Hepatic artery stenosis in liver transplant recipients: primary treatment with percutaneous transluminal angioplasty

Hepatic artery stenosis following adult liver transplantation: evaluation of different endovascular treatment approaches

PURPOSE

To evaluate the efficacy and safety of hepatic artery interventions (HAI) versus extra-hepatic arterial interventions (EHAI) when managing clinically significant hepatic artery stenosis (HAS) after adult orthotopic liver transplantation.

MATERIALS AND METHODS

A single-center retrospective cohort analysis was conducted on liver transplant patients who underwent intervention for clinically significant HAS from September 2012 to September 2021. The HAI treatment arm included hepatic artery angioplasty and/or stent placement while the EHAI treatment arm comprised of non-hepatic visceral artery embolization. Primary outcomes included peri-procedural complications and 1-year liver-related deaths. Secondary outcomes included biliary ischemic events, longitudinal trends in liver enzymes and ultrasound parameters pre-and post-intervention.

RESULTS

The HAI arm included 21 procedures in 18 patients and the EHAI arm included 27 procedures in 22 patients. There were increased 1-year liver-related deaths (10% [2/21] vs 0% [0/27], p = 0.10) and complications (29% [6/21] vs 4% [1/27], p = 0.015) in the HAI group compared to the EHAI group. Both HAI and EHAI groups exhibited similar improvements in transaminitis including changes of ALT (-72 U/L vs -112.5 U/L, p = 0.60) and AST (-58 U/L vs -48 U/L, p = 0.56) at 1-month post-procedure. Both treatment arms demonstrated increases in post-procedural peak systolic velocity of the hepatic artery distal to the stenosis, while the HAI group also showed significant improvement in resistive indices following the intervention.

CONCLUSION

Direct hepatic artery interventions remain the definitive treatment for clinically significant hepatic artery stenosis; however, non-hepatic visceral artery embolization can be considered a safe alternative intervention in cases of unfavorable hepatic anatomy.

Intra-arterial lipo-prostaglandin E1 infusion for arterial spasm in liver transplantation: A case report

BACKGROUND

Hepatic artery obstruction is a critical consideration in graft outcomes after living donor liver transplantation. We report a case of diffuse arterial vasospasm that developed immediately after anastomosis and was managed with an intra-arterial infusion of lipo-prostaglandin E1 (PGE1).

CASE SUMMARY

A 57-year-old male with hepatitis B virus-related liver cirrhosis and hepatocellular carcinoma underwent ABO-incompatible living donor liver transplant. The grafted hepatic artery was first anastomosed to the recipient's right hepatic artery stump. However, the arterial pulse immediately weakened. Although a new anastomosis was performed using the right gastroepiploic artery, the patient's arterial pulse rate remained poor. We attempted angiographic intervention immediately after the operation; it showed diffuse arterial vasospasms like 'beads on a string'. We attempted continuous infusion of lipo-PGE1 overnight via an intra-arterial catheter. The next day, arterial flow improved without any spasms or strictures. The patient had no additional arterial complications or related sequelae at the time of writing, 1-year post-liver transplantation.

CONCLUSION

Angiographic evaluation is helpful in cases of repetitive arterial obstruction, and intra-arterial infusion of lipo-PGE1 may be effective in treating diffuse arterial spasms.

Transplant Hepatic Artery Complications

Hepatic artery complications can be divided into 2 different categories, nonocclusive and steno-occlusive disease. Steno-occlusive disease is a collective term that encompasses hepatic artery thrombosis, hepatic artery stenosis, and hepatic arterial kinks, while nonocclusive arterial disease encompasses less than 5% of complications and is a collective term used to describe arteriovenous fistulae, pseudoaneurysms, arterial rupture and nonocclusive hepatic artery hypoperfusion syndrome. This article details the angiographic techniques and definitions needed to accurately diagnose arterial transplant complications and describes the technical aspects and results of endoluminal management of these arterial complications. In addition, this article discusses the presentation, etiology and indications for treatment, including surgical management of these various complications.

Current Endovascular Management of Arterial Complications After Pediatric Liver Transplantation in a Tertiary Center

PURPOSE

Pediatric liver transplant surgery is burdened by arterial complications whose endovascular treatment is not standardized. We report the outcomes of a cohort of pediatric recipients with hepatic artery complications treated by endoluminal procedures.

MATERIALS AND METHODS

From December 2019 to December 2022, consecutive transplanted pediatric patients who underwent endovascular treatment of hepatic artery complications were reviewed. The analysis included: type of complication (occlusion, stenosis, pseudoaneurysm); onset (acute =  < 15 days, subacute = 15-90 days, late =  > 90 days); endovascular technique (angioplasty, stenting); complications and outcomes. Technical success was defined as the opacification of the hepatic artery at the final angiogram with < 50% residual stenosis and no pseudoaneurysms. Clinical success was defined by graft's and patient's survival.

RESULTS

Seventeen patients (8 males; median age 33 months, IQR 9-103) underwent 21 hepatic arteriography procedures for predominantly acute or subacute occlusions (n = 7) or stenosis (n = 11) with concurrent pseudoaneurysms (n = 4). Primary and secondary technical success was achieved in 13/18 and 3/3 procedures, respectively, with overall technical success of 76%. Angioplasty alone was successful in 5/21 procedures; stent-retriever thrombectomy was performed in one occlusion with thrombosis; stenting was required in 9/17 (53%) patients. Clinical success was obtained in 14/17 (82%) patients with hepatic artery patency after a median of 367 days (IQR 114.5-500). Clinical failure occurred in 3 permanent occlusions, with 2 deaths and 1 re-transplantation. Procedure-related complications included minor events in 3/17 (18%) patients and 1/17 (6%) death.

CONCLUSION

In liver transplanted children with hepatic artery complications, endovascular treatment may provide clinical success, with stenting often required in acute and subacute conditions.

LEVEL OF EVIDENCE

Level 4.

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.

Vascular Complications After Liver Transplantation

OBJECTIVES

Vascular complications after liver transplant can be lethal. High levels of suspicion and aggressive use of diagnostic tools may help with early diagnosis and treatment. Here, we share our experiences regarding this topic.

MATERIALS AND METHODS

Adult and pediatric patients who had liver transplant between February 1997 and June 2018 in our clinic were included in the study. Patients were grouped according to age (pediatric patients were those under 18 years old), male versus female, indication for transplant, type of liver transplant, type of vascular complication, treatment, and survival aftertreatment.We analyzed the statistical incidence of vascular complications according to age, male versus female, and type of liver transplant.

RESULTS

Our analyses included 607 liver transplant procedures, including 7 retransplants, with 349 (57.4%) from living donors and 258 (42.6%) from deceased donors. Of total patients, 539 were adults (89.8%) and 61 were children (10.2%). Vascular complications occurred in 25 patients (4.1%), with hepatic artery complications seen in 13 patients (2.1%) (10 adults [1.8%] and 3 children [4.9%]), portal vein complications seen in 9 patients (1.5%) (6 adults [1.1%] and 3 children [4.9%]), and hepatic vein complications seen in 3 patients (0.5%) (2 adults [0.36%] and 1 child [1.6%]). Rate of vascular complications was statistically higher in pediatric patients (11.4% vs 3.3%; P = .007) and higher but not statistically in recipients of livers from living donors (5.2% vs 2.7%; P = .19). Twelve patients (48.8%) were treated with endovascular approach, and 11 (0.44%)required surgicaltreatment. Two patients underwent immediate retransplant due to hepatic artery thrombosis.

CONCLUSIONS

Because vascular complications are the most severe complications afterlivertransplant,there must be close follow-up of vascular anastomoses, particularly early postoperatively, with radiologic methods. In cases of vascular complications, emergent treatment, including endovascular interventions, surgery, and retransplant, must be performed.

Biliary and Vascular Complications after Liver Transplantation-From Diagnosis to Treatment

The last decades have brought impressive advances in liver transplantation. As a result, there was a notable rise in the number of liver transplants globally. Advances in surgical techniques, immunosuppressive therapies and radiologically guided treatments have led to an improvement in the prognosis of these patients. However, the risk of complications remains significant, and the management of liver transplant patients requires multidisciplinary teams. The most frequent and severe complications are biliary and vascular complications. Compared to vascular complications, biliary complications have higher incidence rates but a better prognosis. The early diagnosis and selection of the optimal treatment are crucial to avoid the loss of the graft and even the death of the patient. The development of minimally invasive techniques prevents surgical reinterventions with their associated risks. Liver retransplantation remains the last therapeutic solution for graft dysfunction, one of the main problems, in this case, being the low number of donors.

Endovascular therapies for hepatic artery stenosis post liver transplantation

PURPOSE

To evaluate primary patency at 12 months after endovascular therapies in hepatic artery stenosis.

METHODS

A retrospective review of all endovascular interventions for hepatic artery stenosis (HAS) after liver transplantation that occurred between June 2013 and November 2020 was performed at a single institution in France. Follow up occurred from 1 month to 4 years (median 15 months). The treatment consisted of dilation with a balloon or stent. We analyzed short-term (technical success and complications) and long-term outcomes (liver function, arterial patency, graft survival at 12 months (GS), and reintervention). We also compared percutaneous balloon angioplasty (PBA) with stent placement. PBA alone was used if < 30% residual stenosis of the hepatic artery was achieved. Stenting was performed if there was greater than 30% residual stenosis and in the case of complications (dissection or rupture).

RESULTS

A total of 18 stenoses were suspected on the basis of routine surveillance duplex ultrasound imaging (peak systolic velocity > 200 cm/s, systolic accelerating time > 10 ms and resistive index < 0.5), all of which were confirmed by angio CT, but only 17 were confirmed by angiography. Seventeen patients were included (14 males, mean age 57 years; and three females, mean age 58 years). Interventions were performed in 17 cases (95%) with PBA only (5/17), stent only (5/17) or both (4/17). Immediate technical success was 100%. Major complications occurred in 1 of 17 cases (5.8%), consisting of target vessel dissection. The analysis of the three (groups PBA only, stent only or both) showed the same procedural success (100%), GS (100%) and normal liver function after the procedures but different rates of complications (20% vs. 0% vs. 0%), arterial patency at 12 months (60% vs. 80% vs. 85%) (p = 0.4), early stenosis (40% vs. 80% vs. 0%) or late stenosis (60% vs. 20% vs. 100%) and requirement for reintervention (40% vs. 20% vs. 14%) (p = 0.56).

CONCLUSION

This study suggests that PBA, stent, or both procedures show the same primary patency at 12 months. It is probably not a definitive answer, but these treatments are safe and effective for extending graft survival in the context of graft shortages.

Role of interventional radiology in management of post-liver transplant anastomotic complications

Background

Liver transplantation is considered to be the treatment of choice in cases of end-stage liver disease; however, as a major procedure, the operation is fraught with complications. The etiology, symptoms, and diagnostic methods for arterial, portal, and biliary issues are thoroughly discussed. Interventional procedures such as balloon angioplasty and stent placement in the arterial and portal systems, as well as biliary interventional procedures, are described.

Results

In our study, we reviewed 25 cases of post-living donor transplanted liver, with anastomotic complications including biliary stenosis 40%, hepatic vein stenosis 20%, portal vein stenosis 16%, biliary leakage 16%, and hepatic artery stenosis or pseudo-aneurysm 16%. We had 10 cases of biliary stenosis, 7 of which were successfully treated with the insertion of an internal/external drain, and one case failed. Two patients died. We had four cases of hepatic venous obstruction with successfully implanted stents and a perfect outcome, efficacy, and patency rate of 100%. We also had two cases of hepatic artery stenosis that were perfectly managed by stent placement, with a patency rate of 100%. We came across two cases of hepatic artery pseudo-aneurysm. One case failed due to large sac size, while the other was successful. Finally, in our study, we had a 100% success rate in 5 cases of portal vein stenosis in the early postoperative period.

Conclusions

Percutaneous IR was effective treatment for hepatic vein occlusion, portal vein stenosis, hepatic artery stenosis, and anastomotic biliary stricture after living donor liver transplantation. The interventional radiology team is now an integral part of the multi-disciplinary care of transplant patients. As new interventional instruments are developed and experience is gained, the outcomes of interventional treatments will continue to improve.

Understanding Local Hemodynamic Changes After Liver Transplant: Different Entities or Simply Different Sides to the Same Coin?

Liver transplantation is an extremely complex procedure performed in an extremely complex patient. With a successful technique and acceptable long-term survival, a new challenge arose: overcoming donor shortage. Thus, living donor liver transplant and other techniques were developed. Aiming for donor safety, many liver transplant units attempted to push the viable limits in terms of size, retrieving smaller and smaller grafts for adult recipients. With these smaller grafts came numerous problems, concepts, and definitions. The spotlight is now aimed at the mirage of hemodynamic changes derived from the recipients prior alterations. This article focuses on the numerous hemodynamic syndromes, their definitions, causes, and management and interconnection with each other. The aim is to aid the physician in their recognition and treatment to improve liver transplantation success.

Risk factors and management of hepatic artery stenosis post liver transplantation

BACKGROUND

Hepatic Artery Stenosis (HAS) after liver transplantation (LT), if untreated, can lead to hepatic artery thrombosis (HAT) that carries significant morbidity.

AIMS

To identify risk factors associated with HAS and determine if endovascular therapy (EVT) reduces the occurrence of HAT.

METHODS

This is a retrospective cohort study of adult LT patients between 2013 and 2018. The primary outcome was development of HAT, and secondary outcomes included graft failure and mortality. Logistic regression was used to ascertain the odds ratio of developing HAS. Outcomes between intervention types were compared with Fisher's-exact test.

RESULTS

The odds of HAS doubled in DCD-donor recipients (OR=2.27; P = 0.04) and transplants requiring vascular reconstruction for donor arterial variation (OR=2.19, P = 0.046). Of the 63 identified HAS patients, 44 underwent EVT, 7 with angioplasty alone, 37 combined with stenting. HAT was not significantly different in those who underwent angioplasty with or without stenting than conservative treatment (P = 0.71). However, compared to patients without HAS, patients with HAS had higher odds of biliary stricture and decreased graft and overall patient survival (log-rank P < 0.001 & P = 0.019, respectively).

CONCLUSION

HAS is significantly higher in DCD-graft recipients. EVT was not associated with reduction in HAT progression. HAS has poor graft and overall survival.

Intraoperative Doppler Ultrasound for Detection of Early Postoperative Vascular Complications in Orthotopic Liver Transplants

Liver transplantation is currently the only curative treatment for patients with end-stage liver disease. However, liver transplantation can be associated with catastrophic complications in the early postoperative setting, including hepatic artery thrombosis (HAT) and portal vein thrombosis (PVT). Postoperative complications are associated with hepatic artery resistive index (RI) < 6, systolic acceleration time (SAT) > 0.08 seconds and peak systolic velocity (PSV) > 200 cm/s on doppler ultrasound (DUS). DUS is also used in an intraoperative setting to assess patency and early complications prior to the end of the operative period, allowing for early correction. This literature review evaluates the prevalence of DUS use in intraoperative settings to identify transplant complications. A lack of consistency and minimal knowledge of intraoperative DUS warrants additional research into its usage and standardization.

Treatment of Hepatic Artery Stenosis in Liver Transplant Patients Using Drug-Eluting versus Bare-Metal Stents

Hepatic artery stenosis after liver transplant is often treated with endovascular stent placement. Our institution has adopted use of drug-eluting stents, particularly in small-caliber arteries. We aimed to compare patency rates of drug-eluting stents vs. traditional bare-metal stents. This was a single-institution, retrospective study of liver transplant hepatic artery stenosis treated with stents. Primary patency was defined as time from stent placement to resistive index on Doppler ultrasonography (<0.5), hepatic artery thrombosis, or any intervention including surgery. Fifty-two patients were treated with stents (31 men; mean age, 57 years): 15, drug-eluting stents; 37, bare-metal stents. Mean arterial diameters were 4.1 mm and 5.1 mm, respectively. Technical success was 100% (52/52). At 6 months, 1, 2, and 3 years, primary patency for drug-eluting stents was 80%, 71%, 71%, and 71%; bare-metal stents: 76%, 65%, 53%, and 46% (p = 0.41). Primary patency for small-caliber arteries (3.5–4.5 mm) with drug-eluting stents was 93%, 75%, 75%, and 75%; bare-metal stents: 60%, 60%, 50%, and 38% (p = 0.19). Overall survival was 100%, 100%, 94%, and 91%. Graft survival was 100%, 98%, 96%, and 90%. Stenting for hepatic artery stenosis was safe and effective. While not statistically significant, patency improved with drug-eluting stents compared with bare-metal stents, especially in arteries < 4.5 mm in diameter. Drug-eluting stents can be considered for liver transplant hepatic artery stenosis, particularly in small-caliber arteries.

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.

Hepatic artery stenosis angioplasty and implantation of Wingspan neurovascular stent: A case report and discussion of stenting in tortuous vessels

BACKGROUND

Hepatic artery stenosis is a complication of orthotopic liver transplant occurring in 3.1%-7.4% of patients that can result in graft failure and need for re-transplantation. Endovascular therapy with angioplasty and stenting has been used with a high degree of technical success and good clinical outcomes, but tortuous hepatic arteries present a unique challenge for intervention. Suitable stents for this application should be maneuverable and conformable while also exerting adequate radial force to maintain a patent lumen.

CASE SUMMARY

Herein we report our experience with a neurovascular Wingspan stent system in a challenging case of recurrent hepatic artery stenosis and discuss the literature of stenting in tortuous transplant hepatic arteries.

CONCLUSION

Wingspan neurovascular stent is self-expanding, has good conformability, and adequate radial resistance and as such it could be added to the armamentarium of interventionalists in the setting of a tortuous and stenotic transplant hepatic artery.

Transplant Hepatic Artery Stenosis: Endovascular Treatment and Complications

Hepatic artery stenosis (HAS) is an infrequent complication of liver transplant; if left untreated, it can lead to hepatic artery thrombosis with high risk of biliary necrosis and graft loss. HAS is diagnosed with screening Doppler ultrasound, together with computed tomography angiography and magnetic resonance angiography. Endovascular treatment with angioplasty ± stent placement is safe and effective with infrequent major complications; however, when complications occur, they can devastate long-term graft survival. Herein, we present two cases of HAS treated with balloon angioplasty with resultant major complications requiring operative intervention.

Primary Stent Placement for Hepatic Artery Stenosis After Liver Transplantation: Improving Primary Patency and Reintervention Rates

Recent studies have reported high rates of reintervention after primary stenting for hepatic artery stenosis (HAS) due to the loss of primary patency. The aims of this study were to evaluate the outcomes of primary stenting after HAS in a large cohort with longterm follow-up. After institutional review board approval, all patients undergoing liver transplantation between 2003 and 2017 at a single institution were evaluated for occurrence of hepatic artery complications. HAS occurred in 37/454 (8%) of patients. HAS was defined as >50% stenosis on computed tomography or digital subtraction angiography. Hepatic arterial patency and graft survival were evaluated at annual intervals. Primary patency was defined as the time from revascularization to imaging evidence of new HAS or reaching a censored event (retransplantation, death, loss to follow-up, or end of study period). Primary stenting was attempted in 30 patients (17 female, 57%; median age, 51 years; range, 24-68 years). Surgical repair of HAS prior to stenting was attempted in 5/30 (17%) patients. Endovascular treatment was performed within 1 week of the primary anastomosis in 5/30 (17%) of patients. Technical success was accomplished in 97% (29/30) of patients. Primary patency was 90% at 1 year and remained unchanged throughout the remaining follow-up period (median, 41 months; interquartile range [IQR], 25-86 months). Reintervention was required in 3 patients to maintain stent patency. The median time period between primary stenting and retreatment was 5.9 months (IQR, 4.4-11.1 months). There were no major complications, and no patient developed hepatic arterial thrombosis or required listing for retransplantation or retransplantation during the follow-up period. In conclusion, primary stenting for HAS has excellent longterm primary patency and low reintervention rates.

Assessment of the Learning Process After Introducing a New Liver Transplantation Procedure in a Center With Extensive Experience in Kidney Transplantation

BACKGROUND

Liver transplantation (LTx) is one of the most complex transplant procedures. The aim of the present study was to determine whether the learning process can be observed after the introduction of LTx in a center with extensive previous experience in renal transplantation.

METHODS

This retrospective analysis included 264 primary LTx procedures performed with the piggyback technique (2005-2016). The procedures were divided into 4 equal groups. The characteristics of the recipients, data related to the surgery, and the postoperative course and complications were analyzed.

RESULTS

We observed a significant reduction in surgical time and in the anhepatic phase duration between Group 1 and the other groups (median surgical time was 455 minutes vs 415 minutes, 410 minutes and 387 minutes, respectively, P < .05; median anhepatic phase duration was 75 min vs 60 min, 62 min, 60 min, respectively, P < .05). There was a decrease in the number of transfused blood units (median in Group 1 of 6 packs vs 3 packs in Group 4, P < .05) and a decrease in blood recovered from the operating field using the Cell Saver system (median in Group 1 of 1570 mL vs 1057 mL, 1123 mL, and 1045 mL, respectively, P < .05). A significant reduction in the number of hemorrhages was found (1.5% in Group 4 vs 13.6%, 10.6%, and 7.6% in the other groups P < .05). The remaining studied parameters were not statistically significant.

CONCLUSIONS

Extensive previous transplantation experience affected the lack of typical features of the learning process.

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.

Interventional radiology in the management of the liver transplant patient

Liver transplantation (LT) is commonly used to treat patients with end-stage liver disease. The evolution of surgical techniques, endovascular methods, and medical care has led to a progressive decrease in posttransplant morbidity and mortality. Despite these improvements, a multidisciplinary approach to each patient remains essential as the early diagnosis and treatment of the complications of transplantation influence graft and patient survival. The critical role of interventional radiology in the collaborative approach to the care of the LT patient will be reviewed. Liver Transplantation 23 1328-1341 2017 AASLD.

Complications after endovascular treatment of hepatic artery stenosis after liver transplantation

BACKGROUND

Hepatic artery stenosis (HAS) after liver transplantation can progress to hepatic artery thrombosis (HAT) and a subsequent 30% to 50% risk of graft loss. Although endovascular treatment of severe HAS after liver transplantation has emerged as the dominant method of treatment, the potential risks of these interventions are poorly described.

METHODS

A retrospective review of all endovascular interventions for HAS after liver transplantation between August 2009 and March 2016 was performed at a single institution, which has the largest volume of liver transplants in the United States. Severe HAS was identified by routine surveillance duplex ultrasound imaging (peak systolic velocity >400 cm/s, resistive index <0.5, and presence of tardus parvus waveforms).

RESULTS

In 1129 liver transplant recipients during the study period, 106 angiograms were performed in 79 patients (6.9%) for severe de novo or recurrent HAS. Interventions were performed in 99 of 106 cases (93.4%) with percutaneous transluminal angioplasty alone (34 of 99) or with stent placement (65 of 99). Immediate technical success was 91%. Major complications occurred in eight of 106 cases (7.5%), consisting of target vessel dissection (5 of 8) and rupture (3 of 8). Successful endovascular treatment was possible in six of the eight patients (75%). Ruptures were treated with the use of a covered coronary balloon-expandable stent graft or balloon tamponade. Dissections were treated with placement of bare-metal or drug-eluting stents. No open surgical intervention was required to manage any of these complications. With a median of follow-up of 22 months, four of eight patients (50%) with a major complication progressed to HAT compared with one of 71 patients (1.4%) undergoing a hepatic intervention without a major complication (P < .001). One patient required retransplantation. Severe vessel tortuosity was present in 75% (6 of 8) of interventions with a major complication compared with 34.6% (34 of 98) in those without (P = .05). In the complication cohort, 37.5% (3 of 8) of the patients had received a second liver transplant before intervention compared with 12.6% (9 of 71) of the patients in the noncomplication cohort (P = .097).

CONCLUSIONS

Although endovascular treatment of HAS is safe and effective in most patients, target vessel injury is possible. Severe tortuosity of the hepatic artery and prior retransplantation were associated with a twofold to threefold increased risk of a major complication. Acute vessel injury can be managed successfully using endovascular techniques, but these patients have a significant risk of subsequent HAT and need close surveillance.

Percutaneous Retrograde Transhepatic Arterial Puncture to Regain Access in the True Lumen of the Dissected and Acutely Occluded Transplant Hepatic Artery

Iatrogenic hepatic artery dissection is a serious complication that can progress to complete hepatic artery occlusion and graft loss. Restoration of arterial flow to the graft is urgent, but the severity and extent of the dissection may interfere with endovascular techniques. The authors describe a technique of percutaneous retrograde transhepatic arterial puncture to regain access into the true lumen of the dissected hepatic artery to restore in-line flow to the liver graft.

Doppler Characteristics of Recurrent Hepatic Artery Stenosis

OBJECTIVES

We sought to assess midterm sonographic findings in patients after stenting for hepatic artery stenosis.

METHODS

Thirty-nine hepatic artery stent procedures were performed for hepatic artery stenosis after liver transplantation between September 2009 and December 2013. Thirty cases were technically successful and met the minimum follow-up time (76 days, defined by earliest diagnosed stenosis). Routine ultrasound surveillance was obtained on all patients, and statistical analysis of the findings in the patency and restenosis groups was performed.

RESULTS

Of the 30 cases, restenosis occurred 9 times in 6 patients. Mean follow-up was 677 days. Mean time to restenosis was 267 days. Five cases (56%) were identified within the first 6 months after stent placement. Four cases (44%) were recognized in the second year after stent placement. Prior to the sonographic diagnosis of restenosis, the mean resistive indices of the main (.64 versus .57, P < .0001), left (.63 versus .54, P < .0001), right anterior (.60 versus .52, P < .0001), and right posterior (.60 versus .53, P = .001) hepatic artery branches differed among patency and restenosis groups, respectively. The mean peak systolic velocity also differed significantly between the 2 groups: 254 cm/sec in patients with eventual restenosis versus 220 cm/sec in patients without restenosis (P = .02).

CONCLUSIONS

The sonographic evaluation of hepatic artery stenosis remains critical during the first 2 years after stent placement. While the vast majority of patients do not restenose, resistive index and peak systolic velocity differed significantly between the 2 groups and may be prognostic surveillance markers for the development of restenosis.

Catheter Thrombolysis of Thrombosed Hepatic Arteries in Liver Transplant Recipients: Predictors of Success and Role of Thrombolysis

Hepatic artery thrombosis is an uncommon complication of liver transplantation. However, it is a major indication for re-transplantation. The use of transcatheter thrombolysis and subsequent surgical revascularization as a graft salvage procedure is discussed. Four of 5 cases (80%) were successful in re-establishing flow and uncovering underlying arterial anatomic defects. None were treated definitively by endoluminal measures due to an inability to resolve the underlying anatomic defects. However, 2 of 5 cases (40%) went on to a successful surgical revascularization and represent successful long-term outcome of transcatheter thrombolysis followed by definitive surgical revascularization. We conclude that, definitive endoluminal success cannot be achieved without resolving associated, and possibly instigating, underlying arterial anatomical defects. However, reestablishing flow to the graft can unmask underlying lesions as well as asses surrounding vasculature thus providing anatomical information for a more elective, better planned and definitive surgical revision.

Intention-to-treat analysis of percutaneous endovascular treatment of hepatic artery stenosis after orthotopic liver transplantation

Hepatic artery stenosis (HAS) is a rare complication of orthotopic liver transplantation (LT). HAS could evolve into complete thrombosis and lead to graft loss, incurring significant morbidity and mortality. Even though endovascular management by percutaneous transluminal angioplasty ± stenting (PTA) is the primary treatment of HAS, its longterm impact on hepatic artery (HA) patency and graft survival remains unclear. This study aimed to evaluate longterm outcomes of PTA and to define the risk factors of treatment failure. From 2006 to 2012, 30 patients with critical HAS (>50% stenosis of HA) and treated by PTA were identified from 870 adult patients undergoing LT. Seventeen patients were diagnosed by post-LT screening, and 13 patients were symptomatic due to HAS. PTA was completed successfully in 27 (90%) patients with angioplasty plus stenting in 23 and angioplasty alone in 4. The immediate technical success rate was 90%. A major complication that was observed was arterial dissection (1 patient) which eventually necessitated retransplantation. Restenosis was observed in 10 (33%) patients. One-year, 3-year, and 5-year HA patency rates were 68%, 62.8%, and 62.8%, respectively. Overall patient survival was 93.3% at 3 years and 85.3% at 5 years. The 3-year and 5-year liver graft survival rates were 84.7% and 64.5%, respectively. No significant difference was observed in patient and graft survivals between asymptomatic and symptomatic patients after PTA. Similarly, no difference was observed between angioplasty alone and angioplasty plus stenting. In conclusion, endovascular therapy ensures a good 5-year graft survival (64.5%) and patient survival (85.3%) in patients with critical HAS by maintaining HA patency with a low risk of serious morbidity (3.3%). Liver Transplantation 22 923-933 2016 AASLD.

Diagnosis and Management of Hepatic Artery Complications After Liver Transplantation

BACKGROUND

We assessed the usefulness of color Doppler imaging in diagnosis and monitoring hepatic artery complications after liver transplantation.

METHODS

Subjects were 421 liver transplant recipients who underwent serial ultrasound (US) color Doppler evaluations of the hepatic arteries after surgery.

RESULTS

We saw 4 hepatic arterial complications after liver transplantation (13 thrombosis, 29 stenosis, 2 kinking, 2 pseudo-aneurysm, and 2 pseudo-aneurysm rupture). All subjects underwent US color Doppler examination periodically after surgery. In 6 cases of early thrombosis, hepatic arterial obstruction was diagnosed with absence of Doppler signals; in the other 7 cases (late hepatic artery thrombosis), thrombosis was suspected for the presence of intra-parenchymal "tardus-parvus" waveforms. In all of the cases, computed tomography angiography showed obstruction of the main arterial trunk and the development of compensatory collateral circles (late hepatic artery thrombosis). In 10 of the 29 cases of stenosis, Doppler ultrasonography examination revealed stenotic tract and intra-hepatic tardus-parvus waveforms; in 17 stenosis cases, the site of stenosis could not be identified, but intra-parenchymal tardus-parvus waveforms were recorded. In 2 patients, hepatic artery stenosis occurred with ischemic complications.

CONCLUSIONS

The use of US color Doppler examination allows the early diagnosis of hepatic arterial complications after liver transplantation. Tardus-parvus waveforms indicated severe impairment of hepatic arterial perfusion from either thrombosis or severe stenosis. The presence of these indirect signs enhanced the accuracy of color Doppler diagnosis, and detection should prompt therapy.

Primary stent placement for hepatic artery stenosis after liver transplantation

OBJECTIVE

Significant hepatic artery stenosis (HAS) after orthotopic liver transplantation (OLT) can lead to thrombosis, with subsequent liver failure in 30% of patients. Although operative intervention or retransplantation has been the traditional solution, endovascular therapy has emerged as a less invasive treatment strategy. Prior smaller studies have been conflicting in the relative efficacy of percutaneous transluminal angioplasty (PTA) vs primary stent placement for HAS.

METHODS

This was a single-center retrospective review of all endovascular interventions for HAS after OLT during a 54-month period (August 2009-December 2013). Patients with ultrasound imaging with evidence of severe HAS (peak systolic velocity >400-450 cm/s, resistive index <0.5) underwent endovascular treatment with primary stent placement or PTA. Outcomes calculated were technical success, primary and primary assisted patency rates, reinterventions, and complications.

RESULTS

Sixty-two interventions for HAS were performed in 42 patients with a mean follow-up of 19.1 ± 15.2 months. During the study period, 654 OLTs were performed. Of 61 patients diagnosed with HAS, 42 underwent an endovascular intervention. The rate of endovascularly treated HAS was 6.4% (42 of 654). Primary technical success was achieved in 95% (59 of 62) of the interventions. Initial treatment was with PTA alone in 17 or primary stent in 25. Primary patency rates after initial stent placement were 87%, 76.5%, 78%, and 78% at 1, 6, 12, and 24 months, respectively, compared with initial PTA rates of 64.7%, 53.3%, 40%, and 0% (P = .19). There were 20 reinterventions in 14 patients (eight stents, six PTAs). The time to the initial reintervention was 51 days in patients with PTA alone vs 105.8 days for those with an initial stent (P = .16). Overall primary assisted patency was 93% at 24 months. Major complications were one arterial rupture and two hepatic artery dissections. The long-term risk of hepatic artery thrombosis in the entire patient cohort was 3.2%.

CONCLUSIONS

HAS after OLT can be treated endovascularly with high technical success and excellent primary assisted patency. This series represents the largest reported cohort of endovascular interventions for HAS to date. Initial use of a stent showed a strong trend toward decreasing the need for reintervention. Avoidance of hepatic artery thrombosis is possible in >95% of patients with endovascular treatment and close follow-up.

Current state of the art in management of vascular complications after pediatric liver transplantation

Vascular complications by compromising the blood flow to the allograft can have significant and sometimes life-threatening consequences after pediatric liver transplantation. High level of suspicion and aggressive utilization of diagnostic modalities can lead to early diagnosis and salvage of the allograft. This review will summarize the current trends in management of vascular complications after pediatric liver transplantation.

Percutaneous Endovascular Treatment for Hepatic Artery Stenosis after Liver Transplantation: The Role of Percutaneous Endovascular Treatment

BACKGROUND

To retrospectively analyze the outcomes of interventional radiology treatment of patients with hepatic artery stenosis (HAS) after liver transplantation at our Institution.

MATERIAL/METHODS

Hepatic artery stenosis was diagnosed and treated by endovascular technique in 8 (2.8%) patients, who underwent liver transplantation between July 2007 and July 2011. Patients entered the follow-up period, during which we analyzed hepatic artery patency with Doppler ultrasound at 1, 3, 6, and 12 months after percutaneous endovascular treatment (PTA), and every six months thereafter.

RESULTS

During the 12-month follow-up period, 6 out of 8 patients (75%) were asymptomatic with patent hepatic artery, which was confirmed by multislice computed tomography (MSCT) angiography, or color Doppler (CD) ultrasound. One patient had a fatal outcome of unknown cause, and one patient underwent orthotopic liver retransplantation (re-OLT) procedure due to graft failure.

CONCLUSIONS

Our results suggest that HAS angioplasty and stenting are minimally invasive and safe endovascular procedures that represent a good alternative to open surgery, with good 12-month follow-up patency results comparable to surgery.

Postoperative doppler evaluation of liver transplants

Doppler ultrasound plays an important role in the postoperative management of hepatic transplantation, by enabling early detection and treatment of various vascular complications. This article describes the normal Doppler findings following liver transplantation and reviews the imaging appearances of various vascular complications associated with it. The article also discusses transient waveform abnormalities, often seen on a post-transplant Doppler examination, and the importance of differentiating them from findings suggestive of ominous vascular complications.

Role of multi-detector computed tomography for biliary complications after liver transplantation

AIM: To investigate the diagnostic performance of multi-detector computed tomography (MDCT) in detecting biliary complications after orthotopic liver transplantation (OLT).

METHODS: Eighty-three consecutive OLT recipients, who presented with clinical or biochemical signs of biliary complications, underwent MDCT examination. Two experienced radiologists assessed MDCT images in consensus to determine biliary complications. Final confirmation was based on percutaneous transhepatic cholangiography or endoscopic retrograde cholangiography in 58 patients, surgery in four patients, liver biopsy in 10, and clinical and sonography follow-up in 11 patients.

RESULTS: Biliary complications were eventually confirmed in 62 of 83 patients (74.7%), including anastomotic biliary strictures in 32, nonanastomotic biliary strictures in 21, biliary stones in nine (5 with biliary strictures), anastomotic bile leak in five, and biloma in six (all with nonanastomotic strictures, and 2 with biligenic hepatic abscess). Twenty-one patients had no detection of biliary complications. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of MDCT for detecting biliary strictures were 90.6%, 86.7%, 89.2%, 92.3% and 83.9%, respectively. For detecting biliary stones, anastomotic bile leak and biloma, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of MDCT were all 100%.

CONCLUSION: MDCT is a useful screening tool for detecting biliary complications after OLT.

Surgical and endovascular treatment of hepatic arterial complications following liver transplant

Vascular complications after liver transplantation increase post-operative morbidity and contribute to the incidence of retransplantation. Vascular complications comprise arterial, caval, and portal venous pathology, with the majority of complications being arterial in etiology, including anastomotic stricture, pseudoaneurysm, and thrombosis. There are two major therapeutic options for the treatment of these arterial complications: endovascular intervention and surgery. The former includes intra-arterial thrombolysis, embolization, percutaneous transluminal angioplasty, and stent placement. The latter includes thrombectomy, reanastomosis, and retransplantation. Although surgical treatment has been considered the first choice for management in the past, advances in endovascular intervention have increased and make it a viable therapeutic option following orthotopic liver transplantation. This review focuses on the role of surgical and endovascular therapy in the management of hepatic arterial complications after liver transplantation.

Complications of transplantation. Part 1: renal transplants

Vascular complications after solid-organ transplantation are not uncommon and may lead to graft dysfunction and ultimately graft loss. A thorough understanding of the surgical anatomy, etiologies, and types of vascular complications, their presentation, and the options for management are important for managing these complex patients. This article reviews the basic surgical anatomy, vascular complications, and endovascular management options of vascular complications in patients with renal transplants.

Incidence, management, and results of hepatic artery stenosis after liver transplantation in the era of donor to recipient match

INTRODUCTION

Hepatic artery stenosis (HAS) is an important complication after liver transplantation. However, studies are not conclusive in terms of definition, incidence, best treatment, and timing of intervention. The aim of this study was to evaluate the incidence of SSHA that occurred in a single center over the past 12 years, pointing out diagnostic and therapeutic strategies.

METHODS

The incidence of HAS was reviewed in 258 liver transplant recipients between January 1999 and December 2011. All patients underwent Doppler ultrasound (DUS) at fixed times. Multidetector computed tomographic angiography (MDCTA) was performed to confirm the DUS findings.

RESULTS

HAS occurred in 23 cases (9.3%). In all cases diagnosis was performed by DUS resulting in a sensitivity of 100% and a specificity of 99.6%. Based on DUS and MDCTA data integration, in 10 cases we adopted the "wait and see" strategy, whereas 13 patients underwent interventional radiology techniques.

CONCLUSION

DUS monitoring is efficacious in the diagnosis of HAS after liver transplantation. Interventional radiology procedures are safe and efficacious.

Reversed saphenous bypass for hepatic artery pseudoaneurysm after liver transplantation

BACKGROUND

Hepatic artery pseudoaneurysm (HAP) is found in 1-2% of liver transplantation (LT) patients. The mortality associated with pseudoaneurysm formation after orthotopic LT is reported to be as high as 75%. Because of the rarity of complications, particularly when considered individually, much of the direction for the management of complications is anecdotal. This article discusses the presentation, etiology, types, treatment indications, and vascular procedures used to manage complications with LT.

METHODS

Between January 2004 and December 2011, 464 LTs were performed at our institution. Of these, 9 (1.9%) consecutive patients underwent surgical treatment of HAP (8 men and 1 woman; median age, 58.4 years [range, 46-67 years]). Four patients underwent transarterial chemoembolization before LT for hepatocellular carcinoma. In all cases, revascularization with a reversed autologous saphenous vein bypass was performed.

RESULTS

Four patients had ruptured pseudoaneurysms, and the others were diagnosed as having asymptomatic pseudoaneurysms during the follow-up period. The median delay between LT and the diagnosis of HAP was 39.6 days (range, 22-92 days). All were anatomically extrahepatic. The median diameter was 15.3 mm (range, 9-30 mm). Four patients had a T-tube. In 6 cases, biliary leakage was associated with the LT and, in the remaining 3, mycosis was recorded. After surgery, 1 patient underwent retransplantation because of ischemic cholangitis. Five years later, 5 patients had normal arterial anatomy, and the other 3 patients had stenosis that was successfully treated by stents. All of the patients had normal liver function at follow-up. One patient died 16 months later because of a heart attack.

CONCLUSIONS

HAP with massive intraperitoneal bleeding is a rare but serious life-threatening complication when it occurs after LT. The majority of HAP cases are associated with bile leakage and mycosis; therefore, surgery must be the treatment of choice. Our conclusions support surgical revascularization with reversed saphenous grafts as a feasible and efficient treatment in cases of HAP.

Arterioportal fistulas in liver transplant recipients

Arterioportal fistulas (APFs) are classified into intrahepatic (>75% of all reported) and extrahepatic (<25% of all reported ). Anecdotally, investigators are more likely to report more sensational cases (typically extrahepatic APFs), so the actual prevalence of intrahepatic APFs is probably much higher (likely >90% of APFs). All reported APFs in liver transplant recipients have been intrahepatic. Hemodynamically significant APFs in liver transplant recipients are rare, occurring in 0.2%; however, APFs (hemodynamically significant or not) are not uncommonly seen in hepatic angiograms of liver transplant recipients (up to 5.4% of hepatic arteriograms in transplants). Interestingly, hemodynamically significant APFs warranting endovascular treatment are reported more commonly in the literature in native compared with transplanted livers (n >280-300 versus n = 13, respectively). This article discusses APFs that are specific to liver transplant recipients; their incidence, etiology, pathogenesis, natural history, clinical presentation, and endovascular management are discussed in detail.

Stent placement versus angioplasty for hepatic artery stenosis after liver transplant: a meta-analysis of case series

BACKGROUND

Hepatic artery stenosis (HAS) is a serious complication of liver transplantation but data on the most effective endovascular management are lacking. We aimed to compare percutaneous balloon angioplasty (PBA) with stent placement.

METHODS

We searched MEDLINE, Cochrane, Web of Science, EMBASE, SCOPUS, and Biosis Previews between 1970 and December 2011 and performed meta-analysis of short-term (procedural success, complications) and long-term outcomes (liver function, arterial patency, survival, re-intervention, re-transplantation). Random effects models were used for the analysis and meta-regression performed for the year of study.

RESULTS

A total of 263 liver transplants in 257 patients [age 43 (±8) years] underwent 147 PBAs and 116 stents. Transplanted livers were from deceased donors in 240 (91 %). Follow-up was 1 month to 4.5 years (median 17 months). PBA and stent had similar procedural success (89 % vs. 98 %), complications (16 % vs. 19 %), normal liver function tests (80 % vs. 68 %), arterial patency (76 % vs. 68 %), survival (80 % vs. 82 %), and requirement for re-intervention (22 % vs. 25 %) or re-transplantation (20 % vs. 24 %) (P non-significant). In the most recent studies re-transplantation was reported less compared to older series (P = 0.04).

CONCLUSION

Both PBA and stent offer comparable results for HAS. These techniques have contributed to a recent decline in re-transplantation.

KEY POINTS

• Interventional radiological procedures are often used to treat post-transplant hepatic artery stenosis. • Meta-analysis shows that percutaneous balloon angioplasty and stent placement are both efficacious. • Percutaneous balloon angioplasty and stent placement appear to have similar complication rates. • Re-transplantation rates have declined, partly due to interventional management for arterial stenosis.

Interventional radiological treatment of perihepatic vascular stenosis or occlusion in pediatric patients after liver transplantation

PURPOSE

Evaluation of the efficacy and safety of percutaneous treatment of vascular stenoses and occlusions in pediatric liver transplant recipients.

METHODS

Fifteen children (mean age 8.3 years) underwent interventional procedures for 18 vascular complications after liver transplantation. Patients had stenoses or occlusions of portal veins (n = 8), hepatic veins (n = 3), inferior vena cava (IVC; n = 2) or hepatic arteries (n = 5). Technical and clinical success rates were evaluated.

RESULTS

Stent angioplasty was performed in seven cases (portal vein, hepatic artery and IVC), and sole balloon angioplasty was performed in eight cases. One child underwent thrombolysis (hepatic artery). Clinical and technical success was achieved in 14 of 18 cases of vascular stenoses or occlusions (mean follow-up 710 days).

CONCLUSION

Pediatric interventional radiology allows effective and safe treatment of vascular stenoses after pediatric liver transplantation (PLT). Individualized treatment with special concepts for each pediatric patient is necessary. The variety, the characteristics, and the individuality of interventional management of all kinds of possible vascular stenoses or occlusions after PLT are shown.

Repeat endovascular treatment of recurring hepatic artery stenoses in orthotopic liver transplantation

Hepatic artery stenosis (HAS) is a complication that impacts the results of orthotopic liver transplantation (OLT). Interventional radiological techniques are important therapeutic options for HAS. The aim of this retrospective study was to evaluate the outcome of repeated radiological treatments in recurring HAS after OLT. Of the 941 patients who underwent OLT at our center from January 1998 to September 2010, 48 (5%) were diagnosed with HAS, 37 (77%) of whom underwent transluminal interventional therapy with the placement of an endovascular stent. Success rate, complications, hepatic artery patency and follow-up were reviewed. After stent placement, artery patency was achieved in all patients. Three patients developed complications, including arterial dissection and hematoma. HAS recurrence was observed in 9 patients (24%), and hepatic artery thrombosis (HAT) occurred in 4 (11%). Radiological interventions were repeated 10 times in 8 patients without complications. At a median follow-up of 66 months (range 10-158), hepatic artery patency was observed in 35 cases (94.6%). The 5-year rates for graft and patient survival were 82.3% and 87.7%, respectively. Restenosis may occur in one-third of patients after endovascular treatment for thrombosis and HAS, but the long-term outcomes of iterative radiological treatment for HAS indicate a high rate of success.

Endovascular treatment of hepatic artery stenosis after liver transplantation

BACKGROUND

Hepatic artery stenosis (HAS) after orthotopic liver transplantation is a significant risk factor for subsequent hepatic artery thrombosis (HAT). HAT is associated with a 30%-50% risk of liver failure culminating in retransplantation or death. Traditional treatment of hepatic artery complications has been surgical, with hepatic artery revision or retransplantation. Endovascular therapy of HAS, described primarily in the interventional radiology literature, may provide a less-invasive treatment option.

METHODS

This was a retrospective review of all endovascular interventions performed for HAS after orthotopic liver transplantation over a 31-month period (August 2009 to January 2012). Patients with duplex ultrasound imaging evidence of severe main HAS (peak systolic velocity of >400 cm/s, resistive index of <.5) underwent endovascular treatment with either primary stent placement or percutaneous transluminal angioplasty (PTA) alone. Patients were followed with serial ultrasound imaging to assess for treatment success and late restenosis. Reintervention was performed if significant restenosis occurred.

RESULTS

Thirty-five hepatic artery interventions were performed in 23 patients. Over the 31-month study period, 318 orthotopic liver transplantations were performed, yielding a 7.4% (23/318) rate of hepatic artery intervention. Primary technical success was achieved in 97% (34/35) of cases. Initial treatment was with PTA alone (n = 10) or primary stent placement (n = 13). The initial postintervention ultrasound images revealed improvements in hepatic artery peak systolic velocity (267 ± 118 [posttreatment] vs 489.9 ± 155 cm/s [pretreatment]; P < .0001) and main hepatic artery resistive index (0.61 ± 0.08 [posttreatment] vs 0.41 ± 0.07 [pretreatment]; P < .0001). At a mean follow-up of 8.2 ± 1.8 months (range, 0-29), there were 12 reinterventions in 10 patients for recurrent HAS. Thirty-one percent (n = 4/13) of patients undergoing initial stent placement required reintervention (at 236 ± 124 days of follow-up) compared with 60% (n = 6/10) of patients undergoing initial PTA (at 62.5 ± 44 days of follow-up). Primary patency rates (Kaplan-Meier) after primary stent placement were 92%, 85%, and 69% at 1, 3, and 6 months, respectively, compared with 70%, 60%, and 50% after PTA (P = .17). Primary-assisted patency for the entire cohort was 97% at 6 and 12 months. Major complications were one arterial rupture managed endovascularly and one artery dissection that precipitated HAT and required retransplantation. The overall rate of HAT in the entire cohort was 4.3% (1/23).

CONCLUSIONS

Endovascular treatment of HAS can be performed with high technical success, excellent primary-assisted patency, and acceptable morbidity. Initial use of a stent may improve primary patency when compared with PTA. The need for reintervention is common, placing particular importance on aggressive surveillance. Longer follow-up and a larger cohort are needed to confirm these encouraging early results.