Management of the biliary complications associated with liver transplantation: 13 years of experience

New diagnosis and therapy model for ischemic-type biliary lesions following liver transplantation--a retrospective cohort study

Ischemic-type biliary lesions (ITBLs) are a major cause of graft loss and mortality after orthotopic liver transplantation (OLT). Impaired blood supply to the bile ducts may cause focal or extensive damage, resulting in intra- or extrahepatic bile duct strictures or dilatations that can be detected by ultrasonography, computed tomography, magnetic resonance cholangiopancreatography, and cholangiography. However, the radiographic changes occur at an advanced stage, after the optimal period for therapeutic intervention. Endoscopic retrograde cholangio-pancreatography (ERCP) and percutaneous transhepatic cholangiodrainage (PTCD) are the gold standard methods of detecting ITBLs, but these procedures cannot be used for continuous monitoring. Traditional methods of follow-up and diagnosis result in delayed diagnosis and treatment of ITBLs. Our center has used the early diagnosis and intervention model (EDIM) for the diagnosis and treatment of ITBLs since February 2008. This model mainly involves preventive medication to protect the epithelial cellular membrane of the bile ducts, regular testing of liver function, and weekly monitor of contrast-enhanced ultrasonography (CEUS) to detect ischemic changes to the bile ducts. If the liver enzyme levels become abnormal or CEUS shows low or no enhancement of the wall of the hilar bile duct during the arterial phase, early ERCP and PTCD are performed to confirm the diagnosis and to maintain biliary drainage. Compared with patients treated by the traditional model used prior to February 2008, patients in the EDIM group had a lower incidence of biliary tract infection (28.6% vs. 48.6%, P = 0.04), longer survival time of liver grafts (24±9.6 months vs. 17±12.3 months, P = 0.02), and better outcomes after treatment of ITBLs.

Newly designed Y-configured single-catheter stenting for the treatment of hilar-type nonanastomotic biliary strictures after orthotopic liver transplantation

PURPOSE

This study was designed to introduce our novel technique of percutaneous single catheter placement into the hilar bile ducts strictures while fulfilling the purpose of bilateral biliary drainage and stenting. We investigated the efficacy and safety of the technique for the treatment of hilar nonanastomotic biliary strictures.

METHODS

Ten patients who were post-orthotopic liver transplantation between July 2000 and July 2010 were enrolled in this study. Percutaneous Y-configured single-catheter stenting for bilateral bile ducts combined with balloon dilation was designed as the main treatment approach. Technical success rate, clinical indicators, complications, and recurrent rate were analyzed.

RESULTS

Technical success rate was 100%. Nine of the ten patients had biochemical normalization, cholangiographic improvement, and clinical symptoms relief. None of them experienced recurrence in a median follow-up of 26 months after completion of therapy and removal of all catheters. Complications were minor and limited to two patients. The one treatment failure underwent a second liver transplantation but died of multiple system organ failure.

CONCLUSIONS

Percutaneous transhepatic Y-configured single-catheter stenting into the hilar bile ducts is technically feasible. The preliminary trial of this technique combined with traditional PTCD or choledochoscopy for the treatment of hilar biliary strictures after orthotopic liver transplantation appeared to be effective and safe. Yet, further investigation is needed.

Evaluation of the efficacy and reproducibility of cholangiopancreatography by magnetic resonance for detecting biliary complications following orthotopic liver transplantation

PURPOSE

To evaluate the accuracy and reproducibility of magnetic resonance cholangiopancreatography (MRCP) in the detection of biliary complications in liver transplanted patients.

METHODS

A study was conducted, with blinded review of 28 MRCP exams of 24 patients submitted to liver transplantation. The images were reviewed by two independent observers, at two different moments, regarding the degree of biliary tree visualization and the presence or absence of biliary complications. The MRCP results were compared, when negative, to at least 3 months of clinical and biochemical follow-up, and when positive, to the findings at surgery or endoscopic retrograde cholangiopancreatography (ERCP).

RESULTS

The degree of intrahepatic biliary tree visualization was considered good or excellent in 78.6% and 82.1% of the exams by the two observers and visualization of the donor duct, recipient duct and biliary anastomosis was considered good or excellent in 100% of the exams, by both observers. Six biliary complications were detected (21.4%), all of them anastomotic strictures. Intra and interobserver agreement were substantial or almost perfect (kappa k values of 0.611 to 0.804) for the visualization of the biliary tree and almost perfect (k values of 0.900 to 1.000) for the detection of biliary complications. MRCP achieved 100% sensitivity, 95.45% specificity, 85.7% positive predictive value and 100% negative predictive value for the detection of biliary complications.

CONCLUSIONS

MRCP is an accurate examination for the detection of biliary complications after orthotopic liver transplantation and it is a highly reproducible method in the evaluation of the biliary tree of liver transplanted patients.

Establishment of a rat model of extrahepatic biliary ischemic stenosis

AIM: To develop a rat model of extrahepatic biliary ischemic stenosis.

METHODS: Forty-eight Sprague-Dawley rats were divided randomly and equally into four groups: rats undergoing sham operation and those subjected to clamping of the common bile duct with a clip for 60, 120, or 180 min. After scheduled clamping, the clip was removed to recover blood supply. The animals were killed 4 and 8 wk after operation. The survival, liver function, and histopathological changes were observed in rats of each group.

RESULTS: The survival rate was 100% in rats undergoing sham operation and those undergoing clamping for 60 or 120min, and 75% in those undergoing clamping for 180 min. At week 4, the body weight of rats undergoing clamping for 60, 120 or 180 min was lower than that of rats undergoing sham operation (240.4 g ± 11.5 g, 212.7 g ± 13.6 g, 200.6 g ± 11.8 g vs 260.6 g ± 15.7 g, all P < 0.05). Liver function parameters were higher in rats undergoing clamping for 60, 120 or 180 min than in those undergoing sham operation (ALT: 55.3 IU/L ± 5.3 IU/L, 215.6 IU/L ± 26.8 IU/L, 245.5 IU/L ± 38.5 IU/L vs 45.5 IU/L ± 3.9 IU/L, all P < 0.05; AST: 161.3 IU/L ± 15.9 IU/L, 645.3 IU/L ± 50.5 IU/L, 698.8 IU/L ± 46.7 IU/L vs 140.3 IU/L ± 6.1 IU/L, all P < 0.05; TILB: 8.5 μmol/L ± 1.2 μmol/L, 72.6 μmol/L ± 11.0 μmol/L, 78.7 μmol/L ± 12.2 μmol/L vs 6.1 μmol/L ± 1.2 μmol/L, all P < 0.05; ALP: 202.4 IU/L ± 20.7 IU/L, 815.4 IU/L ± 68.1 IU/L, 902.9 IU/L ± 96.6 IU/L vs 158.5 IU/L ± 23.6 IU/L, all P < 0.05; GGT: 10.6 IU/L ± 2.7 IU/L, 52.3 IU/L ± 8.6 IU/L, 57.4 IU/L ± 11.3 IU/L vs 7.6 IU/L ± 1.4 IU/L, all P < 0.05). Histopathological examination showed that biliary stenosis was not apparent and wall fibrosis was milder in rats undergoing sham operation and those undergoing clamping for 60 min, while severe biliary stenosis and wall fibrosis were observed in those undergoing clamping for 120 or 180 min. At week 8, these lesions could not regress spontaneously.

CONCLUSION: An animal model of extrahepatic biliary ischemic stenosis is successfully established with the clamping method in rats, which provides a useful tool for basic and clinical research of the etiology, development and prophylaxis of extrahepatic biliary ischemic stenosis after liver transplantation.

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.

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.

Establishment of an animal model of biliary ischemic stenosis with clamping in mice

OBJECTIVE

The objective of this study was to explore a method to establish biliary ischemic stenosis in mice.

METHODS

After the optimal time of biliary ischemia was determined, 20 Kunming mice were equally divided into 2 groups. In the experimental group a 0.4-cm length of common bile duct was clamped for 90 minutes with 2 micro-vessel clamps (width = 0.1 cm). The common bile duct was not clamped in the control group. Twenty-one days later, biliary tract visualization was performed in all mice. Blood samples were collected from the inferior vena cava to determine the serum levels of total bilirubin (TBIL) and alanine aminotransferase (ALT). Meanwhile, samples of the common bile duct and liver tissue were extracted for microscopic examination to observe morphological changes.

RESULTS

In the experimental group, obvious dilatation of the common bile duct appeared over the clamp site. There was no dilatation of the common bile duct in the control group. Twenty-one days later, serum levels of TBIL and ALT were significantly higher among the experimental compared with the control group. Microscopic examination showed that the part of common bile duct at the clamp site was significantly expanded, with a smaller or occluded bile duct lumen necrotic mucosa with determination, and tubular wall with fibrosis and excrustation. A few dead liver cells and many inflammatory cells were observed in liver tissue samples.

CONCLUSIONS

A biliary ischemic stenosis model was established using a clamping method in mice, which may provide a reliable technique for basic and clinical research into mechanisms of biliary ischemic stenosis after liver transplantation.

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.

Endoscopic retrograde cholangiography in post-orthotopic liver transplant population with Roux-en-Y biliary reconstruction

Endoscopic retrograde cholangiography (ERC) is a well-established modality for diagnostic and therapeutic maneuvers in pancreaticobiliary disorders. However, it is technically more challenging in patients with postsurgical anatomy like Roux-en-Y anastomoses. Its effectiveness in post-orthotopic liver transplantation (OLT) patients with Roux-en-Y biliary reconstruction has not been reported. We sought to assess the efficacy and safety of ERC in this patient population. A total of 132 OLTs with Roux-en-Y biliary reconstruction were performed at our institution from June 1998 to August 2005. Data from consenting patients who underwent ERC were reviewed once they were identified through computerized medical index system. Of 132 OLT patients with Roux-en-Y biliary reconstruction, 31 patients (9 female and 22 male subjects ranging in age from 11 months to 70 years) underwent ERC. The indication for liver transplant was end-stage liver disease or occurrence of cholangiocarcinoma from primary sclerosing cholangitis in 28 patients and a case each of chronic hepatitis C, alcoholic liver disease, and metastatic islet cell carcinoma. A variable-stiffness pediatric colonoscope was used in most cases. ERC indications were both diagnostic and therapeutic and included the following: evaluation of increased liver biochemistries and fever in 12 patients, dilation of anastomotic biliary strictures in 10 patients, removal of fractured biliary tube or retained biliary stent in 6 patients, and in 1 patient each, biliary stone removal, management of bile leak, and jejunal tube extension placement for nutritional purpose. ERC was successful in 22 patients (71%). There were no postprocedural complications. Although ERC is technically more difficult and time-consuming in OLT patients with Roux-en-Y anastomoses, these data suggest that ERC is an effective and safe diagnostic and therapeutic modality with few or no complications when performed by experienced endoscopists. ERC was successful in most patients and allowed therapeutic interventions that obviated the need for percutaneous radiological intervention or surgery.

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.

Magnetic resonance cholangiography in the diagnosis of biliary complications after orthotopic liver transplantation

OBJECTIVE

The aim of our study was to evaluate the role of magnetic resonance cholangiography (MRC) in the diagnosis of biliary tract complications (BC) after orthotopic liver transplantation (OLT).

MATERIALS AND METHODS

Among 21 OLT patients who underwent routine follow-up MRC using a breath-hold T2-weighted turbo spin-echo sequence with half-Fourier acquisition (HASTE), 5 had an elevated serum alkaline phosphatase level. Diagnostic confirmation was obtained with endoscopic retrograde cholangiography (ERC) (n = 11), surgery (n = 3), or clinical and laboratory follow-up of at least 1 year (n = 8).

RESULTS

In 13 patients, no abnormality of the biliary tract was detected using MRC. In 8 patients, anastomotic strictures were diagnosed, 7 of which were confirmed at surgery or using ERC. One patient with normal findings at MRC and abnormal liver function test results was found to have a stricture at ERC. All patients with normal MRC and liver function tests had 1 year of uneventful follow-up and were considered true-negative cases. We found that MRC had 87.5% sensitivity, 92.3% specificity, 87.5% positive predictive value, 92.3% negative predictive value, and 90.4% accuracy for the diagnosis of BC.

CONCLUSION

MRC is a valuable examination to detect BC after OLT. It provides useful information for planning interventional procedures.