Association of hepatic artery stenosis and biliary strictures in liver transplant recipients

Impact of Baseline Anti-ABO Antibody Titer on Biliary Complications in ABO-Incompatible Living-Donor Liver Transplantation

Background: Although advancements in desensitization protocols have led to increased ABO-incompatible (ABOi) living-donor liver transplantation (LDLT), a higher biliary complication rate remains a problem. This study evaluated the effect of baseline anti-ABO antibody titers before desensitization on biliary complications after ABOi LDLT. Methods: The study cohort comprised 116 patients in the ABO-compatible group (ABOc), 29 in the ABOi with the low titer (<1:128) group (ABOi-L), and 14 in the high titer (≥1:128) group (ABOi-H). Results: Biliary complications occurred more frequently in the ABOi-H group than in the ABOi-L and ABOc groups (7 [50.0%] vs. 8 [27.6%] and 24 [20.7%], respectively, p = 0.041). Biliary complication-free survival was significantly worse in the ABOi-H group than in the other groups (p = 0.043). Diffuse intrahepatic biliary strictures occurred more frequently in the ABOi-H group than in the other groups (p = 0.005). Multivariable analysis revealed that the high anti-ABO antibody titer (≥1:128) is an independent risk factor for biliary complications (hazard ratio 3.943 [1.635-9.506]; p = 0.002). Conclusions: A high baseline anti-ABO antibody titer (≥1:128), female sex, and hepatic artery complications are significant risk factors for biliary complications.

A practical approach to the endoscopic management of biliary strictures after liver transplantation

Biliary tract complications are an important cause of morbidity and mortality after liver transplantation (LT) occurring in 5% to 25% of patients. The most common biliary complication in LT recipients are strictures representing approximately half of these biliary adverse events. Bile duct strictures can be divided into anastomotic biliary strictures (ABS) and non-anastomotic biliary strictures (NABS) depending on their location in the biliary tree, being ABS the most encountered type. Several risk factors identified in previous studies can predispose to the development of ABS and NABS, especially those related to surgical techniques and donor characteristics. Magnetic resonance cholangiopancreatography (MRCP) is the recommended noninvasive imaging test for detecting post-LT biliary strictures, given its high sensitivity and specificity. Once the diagnosis of a biliary stricture after LT has been made, endoscopic retrograde cholangiopancreatography (ERCP) is the preferred initial therapy with good short and long-term results. Biliary sphincterotomy plus balloon dilation (BD) with placement of multiple plastic stents (MPS) has been the classic endoscopic approach for treating ABS, although fully-covered metallic stents (FCSEMS) have emerged as an alternative thanks to shorter total duration of stenting and fewer endoscopic procedures compared to MPS. In this review, we provide a practical update on the management of biliary strictures after LT, focusing our attention on the available evidence in the endoscopic therapy.

Prognostic Factors for Non-anastomotic Biliary Strictures Following Adult Liver Transplantation: A Systematic Review and Meta-Analysis

INTRODUCTION

The development of non-anastomotic biliary strictures (NAS) following orthotopic adult liver transplantation (OLT) is associated with significant morbidity. We performed a systematic review and meta-analysis to identify all prognostic factors for the development of NAS.

METHODS

A systematic review was conducted following preferred reporting items for systematic reviews and meta-analyses (PRISMA) and the meta-analysis of observational studies in epidemiology (MOOSE) guidelines. We used the Newcastle-Ottawa scale to assess the quality of the included studies. Using the random-effects model, we calculated the weighted pooled odds ratios (OR), mean differences (MD), hazard ratios (HR), and 95% confidence intervals (CI) of the risk factors.

RESULTS

Based on 19 international studies that included a total of 8269 adult LT patients, we calculated an 8% overall incidence of NAS. In this study, 7 potential prognostic factors were associated with a statistically significant hazard ratio for NAS in pooled analyses including (1) DCD donors compared to DBD donors (2) PSC as an indication for a liver transplant (3) Roux-en-Y bile duct reconstruction compared to duct-to-duct reconstruction (4) hepatic artery thrombosis (5) longer cold ischemia time (6) longer warm ischemia time (7) and total operative times.

CONCLUSION

In this systematic review and meta-analysis, we identified 7 prognostic factors for the development of NAS following OLT. These findings might lay the groundwork for development of diagnostic algorithms to better risk stratify patients at risk for development of NAS.

Arterial Anastomosis Using Microsurgical Techniques in Adult Live Donor Liver Transplant: A Focus on Technique and Outcomes at a Single Institution

BACKGROUND

 Microvascular hepatic artery reconstruction (MHAR) is associated with decreased rates of hepatic artery thrombosis (HAT) in living donor liver transplantation (LDLT). There is a paucity of literature describing the learning points and initiation of this technique at the institutional level. The objective of this study is to report our institutional experience using MHAR in adult LDLT with a focus on technique and outcomes.

METHODS

 A retrospective review of adult patients who underwent LDLT from January 2012 to December 2020 was conducted. Patients were divided into two groups, those who underwent LDLT without MHAR and with MHAR. We analyzed cases for technical data including donor and recipient artery characteristics, anastomotic techniques, intraop events, and postop complications. A Mann-Whitney test was performed to compare outcomes between non-MHAR and MHAR patients.

RESULTS

 Fifty non-MHAR and 50 MHAR patients met inclusion criteria. Median age at transplantation was 58 (interquartile range [IQR] 11.8) and 57.5 years (IQR 14.5), respectively. Median follow-up for MHAR patients was 12.8 months (IQR 11.6). The most common recipient arteries were the right hepatic artery (HA) (58%) and left HA (20%). Median size of recipient and donor arteries were 3.3 mm (IQR 0.7) and 3.1 mm (IQR 0.7), resulting in a median mismatch size of 0.3 mm (IQR 0.4). Median microanastomosis time was 44 minutes (IQR 0). HAT, graft failure, and mortality rates were higher in the non-MHAR cohort (6% vs. 0%, 8% vs. 0%, and 16% vs. 6%, respectively); however, these did not reach statistical significance.

CONCLUSION

 This study found lower rates of HAT and graft failure after implementing MHAR, though statistical significance was not achieved. Larger cohort studies are needed to further assess the potential benefit of MHAR in adult LDLT. From our experience, MHAR requires cooperation between the transplant and microsurgical teams, with technical challenges overcome with appropriate instrumentation and planning.

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.

Long-term Clinical Outcomes and Predictive Factors for Living-donor Liver Transplant Recipients With Biliary Strictures

BACKGROUND

Biliary strictures frequently occur in living-donor liver transplant (LDLT) recipients. However, long-term clinical outcomes and their associated factors are unclear.

METHODS

We analyzed an historical cohort of 228 recipients who underwent LDLT with post-liver transplantation biliary strictures. Endoscopic retrograde cholangiography or percutaneous transhepatic biliary drainage were performed to treat biliary strictures. Patients that experienced persistent jaundice over 3 mo after the initial treatment were defined as a remission-failure group.

RESULTS

Median observation period was 8.5 y after the diagnosis of biliary stricture. The 15-y graft survival (GS) rate was 70.6%, and 15-y rate of developing portal hypertension (PH) was 26.1%. Remission failure occurred in 25.0% of study participants. In the multivariate analysis, biopsy-proven acute rejection, and portal vein/hepatic artery abnormalities were risk factors for remission failure. Development of PH, retransplantation, and death were significantly more frequent in the remission-failure group. Remission failure and PH were associated with poor GS. In multivariate analyses, hepatic artery abnormality and biloma were common significant factors that were associated with a poor GS and development of PH.

CONCLUSIONS

The insufficient blood supply reflected by hepatic artery abnormality and biloma might be the most important factor that can predict poor long-term survival in LDLT patients with biliary strictures. Future large-scale prospective studies are needed to validate our observations.

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

Background.

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

Methods.

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

Results.

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

Conclusions.

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

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.

Endoscopic management of biliary strictures post-liver transplantation

Biliary complications play a significant role in morbidity of liver transplant recipients. Biliary strictures occur between 10%-25% of patients with a higher incidence in living donor recipients compared to deceased donors. Strictures can be classified as either anastomotic or non-anastomotic and may be related to ischemic events. Endoscopic management of biliary strictures in the post-transplant setting has become the preferred initial approach due to adequate rates of resolution of anastomotic and non-anastomotic strictures (NAS). However, several factors may increase complexity of the endoscopic approach including surgical anatomy, location, number, and severity of bile duct strictures. Many endoscopic tools are available, however, the approach to management of anastomotic and NAS has not been standardized. Multi-disciplinary techniques may be necessary to achieve optimal outcomes in select patients. We will review the risk factors associated with the development of bile duct strictures in the post-transplant setting along with the efficacy and complications of current endoscopic approaches available for the management of bile duct strictures.

A Review on the Management of Biliary Complications after Orthotopic Liver Transplantation

Orthotopic liver transplantation is the definitive treatment for end-stage liver disease and hepatocellular carcinomas. Biliary complications are the most common complications seen after transplantation, with an incidence of 10-25%. These complications are seen both in deceased donor liver transplant and living donor liver transplant. Endoscopic treatment of biliary complications with endoscopic retrograde cholangiopancreatography (commonly known as ERCP) has become a mainstay in the management post-transplantation. The success rate has reached 80% in an experienced endoscopist's hands. If unsuccessful with ERCP, percutaneous transhepatic cholangiography can be an alternative therapy. Early recognition and treatment has been shown to improve morbidity and mortality in post-liver transplant patients. The focus of this review will be a learned discussion on the types, diagnosis, and treatment of biliary complications post-orthotopic liver transplantation.

Infections in Liver Transplantation

Liver transplantation has become an important treatment modality for patients with end-stage liver disease/cirrhosis, acute liver failure, and hepatocellular carcinoma. Although surgical techniques and immunosuppressive regimens for liver transplantation have improved significantly over the past 20 years, infectious complications continue to contribute to the morbidity and mortality in this patient population. The use of standardized screening protocols for both donors and recipients, coupled with targeted prophylaxis against specific pathogens, has helped to mitigate the risk of infection in liver transplant recipients. Patients with chronic liver disease and cirrhosis have immunological deficits that place them at increased risk for infection while awaiting liver transplantation. The patient undergoing liver transplantation is prone to develop healthcare-acquired infections due to multidrug-resistant organisms that could potentially affect patient outcomes after transplantation. The complex nature of liver transplant surgery that involves multiple vascular and hepatobiliary anastomoses further increases the risk of infection after liver transplantation. During the early post-transplantation period, healthcare-acquired bacterial and fungal infections are the most common types of infection encountered in liver transplant recipients. The period of maximal immunosuppression that occurs at 1–6 months after transplantation can be complicated by opportunistic infections due to both primary infection and reactivation of latent infection. Severe community-acquired infections can complicate the course of liver transplantation beyond 12 months after transplant surgery. This chapter provides an overview of liver transplantation including indications, donor-recipient selection criteria, surgical procedures, and immunosuppressive therapies. A focus on infections in patients with chronic liver disease/cirrhosis and an overview of the specific infectious complications in liver transplant recipients are presented.

Biliary strictures complicating living donor liver transplantation: Problems, novel insights and solutions

Biliary stricture complicating living donor liver transplantation (LDLT) is a relatively common complication, occurring in most transplant centres across the world. Cases of biliary strictures are more common in LDLT than in deceased donor liver transplantation. Endoscopic management is the mainstay for biliary strictures complicating LDLT and includes endoscopic retrograde cholangiography, sphincterotomy and stent placement (with or without balloon dilatation). The efficacy and safety profiles as well as outcomes of endoscopic management of biliary strictures complicating LDLT is an area that needs to be viewed in isolation, owing to its unique set of problems and attending complications; as such, it merits a tailored approach, which is yet to be well established. The diagnostic criteria applied to these strictures are not uniform and are over-reliant on imaging studies showing an anastomotic narrowing. It has to be kept in mind that in the setting of LDLT, a subjective anastomotic narrowing is present in most cases due to a mismatch in ductal diameters. However, whether this narrowing results in a functionally significant narrowing is a question that needs further study. In addition, wide variation in the endotherapy protocols practised in most centres makes it difficult to interpret the results and hampers our understanding of this topic. The outcome definition for endotherapy is also heterogenous and needs to be standardised to allow for comparison of data in this regard and establish a clinical practice guideline. There have been multiple studies in this area in the last 2 years, with novel findings that have provided solutions to some of these issues. This review endeavours to incorporate these new findings into the wider understanding of endotherapy for biliary strictures complicating LDLT, with specific emphasis on diagnosis of strictures in the LDLT setting, endotherapy protocols and outcome definitions. An attempt is made to present the best management options currently available as well as directions for future research in the area.

Impact of aberrant left hepatic artery ligation on the outcome of liver transplantation

The preservation of a graft's aberrant left hepatic artery (LHA) during liver transplantation (LT) ensures optimal vascularization of the left liver but can also be considered a risk factor for hepatic artery thrombosis (HAT). In contrast, ligation of an aberrant LHA may lead to hepatic ischemia with the potential risk of graft dysfunction and biliary complications. The aim of this study was to prospectively analyze the impact on the surgical strategy for LT of 5 tests performed to establish whether an aberrant LHA was an accessory or a replaced artery, thus leading to the design of a decisional algorithm. From August 2005 to December 2016, 395 whole LTs were performed in 376 patients. Five parameters were evaluated to determine whether an aberrant LHA was an accessory or a replaced artery. On the basis of our decision algorithm, an aberrant LHA was ligated during surgery when assessed as accessory and preserved when assessed as replaced. A total of 138 anatomical variants of hepatic arterial vascularization occurred in 120/395 (30.4%) grafts. Overall, the incidence of an aberrant LHA was 63/395 (15.9%). The LHA was ligated in 33 (52.4%) patients and preserved in 30 (47.6%) patients. After a mean follow-up period of 50.9 ± 39.7 months, the incidence of HAT, primary nonfunction, early allograft dysfunction, biliary stricture or leaks, and overall survival was similar in the 2 groups. In conclusion, once shown to be an accessory, an LHA can be safely ligated without clinical consequences on the outcome of LT. Liver Transplantation 24 204-213 2018 AASLD.

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.

Endoscopic management of biliary strictures after living donor liver transplantation

Living donor liver transplantation (LDLT) is an effective alternative to deceased liver transplantation (DDLT) for end-stage liver disease. Although advances in surgical techniques, immunosuppressive management, and post-transplant care have improved the overall outcomes of LDLT, biliary strictures remain the major unsolved problem. Endoscopic retrograde cholangiopancreatography (ERCP) is currently considered the first-line therapy for biliary strictures following LDLT with duct-to-duct reconstruction, with percutaneous and surgical interventions reserved for patients with unsuccessful management via ERCP. Endoscopic management of biliary strictures is technically more challenging in LDLT than in DDLT because of the complexity of the biliary anastomosis, in addition to the tortuous and angulated biliary system. Placement of one or more plastic stents after balloon dilation has been the standard strategy for post-LDLT stricture, but this requires multiple stent exchange to prevent stent occlusion until stricture resolution. Inside stents might prevent duodenobiliary reflux and thus have longer stent patency, obviating the need for multiple ERCPs. Newly developed covered self-expandable metallic stents with anti-migration systems are alternatives to the placement of multiple plastic stents. With the advent of deep enteroscopy, biliary strictures in LDLT patients with Roux-en-Y hepaticojejunostomy are now treatable endoscopically. In this review, we discuss the short- and long-term outcomes of endoscopic management of post-LDLT strictures as well as recent advances in this field.

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.

Liver grafts procured from donors after circulatory death have no increased risk of microthrombi formation

Microthrombi formation provoked by warm ischemia and vascular stasis is thought to increase the risk of nonanastomotic strictures (NAS) in liver grafts obtained by donation after circulatory death (DCD). Therefore, potentially harmful intraoperative thrombolytic therapy has been suggested as a preventive strategy against NAS. Here, we investigated whether there is histological evidence of microthrombi formation during graft preservation or directly after reperfusion in DCD livers and the development of NAS. Liver biopsies collected at different time points during graft preservation and after reperfusion were triple-stained with hematoxylin-eosin (H & E), von Willebrand factor VIII (VWF), and Fibrin Lendrum (FL) to evaluate the presence of microthrombi. In a first series of 282 sections obtained from multiple liver segments of discarded DCD grafts, microthrombi were only present in 1%-3% of the VWF stainings, without evidence of thrombus formation in paired H & E and FL stainings. Additionally, analysis of 132 sections obtained from matched, transplanted donation after brain death and DCD grafts showed no difference in microthrombi formation (11.3% versus 3.3% respectively; P = 0.082), and no relation to the development of NAS (P = 0.73). Furthermore, no microthrombi were present in perioperative biopsies in recipients who developed early hepatic artery thrombosis. Finally, the presence of microthrombi did not differ before or after additional flushing of the graft with preservation solution. In conclusion, the results of our study derogate from the hypothesis that DCD livers have an increased tendency to form microthrombi. It weakens the explanation that microthrombi formation is a main causal factor in the development of NAS in DCD and that recipients could benefit from intraoperative thrombolytic therapy to prevent NAS following liver transplantation. Liver Transplantation 22 1676-1687 2016 AASLD.

Risk factors for biliary complications after orthotopic liver transplantation with T-tube: a single-center cohort of 743 transplants

BACKGROUND

Despite recent advances in organ preservation, surgical procedures, and immunosuppression, biliary reconstruction after orthotopic liver transplantation (OLT) remains as a major source of morbidity. The purpose of this study was to identify risk factors for the development of biliary complications (BCs) after end-to-end choledochocholedochostomy (EE-CC) with a T-tube as the standard technique for biliary reconstruction after OLT.

METHODS

A total of 833 consecutive liver transplantations that took place from February 1996 to April 2010 were retrospectively reviewed. Patients with concomitant hepatic artery complications were excluded, as were those who underwent urgent retransplantation or died within 1 week after transplantation. Finally, the study group comprised 743 patients.

RESULTS

The overall BC rate was 9.8% (73 patients), including stricture in 19 patients (2.6%) and bile leakage in 39 patients (5.2%). After univariate analysis, significant risk factors for BCs were surgery time >5 hours, arterial ischemia time >30 minutes, use of a classic transplant technique, transfusion of red blood cells ≥5 units, anti-cytomegalovirus treatment, and period of transplantation between 1996 and 2002. Stepwise logistic regression study was performed, including those variables with a value of P <.200. Multivariate analysis showed that pretransplant serum creatinine (odds ratio = 1.27; 95% confidence interval [CI], 1.03-1.57; P = .025) and arterial ischemia time >30 minutes (odds ratio = 2.44; 95% CI, 1.45-4.12; P = .001) were the only independent risk factors related to the development of BCs after biliary reconstruction with the T-tube.

CONCLUSIONS

The performance of different variables in predicting occurrence of BCs was assessed with the use of receiver operating characteristic analysis. The area under the receiver operating characteristic curve of our model was 0.637 (95% CI, 0.564-0.710), and therefore we must conclude that other variables not included in our model may have influence in the development of BCs after OLT with an EE-CC with a T-tube as the procedure for biliary reconstruction.

Endoscopic management of benign biliary strictures

Benign biliary strictures are a common indication for endoscopic retrograde cholangiopancreatography (ERCP). Endoscopic management has evolved over the last 2 decades as the current standard of care. The most common etiologies of strictures encountered are following surgery and those related to chronic pancreatitis. High-quality cross-sectional imaging provides a road map for endoscopic management. Currently, sequential placement of multiple plastic biliary stents represents the preferred approach. There is an increasing role for the treatment of these strictures using covered metal stents, but due to conflicting reports of efficacies as well as cost and complications, this approach should only be entertained following careful consideration. Optimal management of strictures is best achieved using a team approach with the surgeon and interventional radiologist playing an important role.

Hepatic artery stenosis after liver transplantation: is endovascular treatment always necessary?

Hepatic artery stenosis (HAS) is thought to predispose patients to biliary complications secondary to ischemic injury. Despite this, the clinical significance of HAS remains poorly defined. The aims of this study were to determine the prevalence and outcomes of HAS and to define which patients might benefit from endovascular treatment. From a prospective database of 662 adult patients undergoing liver transplantation between 2000 and 2011, we identified 54 patients who developed HAS. HAS was defined as any stenosis > 70% that was seen during multidetector computed tomographic angiography (MDCTA) or digital subtraction angiography. The benefit of endovascular therapy was evaluated with propensity score matching. New biliary complications occurred in 17 patients (31.4%), and 23 of the 54 study patients with HAS received endovascular treatment. Among the propensity score-matched patients, the biliary stricture-free survival time was significantly longer for those who received endovascular therapy (P = 0.03). An incidental diagnosis (P = 0.07) and a time from transplantation > 6 months (P = 0.021) were associated with a reduced risk of developing biliary stricture. Patients with symptomatic HAS who received treatment had better biliary stricture-free survival than patients who were treated conservatively, although no significant difference was recorded (P = 0.11). No patient with asymptomatic HAS and normal liver function tests developed biliary strictures. In conclusion, HAS intervention was associated with improved biliary stricture-free survival. In patients with late-onset HAS (≥6 months) and asymptomatic patients, endovascular treatment is not warranted.

Endoscopic retrograde cholangiography for biliary anastomotic strictures after liver transplantation

Biliary complications after liver transplantation (LT) are an important cause of morbidity and mortality. In most cases, an anastomosis of the bile duct is performed as a duct-to-duct reconstruction, which makes endoscopic therapy with endoscopic retrograde cholangiography (ERC) feasible. Biliary anastomotic strictures (AS) are the most common cause of biliary complications. The early detection of an AS, which can sometimes be challenging given that its clinical presentation is often subtle, is of key importance to obtain high treatment success. In this review, we focus on the management of AS after LT with a special emphasis on ERC.

Hepatic transplantation: postoperative complications

Advances in surgical techniques and immunosuppression have made orthotopic liver transplantation a first-line treatment for many patients with end-stage liver disease. The early detection and treatment of postoperative complications has contributed significantly to improved graft and patient survival with imaging playing a critical role in detection. Complications that can lead to graft failure or patient mortality include vascular abnormalities, biliary abnormalities, allograft rejection, and recurrent or post-transplant malignancy. Vascular abnormalities include stenosis and thrombosis of the hepatic artery, portal vein, and inferior vena cava, as well as hepatic artery pseudoaneurysm, arteriovenous fistula, and celiac stenosis. Biliary abnormalities include strictures, bile leak, obstruction, recurrent disease, and infection. While imaging is not used to diagnose allograft rejection, it plays an important role in identifying complications that can mimic rejection. Ultrasound is routinely performed as the initial imaging modality for the detection and follow-up of both early and delayed complications. Cholangiography and magnetic resonance cholangiopancreatography are used to characterize biliary complications and computed tomography is used to confirm abnormal findings on ultrasound or for the evaluation of postoperative collections. The purpose of this article is to describe and illustrate the imaging appearances and management of complications associated with liver transplantation.

Bacterial infection after liver transplantation

Infectious complications are major causes of morbidity and mortality after liver transplantation, despite recent advances in the transplant field. Bacteria, fungi, viruses and parasites can cause infection before and after transplantation. Among them, bacterial infections are predominant during the first two months post-transplantation and affect patient and graft survival. They might cause surgical site infections, including deep intra-abdominal infections, bacteremia, pneumonia, catheter-related infections and urinary tract infections. The risk factors for bacterial infections differ between the periods after transplant, and between centers. Recently, the emergence of multi-drug resistant bacteria is great concern in liver transplant (LT) patients. The instructive data about effects of infections with extended-spectrum beta lactamase producing bacteria, carbapenem-resistant gram-negative bacteria, and glycopeptide-resistant gram-positive bacteria were reported on a center-by-center basis. To prevent post-transplant bacterial infections, proper strategies need to be established based upon center-specific data and evidence from well-controlled studies. This article reviewed the recent epidemiological data, risk factors for each type of infections and important clinical issues in bacterial infection after LT.

Reconstructing single hepatic artery with two arterial stumps: biliary complications in pediatric living donor liver transplantation

INTRODUCTION

Liver grafts can at times have two hepatic arterial stumps. This can result in a dilemma whether to reconstruct single or both the arteries. Hepatic artery (HA) thrombosis is the most dreaded complication in pediatric living donor liver transplantation (LDLT) as it can result in biliary complications and subsequent graft loss. We herein report the feasibility of reconstructing single hepatic artery in pediatric living donor liver transplantation having two arterial stumps in the liver graft.

MATERIALS AND METHODS

From 2008 to 2010, 87 pediatric patients undergoing LDLT were divided into three groups. Group 1 (n = 20): two HA stumps with two HA reconstruction, Group 2 (n = 22): two HA stumps with one HA reconstruction and Group 3 (n = 45): one HA stump with one HA reconstruction. The decision regarding the reconstruction of single or multiple HAs was made depending on the pre-operative radiological and intraoperative assessments.

RESULTS

The incidence of HA thrombosis (p = 0.126) and biliary complications (p = 0.617), was similar in the three groups.

CONCLUSION

Single HA reconstruction does not increase the risk of biliary strictures in pediatric LDLT recipients having dual hepatic arterial stumps in the liver graft.

MicroRNA profiles in graft preservation solution are predictive of ischemic-type biliary lesions after liver transplantation

BACKGROUND & AIMS

Ischemic-type biliary lesions (ITBL) are the second most common cause of graft loss after liver transplantation. Though the exact pathophysiology of ITBL is unknown, bile duct injury during graft preservation is considered to be a major cause. Here we investigated whether the release of cholangiocyte-derived microRNAs (CDmiRs) during graft preservation is predictive of the development of ITBL after liver transplantation.

METHODS

Graft preservation solutions (perfusates) and paired liver biopsies collected at the end of cold ischemia were analysed by RT-qPCR for CDmiR-30e, CDmiR-222, and CDmiR-296 and hepatocyte-derived miRNAs (HDmiRs) HDmiR-122 and HDmiR-148a. MicroRNAs in perfusates were evaluated on their stability by incubation and fractionation experiments. MicroRNA profiles in perfusates from grafts that developed ITBL (n=20) and grafts without biliary strictures (n=37) were compared.

RESULTS

MicroRNAs in perfusates were proven to be stable and protected against degradation by interacting proteins. Ratios between HDmiRs/CDmiRs were significantly higher in perfusates obtained from grafts that developed ITBL (p<0.01) and were identified as an independent risk factor by multivariate analysis (p<0.01, HR: 6.89). The discriminative power of HDmiRs/CDmiRs in perfusates was validated by analysis of separate brain death- (DBD) and cardiac death donors (DBD; p ≤ 0.016) and was superior to expression in liver biopsies (C=0.77 in perfusates vs. C<0.50 in biopsies).

CONCLUSIONS

This study demonstrates that differential release of CDmiRs during graft preservation is predictive of the development of ITBL after liver transplantation. This provides new evidence for the link between graft-related bile duct injury and the risk for later development of ITBL.

The influence of a contemporaneous portal and hepatic artery revascularization protocol on biliary complications after liver transplantation

BACKGROUND

We sought to compare the impact of sequential and contemporaneous revascularizations of portal vein and hepatic artery on biliary complications in patients undergoing liver transplantation.

METHODS

We reviewed 184 patients who underwent liver transplantation in our center, and categorized them into different groups based on the duration of time between the portal venous and hepatic arterial reperfusion: >10 minutes in the sequential portal and hepatic artery revascularization group (SPA; n = 56), and within 1 minute in the contemporaneous portal and hepatic artery revascularization group (CPA; n = 121).The other patients with an interval from 1-10 minutes (n = 7) were excluded. This study then compared the outcomes between the SPA and CPA groups.

RESULTS

Cold ischemic time (mean ± standard deviation) for the SPA and CPA groups were 561 ± 150 vs 577 ± 187 minutes, respectively (P = .53). The incidence of biliary complications for the SPA and CPA groups were 14/56 and 11/121, respectively (25% vs 9%; P = .005). By the Clavien-Dindo Classification of Surgical Complications, the biliary complications in SPA group tended to be more severe compared with the CPA group (grade I, 0% vs 0%; II, 14% vs 36%; IIIa, 71% vs 64%; IIIb, 7% vs 0%; IV, 7% vs 0%; P = .10). Among biliary complications, the incidence of nonanatomic strictures was greater in the SPA group (9% vs 2%; P = .03), whereas the difference was not significant for anastomotic strictures (P = .054). Except for a lower serum albumin level in the SPA group 1 day after liver transplantation (P < .001), there are no differences in post-transplant liver function or renal function at 1, 7, and 30 days after transplantation.

CONCLUSION

The CPA protocol can decrease the incidence of biliary complications substantially after liver transplantation and should replace the SPA protocol used by some centers in liver transplantation.

Surgical site infections in liver transplant recipients in the model for end-stage liver disease era: an analysis of the epidemiology, risk factors, and outcomes

In recipients of liver transplantation (LT), surgical site infection (SSIs) are among the most common types of infection occurring in the first 60 days after LT. In 2007, the Model for End-Stage Liver Disease (MELD) scoring system was adopted as the basis for prioritizing organ allocation. Patients with higher MELD scores are at higher risk for developing SSIs as well as other health care-associated infections. However, there have been no studies comparing the incidence of SSIs in the pre-MELD era with the incidence in the period since its adoption. Therefore, the objectives of this study were to evaluate the incidence, etiology, epidemiology, and outcomes of post-LT SSIs in those 2 periods and to identify risk factors for SSIs. We evaluated all patients who underwent LT over a 10-year period (2002-2011). SSI cases were identified through active surveillance. The primary outcome measure was an SSI during the first 60 days after LT. Risk factors were analyzed via logistic regression, and 60-day survival rates were evaluated via Cox regression. We evaluated 543 patients who underwent LT 597 times. The SSI rates in the 2002-2006 and 2007-2011 periods were 30% and 24%, respectively (P = 0.21). We identified the following risk factors for SSIs: retransplantation, the transfusion of more than 2 U of blood during LT, dialysis, cold ischemia for >400 minutes, and a cytomegalovirus infection. The overall 60-day survival rate was 79%. Risk factors for 60-day mortality were retransplantation, dialysis, and a longer surgical time. The use of the MELD score modified the incidence and epidemiology of SSIs only during the first year after its adoption. Risks for SSIs were related more to intraoperative conditions and intercurrences after LT than to a patient's status before LT.

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.

Endoscopic management of benign bile duct strictures

The use of endoscopic retrograde cholangiopancreatography for treating benign biliary strictures has become the standard of practice, with surgery and percutaneous therapy reserved for selected patients. The gold-standard endoscopic therapy is dilation of the stricture followed by placing and exchanging progressively larger and more numerable plastic stents over a 1-year period. Newer modalities, including the use of fully covered metal stents, are currently under investigation in an effort to improve the treatment of benign biliary strictures.

Endoscopic approach to the post liver transplant patient

Biliary complications occur after liver transplantation. These complications can be effectively and safely managed using endoscopic approaches and can prevent unnecessary and potentially morbid surgery.

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.

Effect of "the Awakening Protocol" in the outcome of liver transplantation

PURPOSE

To analyze mortality (7 days) or graft loss in liver transplantation (Tx) performed within the Awakening Protocol (AP) compared to sequential Tx.

METHODS

Analysis of 243 liver tx (230 patients), divided into sequential tx or PD (early morning) to compare graft loss or death (7 days). Significant differences at p < 0.05

RESULTS

The PD was adopted in 32.5% of tx. The cold ischemia time (p < 0.01) and the interval until transplantation (p < 0.01) were significantly different. Age of the donor and recipient, Donor Risk Index, MELD score, and donor base excess, sodium, creatinine and glucose were not different between groups. Previous abdominal surgery was a risk factor for early mortality, but was equally distributed between the groups. There was no difference in mortality or graft loss within 7 days (p = 0.521)

CONCLUSION

The adoption of PD, to start tx the morning when harvesting occurs after 10p.m. did not result in worse patient and graft survival. Transplant patients with fulminant hepatic failure and high-risk grafts do not apply to this surgical tactics.

Biliary complications after orthotopic liver transplantation: a review of incidence and risk factors

Biliary complications (BCs) are a common source of morbidity after liver transplantation, leading to long-term and repeated therapies. The incidence of BCs currently ranges from 5% and 25%. Biliary strictures and leaks are the most common complications after deceased donor liver transplantation (DDLT), occurring in 9%-12% and 5%-10% of cases, respectively. Hepatic artery complications are recognized as the major risk factor for BCs; however, other circumstances such as advanced donor age, prolonged cold and warm ischemia times, grafts from donors after cardiac death, occurrence of a previous bile leak, T-tube use, cytomegalovirus infection, or graft steatosis have also been reported to be potential risk factors. Use of various preservation solutions has not significantly improved the biliary complication rate after DDLT. Technical modifications in biliary reconstruction have been proposed to improve outcomes after DDLT; the use of a T-tube for biliary reconstruction continues to be controversial. Non anastomotic strictures (NAS) are recognized to be different from anastomotic strictures. Although they have been associated with ischemic or immunological mechanisms, bile salt toxicity has recently been recognized as a potential factor for NAS. Donation after cardiac death is a significant source of organs that has been associated with decreased graft survival due to the increased BCs.

Establishment of a rat liver transplantation model with prolonged biliary warm ischemia time

AIM: To investigate the impact of different time points of secondary warm ischemia on bile duct in a rat autologous liver transplantation model with external bile drainage.

METHODS: One hundred and thirty-six male inbred SD rats were randomly assigned to one of four groups (I-IV) according to the secondary warm ischemia time of 0, 10, 20 and 40 min. A rat model of autologous liver transplantation with continuous external biliary drainage under ether anesthesia was established. Ten rats in each group were used to evaluate the one-week survival rate. At 6 h, 24 h, 3 d and 7 d after reperfusion of the hepatic artery, 6 rats were killed in each group to collect the blood sample via the infrahepatic vena cava and the median lobe of liver for assay. Warm ischemia time of liver, cold perfusion time, anhepatic phase, operative duration for biliary external drainage and survival rates in the four groups were analyzed for the establishment of models.

RESULTS: No significant difference was shown in warm ischemia time, anhepatic phase and operative duration for biliary external drainage among the four groups. Five of the 40 rats in this study evaluated for the one-week survival rate died, including three deaths of severe pulmonary infection in group IV. A significant decrease of one-week survival rate in group IV was noted compared with the other three groups. With the prolongation of the biliary warm ischemia time, the indexes of the liver function assessment were significantly elevated, and biliary epithelial cell apoptosis index also increased. Pathological examinations showed significantly aggravated inflammation in the portal area and bile duct epithelial cell injury with the prolonged secondary warm ischemia time. Microthrombi were found in the micrangium around the biliary tract in some sections from groups III and IV.

CONCLUSION: The relationship between secondary warm ischemia time and the bile duct injury degree is time-dependent, and 20 min of secondary warm ischemia time is feasible for the study of bile duct injury.

Effects of warm ischemia time on biliary injury in rat liver transplantation

AIM: To investigate the effect of different secondary warm ischemia time (SWIT) on bile duct injury in liver-transplanted rats.

METHODS: Forty-eight male inbred Sprague-Dawley rats were randomly assigned into four groups: a sham-operation group and three groups with secondary biliary warm ischemia time of 0 min, 10 min and 20 min. A rat model of autologous liver transplantation under ether anesthesia was established, and six rats were killed in each group and blood samples and the median lobe of the liver were collected for assay at 6 h and 24 h after hepatic arterial reperfusion.

RESULTS: With prolongation of biliary warm ischemia time, the level of vascular endothelial growth factor-A was significantly decreased, and the value at 24 h was higher than that at 6 h after hepatic arterial reperfusion, but with no significant difference. The extended biliary SWIT led to a significant increase in bile duct epithelial cell apoptosis, and a decrease in the number of blood vessels, the bile duct surrounding the blood vessels and bile duct epithelial cell proliferation in the early postoperative portal area. Pathologic examinations showed that inflammation of the rat portal area was aggravated, and biliary epithelial cell injury was significantly worsened.

CONCLUSION: A prolonged biliary warm ischemia time results in aggravated injury of the bile duct and the surrounding vascular plexus in rat autologous orthotopic liver transplantation.