Intrahepatic biliary lesions after orthotopic liver transplantation

The Role of Microbiota in Liver Transplantation and Liver Transplantation-Related Biliary Complications

Liver transplantation as a treatment option for end-stage liver diseases is associated with a relevant risk for complications. On the one hand, immunological factors and associated chronic graft rejection are major causes of morbidity and carry an increased risk of mortality due to liver graft failure. On the other hand, infectious complications have a major impact on patient outcomes. In addition, abdominal or pulmonary infections, and biliary complications, including cholangitis, are common complications in patients after liver transplantation and can also be associated with a risk for mortality. Thereby, these patients already suffer from gut dysbiosis at the time of liver transplantation due to their severe underlying disease, causing end-stage liver failure. Despite an impaired gut-liver axis, repeated antibiotic therapies can cause major changes in the gut microbiome. Due to repeated biliary interventions, the biliary tract is often colonized by several bacteria with a high risk for multi-drug resistant germs causing local and systemic infections before and after liver transplantation. Growing evidence about the role of gut microbiota in the perioperative course and their impact on patient outcomes in liver transplantation is available. However, data about biliary microbiota and their impact on infectious and biliary complications are still sparse. In this comprehensive review, we compile the current evidence for the role of microbiome research in liver transplantation with a focus on biliary complications and infections due to multi-drug resistant germs.

Liver Preservation by Aortic Perfusion Alone Compared With Preservation by Aortic Perfusion and Additional Arterial Ex Situ Back-Table Perfusion With Histidine-Tryptophan-Ketoglutarate Solution: A Prospective, Randomized, Controlled, Multicenter Study

Background

Arterial ex situ back-table perfusion (BP) reportedly reduces ischemic-type biliary lesion after liver transplantation. We aimed to verify these findings in a prospective investigation.

Methods

Our prospective, randomized, controlled, multicenter study involved livers retrieved from patients in 2 German regions, and compared the outcomes of standard aortic perfusion to those of aortic perfusion combined with arterial ex situ BP. The primary endpoint was the incidence of ischemic-type biliary lesions over a follow-up of 2 years after liver transplantation, whereas secondary endpoints included 2-year graft survival, initial graft damage as reflected by transaminase levels, and functional biliary parameters at 6 months after transplantation.

Results

A total of 75 livers preserved via standard aortic perfusion and 75 preserved via standard aortic perfusion plus arterial BP were treated using a standardized protocol. The incidence of clinically apparent biliary lesions after liver transplantation (n = 9 for both groups; P = 0.947), the 2-year graft survival rate (standard aortic perfusion, 74%; standard aortic perfusion plus arterial BP, 68%; P = 0.34), and incidence of initial graft injury did not differ between the 2 perfusion modes. Although 33 of the 77 patients with cholangiography workups exhibited injured bile ducts, only 10 had clinical symptoms.

Conclusions

Contrary to previous findings, the present study indicated that additional ex situ BP did not prevent ischemic-type biliary lesions or ischemia-reperfusion injury after liver transplantation. Moreover, there was considerable discrepancy between cholangiography findings regarding bile duct changes and clinically apparent cholangiopathy after transplantation, which should be considered when assessing ischemic-type biliary lesions.

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 and management of ischemic-type biliary lesions following orthotopic liver transplantation: A single center experience

INTRODUCTION

Biliary complications can cause morbidity, graft loss, and mortality after liver transplantation. The most troublesome biliary complications are ischemic-type biliary lesions (ITBL), which occur since transplants can now be performed after the donor has undergone circulatory death. The exact origin of this type of biliary complication remains unknown.

MATERIAL AND METHODS

A total of 528 patients were retrospectively analyzed following liver transplantation after excluding 30 patients with primary sclerosing cholangitis and those lost to follow-up from January 2007 to January 2014. The incidence of and risk factors for ITBL were evaluated.

RESULTS

Cold ischemia time (CIT) (P = 0.042) and warm ischemia time (WIT) (P = 0.006) were found to be independent risk factors for the development of ITBL. Use of the cytochrome P450 (CYP) 3A5 genotype assay to guide individualization of immunosuppressive medications resulted in significantly fewer ITBL (P = 0.027. Autoimmune hepatitis might be a risk factor for ITBL, as determined using univariate analysis (P = 0.047).

CONCLUSIONS

Efforts should be taken to minimize risk factors associated with ITBL, such as CIT and WIT. The CYP3A5 genotype assay should be used to guide selection of immunosuppressive therapy in an effort to reduce the occurrence of ITBL.

Targeting the Achilles' heel of adult living donor liver transplant: Corner-sparing sutures with mucosal eversion technique of biliary anastomosis

Biliary complications are regarded as the Achilles' heel of liver transplantation, especially for living donor liver transplantation (LDLT) due to smaller, multiple ducts and difficult ductal anatomy. Overall biliary complications reported in most series are between 10% and 30%. This study describes our modified technique of biliary anastomosis and its effects on incidence of biliary complications. This was a single-center retrospective study of 148 adult LDLT recipients between December 2011 and June 2014. Group 1 (n = 40) consisted of the first 40 patients for whom the standard technique of biliary anastomosis (minimal hilar dissection during donor duct division, high hilar division of the recipient bile duct, and preservation of the recipient duct periductal tissue) was used. Group 2 (n = 108) consisted of 108 patients for whom biliary anastomosis was done with the addition of corner-sparing sutures and mucosal eversion of the recipient duct to the standard technique. Primary outcome measures included biliary complications (biliary leaks and strictures). Biliary complications occurred in 7/40 patients in group 1 (17.5%) and in 4/108 patients in group 2 (3.7%). The technical factors mentioned above are aimed at preserving the blood supply of the donor and recipient ducts and hold the key for minimizing biliary complications in adult-to-adult LDLT.

Impact of non-anastomotic biliary strictures after liver transplantation on healthcare consumption, use of ionizing radiation and infectious events

BACKGROUND

Non-anastomotic biliary strictures (NAS) after orthotopic liver transplantation (OLT) have a negative influence on graft survival. Expert opinion suggests a negative effect of NAS on other important aspects of post-transplant care, although its impact is largely unknown as data are scarce.

METHODS

This retrospective single center study analyzed data on healthcare consumption, use of ionizing radiation, infectious complications and development of highly resistant microorganisms (HRMO) in adult patients with NAS. A comparison with a matched control group was made.

RESULTS

Forty-three liver recipients with NAS and 43 controls were included. Hospital admissions were higher in patients with NAS. Most common reason for admission was bacterial cholangitis (BC), with 70% of the patients having at least one episode compared to 9% in the control group. In patients with NAS, 67% received at least one ERCP compared to 21% in the control group (p = 0.001). This resulted in a larger yearly received radiation dose for patients with NAS (p = 0.001). Frequency of intravenous antibiotic therapy was higher (p = 0.001) for patients with NAS, consistently resulting in a higher number of cultures found with HRMO (p = 0.012).

CONCLUSION

NAS after OLT have a negative effect on post-transplant care, increasing readmission rates, interventional procedures, exposure to ionizing radiation, use of antibiotics, and development of HRMO.

Biliary tract reconstruction with or without T-tube in orthotopic liver transplantation: a systematic review and meta-analysis

INTRODUCTION

At present whether to use T-tube or not during orthotopic liver transplantation (OLT) in biliary tract reconstruction still remains controversial. Most transplant centers choose not to use T-tube because the T-tube can increase the incidence of cholangitis, but some centers still use T-tube because the T-tube can decrease the incidence of anastomotic strictures.

AIM

The purpose of this study is to compare biliary complications after biliary tract reconstruction with or without T-tube in OLT.

METHODS

systematic review and meta-analysis of a collection of 15 studies (six randomized control trails (RCTs) and nine comparative studies) to compare biliary complications after biliary tract reconstruction with or without T-tube in OLT.

RESULTS

The data showed that the biliary tract reconstruction with T-tube and without T-tube had equivalent outcomes for overall biliary complications (six RCTs p = 0.76; odd ratio [OR] = 1.19; 95% CI: 0.40, 3.58; all studies p = 0.14; OR = 1.50; 95% CI: 0.88, 2.57), bile leaks (six RCTs p = 0.61; OR = 0.86; 95% CI: 0.49, 1.52; all studies p = 0.09; OR = 1.39; 95% CI: 0.95, 2.02), cholangitis (six RCTs p = 0.13; OR = 5.54; 95% CI: 0.62, 49.79; all studies p = 0.08; OR = 4.27; 95% CI: 0.86, 21.16), hepatic artery thrombosis (two RCTs p = 1.00; OR = 1.00; 95% CI: 0.22, 4.49; all studies p = 0.75; OR = 1.19; 95% CI: 0.41, 3.44). However, in the group with T-tube there were better outcomes for biliary strictures (six RCTs p = 0.0003; OR = 0.34; 95% CI: 0.19, 0.61; all studies p < 0.0001; OR = 0.49; 95% CI: 0.34, 0.69).

DISCUSSION

Although most organizations choose not to use T-tube in OLT, we suggest that use of T-tube in biliary tract reconstruction during OLT for the recipients who possibly have high risks of biliary stricture is useful and necessary.

Biliary complications after orthotopic liver transplantation

PURPOSE OF REVIEW

The incidence, pathogenesis and management of the most common biliary complications are summarized, with an emphasis on nonanastomotic biliary strictures (NAS) and potential strategies to prevent NAS after liver transplantation.

RECENT FINDINGS

NAS have variable presentations in time and localization, suggesting various underlying pathogeneses. Early-onset NAS (presentation within 1 year) have shown to be largely related to ischemia-induced bile duct injury, whereas late-onset NAS [>1 year after orthotopic liver transplantation (OLT)] have more immune-mediated causes. Cytotoxic hydrophobic bile salts and impaired biliary HCO3 secretion may also play a role in the occurrence of NAS. Recently, insufficient biliary epithelial regeneration capacity after transplantation has also been suggested to play a major role in the pathogenesis of NAS. A potential strategy to prevent NAS has been proposed to be preservation by machine perfusion instead of classical static cold storage. Although machine perfusion has been shown to be a better preservation method for the liver parenchyma, efficacy in preventing ischemic injury of the biliary epithelium is largely unknown.

SUMMARY

The potential advantages of machine perfusion are very promising as it may provide better protection of the vulnerable bile ducts against ischemia-reperfusion injury. Clinical trials will be needed to demonstrate the impact of machine perfusion in reducing the incidence of biliary complications, especially NAS, after OLT.

Intrahepatic segmental portal vein thrombosis after living-related donor liver transplantation

BACKGROUND

Intrahepatic segmental portal vein thrombosis after living-related liver transplantation (LRLT) is uncommon. The cause remains unclear.

METHODS

After providing written informed consent, 25 recipients receiving LRLT at our institution from January 2011 to September 2013 were enrolled in this study. We performed triphase computerized tomographic (CT) study of the liver graft of each recipient 1 month after LRLT. The patencies of hepatic artery, portal vein, and hepatic vein were evaluated in detail. The triphase CT scans of the liver of each donor before transplantation also were reviewed. Thrombosis of the intrahepatic segmental portal vein was defined as the occlusion site of the portal vein being intrahepatic. Extrahepatic portal vein thrombosis was excluded in this study.

RESULTS

Among the 25 patients, 2 (8%) developed thrombosis of intrahepatic segmental portal vein. One 47-year-old man received LRLT for hepatitis B viral infection-related liver cirrhosis (Child-Pugh class C) with 3 hepatocellular carcinomas (total tumor volume <8 cm). Another 53-year-old man received LRLT for alcoholic liver cirrhosis (Child-Pugh class C). Both had developed progressive jaundice and cholangitis 1 month after surgery. Intrahepatic biliary stricture was found on the follow-up magnetic resonance images. However, liver triphase CT study demonstrated occlusion of intrahepatic portal vein of segment 8 in each patient. Radiologic interventions and balloon dilatation therapy via percutaneous transhepatic biliary drainage route improved the symptoms and signs of cholangitis and obstructive jaundice for both.

CONCLUSIONS

Thrombosis of intrahepatic segmental portal vein is not common but is usually associated with complications of intrahepatic bile duct. Early detection is important, and follow-up CT study of liver is suggested.

Graft cholangiopathy: etiology, diagnosis, and therapeutic strategies

BACKGROUND

Graft cholangiopathy has been recognized as a significant cause of morbidity, graft loss, and even mortality in patients after orthotopic liver transplantation. The aim of this review is to analyze the etiology, pathogenesis, diagnosis and therapeutic strategies of graft cholangiopathy after liver transplantation.

DATA SOURCE

A PubMed database search was performed to identify articles relevant to liver transplantation, biliary complications and cholangiopathy.

RESULTS

Several risk factors for graft cholangiopathy after liver transplantation have been identified, including ischemia/reperfusion injury, cytomegalovirus infection, immunological injury and bile salt toxicity. A number of strategies have been attempted to prevent the development of graft cholangiopathy, but their efficacy needs to be evaluated in large clinical studies. Non-surgical approaches may offer good results in patients with extrahepatic lesions. For most patients with complex hilar and intrahepatic biliary abnormalities, however, surgical repair or re-transplantation may be required.

CONCLUSIONS

The pathogenesis of graft cholangiopathy after liver transplantation is multifactorial. In the future, more efforts should be devoted to the development of more effective preventative and therapeutic strategies against graft cholangiopathy.

Hepatic artery reconstruction prevents ischemic graft injury, inhibits graft rejection, and mediates long-term graft acceptance in rat liver transplantation

BACKGROUND

Hepatic artery (HA) reconstruction is performed in the clinical liver transplantation.

METHODS

We assessed the importance of HA reconstruction in the success of liver transplantation. Orthotopic liver transplantation was performed without immunosspression from Lewis (RT1l) to Lewis rats (syngeneic transplantation) as well as Lewis to BN (RT1n) rats (allogeneic transplantation) with or without HA reconstruction. We examined graft function, pathology, and mRNA levels using DNA arrays in both arterialized and nonarterialized liver grafts.

RESULTS

In Lewis-to-Lewis syngeneic grafts, both the arterialized and nonarterialized grafts survived >120 days with normal graft function. lnfiltration of CD3(+) T cells and CD68(+) macrophages, marked bile duct proliferation with apoptotic epithelial cells, and expansion and increasing fibrosis of portal areas were evident in the nonarterialized grafts at day 120, although preservation of architecture was noted in the arterialized grafts. DNA array analysis of nonarterialized syngeneic grafts demonstrated the upregulation of mRNA of cell death-related proteins, cell cycle-related proteins, and inflammation-related proteins than those in arterialized grafts. Moreover, the arterialized Lewis-to-BN allogeneic grafts could survive for a long time with less severe graft dysfunction than those in non-arterialized allogeneic grafts.

CONCLUSIONS

HA reconstruction in liver transplantation inhibited hypoxic injury and subsequent inflammation and bile duct proliferation, prevented the augmentation of T-cell-and antibody-mediated rejection, and mediated long-term graft acceptance. HA reconstruction is essential factor in the success of liver transplantation.

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.

Relationship between the histological appearance of the portal vein and development of ischemic-type biliary lesions after liver transplantation

Ischemic-type biliary lesions (ITBLs) are a major cause of morbidity after liver transplantation (LT). Their assumed underlying pathophysiological mechanism is ischemia/reperfusion injury of the biliary tree, in which the portal circulation has been proposed recently to have a role. The aim of this study was to investigate whether early histological changes, particularly in the portal vein, predispose patients to ITBLs. A case-control study of 22 LT recipients was performed through a retrospective assessment of more than 30 histological parameters in 44 intraoperative liver biopsy samples taken after cold ischemia (time 0) and portal reperfusion (time 1). Eleven grafts developed ITBLs requiring retransplantation (the ITBL group), and 11 matched controls had normally functioning grafts 11 years after LT on average (the non-ITBL group). Additionally, 11 liver biopsy samples from hemihepatectomies performed for metastases of colorectal cancer (CRC) were assessed similarly. Analyses showed no significant histological differences at time 0 between the ITBL and non-ITBL groups. However, the time 1 biopsy samples from the ITBL group showed smaller portal vein branches (PVBs) significantly more often than the samples from the non-ITBL group, which also showed persisting paraportal collateral vessels. Larger PVBs and paraportal collateral vessels were also found in the CRC group. A morphometric analysis confirmed these findings and showed that PVB measurements were significantly lower for the ITBL group at time 1 versus the ITBL group at time 0 and the non-ITBL and CRC groups (they were largest in the CRC group). Thus, the PVB dimensions decreased in the ITBL group in comparison with the time 0 biopsy samples, and they were significantly smaller at time 1 in comparison with the dimensions for the non-ITBL and CRC groups. In conclusion, a smaller PVB lumen size in postreperfusion biopsy samples from liver grafts, suggesting a relatively decreased portal blood flow, is associated with a higher incidence of ITBLs. These findings support recent clinical studies suggesting a possible pathophysiological role of portal blood flow in the oxygenation of the biliary tree after LT.

Influence of hepatitis C virus infection and high virus serum load on biliary complications in liver transplantation

BACKGROUND

Biliary complications (BCs) and recurrent hepatitis C virus (HCV) infection are among the major causes of morbidity and graft loss following liver transplantation. The influence of HCV on BCs has not been definitely clarified.

PATIENTS AND METHODS

We performed a retrospective cohort study to analyze risk factors and outcome of post orthotopic liver transplantation (OLT) BCs in 352 liver transplant recipients over 12 years in Munich, Germany (n = 84 with HCV; living donor and re-OLT were excluded). BCs diagnosed with imaging techniques and abnormal liver enzyme pattern, requiring an intervention, were considered.

RESULTS

In a multivariate analysis, HCV serostatus and a high pre-and post-surgery HCV RNA serum load were independent risk factors for anastomotic strictures. HCV positivity and BCs alone did not alter graft loss. HCV-positive patients with BCs, however, had a significantly worse graft outcome (P = 0.02). Non-anastomotic strictures, bile leaks, and the number of interventions needed to treat bile leaks led to worse graft outcome in all patients.

CONCLUSION

HCV positivity and a high HCV RNA serum load were risk factors for anastomotic strictures. BCs and HCV had an additive effect on graft loss.

Meeting report of the International Liver Transplantation Society's 18th annual international congress: Hilton San Francisco Hotel, San Francisco, CA, May 16-19, 2012

From May 16-19, 2012, the International Liver Transplantation Society held its annual congress in San Francisco, CA. More than 1300 registrants attended the meeting, which included a premeeting conference entitled Balancing Risk in Liver Transplantation, focused topic sessions, and a variety of oral and poster presentations. This report is not all-inclusive and focuses on specific research abstracts on key topics in liver transplantation. As always, the new data herein are presented in the context of the published literature to further enhance knowledge in the field.

Early-onset versus late-onset nonanastomotic biliary strictures post liver transplantation: risk factors reflect different pathogenesis

Nonanastomotic biliary strictures (NAS) cause significant morbidity post liver transplantation. Timing of stricture development varies considerably, but the relationship between timing of stricture onset and aetiology has not been fully elucidated. Database analysis was performed on all adult patients undergoing liver transplantation between 1st January 1990 and 31st May 2008. Diagnosis of NAS required demonstration on at least two radiological studies. Early NAS were defined as developing <1 year post transplant (minimum 1-year follow-up) and late NAS developing >1 year post transplant (minimum 10-year follow-up). Ninety-six of 397 patients developed NAS (24%); 54 were early-onset NAS (56%) and 42 late-onset NAS (44%). Primary sclerosing cholangitis (PSC) was the only risk factor for NAS overall (P = 0.001). However, when patients with PSC were excluded, older donor age was a significant risk for NAS (P = 0.003). Early-onset NAS were associated with advanced donor age (P = 0.02), high MELD score (P = 0.001) and ABO-identical grafts (P = 0.02), whereas late-onset NAS were associated with PSC (P = 0.0008), bilio-enteric anastomosis (P = 0.006) and tacrolimus (P = 0.0001). Advanced donor age is a significant risk for NAS in patients without PSC. Importantly, aetiology of NAS varies depending on time to stricture development, suggesting early-onset and late-onset NAS may have different pathogenesis.

Matrix metalloproteinase 2 genotype is associated with nonanastomotic biliary strictures after orthotopic liver transplantation

BACKGROUND

Nonanastomotic biliary strictures (NAS) are a serious complication after orthotopic liver transplantation (OLT). Matrix metalloproteinases (MMPs) are involved in connective tissue remodelling in chronic liver disease and complications after OLT.

AIM

To evaluate the relationship between MMP-2 and MMP-9 gene polymorphisms and NAS.

METHODS

MMP-2 (-1306 C/T) and MMP-9 (-1562 C/T) gene promoter polymorphisms were analysed in 314 recipient-donor combinations. Serum levels of these MMPs were determined in subgroups of patients as well. NAS were identified with various radiological imaging studies performed within 4 years after OLT and defined as any stricture, dilation or irregularity of the intra- or extrahepatic bile ducts of the liver graft followed by an intervention, after exclusion of hepatic artery thrombosis and anastomotic strictures.

RESULTS

The average incidence of NAS was 15%. The major clinical risk factor for the development of NAS was PSC in the recipient. The presence of the MMP-2 CT genotype in donor and/or recipient was associated with a significantly higher incidence of NAS, up to 29% when both donor and recipient had the MMP-2 CT genotype (P=0.003). In the multivariate analyses, pre-OLT PSC (hazard ratio 2.1, P=0.02) and MMP-2 CT genotype (hazard ratio 3.5, P=0.003) were found to be independent risk factors for the development of NAS after OLT. No obvious association was found between NAS and the MMP-9 genotype and serum levels of the MMPs.

CONCLUSION

MMP-2 CT genotype of donor and recipient is an independent risk factor, in addition to PSC, for the development of NAS after OLT.

The combination of primary sclerosing cholangitis and CCR5-Δ32 in recipients is strongly associated with the development of nonanastomotic biliary strictures after liver transplantation

BACKGROUND

The role of the immune system in the pathogenesis of nonanastomotic biliary strictures (NAS) after orthotopic liver transplantation (OLT) is unclear. A loss-of-function mutation in the CC chemokine receptor 5 (CCR5-Δ32) leads to changes in the immune system, including impaired chemotaxis of regulatory T cells.

AIM

To investigate the impact of the CCR5-Δ32 mutation on the development of NAS.

METHODS

In 384 OLTs, we assessed the CCR5 genotype in donors and recipients and correlated this with the occurrence of NAS.

RESULTS

The CCR5-Δ32 allele was found in 65 (16.9%) recipients. The cumulative incidence of NAS at 5 years was 6.5% in wild-type (Wt) recipients vs 17.2% for carriers of the CCR5-Δ32 allele (P<0.01). In recipients with CCR5-Δ32, 50% of all NAS occurred >2 years after OLT, compared with 10% in the Wt group. In multivariate regression analysis, the adjusted risk of developing NAS was four-fold higher in recipients with CCR5-Δ32 (P<0.01). The highest risk of NAS was seen in patients transplanted for primary sclerosing cholangitis (PSC), who also carried CCR5-Δ32 (relative risk 5.4, 95% confidence interval 2.2-12.9; P<0.01). Donor CCR5 genotype had no impact on the occurrence of NAS.

CONCLUSIONS

Patients with the CCR5-Δ32 mutation have a four-fold higher risk of developing NAS, compared with Wt recipients. This risk is even higher in patients with CCR5-Δ32 transplanted for PSC. Late development of NAS is significantly more present in patients with CCR5-Δ32. These data suggest that the immune system plays a critical role in the development of NAS after OLT.

Arterial blood flow predicts graft survival in liver transplant patients

Proper liver perfusion is essential for sufficient organ function after liver transplantation. The aim of this study was to determine the effects of portal and arterial blood flow on liver function and organ survival after liver transplantation. The arterial and portal venous blood flow was measured intraoperatively by transit time flow measurement after reperfusion for 290 consecutive liver transplants. The graft survival, hepatic cell damage (alanine aminotransferase and aspartate aminotransferase), and liver function (prothrombin ratio and bilirubin) were determined. Grafts were stratified into groups according to arterial blood flow measurements [<100 mL/minute for arterial blood flow group I (ART I), 100-240 mL/minute for ART II, and ≥ 240 mL/minute for ART III] and portal venous blood flow measurements (<1300 mL/minute for portal venous blood flow group I and ≥ 1300 mL/minute for portal venous blood flow group II). With multivariate analysis, the impact of blood flow on graft survival was determined, and potential confounders were considered. Decreased portal venous blood flow was associated with significantly less organ survival in univariate analysis but not in multivariate analysis. In contrast, the arterial blood flow was significantly correlated with organ survival after liver transplantation in univariate and multivariate analyses [hazard rate ratio = 2.5, confidence interval = 1.6-4.1, P < 0.001, median survival = 56.6 (ART I), 82.7 (ART II), or 100.7 months (ART III)]. Moreover, low arterial blood flow resulted in impaired postoperative organ function and higher rates of primary nonfunction. Biliary complications were not affected by blood flow. Other risk factors for graft failure that were identified by multivariate analysis included retransplantation, histidine tryptophan ketoglutarate solution versus University of Wisconsin solution, and donor treatment with epinephrine. Impaired arterial blood flow after reperfusion represents a significant predictor of primary graft nonfunction and is associated with impaired graft survival. Whether the intraoperative measurement of hepatic arterial flow is predictive of graft survival should be evaluated in a prospective trial.

The importance of portal venous blood flow in ischemic-type biliary lesions after liver transplantation

Ischemic-type biliary lesions (ITBL) are the most frequent cause of nonanastomotic biliary strictures after liver transplantation. This complication develops in up to 25% of patients, with a 50% retransplantation rate in affected patients. Traditionally, ischemia-reperfusion injury to the biliary system is considered to be the major risk factor for ITBL. Several other risk factors for ITBL have been identified, including the use of liver grafts donated after cardiac death, prolonged cold and warm ischemic times and use of University of Wisconsin preservation solution. In recent years however, impaired microcirculation of the peribiliary plexus (PBP) has been implicated as a possible risk factor. It is widely accepted that the PBP is exclusively provided by blood from the hepatic artery, and therefore, the role of the portal venous blood supply has not been considered as a possible cause for the development of ITBL. In this short report, we present three patients with segmental portal vein thrombosis and subsequent development of ITBL in the affected segments in the presence of normal arterial blood flow. This suggests that portal blood flow may have an important contribution to the biliary microcirculation and that a compromised portal venous blood supply can predispose to the development of ITBL.

RhGH attenuates ischemia injury of intrahepatic bile ducts relating to liver transplantation

BACKGROUND

To study the effect of rhGH administration on intrahepatic cholangiocytes relating to liver transplantation with ischemia of hepatic artery, and ultimately, clarify pathologic mechanism of the injury.

METHODS

Rat orthotopic autologous liver transplantation was performed first. Three hours later, the rats were grouped as followed: HAL (hepatic artery ligation) group; HAL + rhGH (hepatic artery ligation followed by rhGH administration) group; CON (without hepatic artery ligation) group. Specimen was collected after 7 d. ALT and ALP of serum were measured. The pathologic changes of bile ducts of liver tissue were observed. The number of bile ducts and blood vessels in portal area were counted. Immunochemistry for VEGF, VEGFR-2, VEGFR-3, GHR, and IGF-1R of intrahepatic cholangiocytes was performed. Cholangiocytes apoptosis was evaluated by TUNEL analysis. Cholangiocytes proliferation was evaluated by PCNA immunolabeling.

RESULTS

ALT and ALP of HAL + rhGH group were significantly ameliorated compared with untreated animals (P < 0.05). ALT and ALP of HAL group were significantly higher compared with CON group (P < 0.05). In HAL group, the main injury of bile ducts was not reversible, whereas it was reversible in CON and rhGH groups. In HAL group, the number of bile ducts in portal area decreased, while the number of bile ducts not accompanying blood vessels increased (P < 0.05). In rhGH group, the number of bile ducts in portal area increased, while the number of bile ducts accompanying blood vessels increased compared with HAL group (P < 0.05). The expression of VEGF, VEGFR-2, VEGFR-3, GHR, and IGF-1R was significantly lower in HAL group than in CON group (P < 0.05). Following administration of rhGH to HAL rats, the expression of VEGF, VEGFR-2, VEGFR-3, IGF-1R, and GHR was significantly higher (P < 0.05). Administration of rhGH prevented increase in cholangiocytes apoptosis induced by HAL (P < 0.05). Administration of rhGH promoted increase in cholangiocytes proliferation held by HAL (P < 0.05).

CONCLUSIONS

Administration of rhGH appears to attenuate ischemia injury of intrahepatic bile ducts relating to liver transplantation. This function is partly related to the capacity that rhGH inhibits the apoptosis of intrahepatic cholangiocytes and prompts the proliferation and angiogenesis by increasing the expression of VEGF, VEGFR2, VEGFR3, GHR, and IGF1-R.

Liver transplantation following donation after cardiac death: an analysis using matched pairs

Grafts from donation after cardiac death (DCD) donors are used to increase the number of organs available for liver transplantation. There is concern that warm ischemia may impair graft function. We compared our DCD recipients with a case-matched group of donation after brain death (DBD) recipients. Between January 2002 and April 2008, 39 DCD grafts were transplanted. These were matched with 39 DBD recipients on the basis of identified variables that had a significant impact on mortality. These were used to individually match DCD and DBD patients with similar predictive mortality. We compared patient/graft survival, primary non-function (PNF), and rates of complications. Of all liver transplants, 6.1% were DCD grafts. PNF occurred twice in the DCD group. The incidence of nonanastomotic biliary strictures (NABS; 20.5% versus 0%, P = 0.005) and hepatic artery stenosis (HAS; 12.8% versus 0%, P = 0.027) in the DCD group was higher. One-year (79.5% versus 97.4%, P = 0.029) and 3-year (63.6% versus 97.4%, P = 0.001) graft survival was lower in the DCD group. Three-year patient survival was also lower (68.2% versus 100%, P < 0.0001). Our study is the first to use case-matched patients and compare groups with similar predictive mortality. There was a higher incidence of NABS and HAS in the DCD group. NABS were likely a result of warm ischemia. HAS may have been due to ischemia or arterial injury during retrieval. The DCD group had significantly poorer outcomes, but DCD grafts remain a valuable resource. With careful donor/recipient selection, minimization of ischemia, and good postoperative care, acceptable results can be achieved.

Is Roux-en-Y choledochojejunostomy an independent risk factor for nonanastomotic biliary strictures after liver transplantation?

Biliary reconstruction using Roux-en-Y choledochojejunostomy has been suggested as a risk factor for the development of nonanastomotic biliary strictures (NAS) after liver transplantation. Roux-en-Y reconstruction, however, is preferentially used in patients transplanted for primary sclerosing cholangitis (PSC), and the disease itself is also associated with a higher incidence of NAS. The aim of this study was to determine whether Roux-en-Y reconstruction is really an independent risk factor for NAS. A series of 486 consecutive adult liver transplants were studied. Biliary reconstruction in patients transplanted for PSC was either by Roux-en-Y choledochojejunostomy or by duct-to-duct anastomosis, depending on the quality of the recipient's extrahepatic bile duct. Univariate and multivariate statistical analyses were used to identify risk factors for the development of NAS. The overall incidence of NAS was 16.5% (80/486). In univariate analyses, the following variables were significantly associated with NAS: PSC as the indication for transplantation, type of biliary reconstruction (Roux-en-Y versus duct-to-duct), and postoperative cytomegalovirus infection. After multivariate logistic regression analysis, PSC as the indication for transplantation (odds ratio, 2.813; 95% confidence interval, 1.624-4.875; P < 0.001) and postoperative cytomegalovirus infection (odds ratio, 2.098; 95% confidence interval, 1.266-3.477; P = 0.004) remained as independent risk factors for NAS. Biliary reconstruction using Roux-en-Y choledochojejunostomy was not identified as an independent risk factor for NAS. In conclusion, the association between Roux-en-Y choledochojejunostomy and NAS observed in previous studies can be explained by the more frequent use of Roux-en-Y reconstruction in patients with PSC. Roux-en-Y reconstruction itself is not an independent risk factor for NAS. Liver Transpl 15:924-930, 2009. (c) 2009 AASLD.

Urokinase perfusion prevents intrahepatic ischemic-type biliary lesion in donor livers

AIM

To evaluate whether urokinase perfusion of non-heart-beating cadaveric donor livers reduces the incidence of intrahepatic ischemic-type biliary lesions (IITBLs).

METHODS

A prospective study was conducted to investigate potential microthrombosis in biliary microcirculation when non-heart-beating cadaveric livers were under warm or cold ischemic conditions. The experimental group included 140 patients who underwent liver transplantation during the period of January 2006 to December 2007, and survived for more than 1 year. The control group included 220 patients who received liver transplantation between July 1999 and December 2005 and survived for more than 1 year. In the experimental group, the arterial system of the donor liver was perfused twice with urokinase during cold perfusion and after trimming of the donor liver. The incidence of IITBLs was compared between the two groups.

RESULTS

In the control group, the incidence of IITBLs was 5.9% (13/220 cases) after 3-11 mo of transplantation. In the experimental group, two recipients (1.4%) developed IITBLs at 3 and 6 mo after transplantation, respectively. The difference in the incidence between the two groups was statistically significant (P < 0.05).

CONCLUSION

Double perfusion of cadaveric livers from non-heart-beating donors with urokinase may reduce the incidence of IITBLs.

Biliary complications after liver transplantation: A review

After liver transplantation, the prevalence of complications related to the biliary system is 6-35%. In recent years, the diagnosis and treatment of biliary problems has changed markedly. The two standard methods of biliary reconstruction in liver transplant recipients are the duct-to-duct choledochocholedochostomy and the Roux-en-Y-hepaticojejunostomy. Biliary leakage occurs in approximately 5-7% of transplant cases. Leakage from the site of anastomosis, the T-tube exit site and donor or recipient remnant cystic duct is well described. Symptomatic bile leakage should be treated by stenting of the duct by endoscopic retrograde cholangiopancreatography (ERCP) or percutaneous transhepatic cholangiography (PTCD). Biliary strictures can occur at the site of the anastomosis (anastomotic stricture; AS) or at other locations in the biliary tree (non-anastomotic strictures; NAS). AS occur in 5-10% of cases and are due to fibrotic healing. Treatment by ERCP or PTCD with dilatation and progressive stenting is successful in the majority of cases. NAS can occur in the context of a hepatic artery thrombosis, or with an open hepatic artery (ischaemic type biliary lesions or ITBL). The incidence is 5-10%. NAS has been associated with various types of injury, e.g. macrovascular, microvascular, immunological and cytotoxic injury by bile salts. Treatment can be attempted with multiple sessions of dilatation and stenting of stenotic areas by ERCP or PTCD. In cases of localized diseased and good graft function, biliary reconstructive surgery is useful. However, a significant number of patients will need a re-transplant. When biliary strictures or ischaemia of the graft are present, stones, casts and sludge can develop.

Endogenous bile salts are associated with bile duct injury in the rat liver transplantation model

BACKGROUND

Nonanastomotic biliary strictures are a serious complication after orthotopic liver transplantation (OLT) and are difficult to cure. We examined the role of endogenous bile salt toxicity in the pathogenesis of bile duct injury after OLT.

MATERIALS AND METHODS

A total of 90 Sprague-Dawley rats were divided into three groups: Sham-operated group (Sham, n=30), OLT group with 1 hr donor liver preservation (OLT-1h, n=30), and OLT group with 12 hr donor liver preservation (OLT-12h, n=30). Bile was collected and analyzed biochemically. The histopathologic study was performed to determine the intrahepatic bile duct morphologic changes. Hepatic expressions of bile transporters Ntcp, Bsep, Mdr2, and Oatps were detected.

RESULTS

During the first 2 weeks after transplantation, bile salt secretion was not parallel with phospholipid secretion, resulting in high biliary bile salt-to-phospholipid (BS:PL) ratio. The expression of bile transporters was consistent with the change of bile composition. Bile duct injury correlated significantly with bile salt secretion and BS:PL ratio. Moreover, OLT group with longer donor liver preservation time (OLT-12h) had significantly lower Mdr2 messenger RNA/protein level, higher BS:PL ratio, and better correlation between BS:PL ratio and bile duct injury compared with those of OLT-1h.

CONCLUSIONS

The unparallel secretion of bile salts and phospholipids results in cytotoxic bile formation with high BS:PL ratio after liver transplantation. Longer donor liver preservation time will increase graft bile cytotoxicity. The results of this study suggest that endogenous bile salts play a role in the pathogenesis of bile duct injury after OLT.

Seeking beyond rejection: an update on the differential diagnosis and a practical approach to liver allograft biopsy interpretation

Pathologic evaluation of liver allograft biopsies plays an integral role in the management of patients after liver transplantation. This review summarizes the clinical context and classical histology of different types of allograft rejection and also the common entities that enter the differential diagnosis of allograft rejection, and provides practical approaches to liver allograft biopsy interpretation. In addition, some of the new developments in the field of liver transplant pathology are updated. The purpose of this review is to provide guidance for pathologists interpreting liver allograft biopsies, particularly those interested in developing expertise in the field of liver transplant pathology.

Altered bile composition after liver transplantation is associated with the development of nonanastomotic biliary strictures

BACKGROUND/AIMS

Nonanastomotic biliary strictures are troublesome complications after liver transplantation. The pathogenesis of NAS is not completely clear, but experimental studies suggest that bile salt toxicity is involved.

METHODS

In one hundred and eleven adult liver transplants, bile samples were collected daily posttransplantation for determination of bile composition. Expression of bile transporters was studied perioperatively.

RESULTS

Nonanastomotic biliary strictures were detected in 14 patients (13%) within one year after transplantation. Patient and donor characteristics and postoperative serum liver enzymes were similar between patients who developed nonanastomotic biliary strictures and those who did not. Secretions of bile salts, phospholipids and cholesterol were significantly lower in patients who developed strictures. In parallel, biliary phospholipids/bile salt ratio was lower in patients developing strictures, suggestive for increased bile cytotoxicity. There were no differences in bile salt pool composition or in hepatobiliary transporter expression.

CONCLUSIONS

Although patients who develop nonanastomotic biliary strictures are initially clinically indiscernible from patients who do not develop nonanastomotic biliary strictures, the biliary bile salts and phospholipids secretion, as well as biliary phospholipids/bile salt ratio in the first week after transplantation, was significantly lower in the former group. This supports the concept that bile cytotoxicity is involved in the pathogenesis of nonanastomotic biliary strictures.

Biliary strictures following liver transplantation: past, present and preventive strategies

Biliary complications are still the major source of morbidity for liver transplant recipients. The reported incidence of biliary strictures is 5%-15% after deceased donor liver transplantation and 28%-32% after right-lobe live donor surgery. Presentation is usually within the first year, but the incidence is known to increase with longer follow-up. The anastomotic variant is due to technical factors, whereas the nonanastomotic form is due to immunological and ischemic events, which later may lead to graft loss. Endoscopic management of anastomotic strictures achieves a success rate of 70%-100%; it drops to 50%-75% for nonanastomotic strictures with a higher recurrence rate. Results of endoscopic maneuvers are disappointing for biliary strictures after live donor liver transplantation, and the success rate is 60%-75% for anastomotic strictures and 25%-33% for the nonanastomotic variant. Preventive strategies in the cadaveric donor include the standardization of the type of anastomosis and maintenance of a vascularized ductal stump. In right-lobe live donor livers, donor liver duct harvesting also involves a major risk. The concept of high hilar intrahepatic Glissonian dissection, dissecting the artery and the duct as one unit, use of microsurgical techniques for smaller ducts, use of ductoplasty, and flexibility in the performance of double ductal anastomosis are the critical components of the preventive strategies in the recipient. In the case of live donors, judicious use of intraoperative cholangiograms, minimal dissection of the hilar plate, and perpendicular transection of the duct constitute the underlying principals for obtaining a vascularized duct.

Six consecutive cases of successful adult ABO-incompatible living donor liver transplantation: a proposal for grading the severity of antibody-mediated rejection

BACKGROUND

The clinical symptoms, histological findings, and treatments for antibody-mediated rejection (AMR), which is the leading cause of graft loss in adult ABO-incompatible liver transplantation (ABO-I-LT), have rarely been discussed.

METHODS

We performed adult living donor ABO-I-LT on six patients. We used anti-CD20 monoclonal antibody combined with plasma exchange preoperatively and intraportal or hepatic-arterial infusion, consisting of prostaglandin E1, corticosteroids, and protease inhibitor postoperatively to prevent AMR. Splenectomy was performed in patients 1, 4, 5 and 6 but not in patients 2 and 3. Weekly liver biopsies were performed after ABO-I-LT. When severe AMR was diagnosed, we performed plasma exchange combined with gamma-globulin bolus infusion (PE+IVIG).

RESULTS

In patients 1-3, severe jaundice, rapid decreases in platelet counts, and severe coagulopathy were observed in the early postoperative period. Liver biopsies sampled after the onset of these clinical findings were characterized by severe periportal and lobular hemorrhagic and neutrophil infiltration, suggesting that severe AMR occurred. However, after the initiation of PE+IVIG, AMR was remedied in all three patients. In patients 4-6, severe AMR was not observed. Mild AMR characterized by mild portal hemorrhagic infiltration was observed in patient 4, and moderate AMR characterized by moderate periportal and lobular hemorrhagic infiltration was observed in patient 6. Patients 4-6 did not require PE+IVIG and their clinical course was uneventful.

CONCLUSION

Given the experience of these six patients, we consider that AMR may be graded based on liver biopsy findings including hemorrhagic infiltration and neutrophil infiltration, as well as clinical findings. All six patients are currently doing well.

Biliary complications after liver transplantation from maastricht category-2 non-heart-beating donors

BACKGROUND

There are unresolved issues regarding the security of liver transplantation with non-heart-beating donors (NHBDs). Recently, an increased incidence of biliary complications, mainly intrahepatic ischemic-type biliary strictures, has been described after controlled NHBDs.

METHODS

We studied the incidence and risk factors for biliary complications among uncontrolled NHBDs recipients compared with a large population of HBD recipients.

RESULTS

Overall, 16.8% of patients in the HBD group and 41.7% of patients in the NHBD group suffered any type of biliary complication (P=0.66). However, the incidence of nonanastomotic biliary strictures was significantly greater in the NHBD group (P<0.001). Multivariate analysis showed that independent risk factors for nonanastomotic strictures were hepatic artery thrombosis (relative risk; 98.7) and receiving a liver from a NHBD (relative risk; 47.1).

CONCLUSIONS

If this type of donors is accepted as a source of liver organs, the high incidence of biliary complications should be considered and efforts should be made to decrease ischemic injury.

Nonanastomotic biliary strictures after liver transplantation, part 1: Radiological features and risk factors for early vs. late presentation

Nonanastomotic biliary strictures (NAS) are a serious complication after orthotopic liver transplantation (OLT). The exact pathogenesis is unclear. Purpose of this study was to identify risk factors for the development of NAS after OLT. A total of 487 adult liver transplants with a median follow-up of 7.9 years were studied. All imaging studies of the biliary tree were reviewed. Cholangiography was routinely performed between postoperative days 10-14 and later on demand. Localization of NAS at first presentation was categorized into 4 anatomical zones of the biliary tree. Severity of NAS was semiquantified as mild, moderate, or severe. Donor, recipient, and surgical characteristics and variables were analyzed to identify risk factors for NAS. NAS developed in 81 livers (16.6%). Thirty-seven (7.3%) were graded as moderate to severe. In 85% of the cases, anatomical localization of NAS was around or below the bifurcation of the common bile duct. A large variation was observed in the time interval between OLT and first presentation of NAS (median 4.1 months; range 0.3-155 months). NAS presenting early (< or =1 year) after OLT were associated with preservation-related risk factors. Cold and warm ischemia times were significantly longer in patients with early NAS compared with NAS presenting late (>1 year) after OLT (694 minutes vs. 490 minutes, P = 0.01, and 57 minutes vs. 53 minutes, P < 0.05, respectively), and early NAS were more frequently located in the central bile ducts. NAS presenting late (>1 year) after OLT were found more frequently in the periphery of the liver and were more frequently associated with immunological factors, such as primary sclerosing cholangitis, as the indication for OLT (24% vs. 45%, P < 0.05). By separating cases of NAS on the basis of the time of presentation after transplantation, we were able to identify differences in risk factors, indicating different pathogenic mechanisms depending on the time of initial presentation.

Nonanastomotic biliary strictures after liver transplantation, part 2: Management, outcome, and risk factors for disease progression

Nonanastomotic biliary strictures (NAS) after orthotopic liver transplantation (OLT) are associated with high retransplant rates. The aim of the present study was to describe the treatment of and identify risk factors for radiological progression of bile duct abnormalities, recurrent cholangitis, biliary cirrhosis, and retransplantation in patients with NAS. We retrospectively studied 81 cases of NAS. Strictures were classified according to severity and location. Management of strictures was recorded. Possible prognostic factors for bacterial cholangitis, radiological progression of strictures, development of severe fibrosis/cirrhosis, graft survival, and patient survival were evaluated. Median follow-up after OLT was 7.9 years. NAS were most prevalent in the extrahepatic bile duct. Twenty-eight patients (35%) underwent some kind of interventional treatment, leading to a marked improvement in biochemistry. Progression of disease was noted in 68% of cases with radiological follow-up. Radiological progression was more prevalent in patients with early NAS and one or more episodes of bacterial cholangitis. Recurrent bacterial cholangitis (>3 episodes) was more prevalent in patients with a hepaticojejunostomy. Severe fibrosis or cirrhosis developed in 23 cases, especially in cases with biliary abnormalities in the periphery of the liver. Graft survival, but not patient survival, was influenced by the presence of NAS. Thirteen patients (16%) were retransplanted for NAS. In conclusion, especially patients with a hepaticojejunostomy, those with an early diagnosis of NAS, and those with NAS presenting at the level of the peripheral branches of the biliary tree, are at risk for progressive disease with severe outcome.

Causes and consequences of ischemic-type biliary lesions after liver transplantation

Biliary complications are a major source of morbidity, graft loss, and even mortality after liver transplantation. The most troublesome are the so-called ischemic-type biliary lesions (ITBL), with an incidence varying between 5% and 15%. ITBL is a radiological diagnosis, characterized by intrahepatic strictures and dilatations on a cholangiogram, in the absence of hepatic artery thrombosis. Several risk factors for ITBL have been identified, strongly suggesting a multifactorial origin. The main categories of risk factors for ITBL include ischemia-related injury; immunologically induced injury; and cytotoxic injury, induced by bile salts. However, in many cases no specific risk factor can be identified. Ischemia-related injury comprises prolonged ischemic times and disturbance in blood flow through the peribiliary vascular plexus. Immunological injury is assumed to be a risk factor based on the relationship of ITBL with ABO incompatibility, polymorphism in genes coding for chemokines, and pre-existing immunologically mediated diseases such as primary sclerosing cholangitis and autoimmune hepatitis. The clinical presentation of patients with ITBL is often not specific; symptoms may include fever, abdominal complaints, and increased cholestasis on liver function tests. Diagnosis is made by imaging studies of the bile ducts. Treatment starts with relieving the symptoms of cholestasis and dilatation by endoscopic retrograde cholangiopancreaticography (ERCP) or percutaneous transhepatic cholangiodrainage (PTCD), followed by stenting if possible. Eventually up to 50% of the patients with ITBL will require a retransplantation or may die. In selected patients, a retransplantation can be avoided or delayed by resection of the extra-hepatic bile ducts and construction of a hepaticojejunostomy. More research on the pathogenesis of ITBL is needed before more specific preventive or therapeutic strategies can be developed.

Liver biopsy in evaluation of complications following liver transplantation

AIM: To analyze the role of liver biopsies in differential diagnosis after liver transplantation.

METHODS: A total of 50 biopsies from 27 patients with liver dysfunction out of 52 liver transplantation cases were included. Biopsies were obtained 0-330 d after operation, in which, 44 were fine needle biopsies, another 6 were wedge biopsies during surgery. All tissues were stained with haemotoxylin-eosin. Histochemical or immunohistochemical stain was done.

RESULTS: The rate of acute rejection in detected cases and total transplantation cases was 48.2% and 25.0%, chronic rejection rate in detected cases and total transplan-tation cases was 14.8% and 7.7%, preservation-reperfusion injury in detected cases and total transplantation cases was 25.9% and 13.5%, hepatic artery thrombosis rate in detected cases and total transplantation cases was 11.1% and 5.8%, intrahepatic biliary injury rate in detected cases and total transplantation cases was 7.4 % and 3.8%, CMV infection rate in detected cases and total transplantation cases was 3.7% and 1.9%, hepatitis B recurrence rate in detected cases and total transplantation cases was 3.7% and 1.9%, the ratio of suspicious drug-induced hepatic injury in detected cases and total transplantation cases was 11.1% and 5.8%.

CONCLUSION: Acute rejection and preservation-reperfusion injury are the major factors in early liver dysfunction after liver transplantation. Hepatic artery thrombosis and prolonged cold preservation may result in intrahepatic biliary injury. Acute rejection and viral infection may involve in the pathogenesis of chronic rejection. Since there are no specific lesions in drug-induced hepatic injury, the diagnosis must closely combine clinical history and rule out other possible complications.

Liver transplantation from controlled non-heart-beating donors: an increased incidence of biliary complications

BACKGROUND

Hepatic allografts from non-heart-beating donors (NHBD) have been cited as a means to expand the supply of donor livers. Concern exists that donor warm ischemic time in addition to subsequent cold ischemia-reperfusion injury may result in damage to sensitive cell populations within the liver. Because the biliary epithelium is sensitive to ischemia-reperfusion injury, the authors surmised that an increased incidence of biliary complications might occur among recipients of an NHBD allograft.

METHODS

This study was a retrospective evaluation of NHBD recipients compared to a group of heart-beating donor (HBD) recipients from a single institution.

RESULTS

Fifteen patients received a hepatic allograft from a controlled NHBD donor. NHBD and HBD (n=221) graft survival did not differ at 1 (71.8% vs. 85.4%, P=0.23) or 3 years (71.8% vs. 73.9%, P=0.68). Patient survival at 1 (79% vs. 90.9%, P=0.16) and 3 years (79.0% vs. 77.7%, P=0.8) was also similar. Major biliary complications occurred in five (33.3%) NHBD recipients; 66.6% of the NHBD biliary complications consisted of intrahepatic strictures versus 19.2% among HBD recipients (P<0.01). Major biliary complications in the NHBD recipients resulted in multiple interventional procedures, retransplantation, and death.

CONCLUSIONS

Donor warm ischemic time may predispose hepatic allografts to an increased incidence of ischemic type strictures. Although graft and patient survival was similar to a cohort of HBD recipients, caution is urged with the use of these organs.