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

Intra-arterial thrombolysis for early hepatic artery thrombosis after liver transplantation

BACKGROUND

Early hepatic artery thrombosis (E-HAT) is a serious complication after liver transplantation (LT), which often results in graft failure and can lead to patient deaths. Treatments such as re-transplantation and re-anastomosis are conventional therapeutic methods which are restricted by the shortage of donors and the patient’s postoperative intolerance to re-laparotomy. Due to the advances in interventional techniques and thrombolytics, endovascular treatments are increasingly being selected by more and more centers. This study reviews and reports our single-center experience with intra-arterial thrombolysis as the first choice therapy for E-HAT after deceased donor LT.

AIM

To evaluate the feasibility and reasonability of intra-arterial thrombolysis for E-HAT after deceased donor LT.

METHODS

A total of 147 patients who underwent deceased donor LT were retrospectively reviewed in our hospital between September 2011 and December 2016. Four patients were diagnosed with E-HAT. All of these patients underwent intra-arterial thrombolysis with alteplase as the first choice therapy after LT. The method of arterial anastomosis and details of the diagnosis and treatment of E-HAT were collated. The long-term prognosis of E-HAT patients was also recorded. The median follow-up period was 26 mo (range: 23 to 30 mo).

RESULTS

The incidence of E-HAT was 2.7% (4/147). E-HAT was considered when Doppler ultrasonography showed no blood flow signals and a definite diagnosis was confirmed by immediate hepatic arterial angiography when complete occlusion of the hepatic artery was observed. The patients were given temporary thrombolytics (mainly alteplase) via a 5-Fr catheter which was placed in the proximal part of the thrombosed hepatic artery followed by continuous alteplase using an infusion pump. Alteplase dose was adjusted according to activated clotting time. The recanalization rate of intra-arterial thrombolysis in our study was 100% (4/4) and no thrombolysis-related mortality was observed. During the follow-up period, patient survival rate was 75% (3/4), and biliary complications were present in 50% of patients (2/4).

CONCLUSION

Intra-arterial thrombolysis can be considered first-line treatment for E-HAT after deceased donor LT. Early diagnosis of E-HAT is important and follow-up is necessary even if recanalization is successful.

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.

Percutaneous Transarterial Stent Placement in a Transplant Liver Hepatic Artery Complicated by Angioplasty Balloon Rupture and Fragmentation

The incidence of posttransplant hepatic arterial stenosis (HAS) has been reported in 5 to 10% of orthotopic liver transplants and, left untreated, can lead to hepatic arterial thrombosis. Most vascular complications develop less than 3 months after initial transplant, with thrombosis representing over half of all complications. There has been a trend toward minimally invasive, endovascular techniques for treating HAS with angioplasty and stenting. In one review of endovascular therapies for HAS, primary technical success was achieved in 95% of the interventions. Complication rates following endovascular repair of HAS have been reported to be between 0 and 23% in the literature. The main risk factors for complications include tortuosity of the hepatic artery and history of a second liver transplant. Other associated risk factors include female gender, age greater than 60 years, prior history of transarterial chemoembolization, and multiple arterial graft anastomoses. The case presented here is representative of a complication of balloon rupture and fragmentation in a patient undergoing hepatic arterial stent placement post-liver transplant.

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.

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.

Rescue Arterial Revascularization Using Cryopreserved Iliac Artery Allograft in Liver Transplant Patients

OBJECTIVES

Management of hepatic arterial complications after liver transplant remains challenging. The aim of our study was to assess the efficacy of rescue arterial revascularization using cryopreserved iliac artery allografts in this setting.

MATERIALS AND METHODS

Medical records of patients with liver transplants who underwent rescue arterial revascularization using cryopreserved iliac artery allografts at a single institution were reviewed.

RESULTS

From 1992 to 2015, 7 patients underwent rescue arterial revascularization using cryopreserved iliac artery allografts for hepatic artery pseudoaneurysm (3 patients), thrombosis (2 patients), aneurysm (1 patient), or stenosis (1 patient). Two patients developed severe complications, comprising one biliary leakage treated percutaneously, and one acute necrotizing pancreatitis causing death on postoperative day 29. After a median follow-up of 75 months (range, 1-269 mo), 2 patients had an uneventful long-term course, whereas 4 patients developed graft thrombosis after a median period of 120 days (range, 2-488 d). Among the 4 patients who developed graft thrombosis, 1 patient developed ischemic cholangitis, 1 developed acute ischemic hepatic necrosis and was retransplanted, and 2 patients did not develop any further complications.

CONCLUSIONS

Despite a high rate of allograft thrombosis, rescue arterial revascularization using cryopreserved iliac artery allografts after liver transplant is an effective and readily available approach, with a limited risk of infection and satisfactory long-term graft and patient survival.

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.

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.

Vascular complications following liver transplantation: A literature review of advances in 2015

Although vascular complications (VCs) following orthotopic liver transplantation (OLT) seldom occur, they are the most feared complications with a high incidence of both graft loss and mortality, as they compromise the blood flow of the transplant (either inflow or outflow). Diagnosis and therapeutic management of VCs constitute a major challenge in terms of increasing the success rate of liver transplantation. While surgical treatment used to be considered the first choice for management, advances in endovascular intervention have increased to make this a viable therapeutic option. Considering VC as a rare but a major and dreadful issue in OLT history, and in view of the continuing and rapid progress in recent years, an update on these uncommon conditions seemed necessary. In this sense, this review comprehensively discusses the important features (epidemiological, clinical, paraclinical, prognostic and therapeutic) of VCs following OLT.

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.

Endoscopic treatment of post-liver transplantation anastomotic biliary stricture: systematic review and meta-analysis

CONTEXT

Biliary strictures after liver transplantation are recognized as its Achilles' heel. The strictures are classified in anastomotic and ischemic or non-anastomotic biliary strictures, and they figure among the most common complications after liver transplantation. There are some treatment options including balloon dilation, the placement of multiple plastic stents and the placement of self-expandable metal stents and all of them seem to have good results.

OBJECTIVES

The aim of this study was to systematically review the literature concerning the results of the endoscopic treatment of anastomotic biliary strictures after liver transplantation.

METHODS

A systematic review of the literature was performed on the management of anastomotic biliary strictures post- orthotopic liver transplantation. The Medline-PubMed, EMBASE, Scielo-LILACS, and Cochrane Databases were electronically searched from January 1966 to April 2013.

RESULTS

No well-designed randomized controlled trial was found. Most studies were retrospective or prospective comparisons in design. One study (86 patients) compared the endoscopic and the percutaneous accesses. The sustained clinical success rates were similar but the treatment duration was longer in the percutaneous group access. Two studies (56 patients) compared balloon dilation with balloon dilation and multiple plastic stents. There were no differences concerning sustained clinical success and complication rates.

CONCLUSIONS

Balloon dilation is as effective as balloon dilation plus multiple plastic stenting for the resolution of the anastomotic biliary strictures. Well-designed randomized trials are still needed to compare balloon dilation versus multiple plastic stenting versus metallic stenting.

Delayed rearterialization unlikely leads to nonanastomotic stricture but causes temporary injury on bile duct after liver transplantation

Nonanastomotic strictures (NAS) are common biliary complications after liver transplantation (LT). Delayed rearterialization induces biliary injury in several hours. However, whether this injury can be prolonged remains unknown. The correlation of this injury with NAS occurrence remains obscure. Different delayed rearterialization times were compared using a porcine LT model. Morphological and functional changes in bile canaliculus were evaluated by transmission electron microscopy and real-time PCR. Immunohistochemistry and TUNEL were performed to validate intrahepatic bile duct injury. Three months after LT was performed, biliary duct stricture was determined by cholangiography; the tissue of common bile duct was detected by real-time PCR. Bile canaliculi were impaired in early postoperative stage and then exacerbated as delayed rearterialization time was prolonged. Nevertheless, damaged bile canaliculi could fully recover in subsequent months. TNF-α and TGF-β expressions and apoptosis cell ratio increased in the intrahepatic bile duct only during early postoperative period in a time-dependent manner. No abnormality was observed by cholangiography and common bile duct examination after 3 months. Delayed rearterialization caused temporary injury to bile canaliculi and intrahepatic bile duct in a time-dependent manner. Injury could be fully treated in succeeding months. Solo delayed rearterialization cannot induce NAS after LT.

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.