Interventional Treatment for Hepatic Artery Thrombosis after Liver Transplantation

Algorithmic Approach to Deranged Liver Functions After Transplantation

Liver transplant (LT) recipients require close follow-up with regular monitoring of the liver function tests (LFTs). Evaluation of deranged LFT should be individualized depending upon the time since LT, peri-operative events, clinical course, and any complications. These derangements can range from mild and asymptomatic to severe and symptomatic elevations requiring expedited personalized assessment and management. Pattern of LFT derangement (hepatocellular, cholestatic, or mixed), donor-recipient risk factors, timing after LT (post-operative, 1-12 months, and >12 months since LT) along with clinical context and symptomatology are important considerations before proceeding with the initial evaluation. Compliance to immunosuppression and drug interactions should be ascertained along with local epidemiology of infections. Essential initial evaluation must include an ultrasound abdomen with Doppler to rule out any structural causes such as biliary or vascular complications apart from focussed laboratory evaluation. Early allograft dysfunction, ischemia reperfusion injury, small-for-size syndrome, biliary leaks, hepatic artery, and portal vein thrombosis are usual culprits in the early post-operative period whereas viral hepatitis (acute or reactivation), opportunistic infections, and recurrence of the primary disease are more frequent in the later period. Graft rejection, biliary strictures, sepsis, and drug induced liver injury remain possible etiologies at all times points after LT. Initial evaluation algorithm must be customized based on history, clinical examination, risk factors, and pattern and severity of deranged LFT. Allograft rejection is a diagnosis of exclusion and requires liver biopsy to confirm and assess severity. Empirical treatment of rejection sans liver biopsy is discouraged.

Improving the radiological diagnosis of hepatic artery thrombosis after liver transplantation: Current approaches and future challenges

Hepatic artery thrombosis (HAT) is a devastating vascular complication following liver transplantation, requiring prompt diagnosis and rapid revascularization treatment to prevent graft loss. At present, imaging modalities such as ultrasound, computed tomography, and magnetic resonance play crucial roles in diagnosing HAT. Although imaging techniques have improved sensitivity and specificity for HAT diagnosis, they have limitations that hinder the timely diagnosis of this complication. In this sense, the emergence of artificial intelligence (AI) presents a transformative opportunity to address these diagnostic limitations. The develo pment of machine learning algorithms and deep neural networks has demon strated the potential to enhance the precision diagnosis of liver transplant com plications, enabling quicker and more accurate detection of HAT. This article examines the current landscape of imaging diagnostic techniques for HAT and explores the emerging role of AI in addressing future challenges in the diagnosis of HAT after liver transplant.

Complications in Post-Liver Transplant Patients

Liver transplantation (LT) is the treatment of choice for liver failure and selected cases of malignancies. Transplantation activity has increased over the years, and indications for LT have been widened, leading to organ shortage. To face this condition, a high selection of recipients with prioritizing systems and an enlargement of the donor pool were necessary. Several authors published their case series reporting the results obtained with the use of marginal donors, which seem to have progressively improved over the years. The introduction of in situ and ex situ machine perfusion, although still strongly debated, and better knowledge and treatment of the complications may have a role in achieving better results. With longer survival rates, a significant number of patients will suffer from long-term complications. An extensive review of the literature concerning short- and long-term outcomes is reported trying to highlight the most recent findings. The heterogeneity of the behaviors within the different centers is evident, leading to a difficult comparison of the results and making explicit the need to obtain more consent from experts.

Hepatic artery-related complications after live donor liver transplantation

BACKGROUND

Hepatic artery-related complications (HARC) after live donor liver transplantation (LDLT) is associated with high morbidity and mortality rate.

METHODS

Prospectively maintained data from July 2011 to September 2020 was analyzed for etiology, detection, management, and outcome of HARC.

RESULTS

Six hundred fifty-seven LDLT (adult 572/pediatrics 85) were performed during the study period. Twenty-one (3.2%) patient developed HARC; 16 (2.4%) hepatic artery thrombosis (HAT) and 5 (0.76%) non-thrombotic hepatic artery complication (NTHAC). Ninety percent (19/21) HARC were asymptomatic and detected on protocol Doppler. Median time to detection was day 4 (range - 1 to 35), which included 18 early (within 7 days) vs 3 late incidents. Only one pediatric patient had HAT. Seven patients underwent surgical revascularization, 11 had endovascular intervention and 3 with attenuated flow required only systemic anticoagulation. All NTHAC survived without any sequelae. Revascularization was successful in 81% (13/16) with HAT. Biliary complications were seen in 5 (23.8%); four were managed successfully. Overall mortality was 14.8% (3/21). The 1-year and 5-year survival were similar to those who did not develop HARC (80.9% vs 84.2%, p = 0.27 and 71.4% vs 75.19%, p = 0.36 respectively) but biliary complications were significantly higher (23.8% vs 14.2%, p = 0.03). On multivariate analysis, clockwise technique of arterial reconstruction was associated with decreased risk of HAT (1.7% vs 4.1% (p value - 0.003)).

CONCLUSION

Technical refinement, early detection, and revascularization can achieve good outcome in patients with HARC after LDLT.

Our evolution in the treatment of hepatic artery and portal vein thrombosis in pediatric liver transplantation: Success with catheter-directed therapies

BACKGROUND

In pediatric liver transplant recipients, hepatic artery thrombosis and portal vein thrombosis are major causes of acute graft failure and mortality within 30 days of transplantation. There is, however, a strong possibility of graft salvage if flow can be re-established to reduce ischemic injury. The current standard treatment is surgical revascularization, and if unsuccessful, retransplantation. Due to our success in treating these complications with catheter-directed therapies, we sought to summarize and publish the outcomes of all patients who experienced hepatic artery thrombosis or portal vein thrombosis within 30 days of liver transplantation.

METHODS

We conducted a retrospective cohort analysis of 27 pediatric liver transplant recipients who experienced hepatic artery thrombosis (n = 13), portal vein thrombosis (n = 9), or both (n = 5) between September 2012 and March 2021. We collected and tabulated data on the patients and therapies performed to treat them, including success rates, primary and secondary patency, and clinical outcomes.

RESULTS

Among these patients, 6 were managed with anticoagulation and relisting for transplant and 21 had a primary revascularization attempt. Surgical recanalization was attempted in 7 patients of which 3 had successful recanalization (43%) and catheter-directed recanalization was attempted in 14 patients with 100% success in re-establishing blood flow to the graft. Additionally, patency was increased, and mortality was decreased in patients treated with catheter-directed recanalization compared to surgical revascularization or anticoagulation alone.

CONCLUSION

This data illustrates the need to further investigate catheter-directed thrombolysis as a potential first-line treatment for postoperative HAT and PVT in pediatric liver transplant recipients.

Hepatic Artery Thrombosis After Orthotopic Liver Transplant: Experience in the Last 10 Years

BACKGROUND

Hepatic artery thrombosis (HAT) is the second cause of graft failure, after primary disfunction. It has a significant morbidity, with a retransplant and mortality rate in early hepatic artery thrombosis of 50%. The incidence of this event goes from 2% to 9% in the adult population.

METHODS

The objective is to assess the incidence of HAT in a third-level hospital. The study design is an observational retrospective study, collecting data of the transplant recipient from 2010 to 2020.

RESULTS

Incidence of HAT was 5.33% (39/732). A statistical difference was found with the blood intraoperative administration (P = .002) and with the presence of anatomic abnormalities in the hepatic artery between the HAT and the non-HAT group. We did not find any statistical difference with portal thrombosis (P = .73) between the groups.

CONCLUSIONS

HAT is a fatal complication after an orthotopic liver transplant, which can lead to graft loss and even recipient death. For these reasons, we should early identify risk factors associated with this event early and try to minimize them to avoid the devastating consequences.

Endovascular thromboaspiration with neurointerventional devices for early hepatic artery thrombosis after split liver transplant

We report the case of a 38-year-old woman who underwent orthotopic 'split' liver transplant, complicated by hepatic artery thrombosis on the first postoperative day. The patient was successfully treated with an endovascular approach by mechanical thromboaspiration of the hepatic artery, using neurovascular devices, angioplasty and stenting at the site of the surgical anastomosis.

Liver Transplantation in Children: An Overview of Organ Allocation and Surgical Management

Liver transplantation is the standard treatment for children with end-stage liver disease, primary hepatic neoplasms, or liver-localized metabolic defects. Perioperative mortality is almost absent, and long-term survival exceeds 90%. Organ shortage is managed thanks to advances in organ retrieval techniques; living donation and partial liver transplantation almost eliminated waiting list mortality, thus leading to expanding indications for transplantation. The success of pediatric liver transplantation depends on the prompt and early referral of patients to transplant Centers and on the close and integrated multidisciplinary collaboration between pediatricians, hepatologists, surgeons, intensivists, oncologists, pathologists, coordinating nurses, psychologists, and social workers.

Safety and efficacy of an integrated endovascular treatment strategy for early hepatic artery occlusion after liver transplantation

BACKGROUND

Hepatic artery occlusion (HAO) after liver transplantation (LT) is typically comprised of hepatic artery thrombosis (HAT) and stenosis (HAS), both of which are severe complications that coexist and interdependent. This study aimed to evaluate an integrated endovascular treatment (EVT) strategy for the resolution of early HAO and identify the risk factors associated with early HAO as well as the procedural challenge encountered in the treatment strategy.

METHODS

Consecutive orthotopic LT recipients (n = 366) who underwent transplantation between June 2017 and December 2018 were retrospectively investigated. EVT was performed using an integrated strategy that involved thrombolytic therapy, shunt artery embolization plus vasodilator therapy, percutaneous transluminal angioplasty, and/or stent placement. Simple EVT was defined as the clinical resolution of HAO by one round of EVT with thrombolytic therapy and/or shunt artery embolization plus vasodilator therapy. Otherwise, it was defined as complex EVT.

RESULTS

Twenty-six patients (median age 52 years) underwent EVT for early HAO that occurred within 30 days post-LT. The median interval from LT to EVT was 7 (6-16) days. Revascularization time (OR = 1.027; 95% CI: 1.005-1.050; P = 0.018) and the need for conduit (OR = 3.558; 95% CI: 1.241-10.203, P = 0.018) were independent predictors for early HAO. HAT was diagnosed in eight patients, and four out of those presented with concomitant HAS. We achieved 100% technical success and recanalization by performing simple EVT in 19 patients (3 HAT+/HAS- and 16 HAT-/HAS+) and by performing complex EVT in seven patients (1 HAT+/HAS-, 4 HAT+/HAS+, and 2 HAT-/HAS+), without major complications. The primary assisted patency rates at 1, 6, and 12 months were all 100%. The cumulative overall survival rates at 1, 6, and 12 months were 88.5%, 88.5%, and 80.8%, respectively. Autologous transfusion < 600 mL (94.74% vs. 42.86%, P = 0.010) and interrupted suture for hepatic artery anastomosis (78.95% vs. 14.29%, P = 0.005) were more prevalent in simple EVT.

CONCLUSIONS

The integrated EVT strategy was a feasible approach providing effective resolution with excellent safety for early HAO after LT. Appropriate autologous transfusion and interrupted suture technique helped simplify EVT.

Endovascular Treatment of Aortohepatic Conduit Stenosis Following Liver Transplant

BACKGROUND

Aortohepatic conduits (AHCs) are valuable alternatives when conventional hepatic artery anastomoses are not possible. However, AHCs have earlier and higher occlusion rates and reduced graft and patient survival. While endovascular therapy is safe and effective for conventional anastomotic stenoses, data on AHC stenoses are limited. This study reviewed outcomes for endovascular management of AHC stenosis at a single liver transplant center.

METHODS

A retrospective review of a prospectively maintained database was performed on the endovascular management of AHC stenosis between January 1, 2000, and December 31, 2016. Medical records, laboratory data, and imaging were analyzed for technical and hemodynamic success, primary and assisted primary patency, and patient and graft survival.

RESULTS

Seven patients underwent angioplasty a median of 142 days after transplant, and 2 required reintervention. The primary patency rate was 67% at 6 months and 22% at 1 year. The assisted primary patency rate was 83% at 6 months and 42% at 1, 3, and 5 years. Patient and graft survival were 86% at 6 months and 71%, 57%, and 38% at 1, 3, and 5 years, respectively. Four conduits were patent at last follow-up. There were no major adverse events after angioplasty. One reintervention was complicated by acute AHC thrombosis after stenting, causing biliary necrosis, sepsis, and death. There was no 30-day mortality, retransplant, or surgical revascularization because of endovascular intervention.

CONCLUSIONS

Endovascular treatment of AHC stenosis appears to be safe with a high technical success rate but lower long-term patency than standard hepatic arterial anastomoses.

The devil is in the detail: current management of perioperative surgical complications after liver transplantation

PURPOSE OF REVIEW

Despite advances in the field, perioperative morbidity is common after liver transplantation. This review examines the current literature to provide up-to-date management of common surgical complications associated with liver transplantation.

RECENT FINDINGS

Research focuses on problems with anastomoses of the vena cava, portal vein, hepatic artery, and bile ducts. Interventional endoscopic and radiological techniques are used more frequently to avoid reoperation.

SUMMARY

Advances in the management of perioperative surgical complications have focused on minimally invasive measures that successfully treat technical problems with implantation of liver allografts from both living and deceased donors.

Hepatic artery occlusion in liver transplantation: What counts more, the type of reconstruction or the severity of the recipient's disease?

Although the type of hepatic artery revascularization technique is known to have an impact on patency rates, independent perioperative risk factors on patient outcomes are poorly defined. All consecutive adult patients undergoing cadaveric liver transplantation (n = 361) from July 2007 to June 2016 in a single institution were analyzed. Primary outcomes were early (<30 days) hepatic artery occlusion and primary hepatic artery patency rate. A multivariate model was used to identify independent risk factors for occlusion and the need of arterial conduit, as well as their impact on graft and patient survival. Arterial revascularization without additional reconstruction (end-to-end arterial anastomosis [AA]) was performed in 77% (n = 279), arterial reconstruction (AR) in 15% (n = 53), and aortohepatic conduit (AHC) in 8% (n = 29) of patients. AHC had the highest mean intraoperative flow (275 mL/minute; P = 0.02) compared with AA (250 mL/minute) and AR (200 mL/minute; P = 0.02). There were 43 recipients (12%) who had an occlusive event with successful revascularization in 20 (47%) recipients. One-year primary patency rates of AA, AR, and AHC were 97%, 88%, and 74%, respectively. Aortic calcification had an impact on early occlusion. AR (odds ratio [OR], 3.68; 95% confidence interval [CI], 1.26-10.75; P = 0.02) and AHC (OR, 6.21; 95% CI, 2.02-18.87; P = 0.001) were independent risk factors for early occlusion. Dyslipidemia additionally independently contributed to early occlusion (OR, 2.74; 95% CI, 0.96-7.87; P = 0.06). The 1- and 5-year graft survival rates were 83% and 70% for AA, 75% and 69% for AR, and 59% and 50% for AHC (P = 0.004), respectively. In conclusion, arterial patency is primarily determined by the type of vascular reconstruction rather than patient or disease characteristics. The preoperative lipid status is an independent risk factor for early occlusion, whereas overall occlusion is only based on the performed vascular reconstruction, which is also associated with reduced graft and patient survival. Liver Transplantation 24 790-802 2018 AASLD.

Transplant artery thrombosis and outcomes

Post-transplantation allograft arterial thrombosis is a well-recognized complication associated with solid organ transplantation. Much of the literature is centered on liver and kidney transplantation, which will therefore serve as the principle basis for this review, with a brief discussion on pancreas transplantation and associated arterial complications. The number of solid organ transplants has been steadily increasing over the past decade in parallel with growing demand for organs and expansion of the transplantation criteria for both donors and recipients. This increase has been accompanied by a number of innovative medical advances and surgical techniques, as well as improved imaging that has allowed for thoughtful exploration of vascular anatomic variants and the possibilities for transplant with which they are associated. It has also been accompanied by a growing field of behavioral research, as potential recipients must weigh the risk of accepting certain organs based on perceived outcomes that may differ according to the quality of the underlying organ. Improvements in imaging technology have brought greater sensitivity to detecting arterial complications in post-operative surveillance examinations and have allowed for further development of tailored endovascular and surgical interventions for transplant-associated vascular complications. This review will focus on post-transplantation solid organ allograft artery thrombosis, including discussion of risk factors, diagnostic imaging, natural history, and therapeutic options.