Ischemic-type biliary lesions in liver transplant recipients: evaluation with magnetic resonance cholangiography

Prospective, single-centre, randomised controlled trial to evaluate the efficacy and safety of ischaemia-free liver transplantation (IFLT) in the treatment of end-stage liver disease

INTRODUCTION

During conventional liver transplantation (CLT), ischaemia-reperfusion injury (IRI) is inevitable and is associated with complications such as early allograft dysfunction (EAD), primary non-function and ischaemic-type biliary lesions. We have established a novel procedure called ischaemia-free liver transplantation (IFLT). The results from a pilot study suggest that IFLT might prevent IRI and yield better transplant outcomes than CLT. The purpose of this study was to further assess the efficacy and safety of IFLT versus CLT in patients with end-stage liver disease.

METHODS AND ANALYSIS

This is an investigator-initiated, open-label, phase III, prospective, single-centre randomised controlled trial on the effects of IFLT in patients with end-stage liver disease. Adult patients (aged 18-75 years) eligible for liver transplantation will be screened for participation in this trial and will be randomised between the IFLT group (n=34) and the CLT group (n=34). In the IFLT group, the donor liver will be procured, preserved and implanted with continuous normothermic machine perfusion (NMP). In the CLT group, the donor liver will be procured after a fast cold flush, preserved in 0°C-4°C solution and implanted under hypothermic and hypoxic conditions. Patients in both groups will be managed according to the standard protocol of our centre. The primary end point is the incidence of EAD after liver transplantation. Intraoperative and postoperative parameters of donor livers and recipients will be observed and recorded, and postoperative liver graft function, complications and recipient and graft survival will be evaluated. After a 12-month follow-up of the last enrolled recipient, the outcomes will be analysed to evaluate the safety and efficacy of IFLT versus CLT in patients with end-stage liver disease.

ETHICS AND DISSEMINATION

The protocol was reviewed and approved by the Ethics Committee of The First Affiliated Hospital of Sun Yat-sen University. The findings will be disseminated to the public through conference presentations and peer-reviewed scientific journals.

TRIAL REGISTRATION NUMBER

ChiCTR1900021158.

Biliary complications following orthotopic liver transplantation: May contrast-enhanced MR Cholangiography provide additional information?

PURPOSE

To assess whether contrast-enhanced T1-weighted MR Cholangiography may provide additional information in the evaluation of biliary complications in orthotopic liver transplant recipients.

MATERIAL AND METHODS

Eighty liver transplant patients with suspicion of biliary adverse events underwent MR imaging at 1.5 T scanner. After acquisition of axial T1-/T2-weighted images and conventional T2-weighted MR Cholangiography (image set 1), 3D gradient-echo T1-weighted fat-suppressed LAVA (Liver Acquisition with Volume Acceleration) sequences were obtained about 30 min after intravenous infusion of mangafodipir trisodium (Mn-DPDP,Teslascan(®)) (image set 2). The diagnostic value of mangafodipir trisodium-enhanced MR Cholangiography in the detection of biliary complications was tested by separate analysis results of image set 1 alone and image set 1 and 2 together. MRI results were correlated with direct cholangiography in 46 patients, surgery in 14 and/or clinical-radiological follow-up in the remaining 20 cases.

RESULTS

The level of confidence in the assessment of biliary adverse events was significantly increased by the administration of mangafodipir trisodium (p < 0.05). Particularly, contrast-enhanced T1-weighted LAVA sequences tended to out-perform conventional T2-weighted MR Cholangiography in the delineation of anastomotic and non-anastomotic biliary strictures and in the diagnosis of biliary leak.

CONCLUSIONS

Contrast-enhanced T1-weighted MR Cholangiography may improve the level of diagnostic confidence provided by conventional T2-weighted MR Cholangiography in the evaluation of biliary complications after orthotopic liver transplantation.

Ultrasonography, laboratory, and cholangiography correlation of biliary complications in pediatric liver transplantation

The aim of this study is to correlate the US, laboratory, and cholangiography findings in pediatric liver transplant patients with biliary complications, trying to identify reliable decision-making tools for the management of these complications. Retrospective review was carried out of US results in 39 consecutive patients, from 2011 to 2013, with biliary complications after LT, documented by PTC. According to US biliary dilation, patients were classified as: mild, moderate, and severe, and according to laboratory findings as: normal or abnormal serum bilirubin and level of serum GGT. Data were correlated with PTC findings, divided in three groups: mild, moderate, and severe/occlusive BDS. There was no statistically significant correlation between the US findings and the laboratory findings and between US findings with PTC. There was a statistically significant correlation between GGT and cholangiography. In our series, abnormal US could not predict the severity of BDS on PTC. Bilirubin results were not able to predict the US findings either. GGT results demonstrated a statistically significant correlation with the severity of BDS found on PTC. These findings emphasize the role of GGT in the evaluation and decision of biliary interventions in pediatric liver transplant recipients.

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

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

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.

Postoperative biliary adverse events following orthotopic liver transplantation: Assessment with magnetic resonance cholangiography

Biliary adverse events following orthotopic liver transplantation (OLT) are relatively common and continue to be serious causes of morbidity, mortality, and transplant dysfunction or failure. The development of these adverse events is heavily influenced by the type of anastomosis during surgery. The low specificity of clinical and biologic findings makes the diagnosis challenging. Moreover, direct cholangiographic procedures such as endoscopic retrograde cholangiopancreatography and percutaneous transhepatic cholangiography present an inadmissible rate of adverse events to be utilized in clinically low suspected patients. Magnetic resonance (MR) maging with MR cholangiopancreatography is crucial in assessing abnormalities in the biliary system after liver surgery, including liver transplant. MR cholangiopancreatography is a safe, rapid, non-invasive, and effective diagnostic procedure for the evaluation of biliary adverse events after liver transplantation, since it plays an increasingly important role in the diagnosis and management of these events. On the basis of a recent systematic review of the literature the summary estimates of sensitivity and specificity of MR cholangiopancreatography for diagnosis of biliary adverse events following OLT were 0.95 and 0.92, respectively. It can provide a non-invasive method of imaging surgical reconstruction of the biliary anastomoses as well as adverse events including anastomotic and non-anastomotic strictures, biliary lithiasis and sphincter of Oddi dysfunction in liver transplant recipients. Nevertheless, conventional T2-weighted MR cholangiography can be implemented with T1-weighted contrast-enhanced MR cholangiography using hepatobiliary contrast agents (in particular using Gd-EOB-DTPA) in order to improve the diagnostic accuracy in the adverse events’ detection such as bile leakage and strictures, especially in selected patients with biliary-enteric anastomosis.

Is MRCP equivalent to ERCP for diagnosing biliary obstruction in orthotopic liver transplant recipients? A meta-analysis

BACKGROUND

Biliary complications are the second leading cause of morbidity and mortality in orthotopic liver transplant (OLT) recipients. Endoscopic retrograde cholangiography (ERC) is considered the diagnostic criterion standard for post-orthotopic liver transplantation biliary obstruction, but incurs significant risks.

OBJECTIVE

To determine the diagnostic accuracy of MRCP for biliary obstruction in OLT patients.

DESIGN

A systematic literature search identified studies primarily examining the utility of MRCP in detecting post-orthotopic liver transplantation biliary obstruction. A meta-analysis was then performed according to the Quality of Reporting Meta-Analyses statement.

SETTING

Meta-analysis of 9 studies originally performed at major transplantation centers.

PATIENTS

A total of 382 OLT patients with clinical suspicion of biliary obstruction.

INTERVENTIONS

MRCP and ERCP or clinical follow-up.

MAIN OUTCOME MEASUREMENTS

Sensitivity and specificity of MRCP for diagnosis of biliary obstruction.

RESULTS

The composite sensitivity and specificity were 0.96 (95% CI, 0.92-0.98) and 0.94 (95% CI, 0.90-0.97), respectively. The positive and negative likelihood ratios were 17 (95% CI, 9.4-29.6) and 0.04 (95% CI, 0.02-0.08), respectively.

LIMITATIONS

All but 1 included study had significant design flaws that may have falsely increased the reported diagnostic accuracy.

CONCLUSIONS

The high sensitivity and specificity demonstrated in this meta-analysis suggest that MRCP is a promising test for diagnosing biliary obstruction in patients who have undergone liver transplantation. However, given the significant design flaws in most of the component studies, additional high-quality data are necessary before unequivocally recommending MRCP in this setting.

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.

MR cholangiography in orthotopic liver transplantation: sensitivity and specificity in detecting biliary complications

BACKGROUND

To assess the diagnostic value of magnetic resonance cholangiography (MRC) when evaluating biliary complications in a large series of liver transplants.

METHODS

One hundred and twenty-nine patients prospectively underwent magnetic resonance (MR) imaging and MR cholangiography at 1.5-T device after orthotopic liver transplantation (OLT). After the preliminary acquisition of axial T1- and T2-weighted images, MRC involved respiratory-triggered, thin-slab (2 mm), heavily T2-weighted fast spin-echo and breath-hold, thick-slab (10-50 mm), single-shot T2-weighted sequences. MR images were blindly evaluated by two experienced readers in conference to determine the biliary anatomy and the presence of complications, whose final diagnosis was based on endoscopic retrograde cholangiography, percutaneous trans-hepatic cholangiography, and by integrating clinical follow-up with ultrasound and/or MR findings.

RESULTS

Biliary complications were found in 60 patients (46.5%) and were represented by ischemic-type biliary lesions (n=21); anastomotic strictures (n=13); non-anastomotic strictures (n=5); anastomotic strictures associated to lithiasis (n=6); lithiasis (n=6); papillary dysfunctions (n=9). The sensitivity, specificity, positive predictive value, and negative predictive value of the reviewers for the detection of all types of biliary complications in patients with OLT were 98%, 94%, 94%, and 98%, respectively.

CONCLUSIONS

MRC is a reliable technique for detecting post-OLT biliary complications and should be recommended before planning therapeutic interventions.

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.

Establishment of an animal model of ischemic type intrahepatic biliary lesion in rabbits

AIM

To explore a method to establish an animal model of ischemic type intrahepatic biliary lesion in rabbits.

METHODS

Forty Japanese white rabbits of clean grade were divided randomly into four groups (10 rabbits per group) including sham operation (SO) group, and artery-bile obstruction (ABO)-1 h group, ABO-2 h group and ABO-3 h group. All the rabbits in this study underwent the same initial surgical procedure in which the liver was prepared as for graft removal during liver transplantation. Subsequently in the SO group, no additional vascular intervention was performed, while in groups ABO-1 h, ABO-2 h and ABO-3 h, the animals underwent combined clamping of the hepatic artery and common bile duct with microvascular clips for 1, 2 and 3 h, respectively. After the scheduled occlusion time, the clip was removed to recover blood supply. The animals were killed 4 wk after operation. The survival rate, liver function, cholangiography and histopathological manifestation of the rabbits in each group were observed.

RESULTS

The survival rate was 100% in groups SO, ABO-1 h and ABO-2 h, while it was 60% in group ABO-3 h. At each observation time, the change degree of the indexes of liver function was proportional to the clamping time (ABO-3 h > ABO-2 h > ABO-1 h > SO, P < 0.05). Cholangiographical and histopathologic manifestations both showed that intrahepatic biliary lesion aggravated proportionally with the increase of the clamping time.

CONCLUSION

An animal model of ischemic type intrahepatic biliary lesion in rabbits is successfully established, which may provide a reliable technique for basic and clinical research into the etiology, development and prophylaxis of ischemic type intrahepatic biliary lesion after liver transplantation.

Biliary complications after orthotopic liver transplantation: MRCP findings

Orthotopic liver transplantation is a widely accepted treatment for end-stage liver disease and selected cases of hepatocellular carcinoma. Despite surgical progresses, biliary complications after transplantation remain a serious cause of morbidity, mortality, and graft dysfunction or failure in recipients. Early complications occur within a few weeks after transplantation and are mainly represented by bile leakage. Late complications, which become evident from 3 months to years, include strictures, stones, intraductal debris or sludge formation, kinking and ampullary dysfunction. Donor-to-recipient common bile duct disproportion has been reported as a borderline condition. Diagnosis is challenging because of the low specificity of clinical and biologic findings. Sonography does not provide projectional images of the biliary tract or direct evaluation of the anastomoses. Moreover, direct cholangiographic procedures have an unacceptable rate of complications to be used in patients with low clinical suspicion. Magnetic resonance cholangiography is a safe and accurate tool, playing an increasing role in the diagnosis and management of biliary complications. Heavily T2-weighted images provide panoramic, detailed evaluation of the biliary tract, showing biliary complications as a variable combination of bile duct dilatation, strictures, filling defects, fluid collections and peculiar morphologic changes, as described in this paper.

Biliary strictures after liver transplantation. Predictive factors for response to endoscopic management and long-term outcome

BACKGROUND

Biliary strictures after liver transplantation are frequent. The long-term prognosis and predictive factors of response to endoscopic treatment are not well known.

METHODS

The aim of this study was to demonstrate the role of endoscopic treatment, predictive factors of response, and outcome in patients with biliary stricture after liver transplantation. We performed a retrospective review of medical records of all consecutive post-liver transplantation patients who underwent endoscopic retrograde cholangiography in our center during the period from October 2001 to October 2006.

RESULTS

Twenty-five of 43 patients referred for endoscopic retrograde cholangiography had biliary stricture. Eighteen had stricture at the area of the anastomosis alone, 2 patients had a stricture at the area of the anastomosis and also another area, and 5 had nonanastomotic biliary strictures. Twenty-one patients had a single stricture and 4 had more than 1 stricture. Initially 19 of 24 patients (79%) responded to endoscopic management with normalization of liver enzymes. Four patients (16%) did not respond clinically despite a successful endoscopic approach. All patients who did not respond to endoscopic dilation had more than 1 area of stricture. There was a significantly better response to endoscopic treatment in patients with an anastomotic stricture versus patients with nonanastomotic strictures 17/19 versus 2/5 (P = 0.042).

CONCLUSIONS

In our experience, endoscopic treatment of anastomotic biliary strictures is highly effective with a good long-term outcome. The presence of nonanastomotic and multiple strictures should be considered a factor associated with poor response to endoscopic management.

MR cholangiopancreatography features of the biliary tree after liver transplantation

OBJECTIVE

Our objective was to show the usefulness of MR cholangiopancreatography in assessing biliary complications after liver transplantation.

CONCLUSION

MR cholangiopancreatography is the best noninvasive tool for the diagnosis and assessment of biliary complications.

Biliary complications following orthotopic liver transplantation. The Hungarian experience

A szerzők összefoglalják a magyar májátültetési program epeúti szövődményeinek jellemzőit. Feltárják az epeúti szövődmények előfordulási gyakoriságát. Elemzik az epeúti szövődmények típusait és azok megoszlását, valamint hatásukat a beteg-, illetve graftvesztésre. Elemzik az irodalomban már ismert rizikófaktorokat a hazai betegpopulációban. Ismertetik az epeúti szövődmények kezelési lehetőségeit. Retrospektív vizsgálat során a betegeket két csoportba osztották aszerint, hogy a májátültetés után kialakult-e epeúti szövődmény, vagy nem, majd a két csoportot összehasonlították számos vizsgált paraméter, valamint a túlélések szempontjából. Az epeúti szövődményes betegeket tovább csoportosították annak alapján, hogy a szövődmény a májátültetés után három hónapon belül vagy később alakult ki. Ezt a két csoportot szintén összehasonlították a fentebb említett kontrollcsoporttal. Egyvariációs összehasonlítások esetén a folytonos adatokat a populáció homogenitásának vizsgálata után (Levene-teszt) kétmintás t -próbával, illetve Mann–Whitney-féle U-teszttel, a kategorikus adatokat χ 2 -próbával, illetve Kaplan–Meier-analízissel vizsgálták. A túlélést Kaplan–Meier-metodikával vizsgálták. Az eredményeket valamennyi statisztikai próbánál akkor tekintették szignifikánsnak, ha a p < 0,05 volt. Eredmények: Epeúti szövődmény a betegek 26%-ában jelent meg, 290 vizsgált beteg közül 76 esetben. A leggyakoribb a szűkület (18%), majd az epecsorgás (9%), a necrosis (6%), végül az ischaemiás típusú epeúti károsodás (3%). Epeúti szövődmények esetén az 5 éves kumulatív túlélés rosszabb (55%), mint ezek hiányában (66%), és a retranszplantációk aránya is magasabb (15%) volt. A leggyakoribb kezelési típusok: intervenciós radiológiai (69%), sebészi (17%), ERCP (14%). Következtetések: Az epeúti szövődmények aránya megfelel a nemzetközi közléseknek, 2002 óta arányuk csökkent. Epeúti szövődmények kialakulásának rizikófaktorai: cholangitis, az arteria hepatica thrombosisa és stenosisa, magas bevitt intraoperatív volumen, valamint az akut rejectio. Korai epeúti szövődmények gyakran társultak a beültetett májgraft kezdeti gyenge működésével (ún. „initial poor function”). A korai epeúti szövődmények felelősek a túlélés csökkenéséért, a késői szövődmények inkább az életminőséget rontják. Az epeúti szövődményes betegeket döntően intervenciós radiológiai módszerekkel kezelték.

Multimodality postoperative imaging of liver transplantation

Liver transplantation is the only effective and definitive treatment for patients with end-stage liver disease. The shortage of cadaveric livers has lead to the increasing use of split-liver transplantation and living-donor liver transplantation, but the expansion of the donor pool has increased the risk for postoperative vascular and biliary complications. Early recognition of the imaging appearances of the various postoperative complications of liver transplantation is crucial for both graft and patient survival. This review describes the imaging findings of normal and abnormal transplanted liver parenchyma and of vascular and biliary post-transplantation complications.

Assessment of biliary complications after orthotopic liver transplantation with magnetic resonance imaging

AIM: To analyze the MR findings of early and late biliary complications after orthotopic liver transplantation (OLT) and to evaluate the clinical value of MR cholangiopancreatography (MRCP) combined with MR cross-sectional images in diagnosing biliary complications after OLT.

METHODS: Fifty-seven consecutive patients with clinical suspicion of biliary complications after receiving OLT were evaluated on the basis of MRCP and MR cross-sectional images, the latter including T1W axial unenhanced and Gadolinum-enhanced sequences, Gadolinum-enhanced VIBE sequences, unenhanced T2W axial images and coronal True-FISP sequences. The diagnostic accuracy rates were compared between MRCP and MRCP combined with MR cross-sectional images.

RESULTS: The incidence of biliary complications after OLT was 64.9% (37/57). The final diagnoses were as follows anastomotic stricture (n = 14), nonanastomotic stricture (n = 8), solitary biliary stone or sludge (n = 5), cholangitis and periangiocholitis (n = 3), biloma (n = 3), donor-to-recipient common bile duct disproportion (n = 3), and elongation of extrahepatic biliary duct (n = 1). In 37 cases of biliary complications, the accuracies of MRCP and MRCP combined with MR cross-sectional images were 75.7% (28/37) and 94.6% (35/37), respectively. The difference was statistically significant (P < 0.05).

CONCLUSION: MRCP combined with MR cross-sectional images can improve the diagnostic accuracy of biliary complications, especially the diagnosis of biloma, cholangitis and periangiocholitis.

Magnetic resonance cholangiography of biliary strictures after liver transplantation: a prospective double-blind study

PURPOSE

To compare magnetic resonance cholangiography (MRC) with endoscopic retrograde cholangiography (ERC) in quantitatively evaluating biliary strictures in liver transplant recipients.

MATERIALS AND METHODS

Eight liver transplant recipients with suspected biliary complications were referred for ERC and also underwent MRC within 24 hours using a combination of single-shot rapid acquisition with relaxation enhancement (SS-RARE) and three-dimensional (3D)-RARE sequences. The studies were independently interpreted by two blinded radiologists and a single blinded endoscopist who recorded the presence of a stricture and/or upstream dilatation, the ratio of recipient-to-donor duct diameters at the anastomosis, as well as the proximal duct diameter, length, and percent stenosis of any stricture detected.

RESULTS

Using ERC as the standard of reference, MRC had a sensitivity and negative predictive value of 100%, mean specificity of 83.3%, and mean positive predictive value of 92.9% in the detection of six strictures. Compared with ERC, MRC obtained accurate measurements of recipient-to-donor duct diameter ratios (r, 0.91; P < 0.01), proximal duct diameters (r, 0.83, P < 0.05), stricture lengths (r, 0.58; P = 0.06), and percent stenosis (r, 0.78; P = 0.06).

CONCLUSION

MRC can provide equivalent imaging to ERC and can reliably identify and quantitatively evaluate biliary strictures in post-orthotopic liver transplantation (OLT) patients.

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.

Biliary complications after deceased-donor orthotopic liver transplantation

A wide range of potential biliary complications can occur after orthotopic liver transplantation (OLT). The most common biliary complications are bile leaks, anastomotic and intrahepatic strictures, stones, and ampullary dyfunction, which may occur in up to 20%-40% of OLT recipients. Leaks predominate in the early posttransplant period; stricture formation typically develops gradually over time. However, with the advent of new techniques, such as split-liver, reduced-size, and living-donor liver transplantation, the spectrum of biliary complications has changed. Risk factors for biliary complications comprise technical failure; T-tube or stent-related complications; hepatic artery thrombosis; bleeding; ischemia/reperfusion injury; and other immunological, nonimmunological, and infectious complications. Noninvasive diagnostic methods have been established and treatment modalities have been modified towards a primarily nonoperative, endoscopy-based strategy. Besides, the management of biliary complications after OLT requires a multidisciplinary approach, in which interventional and endoscopic treatment options have to be weighed up against surgical treatment options. The etiology and spectrum of bile duct complications, their diagnosis, and their treatment will be reviewed in this article.

Pediatric liver transplantation: a pictorial essay of early and late complications

Orthotopic liver transplantation is currently the treatment of choice in patients with end-stage liver disease for which no other therapy is available. In children, segmental liver transplantation with living donor, reduced-size cadaveric, and split cadaveric allografts has become an important therapeutic option. However, the resulting expansion of the donor pool has increased the risk for postoperative vascular and biliary complications, which affect children more frequently than adults. Early recognition of these complications requires radiologic evaluation because their clinical manifestations are frequently nonspecific and vary widely. Doppler ultrasonography (US) plays the leading role in the postoperative evaluation of pediatric patients. Current magnetic resonance (MR) imaging techniques, including MR angiography and MR cholangiography, may provide a wealth of pertinent information and should be used when findings at US are inconclusive. Computed tomography is a valuable complement to US in the evaluation of complications involving the hepatic parenchyma as well as extrahepatic sites and is commonly used to guide percutaneous aspiration and fluid collection drainage. Familiarity with and early recognition of the imaging appearances of the various postoperative complications of pediatric liver transplantation are crucial for graft and patient survival.