Retransplantation in Late Hepatic Artery Thrombosis: Graft Access and Transplant Outcome

Early thrombotic and hemorrhagic complications associated with a risk-adjusted postoperative anticoagulation protocol after pediatric liver transplantation

BACKGROUND

Systemic anticoagulation after pediatric liver transplantation (pLT) is believed to reduce the incidence of vascular thrombosis, but it may also cause an increase in hemorrhagic complications.

PROCEDURE

A 5-year retrospective review of pLT done at our institution was performed (2014-2018). The occurrence of early hemorrhagic and thrombotic complications was compared when using low-dose or high-dose anticoagulation after transplant (p < .05 considered significant).

RESULTS

Sixty-nine patients received 73 transplants during the study period. Median age at transplant was 2.3 years (40 days to 18.5 years). Low-dose anticoagulation was utilized in 71% cases. Additionally, six patients were converted from low-dose to high-dose anticoagulation because of a thrombotic event or concerns for suboptimal vascular inflow. Postoperative anticoagulation was discontinued in 18 occurrences due to bleeding (low dose 19%, high dose 47% vs. low dose to high dose 17%, p = .085). Surgical take back for bleeding occurred in 17 occasions (low dose 13.5%, high dose 53% vs. low dose to high dose 33%, p = .005). The overall incidence of hepatic artery thrombosis (HAT) and portal vein thrombosis were each 5.5%, respectively. While patient survival was not statistically different between groups, graft survival was significantly lower in the high-dose group (low dose 93%, high dose 73% vs. low dose to high dose 100%, p = .046). However, graft losses from HAT were similar between groups (low dose 2%, high dose 7% vs. low dose to high dose 0%, p = .56).

CONCLUSION

The use of a standardized risk-adjusted anticoagulation protocol after pLT is associated with a low occurrence of thrombotic and hemorrhagic complications. High-dose anticoagulation leads to more bleeding, but those risks outweigh the risks of possible graft loss.

Normothermic Machine Perfusion—Improving the Supply of Transplantable Livers for High-Risk Recipients

The effectiveness of liver transplantation to cure numerous diseases, alleviate suffering, and improve patient survival has led to an ever increasing demand. Improvements in preoperative management, surgical technique, and postoperative care have allowed increasingly complicated and high-risk patients to be safely transplanted. As a result, many patients are safely transplanted in the modern era that would have been considered untransplantable in times gone by. Despite this, more gains are possible as the science behind transplantation is increasingly understood. Normothermic machine perfusion of liver grafts builds on these gains further by increasing the safe use of grafts with suboptimal features, through objective assessment of both hepatocyte and cholangiocyte function. This technology can minimize cold ischemia, but prolong total preservation time, with particular benefits for suboptimal grafts and surgically challenging recipients. In addition to more physiological and favorable preservation conditions for grafts with risk factors for poor outcome, the extended preservation time benefits operative logistics by allowing a careful explant and complicated vascular reconstruction when presented with challenging surgical scenarios. This technology represents a significant advancement in graft preservation techniques and the transplant community must continue to incorporate this technology to ensure the benefits of liver transplant are maximized.

Normothermic Machine Perfusion as a Tool for Safe Transplantation of High-Risk Recipients

Normothermic machine perfusion (NMP) should no longer be considered a novel liver graft preservation strategy, but rather viewed as the standard of care for certain graft–recipient scenarios. The ability of NMP to improve the safe utilisation of liver grafts has been demonstrated in several publications, from numerous centres. This is partly mediated by its ability to limit the cold ischaemic time while also extending the total preservation period, facilitating the difficult logistics of a challenging transplant operation. Viability assessment of both the hepatocytes and cholangiocytes with NMP is much debated, with numerous different parameters and thresholds associated with a reduction in the incidence of primary non-function and biliary strictures. Maximising the utilisation of liver grafts is important as many patients require transplantation on an urgent basis, the waiting list is long, and significant morbidity and mortality is experienced by patients awaiting transplants. If applied in an appropriate manner, NMP has the ability to expand the pool of grafts available for even the sickest and most challenging of recipients. In addition, this is the group of patients that consume significant healthcare resources and, therefore, justify the additional expense of NMP. This review describes, with case examples, how NMP can be utilised to salvage suboptimal grafts, and our approach of transplanting them into high-risk recipients.

Biliary Strictures Are Associated With Both Early and Late Hepatic Artery Stenosis

Background.

Hepatic artery stenosis (HAS) following liver transplantation results in hypoperfusion and ischemic damage to the biliary tree. This study aimed to investigate how vascular intervention, liver function test derangement, and time point of HAS onset influence biliary complications.

Methods.

A single-center retrospective study of adult patients that underwent primary liver transplantation. Patients were grouped according to the presence or absence of HAS and then into early (≤90 d) or late (>90 d) subgroups. Biliary complications comprised anastomotic (AS) or non ASs (NASs).

Results.

Computed tomography angiography confirmed HAS was present in 39 of 1232 patients (3.2%). This occurred at ≤90 and >90 days in 20 (1.6%) and 19 (1.5%), respectively. The incidence of biliary strictures (BSs) in the group with HAS was higher than the group without (13/39; 33% versus 85/1193; 7.1%, P = 0.01). BS occurred in 8/20 (40.0%) and 5/19 (26.3%) of the early and late groups, respectively. The need for biliary intervention increased if any liver function test result was ≥3× upper limit of normal (P = 0.019).

Conclusions.

BS occurs at a significantly higher rate in the presence of HAS. Onset of HAS at ≤90 or ≥90 days can both be associated with morbidity. Significant liver function test derangement at HAS diagnosis indicates a higher likelihood of biliary intervention for strictures.

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.

VI consensus document by the Spanish Liver Transplantation Society

The goal of the Spanish Liver Transplantation Society (La Sociedad Española de Trasplante Hepático) is to promote and create consensus documents about current topics in liver transplantation with a multidisciplinary approach. To this end, on October 20, 2016, the 6th Consensus Document Meeting was held, with the participation of experts from the 24 authorized Spanish liver transplantation programs. This Edition discusses the following subjects, whose summary is offered below: 1) limits of simultaneous liver-kidney transplantation; 2) limits of elective liver re-transplantation; and 3) liver transplantation after resection and hepatocellular carcinoma with factors for a poor prognosis. The consensus conclusions for each of these topics is provided below.

Ischemic Cholangiopathy 11 Years after Liver Transplantation from Asymptomatic Chronic Hepatic Artery Thrombosis

Hepatic artery thrombosis is a concerning complication of orthotopic liver transplantation, and it most often occurs early in the posttransplant period. However, on rare occasions it can occur at a time remote from transplant. We present a case of ischemic cholangiopathy complicated by stricture and anastomotic bile leak from chronic hepatic artery thrombosis that occurred 11 years after the transplant. The initial biliary stenting helped with the resolution of the leak but she was found to have stones, sludge and copious pus at the time of stent exchange. Hepatic arteriography demonstrated complete occlusion of the transplant hepatic artery with periportal collaterals reconstituting intrahepatic hepatic arterial branches. The patient was subsequently referred for repeat liver transplantation.

VI consensus document by the Spanish Liver Transplantation Society

The goal of the Spanish Liver Transplantation Society (La Sociedad Española de Trasplante Hepático) is to promote and create consensus documents about current topics in liver transplantation with a multidisciplinary approach. To this end, on October 20, 2016, the 6th Consensus Document Meeting was held, with the participation of experts from the 24 authorized Spanish liver transplantation programs. This Edition discusses the following subjects, whose summary is offered below: 1) limits of simultaneous liver-kidney transplantation; 2) limits of elective liver re-transplantation; and 3) liver transplantation after resection and hepatocellular carcinoma with factors for a poor prognosis. The consensus conclusions for each of these topics is provided below.