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

Endohepatology: Applications in Liver Transplant

The term "endohepatology" was coined over the last 15 years to describe the integration of interventional endoscopy and hepatology for the management of patients with chronic liver disease. In this article, we will review the diagnostic and therapeutic applications of endoscopic ultrasound and endoscopic retrograde cholangiopancreatography among liver transplantation candidates and recipients.

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

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

Management of Biliary Complications in Liver Transplant Recipients

Biliary complications are often referred to as the Achilles' heel of liver transplantation (LT). The most common of these complications include strictures, and leaks. Prompt diagnosis and management is key for preservation of the transplanted organ. Unfortunately, a number of factors can lead to delays in diagnosis and make adequate treatment a challenge. Innovations in advanced endoscopic techniques have increased non-surgical options for these complications and in many cases is the preferred approach.

Non-invasive diagnosis and follow-up in liver transplantation

The field of liver transplantation directly or indirectly embodies all liver diseases, in addition to specific ones related to organ rejection (cellular and humoral). The recommended non-invasive methods for determining the indication for liver transplantation are the Model for End-stage Liver Disease score, and the alpha-foetoprotein score in case of hepatocellular carcinoma. Radiological methods are the cornerstones for the diagnosis of vascular and biliary complications after liver transplantation. The possible diseases of the liver graft after transplantation are multiple and often intertwined. Non-invasive diagnostic methods have been poorly evaluated in this context, apart from the recurrence of hepatitis C. Liver biopsy remains the gold standard for evaluating graft lesions in the majority of cases, especially graft rejection.

Early Allograft Dysfunction and Complications in DCD Liver Transplantation: Expert Consensus Statements From the International Liver Transplantation Society

Livers for transplantation from donation after circulatory death donors are relatively more prone to early and ongoing alterations in graft function that might ultimately lead to graft loss and even patient death. In consideration of this fact, this working group of the International Liver Transplantation Society has performed a critical evaluation of the medical literature to create a set of statements regarding the assessment of early allograft function/dysfunction and complications arising in the setting of donation after circulatory death liver transplantation.

The real incidence of biliary tract complications after adult liver transplantation: the role of the prospective routine use of cholangiography during post-transplant follow-up

Biliary tract complications (BTCs) still burden liver transplantation (LT). The wide reporting variability highlights the absence of systematic screening. From 2000 to 2009, simultaneous liver biopsy and direct biliary visualization were prospectively performed in 242 recipients at 3 and 6 months (n = 212, 87.6%) or earlier when indicated (n = 30, 12.4%). Median follow-up was 148 (107-182) months. Seven patients (2.9%) experienced postprocedural morbidity. BTCs were initially diagnosed in 76 (31.4%) patients; 32 (42.1%) had neither clinical nor biological abnormalities. Acute cellular rejection (ACR) was present in 27 (11.2%) patients and in 6 (22.2%) BTC patients. Nine (3.7%) patients with normal initial cholangiography developed BTCs after 60 (30-135) months post-LT. BTCs directly lead to 7 (2.9%) re-transplantations and 14 (5.8%) deaths resulting in 18 (7.4%) allograft losses. Bile duct proliferation at 12-month biopsy proved an independent risk factor for graft loss (P = 0.005). Systematic biliary tract and allograft evaluation allows the incidence and extent of biliary lesions to be documented more precisely and to avoid erroneous treatment of ACR. The combination 'abnormal biliary tract-canalicular proliferation' is an indicator of worse graft outcome. BTCs are responsible for important delayed allograft and patient losses. These results underline the importance of life-long follow-up and appropriate timing for re-transplantation.

Endoscopic retrograde cholangiopancreatography and liver biopsy in the evaluation of elevated liver function tests after liver transplantation

BACKGROUND

Abnormal liver function tests (LFTs) in post-liver transplant (LT) patients pose a challenge in the timing and selection of diagnostic modalities. There are little data regarding the accuracy of endoscopic retrograde cholangiopancreatography (ERCP) and liver biopsy (LB) in diagnosing post-transplant complications.

AIM

To evaluate the diagnostic performance of ERCP and LB in patients with non-vascular post-LT complications.

METHODS

This single-center retrospective study evaluated patients undergoing both ERCP and LB for evaluation of elevated LFTs within 6 mo of LT from 2000 to 2017. Diagnostic operating characteristics including accuracy, sensitivity and specificity for various diagnoses were calculated for ERCP and LB. The R factor (ratio of alkaline phosphatase to alanine aminotransferase) was also calculated for each patient.

RESULTS

Of the 1284 patients who underwent LT, 91 patients (74.7% males, mean age of 51) were analyzed. Anastomotic strictures (AS, 24.2%), acute cellular rejection (ACR, 11%) and concurrent AS/ACR (14.3%) were the most common diagnoses. ERCP carried an accuracy of 79.1% (95%CI: 69.3-86.9), LB had an accuracy of 93.4% (95%CI: 86.2-97.5), and the combination of the two had an accuracy of 100% (95%CI: 96-100). There was no difference between patients with AS and ACR in mean R factor (AS: 1.9 vs ACR: 1.1, P = 0.24). Adverse events did not differ between the two tests (ERCP: 3.1% vs LB: 1.1%, P = 0.31).

CONCLUSION

In patients with abnormal LFTs after LT without vascular complications, the combination of LB and ERCP carries low risk and improves diagnostic accuracy over either test alone.

Diagnosis and management of benign biliary strictures post liver transplantation in adults

Benign biliary strictures after liver transplantation are common and can lead to graft dysfunction and decreased patient survival. Post-transplant strictures are classified as anastomotic or non-anastomotic which differ in response to therapy. Risk factors for biliary strictures following transplantation include impaired blood supply, surgical factors, and biliary anomalies. Patients can present with biliary obstruction but most will be asymptomatic, with only abnormal graft function. MRCP is the most sensitive noninvasive tool for diagnosing biliary complications. In most centres worldwide endoscopy is used first-line in the management of anastomotic strictures, although there is significant variation in endoscopic technique employed; including dilation, placing a single or multiple plastic stents, a fully covered metal stent and most recently using intra-ductal fully covered metal stents. With the introduction of fully covered metal stents the number of interventions patients require has reduced and overall the clinical success of the endoscopic approach has steadily improved. Percutaneous and surgical treatments are now reserved for patients in whom endoscopic management fails or who have had Roux-en-Y anastomoses. However even in these cases, combined procedures with interventional radiology, or implementation of enteroscopy and EUS-guided approaches now means very few patients ultimately require surgical revision.

Can ultrasonography differentiate anastomotic and non-anastomotic biliary strictures after orthotopic liver transplantation- a single-center experience

PURPOSE

To evaluate the role of ultrasonography (US) in differentiating anastomotic biliary strictures (AS) and non-anastomotic biliary strictures (NAS) after orthotopic liver transplantation (OLT).

METHOD

This retrospective study included 1259 OLT recipients between 2005-2018. Seventy-six with anastomotic strictures (AS) and 103 with non-anastomotic strictures (NAS) were analyzed. The reference standard was cholangiography. The sensitivity, specificity, accuracy of US was evaluated.

RESULTS

There were significant differences between AS and NAS groups (p < 0.001) for skipped and irregular dilatation of intrahepatic bile duct and visualization of hilar biliary lumen. The better US imaging feature for NAS was poorly visualized and non- visible hilar bile duct luminal contour. The sensitivity, specificity and accuracy were 94.2 %, 84.2 % and 88.9 % respectively. Combined two predictors greatly increased the specificity to 93.4 % while diminished its sensitivity and accuracy.

CONCLUSION

US is useful and efficient to differentiate AS and NAS after OLT.

Practical review for diagnosis and clinical management of perihilar cholangiocarcinoma

Cholangiocarcinoma (CCC) is the most aggressive malignant tumor of the biliary tract. Perihilar CCC (pCCC) is the most common CCC and is burdened by a complicated diagnostic iter and its anatomical location makes surgical approach burden by poor results. Besides its clinical presentation, a multimodal diagnostic approach should be carried on by a tertiary specialized center to avoid miss-diagnosis. Preoperative staging must consider the extent of liver resection to avoid post-surgical hepatic failure. During staging iter, magnetic resonance can obtain satisfactory cholangiographic images, while invasive techniques should be used if bile duct samples are needed. Consistently, to improve diagnostic potential, bile duct drainage is not necessary in jaundice, while it is indicated in refractory cholangitis or when liver hypertrophy is needed. Once resecability criteria are identified, the extent of liver resection is secondary to the longitudinal spread of CCC. While in the past type IV pCCC was not considered resectable, some authors reported good results after their treatment. Conversely, in selected unresectable cases, liver transplantation could be a valuable option. Adjuvant chemotherapy is the standard of care for resected patients, while neoadjuvant approach has growing evidences. If curative resection is not achieved, radiotherapy can be added to chemotherapy. This multistep curative iter must be carried on in specialized centers. Hence, the aim of this review is to highlight the main steps and pitfalls of the diagnostic and therapeutic approach to pCCC with a peculiar attention to type IV pCCC.

Magnetic compression anastomosis for the treatment of benign biliary strictures: a clinical study from China

BACKGROUND

Magnetic compression anastomosis (MCA) is a revolutionary minimally invasive method to perform choledochocholedochostomy in patients with benign biliary stricture (BBS). We conducted MCA for the treatment of severe BBS that could not be treated by conventional methods.

PATIENTS AND METHODS

Patients with BBSs that could not be treated using conventional treatments were included. All patients underwent percutaneous transhepatic biliary drainage (PTBD) before MCA, and underwent cholangiography via simultaneous PTBD and endoscopic retrograde cholangiopancreatography (ERCP). The MCA device consisted of a parent and a daughter magnet. The daughter magnet was delivered via the PTBD route to the proximal end of the obstruction, and the parent magnet was delivered via ERCP to the distal end of the obstruction. After recanalization, the MCA device was removed, and biliary stenting (or PTBD) was performed for at least 6 months.

RESULTS

Of the 9 patients (age 49 ± 12.9 years), 6 had undergone orthotopic liver transplantation. MCA was successful in all 9 patients. The stricture length was 3 ± 1.7 mm, and recanalization occurred after 16.3 ± 13.2 days. Multiple plastic stents (4 patients), fully covered self-expandable metallic stents (4 patients), or PTBD (1 patient) was used after recanalization. Two mild adverse events occurred (cholangitis, 1 patient; biliary bleeding, 1 patient), but were resolved with conservative treatment. Stents were retrieved after > 6 months, and no stenosis occurred during 2-66 months of stent-free follow-up.

CONCLUSION

The MCA technique is a revolutionary method for choledochocholedochostomy in patients with severe BBS unresponsive to conventional procedures.

Endoscopic Management of Benign Biliary Strictures After Liver Transplantation

Biliary strictures represent some of the most frequent complications encountered after orthotopic liver transplantation. They comprise an array of biliary abnormalities with variations in anatomical location, clinical presentation, and different pathogenesis. Magnetic resonance cholangiography represents the most accurate noninvasive imaging test that can provide detailed imaging of the whole biliary system-below and above the anastomosis. It is of particular value in those harboring complex hilar or intrahepatic strictures, offering a detailed roadmap for planning therapeutic procedures. Endoscopic therapy of biliary strictures usually requires biliary sphincterotomy plus balloon dilation and stent placement. However, endoscopic management of nonanastomotic biliary strictures is much more complex and challenging as compared with anastomotic biliary strictures. The present article is a narrative review presenting the results of endoscopic treatment of biliary strictures occurring after liver transplantation, describing the different strategies based on the nature of the stricture and summarizing their outcomes.

Impact of machine perfusion of the liver on post-transplant biliary complications: A systematic review

AIM

To review the clinical impact of machine perfusion (MP) of the liver on biliary complications post-transplantation, particularly ischaemic-type biliary lesions (ITBL).

METHODS

This systematic review was performed in accordance with the Preferred Reporting Systematic Reviews and Meta-Analysis (PRISMA) protocol. The following databases were searched: PubMed, MEDLINE and Scopus. The keyword “liver transplantation” was used in combination with the free term “machine perfusion”. Clinical studies reporting results of transplantation of donor human livers following ex situ or in situ MP were analysed. Details relating to donor characteristics, recipients, technique of MP performed and post-operative biliary complications (ITBL, bile leak and anastomotic strictures) were critically analysed.

RESULTS

Fifteen articles were considered to fit the criteria for this review. Ex situ normothermic MP was used in 6 studies, ex situ hypothermic MP in 5 studies and the other 4 studies investigated in situ normothermic regional perfusion (NRP) and controlled oxygenated rewarming. MP techniques which have per se the potential to alleviate ischaemia-reperfusion injury: Such as hypothermic MP and NRP, have also reported lower rates of ITBL. Other biliary complications, such as biliary leak and anastomotic biliary strictures, are reported with similar incidences with all MP techniques. There is currently less clinical evidence available to support normothermic MP as a mitigator of biliary complications following liver transplantation. On the other hand, restoration of organ to full metabolism during normothermic MP allows assessment of hepatobiliary function before transplantation, although universally accepted criteria have yet to be validated.

CONCLUSION

MP of the liver has the potential to have a positive impact on post-transplant biliary complications, specifically ITBL, and expand extended criteria donor livers utilisation.

Percutaneous Biliary Interventions

Biliary drainage is important in the care of patients with benign and malignant biliary obstruction. Careful preprocedure evaluation of high-quality cross-sectional imaging and inventory of symptoms are necessary to determine whether a percutaneous, endoscopic, or surgical approach is most appropriate. High bile duct obstruction is usually best managed percutaneously; a specific duct can be targeted and enteric contamination of isolated ducts can be avoided. Options for percutaneous biliary intervention include external or internal/external biliary drainage, stent placement, biliary stone retrieval, and bile duct biopsy. Preprocedure evaluation, technique, and indications for percutaneous intervention in benign and malignant diseases are summarized.

Severe Unresolved Cholestasis Due to Unknown Etiology Leading to Early Allograft Failure Within the First 3 Months of Liver Transplantation

BACKGROUND

Causes of severe cholestasis after liver transplantation (LT) are multi-factorial. Although the etiology is predictable in some, others culminate in graft/patient loss without a definitive cause identified. Severe cholestasis is usually associated with overlapped histological findings of rejection and biliary features, and diagnostic interpretation may pose a challenge.

METHODS

This is 10-year retrospective analysis of patients with unexplained severe cholestasis resulting in death/graft loss within 90 days of LT. Of 1 583 LT during the study period, 90-day graft failure occurred in 129 (8%) cases; a total of 45 (3%) patients had unresolving severe cholestasis (bilirubin, >100 μmol/L; alkaline phosphatase, >400 UI/L after 15 days from LT), excluding those due to primary nonfunction/sepsis/vascular causes (n = 84). Demographics, allograft biopsies, radiological investigations, and clinical outcome were analyzed.

RESULTS

All patients had persistent abnormal liver biochemistry. Doppler ultrasound scan was normal in all cases. Thirty-five (78%) recipients had at least 1 allograft biopsy (2 [1-9]). On the first biopsy, 22 (63%) patients had acute rejection, 4 (18%) early-chronic rejection, 12 (34%) antibody-mediated rejection. In subsequent biopsies chronic rejection was evident in 5 (14%) cases. Donor-specific antibodies were detected in all patients tested. Biliary anatomy was studied in detail in 9 (20%) patients, all presenting biliary strictures. The majority (n = 39; 87%) died within 32 (10-91) days, only survivors were from retransplantation (n = 3;6.5%) and biliary intervention (n = 3;6.5%).

CONCLUSIONS

Unresolving severe cholestasis after LT is a key parameter predicting patient/allograft outcome. Histologically, rejection seems to overlap with biliary strictures; hence, allograft biopsy with signs of rejection should not be a reason to overlook biliary problems, in particular when biliary features are present. Only extensive radiological investigation/intervention or retransplantation prevents patient/allograft loss.

Biliary complications after liver transplantation: Assessment with MR cholangiopancreatography and MR imaging at 3T device

PURPOSE

Our study was aimed to assess the diagnostic value of MR cholangiopancreatography (MRCP) and MR imaging at 3 T device when evaluating biliary adverse events after liver transplantation.

MATERIALS AND METHODS

A series of 384 MR examinations in 232 liver transplant subjects with suspected biliary complications (impaired liver function tests and/or biliary abnormalities on ultrasound) were performed at 3 T device (GE-DISCOVERY MR750; GE Healthcare). After the acquisition of axial 3D dual-echo T1-weighted images and T2-weighted sequences (propeller and SS-FSE), MRCP was performed through coronal thin-slab 3D-FRFSE and coronal oblique thick-slab SSFSE T2w sequences. DW-MRI of the liver was performed using an axial spin-echo echo-planar sequence with multiple b values (150, 500, 1000, 1500 s/mm²) in all diffusion directions. Contrast-enhanced MRCP was performed in 25/232 patients. All MR images were blindly evaluated by two experienced abdominal radiologists in consensus to determine the presence of biliary complications, whose final diagnosis was based on direct cholangiography, surgery and integrating clinical follow-up with ultrasound and/or MRI findings.

RESULTS

In 113 patients no biliary abnormality was observed. The remaining 119 subjects were affected by one or more of the following complications: non-anastomotic strictures including typical ischemic-type biliary lesions (n = 67), anastomotic strictures (n = 34), ampullary dysfunction (n = 4), anastomotic leakage (n = 4), stones, sludge and casts (n = 65), vanishing bile duct (n = 1). The sensitivity, specificity, PPV, NPV and diagnostic accuracy of the reviewers for the detection of all types of biliary complications were 99%, 96%, 95%, 99% and 97%, respectively.

CONCLUSION

MR cholangiopancreatography and MR imaging at 3 T device are extremely reliable for detecting biliary complications after liver transplantation.

The gastroenterologist's guide to management of the post-liver transplant patient

The management of the post-liver transplant patient is complex and involves a large interdisciplinary team. After referral to a transplant center, evaluation and listing, and eventual transplantation, the patient is cared for closely by the transplant center. Once deemed ready for discharge, the patient returns to the primary care provider for ongoing management of the various issues that increase in incidence post transplant such as osteoporosis, cardiovascular, and renal diseases, as well as metabolic syndrome. The role of the gastroenterologist is not well defined, but certainly, he or she may be called upon for the initial evaluation and ongoing management of gastrointestinal as well as hepatobiliary issues. This includes but is not limited to the investigation of abnormal liver tests, non-specific gastrointestinal complaints such as nausea, vomiting, or diarrhea, biliary complications, and even recurrent hepatic disease. Having familiarity with post-transplant immunosuppressive agents, drug interactions, and potential infectious and malignancy-related complications of transplant is essential, as the primary gastroenterologist may be expected in some situations to field the initial work-up, if patient access to the transplant center is limited. The aim of this review is to summarize the gastroenterologist's role in the management of the post-liver transplant patient.

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

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

Role of MRCP in Diagnosing Biliary Anastomotic Strictures After Liver Transplantation: A Single Tertiary Care Center Experience

BACKGROUND

Biliary strictures (BS) are common complication after liver transplantation. We aimed to determine the accuracy of magnetic resonance cholagiopancreatography (MRCP) in diagnosing BS in liver transplant recipients (LTRs) when compared to direct cholangiographic methods (endoscopic resonance cholagiopancreatography [ERCP] and/or percutaneous transhepatic cholangiography [PTC]).

METHODS

Retrospective chart review of 910 LTRs (July 2008 to April 2015) was performed, and a total of 39 patients with duct-to-duct anastomosis (22 males; 56.4%; mean age, 52.8 ± 8.3 years) were included who had an MRCP followed by either ERCP and/or PTC within 4 weeks. A cholangiographic narrowing (on ERCP and/or PTC) that required balloon dilation and/or stent placement was considered a BS and was considered clinically significant if the intervention resulted in at least 30% improvement of bilirubin within 2 weeks. Sensitivity, specificity, accuracy, positive predictive values and negative predictive values of MRCP in diagnosing BS were calculated.

RESULTS

Magnetic resonance cholagiopancreatography showed anastomotic BS in 17 of 39 patients, and subsequent ERCP and/or PTC revealed a total of 25 BS (positive predictive value of 0.94). Nine BS on cholangiography (ERCP, 8; PTC, 1) were not detected on earlier MRCP (sensitivity, 0.64; 95% CI, 0.45-0.82); 2 were clinically significant BS and 6 of the remaining 7 had no improvement in their liver function test with biliary intervention. Thirteen LTRs had no BS on either modality (specificity, 0.93; 95% CI, 0.66-0.99). The negative predictive value of MRCP was 0.59 for cholangiographic BS. The overall accuracy of MRCP is 0.74 (exact 95% CI, 0.58-0.87). Inclusion of age, race, and alanine aminotransferase level improved the predictive value of MRCP (area under the curve = 0.94, 95% CI: 0.86-1.00).

CONCLUSIONS

Magnetic resonance cholagiopancreatography has high specificity but low sensitivity in diagnosing cholangiographic BS in LTRs, although the predictive value further improved with inclusion of age, race, and alanine aminotransferase. Clinical significance of BS in LTRs not identified on MRCP is questionable because ERCP with intervention did not improve their liver function tests in the vast majority.

Computed tomography findings in ABO-incompatible living donor liver transplantation recipients with biliary strictures

OBJECTIVES

To evaluate CT findings of biliary strictures in ABO-incompatible living donor liver transplantation (LDLT) recipients, with emphasis on associated 1-month post-transplantation CT findings, and evaluate clinical outcomes.

METHODS

Of 351 ABO-incompatible recipients, we retrospectively evaluated CT scans in 65 recipients with biliary stricture. The biliary strictures on CT scans were classified as type A (perihilar) and type B (diffuse). Precedent CT abnormality patterns and the presence of a periportal halo sign at 1-month post-transplantation were evaluated. For each patient, clinical outcomes were evaluated.

RESULTS

Of 65 ABO-incompatible recipients with biliary strictures, 36.9% had type B strictures. Compared with biliary strictures at diagnosis, similar CT abnormality patterns were observed for 84.4% in type A and 86.4% in type B strictures at 1-month post-transplantation. Complex periportal halo signs on the 1-month post-transplantation CT were more frequently noted for type B than type A strictures (86.4% vs. 3.1%, P < 0.001). Progressive clinical outcomes were more frequently observed for type B than type A strictures (79.2% vs. 26.8%, P < 0.001), with a significantly shorter graft survival time (46.4 months vs. 90.8 months, P < 0.001).

CONCLUSION

CT abnormality patterns and complex periportal halo signs on 1-month post-transplantation CT may be clinically useful for managing biliary strictures in ABO-incompatible LDLT recipients. Key Points • Of ABO-incompatible LDLT recipients, type B biliary stricture incidence was 6.8%. • Of type B strictures, 86.4% exhibited similar CT abnormality patterns at 1-month post-transplantation. • Complex periportal halo at 1 month was significantly associated with type B strictures. • Progressive clinical outcomes were more frequently observed in type B strictures.

Diagnostic Accuracy of Laboratory Tests and Diagnostic Imaging in Detecting Biliary Strictures After Liver Transplantation

BACKGROUND

Endoscopic retrograde cholangiopancreatography (ERCP) is often required to diagnose post-liver transplant (LT) biliary strictures. We evaluated the diagnostic accuracy of noninvasive laboratory and imaging tests in detecting post-LT biliary strictures.

METHODS

Adult LT recipients who underwent ERCP between 2008 and 2015 were evaluated. Biliary strictures were diagnosed after blinded review of cholangiograms by three interventional endoscopists. The accuracy of liver enzymes, ultrasound, and MRI was determined using cholangiography as the reference standard. To evaluate the accuracy of change in liver enzymes, the difference between baseline and liver enzymes prior to ERCP (Δlab) was utilized.

RESULTS

Biliary strictures were present on cholangiogram in 48 (58%) of 82 LT recipients meeting inclusion criteria. Baseline liver enzyme values did not differ significantly between patients with and without strictures. The optimal cutoffs for ΔALT, ΔAST, Δbilirubin, and Δalkaline phosphatase (AP) were determined to be 174 IU/L, 75 IU/L, 3.1 mg/dL, and 225 IU/L, respectively. ΔALT had a sensitivity of 100%, specificity 43%, and negative predictive value 100%. ΔAP had the highest specificity (53%) but modest sensitivity (69%) with a positive predictive value of 67%. Ultrasound had sensitivity of 29% and specificity of 69%, while MRI had sensitivity of 78% and specificity of 56%.

DISCUSSION

The diagnostic accuracy of liver enzymes and imaging modalities is modest in detecting post-LT biliary strictures and cannot be used solely to identify patients needing further workup.

Evaluation of biliary complications on magnetic resonance cholangiopancreatography and comparison with direct cholangiography after living-donor liver transplantation

AIM

To evaluate the imaging characteristics of biliary complications following liver transplantation on magnetic resonance cholangiopancreatography (MRCP) and its diagnostic accuracy in comparison with direct cholangiography.

MATERIAL AND METHODS

In this prospective study, 34 patients being evaluated for possible biliary complications after living-donor liver transplantation (LDLT) with abnormal MRCP findings were followed up for information regarding direct cholangiography either endoscopic retrograde cholangiopancreatography (ERCP) or percutaneous transhepatic cholangiography (PTC) within 7 days of MRCP. Twenty-nine patients underwent ERCP and five patients underwent PTC.

RESULTS

Compared to findings at direct cholangiography, MRCP presented 96.9% sensitivity, 96.9% positive predictive value, and 94.1% accuracy for the detection of biliary complications. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for detection of anastomotic strictures, biliary leak, and biliary stone or sludge on MRCP was found to be 100%, 84.6%, 91.3%, 100% and 94.1%; 72.7%, 95.7%, 88.9%, 88% and 88.2%; 80%, 100%, 100%, 96.7% and 97.1%, respectively.

CONCLUSION

MRCP is a reliable non-invasive technique to evaluate the biliary complications following LDLT. MRCP should be the imaging method of choice for diagnosis in this setting and direct cholangiography should be reserved for cases that need therapeutic interventions.

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.

Current diagnosis and treatment of benign biliary strictures after living donor liver transplantation

Despite advances in surgical techniques, benign biliary strictures after living donor liver transplantation (LDLT) remain a significant biliary complication and play an important role in graft and patient survival. Benign biliary strictures after transplantation are classified into anastomotic or non-anastomotic strictures. These two types differ in presentation, outcome, and response to therapy. The leading causes of biliary strictures include impaired blood supply, technical errors during surgery, and biliary anomalies. Because patients usually have non-specific symptoms, a high index of suspicion should be maintained. Magnetic resonance cholangiography has gained widespread acceptance as a reliable noninvasive tool for detecting biliary complications. Endoscopy has played an increasingly prominent role in the diagnosis and treatment of biliary strictures after LDLT. Endoscopic management in LDLT recipients may be more challenging than in deceased donor liver transplantation patients because of the complex nature of the duct-to-duct reconstruction. Repeated aggressive endoscopic treatment with dilation and the placement of multiple plastic stents is considered the first-line treatment for biliary strictures. Percutaneous and surgical treatments are now reserved for patients for whom endoscopic management fails and for those with multiple, inaccessible intrahepatic strictures or Roux-en-Y anastomoses. Recent advances in enteroscopy enable treatment, even in these latter cases. Direct cholangioscopy, another advanced form of endoscopy, allows direct visualization of the inner wall of the biliary tree and is expected to facilitate stenting or stone extraction. Rendezvous techniques can be a good option when the endoscopic approach to the biliary stricture is unfeasible. These developments have resulted in almost all patients being managed by the endoscopic approach.

Nonvascular post-liver transplantation complications: from US screening to cross-sectional and interventional imaging

Orthotopic liver transplantation is becoming an increasingly routine procedure for a variety of benign and malignant diseases of the liver and biliary system. Continued improvements in surgical techniques and post-transplantation immunosuppression regimens have resulted in better graft and patient survival. A number of potentially treatable nonvascular complications of liver transplantation are visible at imaging, and accurate diagnosis of these complications allows patients to benefit from potential treatment options. Biliary complications include stricture (anastomotic and nonanastomotic), leak, biloma formation, and development of intraductal stones. Pathologic conditions, including hepatitis C infection, hepatocellular carcinoma, hepatic steatosis, and primary sclerosing cholangitis, may recur after liver transplantation. Transplant patients are at increased risk for developing de novo malignancy, including post-transplantation lymphoproliferative disorder, which results from immunosuppression. Patients are also at increased risk for systemic infection from immunosuppression, and patients with hepatic artery and biliary complications are at increased risk for liver abscess. Transplant recipients are typically followed with serial liver function testing; abnormal serum liver function test results may be the first indication that there is a problem with the transplanted liver. Ultrasonography is typically the first imaging test performed to try to identify the cause of abnormal liver function test results. Computed tomography, magnetic resonance imaging, angiography, and/or cholangiography may be necessary for further evaluation. Accurately diagnosing nonvascular complications of liver transplantation that are visible at imaging is critically important for patients to benefit from appropriate treatment.

Management of liver transplantation biliary stricture: Results from a tertiary hospital

AIM: To review results of endoscopic treatment for anastomotic biliary strictures after orthotopic liver transplantation (OLT) during an 8-year period.

METHODS: This is a retrospective review of all endoscopic retrograde cholangiopancreatographys (ERCPs) performed between May 2006 and June 2014 in deceased OLT recipients with anastomotic stricture at a tertiary care hospital. Patients were divided into 2 groups, according to the type of stent used (multiple plastic or covered self-expandable metal stents), which was chose on a case-by-case basis and their characteristics. The primary outcome was anastomotic stricture resolution rate determined if there was no more than a minimum waist at cholangiography and a 10 mm balloon could easily pass through the anastomosis with no need for further intervention after final stent removal. Secondary outcomes were technical success rate, number or ERCPs required per patient, number of stents placed, stent indwelling, stricture recurrence rate and therapy for recurrent anastomotic biliary stricture (AS). Stricture recurrence was defined as clinical laboratorial and/or imaging evidence of obstruction at the anastomosis level, after it was considered completely treated, requiring subsequent interventional procedure.

RESULTS: A total of 195 post-OLT patients were assessed for eligibility. One hundred and sixty-four (164) patients were diagnosed with anastomotic biliary stricture. ERCP was successfully performed in 157/164 (95.7%) patients with AS, that were treated with either multiple plastic (n = 109) or metallic billiary stents (n = 48). Mean treatment duration, number of procedures and stents required were lower in the metal stent group. Acute pancreatitis was the most common procedure related complication, occurring in 17.1% in the covered self-expandable metal stents (cSEMS) and 4.1% in the multiple plastic stent (MPS) group. Migration was the most frequent stent related complication, observed in 4.3% and 5.5% (cSEMS and MPS respectively). Stricture resolution was achieved in 86.8% in the cSEMS group and in 91% in MPS group. Stricture recurrence after a median follow up of 20 mo was observed in 10 (30.3%) patients in the cSEMS and 7 (7.7%) in the plastic stent group, a statistically significant difference (P = 0.0017). Successful stricture resolution after secondary treatment was achieved in 66.6% and 62.5% of patients respectively in the cSEMS and plastic stents groups.

CONCLUSION: Multiple plastic stents are currently the first treatment option for AS in patients with duct-to-duct anastomosis. cSEMS was associated with increased pancreatitis risk and higher recurrence rate.

Endoscopic management of post-liver transplant biliary complications

Biliary complications are being increasingly encountered in post liver transplant patients because of increased volume of transplants and longer survival of these recipients. Overall management of these complications may be challenging, but with advances in endoscopic techniques, majority of such patients are being dealt with by endoscopists rather than the surgeons. Our review article discusses the recent advances in endoscopic tools and techniques that have proved endoscopic retrograde cholangiography with various interventions, like sphincterotomy, bile duct dilatation, and stent placement, to be the mainstay for management of most of these complications. We also discuss the management dilemmas in patients with surgically altered anatomy, where accessing the bile duct is challenging, and the recent strides towards making this prospect a reality.

Changing pattern of indications of endoscopic retrograde cholangiopancreatography in children and adolescents: a twelve-year experience

BACKGROUND

There are few data regarding endoscopic retrograde cholangiopancreatography (ERCP) usefulness in children and adolescents. We reviewed the long-term experience with diagnostic and therapeutic ERCP in a tertiary single center in Southern Brazil.

METHODS

A retrospective chart review of patients aged 0-18 years who had undergone ERCPs from January 2000 to June 2012 was done. Data on demographics, indications, diagnosis, treatments, and complications were collected.

RESULTS

Seventy-five ERCPs were performed in 60 patients. The median age of the patients at the procedure was 13.9 years (range: 1.2-17.9). Of the 60 patients, 47 (78.3%) were girls. Of all ERCPs, 48 (64.0%) were performed in patients above 10 years and 35 (72.9%) of them were in girls. ERCP was indicated for patients with bile duct obstruction (49.3%), sclerosing cholangitis (18.7%), post-surgery complication (12%), biliary stent (10.7%), choledochal cyst (5.3%), and pancreatitis (4%). The complication rate of ERCP was 9.7% involving mild bleeding, pancreatitis and cholangitis. Patients who had therapeutic procedures were older (13.7±3.9 vs. 9.9±4.9 years; P=0.001) and had more extrahepatic biliary abnormalities (82% vs. 50%; P=0.015) than those who had diagnostic ERCPs. A marked change in the indications of ERCPs was found, i.e., from 2001 to 2004, indications were more diagnostic and from 2005 therapeutic procedures were predominant.

CONCLUSIONS

Diagnostic ERCPs are being replaced by magnetic resonance cholangiopancreatography and also by endoscopic ultrasound. All these procedures are complementary and ERCP still has a role for therapeutic purposes.

Clinical algorithm to guide the need for endoscopic retrograde cholangiopancreatography to evaluate early postliver transplant cholestasis

OBJECTIVES

Severe cholestasis after liver transplant is common. In this study, our aim was to develop an algorithm to guide biliary intervention in these patients.

MATERIALS AND METHODS

A retrospective review was performed on patients who had undergone a hepatobiliary scan, with or without subsequent endoscopic retrograde cholangiogram, during the immediate postoperative period. These findings were evaluated along with laboratory values to determine the benefit for this evaluative process. Biliary duct obstruction was defined as > than a 50% reduction in serum bilirubin within 48 hours of endoscopic retrograde cholangiogram intervention.

RESULTS

Twelve patients had endoscopic retrograde cholangiogram with 6 stents in 25 patients with normal a hepatobiliary scan, and 2 patients met criteria for biliary duct obstruction. Twenty-two patients had endoscopic retrograde cholangiogram with 14 stents in 32 patients with delayed uptake, suggesting hepatocellular dysfunction on a hepatobiliary scan, and 4 patients met criteria for biliary duct obstruction. In the 57 patients with severe hyperbilirubinemia, 6 patients (11%) had biliary duct obstruction as a cause. Among the 34 endoscopic retrograde cholangiograms performed, 17% had biliary obstruction. On multivariate analysis, patients having both serum aspartate transaminase concentrations < 1500 IU/L and serum total bilirubin levels > 257 μmol/L had an odds ratio of 25.1 for predicting biliary obstruction (95% CI: 6-37; P = .002).

CONCLUSIONS

A hepatobiliary scan with a combination peak serum aspartate transaminase and peak serum total bilirubin levels offer a valuable tool to identify patients with hepatocellular dysfunction and can avoid endoscopic retrograde cholangiogram in the immediate posttransplant period.

Endoscopic retrograde cholangiography for biliary anastomotic strictures after liver transplantation

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

Role of multi-detector computed tomography for biliary complications after liver transplantation

AIM: To investigate the diagnostic performance of multi-detector computed tomography (MDCT) in detecting biliary complications after orthotopic liver transplantation (OLT).

METHODS: Eighty-three consecutive OLT recipients, who presented with clinical or biochemical signs of biliary complications, underwent MDCT examination. Two experienced radiologists assessed MDCT images in consensus to determine biliary complications. Final confirmation was based on percutaneous transhepatic cholangiography or endoscopic retrograde cholangiography in 58 patients, surgery in four patients, liver biopsy in 10, and clinical and sonography follow-up in 11 patients.

RESULTS: Biliary complications were eventually confirmed in 62 of 83 patients (74.7%), including anastomotic biliary strictures in 32, nonanastomotic biliary strictures in 21, biliary stones in nine (5 with biliary strictures), anastomotic bile leak in five, and biloma in six (all with nonanastomotic strictures, and 2 with biligenic hepatic abscess). Twenty-one patients had no detection of biliary complications. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of MDCT for detecting biliary strictures were 90.6%, 86.7%, 89.2%, 92.3% and 83.9%, respectively. For detecting biliary stones, anastomotic bile leak and biloma, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of MDCT were all 100%.

CONCLUSION: MDCT is a useful screening tool for detecting biliary complications after OLT.

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.

Magnetic resonance cholangiography in the assessment and management of biliary complications after OLT

Despite advances in patient and graft management, biliary complications (BC) still represent a challenge both in the early and delayed period after orthotopic liver transplantation (OLT). Because of unspecific clinical presentation, imaging is often mandatory in order to diagnose BC. Among imaging modalities, magnetic resonance cholangiography (MRC) has gained widespread acceptance as a tool to represent the reconstructed biliary tree noninvasively, using both the conventional technique (based on heavily T2-weighted sequences) and contrast-enhanced MRC (based on the acquisition of T1-weighted sequences after the administration of hepatobiliary contrast agents). On this basis, MRC is generally indicated to: (1) avoid unnecessary procedures of direct cholangiography in patients with a negative examination and/or identify alternative complications; and (2) provide a road map for interventional procedures or surgery. As illustrated in the review, MRC is accurate in the diagnosis of different types of biliary complications, including anastomotic strictures, non-anastomotic strictures, leakage and stones.

Safety and yield of diagnostic ERCP in liver transplant patients with abnormal liver function tests

Background. Abnormal liver enzymes postorthotopic liver transplant (OLT) may indicate significant biliary pathology or organ rejection. There is very little known in the literature regarding the current role of diagnostic ERCP in this scenario. Aim. To review the utility of diagnostic ERCP in patients presenting with abnormal liver function tests in the setting of OLT. Methods. A retrospective review of diagnostic ERCPs in patients with OLT from 2002 to 2013 from a prospectively maintained, IRB approved database. Results. Of the 474 ERCPs performed in OLT patients, 210 (44.3%; 95% CI 39.8-48.8) were performed for abnormal liver function tests during the study period. Majority of patients were Caucasian (83.8%), male (62.4%) with median age of 55 years (IQR 48-62 years). Biliary cannulation was successful in 99.6% of cases and findings included stricture in 45 (21.4 %); biliary stones/sludge in 23 (11%); biliary dilation alone in 31 (14.8%); and normal in 91 (43.3%). Three (1.4%) patients developed mild, self-limiting pancreatitis; one patient (0.5%) developed cholangitis and two (1%) had postsphincterotomy bleeding. Multivariate analyses showed significant association between dilated ducts on imaging with a therapeutic outcome. Conclusion. Diagnostic ERCP in OLT patients presenting with liver function test abnormalities is safe and frequently therapeutic.

Magnetic resonance cholangiography in assessing biliary anatomy in living donors: A meta-analysis

AIM: To establish the role of magnetic resonance cholangiography (MRC) in diagnosis of biliary anatomy in living-donor liver transplantation (LDLT) donors.

METHODS: A systematic review was performed by searching electronic bibliographic databases prior to March 2013. Studies with diagnostic results and fulfilled inclusion criteria were included. The methodological quality of the studies was assessed. Sensitivity, specificity and other measures of the accuracy of MRC for diagnosis of biliary anatomy in LDLT donors were summarized using a random-effects model or a fixed-effects model. Summary receiver operating characteristic (SROC) curves were used to summarize overall test performance. Publication bias was assessed using Deek’s funnel plot asymmetry test. Sensitivity analysis was adopted to explore the potential sources of heterogeneity.

RESULTS: Twelve studies involving 869 subjects were eligible to the analysis. The scores of Quality Assessment of Diagnostic Accuracy Studies for the included studies ranged from 11 to 14. The summary estimates of sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic OR of MRC in diagnosis of biliary anatomy in LDLT donor were 0.88 (95%CI: 0.84-0.92), 0.95 (95%CI: 0.93-0.97), 15.33 (95%CI: 10.70-21.95), 0.15 (95%CI: 0.11-0.20) and 130.77 (95%CI: 75.91-225.27), respectively. No significant heterogeneity was detected in all the above four measures. Area under SROC curve was 0.971. Little publication bias was noted across the studies (P = 0.557). Sensitivity analysis excluding a study with possible heterogeneity got a similar overall result, which suggested the little influence of this study on the overall results.

CONCLUSION: Our results suggest that MRC is a high specificity but moderate sensitivity technique in diagnosis of biliary anatomy in LDLT donors.

Clinical yield of diagnostic endoscopic retrograde cholangiopancreatography in orthotopic liver transplant recipients with suspected biliary complications

Diagnostic endoscopic retrograde cholangiopancreatography (D-ERCP) is commonly performed for the evaluation of biliary complications after orthotopic liver transplantation (OLT). This practice is contrary to the national trend of reserving endoscopic retrograde cholangiopancreatography (ERCP) for therapeutic purposes. Our aim was to evaluate the clinical yield and complications of D-ERCP in OLT recipients. In this retrospective study, 165 OLT recipients who underwent ERCP between January 2006 and December 2010 at the University of Michigan were divided into 2 groups: (1) a therapeutic endoscopic retrograde cholangiopancreatography (T-ERCP) group (if they met prespecified criteria that suggested a high likelihood of endoscopic intervention) and (2) a D-ERCP group (if there was clinical suspicion of biliary disease but they did not meet any criteria). The 2 groups were compared with respect to the proportion of subjects undergoing high-yield ERCP, which was defined as a procedure resulting in a clinically important intervention that modified the disease course. 66.3% of the D-ERCP procedures were classified as high-yield, whereas 90.1% of the T-ERCP procedures were (P < 0.001). Serious complications were infrequent in both groups. A survey of practitioners caring for OLT recipients suggested that the rate of high-yield D-ERCP seen in this study is congruent with what is considered acceptable in clinical practice. In conclusion, although T-ERCP is more likely to reveal a pathological process requiring an intervention, D-ERCP appears to be an acceptable clinical strategy for OLT recipients because of the high likelihood of a high-yield study and the low rate of serious complications.