen, Denmark) and the study quality was evaluated using the Newcastle-Ottawa Scale.

RESULTS

Ten studies met our inclusion criteria. Heterogeneity in donation after cardiac death (DCD) and donation after brain death (DBD) recipients was observed and minimized after pooling a subgroup analysis. This latter analysis focused on biliary stricture, biliary leaks and stones, and vascular thrombosis and stenosis. Meta-analyses showed that patients receiving DCD organs have a greatly increased risk of biliary complications compared to those receiving DBD organs, particularly the following: biliary leaks and stones (odds ratio [OR] = 1.69, 95% confidence interval [CI] 1.22-2.34); and biliary stricture (OR = 1.58, 95% CI 1.21-2.06). DCD grafts tended to be but were not significantly associated with DBD regarding vascular thrombosis (OR = 1.62, 95% CI 1.05-2.50), and the risk of vascular stenosis in DCD grafts was not statistically significant (OR = 1.25, 95% CI, .70-2.25).

CONCLUSION

DCD was associated with an increased risk of biliary complications after LT, tended to indicate an increased risk of vascular thrombosis versus, and was not associated with an increased risk of vascular stenosis compared to DBD. There was no significant difference between the grafts.

Liver transplantation in the treatment of severe iatrogenic liver injuries

The place of liver transplantation in the treatment of severe iatrogenic liver injuries has not yet been widely discussed in the literature. Bile duct injuries during cholecystectomy represent the leading cause of liver transplantation in this setting, while other indications after abdominal surgery are less common. Urgent liver transplantation for the treatment of severe iatrogenic liver injury may-represent a surgical challenge requiring technically difficult and time consuming procedures. A debate is ongoing on the need for centralization of complex surgery in tertiary referral centers. The early referral of patients with severe iatrogenic liver injuries to a tertiary center with experienced hepato-pancreato-biliary and transplant surgery has emerged as the best treatment of care. Despite widespread interest in the use of liver transplantation as a treatment option for severe iatrogenic injuries, reported experiences indicate few liver transplants are performed. This review analyzes the literature on liver transplantation after hepatic injury and discusses our own experience along with surgical advances and future prospects in this uncommon transplant setting.