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

Surgical Versus Image-Guided Interventions in the Management of Complications After Liver Transplantation

Liver transplantation is a technically demanding surgical procedure with known complications, and the optimal approach to addressing vascular and biliary complications requires a coordinated effort between surgical and interventional radiology teams. Vascular complications involving the hepatic artery, portal vein, or hepatic veins can be characterized by their mechanism, chronicity, and timing of presentation. These factors help determine whether the optimal therapeutic approach is surgical or endovascular. Very early presentation in the perioperative period favors surgical revision, while later presentation is best addressed endovascularly. Biliary complications can be categorized as leaks or strictures, and coordinated surgical, endoscopic, and percutaneous management is needed to address these types of complications. Through advances in technique and the management of complications, outcomes after liver transplantation continue to improve.

Redo hepatic artery reconstruction for thrombosis without retransplantation in 1355 adult living donor liver transplantations

Hepatic artery thrombosis (HAT) after liver transplantation is associated with a marked increase in morbidity, leading to graft and patient loss. We evaluated the outcomes of adult living donor liver transplantation patients with HAT under an aggressive surgical intervention. A total of 1355 recipients underwent adult living donor liver transplantation at the Seoul National University Hospital. Surgical redo reconstruction for HAT was performed in all cases except in those with graft hepatic artery injury and late detection of HAT. Postoperative HAT developed in 33 cases (2.4%) at a median time of 3.5 days. Thirty patients (90.9%) underwent redo-arterial reconstruction. The survival rates in patients with HAT were similar to the rates in those without HAT (72.7% vs. 83.8%, p = 0.115). Although graft survival rates were lower in patients with HAT (84.8%) than in those without HAT (98.0%) ( p < 0.001), the graft survival rate was comparable (92.0% vs. 98.0%, p = 0.124) in the 25 patients with successful revascularization. Biliary complication rates were higher in patients with HAT (54.5%) than in those without HAT (32.0%) ( p = 0.008). In conclusion, the successful redo reconstruction under careful selection criteria saved the graft without retransplantation in 96.0% of the cases. Surgical revascularization should be preferentially considered for the management of HAT in adult living donor liver transplantation.

Graft aberrant hepatic arteries in deceased donor liver transplantation: The "one liver, one artery" approach

In liver transplantation (LT), graft aberrant hepatic arteries (aHAs) frequently require complex arterial reconstructions, potentially increasing the risk of post-operative complications. However, intrahepatic hilar arterial shunts are physiologically present and may allow selective aHA ligation. Thus, we performed a retrospective study from a single-center cohort of 618 deceased donor LTs where a selective reconstruction policy of aHAs was prospectively applied. In the presence of any aHA, the vessel with the largest caliber was first reconstructed. In case of adequate bilobar arterial perfusion assessed on intraparenchymal Doppler ultrasound, the remnant vessel was ligated; otherwise, it was reconstructed. Consequently, outcomes of three patient groups were compared: the "no aHAs" group (n = 499), the "reconstructed aHA" group (n = 25), and the "ligated aHA" group (n = 94). Primary endpoint was rate of biliary complications. Only 38.4% of right aHAs and 3.1% of left aHAs were reconstructed. Rates of biliary complications in the no aHA, reconstructed aHA, and ligated aHA groups were 23.4%, 28%, and 20.2% (p = 0.667), respectively. The prevalence rates of primary non-function (p = 0.534), early allograft dysfunction (p = 0.832), and arterial complications (p = 0.271), as well as patient survival (p = 0.266) were comparable among the three groups. Retransplantation rates were 3.8%, 4%, and 5.3% (p = 0.685), respectively. In conclusion, a selective reconstruction policy of aHAs based on Doppler assessment of bilobar intraparenchymal arterial flow did not increase post-operative morbidity and avoided unnecessary and complex arterial reconstructions.

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.

Neuroform EZ Stents for Hepatic Artery Stenosis After Liver Transplantation: A Single-Center Preliminary Report

PURPOSE

This preliminary study evaluated the safety and effectiveness for off-label use of Neuroform EZ (NEZ) stents in the revascularization of hepatic artery stenosis (HAS) after orthotopic liver transplantation (OLT).

MATERIALS AND METHODS

Nine of 489 (5%) OLTs with HAS were managed with NEZ stents between September 2016 and July 2021. Stenting outcomes were evaluated based on the technical success rate, procedure-related complications, and primary patency.

RESULTS

A total of 10 NEZ stents (4.5 mm × 3 cm, n = 6; 4 mm × 3 cm, n = 4) were successfully deployed in 9 torturous hepatic arteries and in 1 relatively straight artery without any procedure-related complications. Combined thrombolysis (n = 3) and balloon angioplasty (n = 6) was performed. The median duration of follow-up was 438 days (range, 120-1126 days). Asymptomatic re-stenoses were detected in 2 stents on days 60 and 433 after stenting. A Kaplan-Meier curve predicted cumulative primary stent patencies at 1, 2, and 3 years of 90%, 75%, and 75%, respectively.

CONCLUSION

NEZ stents can be safely used to treat HAS after OLT with high technical success and favorable primary patency.

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

OBJECTIVE

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

BACKGROUND

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

STUDY DESIGN

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

RESULTS

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

CONCLUSION

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

Association of shear-wave elastography with clinical outcomes post-liver transplantation

PURPOSE

Two-dimensional shear-wave elastography (2D-SWE) assessment of liver stiffness has the advantage of being obtained during conventional ultrasound. Liver-stiffness values on 2D-SWE for grafted livers are unknown, as are their potential link to post-transplantation morbidity. This study was undertaken to determine liver-stiffness values on 2D-SWE for grafted livers without complications, and examine relationships between liver-stiffness values on 2D-SWE and early post-operative arterial or biliary complications.

METHODS

In our facility, all liver-transplant recipients are entered in a comprehensive surgical database, where donor, procedure and recipient characteristics are described. All patients underwent systematic 2D-SWE assessment. Potential relationships were analyzed between liver-stiffness findings and donor, procedure and recipient characteristics, and follow-up events, including death, arterial or biliary complications, graft removal and allograft-dysfunction scores.

RESULTS

Liver-stiffness values on 2D-SWE of 337 ultrasound examinations from 165 liver-transplant recipients were collected retrospectively. Median time from transplantation to 2D-SWE examination was 149 days, with median follow-up at 36 months. The mean±SD stiffness value for grafts without complications was 7.3±2.3kPa; it was significantly higher during the first 90 days (8.2±2.5kPa) post-transplant than after 1year (7.0±2.4kPa) (P=0.01). Patients with biliary complications during the first-year post-transplantation had significantly higher mean liver-stiffness values on 2D-SWE than those without, respectively: 9.8±7.0 vs 7.5±1.8kPa (P=0.01).

CONCLUSIONS

Post-transplantation patients without complications had stiffer livers than the general population, with higher values during the first 90 days after surgery. Liver-stiffness values on 2D-SWE were significantly higher for patients with biliary, but not arterial, complications.

Time is of the essence: A single-center experience of hepatic arterial supply impairment management in pediatric liver transplant recipients

BACKGROUND

Impairment of hepatic arterial flow including hepatic arterial thrombosis (HAT), hepatic arterial stenosis (HAS), and splenic artery steal syndrome (SASS) is potentially life-threatening complications. The proposed early diagnosis and urgent treatment strategy of graft arterial flow reduction aim to decrease morbidity and mortality.

METHODS

Pediatric patients with known hepatic arterial flow impairment were retrospectively reviewed. Patients were grouped by occlusive (HAT) and non-occlusive (HAS/SASS) arterial flow reduction. Patients with HAT were further divided in two groups based on the estimated maximal hepatic artery occlusion time ≤8 and >8 hours.

RESULTS

Impairment of hepatic arterial flow developed in 32 of 416 pediatric liver transplant recipients. HAT, HAS, and SASS incidences were 4.1% (n = 17), 2.2% (n = 9), and 1.4% (n = 6), respectively. Neither graft loss nor death occurred in the non-occlusive group. The probabilities of sepsis (OR, 1.7; 95% CI, 1.14-2.53; P=.008) and graft loss or death (OR, 1.42; 95% CI, 1.04-1.92; P=.046) were higher in the occlusive group. Patients with estimated maximal duration of hepatic artery occlusion ≤ 8 hours (n = 7; 41.2%) did not have ischemic-type biliary lesions and sepsis (P=.044 and 0.010, respectively) but had excellent 3-year graft survival compared with > 8 hours group (100% vs 40%; P=.037). Multivariate analysis revealed HAT manifestation by fever was associated with increased chances of graft loss or death.

CONCLUSION

Occlusive arterial complications impose higher risks of graft loss and death. Thorough arterial supply monitoring by Doppler ultrasonography and urgent endovascular arterial flow restoration may salvage both graft and the recipient.

Diagnostic accuracy of Doppler ultrasound for detecting hepatic artery stenosis after liver transplantation

AIM

To evaluate the diagnostic accuracy of Doppler ultrasound (DUS) in detecting hepatic artery stenosis (HAS) after liver transplantation using computed tomography angiography (CTA) as the reference standard.

MATERIALS AND METHODS

This study included data from January 2005 to November 2017, where DUS of the hepatic artery of living and deceased donor liver grafts were compared with the reference standard, CTA. DUS parameters, such as intrahepatic artery (IHA) peak systolic velocity (PSV), resistive index (RI), systolic acceleration time (SAT); and extrahepatic artery (EHA) PSV were taken. The optimum cut-off was estimated using area under the receiver operating characteristic curve (AUC). Multivariable logistic regression analysis was developed to predict HAS.

RESULTS

Ninety-nine liver transplant cases were retrieved, 50 met the inclusion criteria where nine patients had significant HAS. HAS patients had a significantly low IHAPSV with a cut-off of 35.1 cm/s (sensitivity 53.8%, specificity 78.4%, AUC 0.701). IHARI had a significantly low RI with a cut-off 0.585 (sensitivity 86.7%, specificity 85.4%, AUC 0.913). The IHASAT cut-off was 0.045 seconds (sensitivity 80%, specificity 91.4%, AUC 0.857). The EHAPSV cut-off was 197.4 cm/s (sensitivity 50%, specificity 99.1%, AUC 0.648). The prediction model using DUS parameters IHARI and IHASAT demonstrated good discrimination with an AUC of 0.930 (95% CI: 0.843, 1.000; sensitivity 93.3%, specificity 88%).

CONCLUSION

A prediction model using the DUS parameters IHARI and IHASAT showed good diagnostic accuracy of 88.6% for monitoring liver transplant patients. If validated externally, this DUS model could be utilised to diagnose HAS in liver transplant recipients.

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.

Endovascular Therapy of Arterial Complications Within the First Week After Liver Transplant

BACKGROUND

Recent radiologic advances have made endovascular treatment a very successful option for arterial complications after liver transplant. This article presents our experience of using endovascular treatments during the first week after liver transplant.

METHODS

This study is a retrospective, single-center analysis. Liver transplants performed between 2010 and 2018 were analyzed. All patients underwent Doppler ultrasonography on days 1 and 7. Endovascular therapy was indicated in hepatic artery thrombosis diagnosed early after transplant and in stenosis when hepatic narrowing was > 70%. Patients were treated with subcutaneous anticoagulant therapy and with antiplatelet agents after endovascular therapy.

RESULTS

Seven patients (1.1%) were included in the study. Stenosis was the reason in 5 patients while 2 patients had symptoms of thrombosis. The first 2 patients were initially treated with angioplasty; both had restenosis and were treated with angioplasty and stent placement, respectively. The 5 most recent patients received stenting as a primary treatment. Two of these patients developed a new stenosis. No patient developed any hepatic artery complication related to the procedure, and only 1 patient experienced a postprocedure complication (femoral artery pseudoaneurysm), which was managed conservatively. No patient required retransplant. After a median follow-up of 48 months (range, 35-85 months) 1 patient had died, and the rest were alive and asymptomatic.

CONCLUSIONS

Although there is scant experience of the use of endovascular therapy very shortly after liver transplant, recent advances in interventional radiology have made the technique feasible and safe, and it achieves a high success rate.

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 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.

Risk factors of hepatic artery thrombosis in pediatric deceased donor liver transplantation

PURPOSE

Hepatic artery thrombosis (HAT) remains a life-threatening complication in liver transplantation. We aim to investigate the risk factors of HAT in deceased donor pediatric liver transplantation.

METHODS

104 recipients from 2014 to 2016 were enrolled; donor and recipient characteristics, surgical variables, graft and recipient survival rate were compared between recipients with or without HAT. Univariate and multivariate analysis were applied to identify the risk factors of HAT.

RESULTS

The recipient survival rate was 87.0% and 96.3% at 1 year, and 87.0% and 96.3% at 3 years in HAT and non-HAT groups without significant difference. The graft survival rate was 73.9% and 96.3% at 1 year, and 73.9% and 95.1% at 3 years in HAT and non-HAT groups; significant difference was observed between two groups at both 1 and 3 years. Donor age less than 8.5 months, graft weight less than 190 g and GRWR less than 2.2% were identified as independent risk factors for HAT. Recipients with HAT were associated with higher incidence of post-operative biliary complications.

CONCLUSIONS

Young donor age and small liver graft are risk factors for HAT in deceased donor pediatric liver transplantation.