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

American Society for Gastrointestinal Endoscopy guideline on management of post-liver transplant biliary strictures: summary and recommendations

This clinical practice guideline from the American Society for Gastrointestinal Endoscopy provides an evidence-based approach for strategies to manage biliary strictures in liver transplant recipients. This document was developed using the Grading of Recommendations Assessment, Development and Evaluation framework. The guideline addresses the role of ERCP versus percutaneous transhepatic biliary drainage and covered self-expandable metal stents (cSEMSs) versus multiple plastic stents for therapy of post-transplant strictures, use of MRCP for diagnosing post-transplant biliary strictures, and administration of antibiotics versus no antibiotics during ERCP. In patients with post-transplant biliary strictures, we suggest ERCP as the initial intervention and cSEMSs as the preferred stent for extrahepatic strictures. In patients with unclear diagnoses or intermediate probability of a stricture, we suggest MRCP as the diagnostic modality. We suggest that antibiotics should be administered during ERCP when biliary drainage cannot be ensured.

American Society for Gastrointestinal Endoscopy guideline on management of post-liver transplant biliary strictures: methodology and review of evidence

This clinical practice guideline from the American Society for Gastrointestinal Endoscopy provides an evidence-based approach for strategies to manage biliary strictures in liver transplant recipients. This document was developed using the Grading of Recommendations Assessment, Development and Evaluation framework. The guideline addresses the role of ERCP versus percutaneous transhepatic biliary drainage and covered self-expandable metal stents (cSEMSs) versus multiple plastic stents for therapy of strictures, use of MRCP for diagnosing post-transplant biliary strictures, and administration of antibiotics versus no antibiotics during ERCP. In patients with post-transplant biliary strictures, we suggest ERCP as the initial intervention and cSEMSs as the preferred stent. In patients with unclear diagnosis or intermediate probability of a stricture, we suggest MRCP as the diagnostic modality. We suggest that antibiotics should be administered during ERCP when biliary drainage cannot be assured.

Outcomes of endoscopic retrograde cholangiography and percutaneous transhepatic biliary drainage in liver transplant recipients with a Roux-en-Y biliary-enteric anastomosis

Backgrounds/Aims

Data regarding outcomes of endoscopic retrograde cholangiography (ERC) in liver transplant (LT) recipients with biliary-enteric (BE) anastomosis are limited. We report outcomes of ERC and percutaneous transhepatic biliary drainage (PTBD) as first-line therapies in LT recipients with BE anastomosis.

Methods

All LT recipients with Roux-BE anastomosis from 2001 to 2020 were divided into ERC and PTBD subgroups. Technical success was defined as the ability to cannulate the bile duct. Clinical success was defined as the ability to perform cholangiography and therapeutic interventions.

Results

A total of 36 LT recipients (25 males, age 53.5 ± 13 years) with Roux-BE anastomosis who underwent biliary intervention were identified. The most common indications for a BE anastomosis were primary sclerosing cholangitis (n = 14) and duct size mismatch (n = 10). Among the 29 patients who initially underwent ERC, technical success and clinical success were achieved in 24 (82.8%) and 22 (75.9%) patients, respectively. The initial endoscope used for the ERC was a single balloon enteroscope in 16 patients, a double balloon enteroscope in 7 patients, a pediatric colonoscope in 5 patients, and a conventional reusable duodenoscope in 1 patient. Among the 7 patients who underwent PTBD as the initial therapy, six (85.7%) achieved technical and clinical success (p = 0.57).

Conclusions

In LT patients with Roux-BE anastomosis requiring biliary intervention, ERC with a balloon-assisted enteroscope is safe with a success rate comparable to PTBD. Both ERC and PTBD can be considered as first-line therapies for LT recipients with a BE anastomosis.

Comparative accuracy of endosonographic shear wave elastography and transcutaneous liver stiffness measurement: a pilot study

BACKGROUND AND AIMS

Vibration-controlled transient elastography (VCTE) is a validated test for assessing liver fibrosis but may be unreliable in select patients, including those with morbid obesity. The limitations of VCTE may be overcome by EUS-guided shear wave elastography (EUS-SWE).

METHODS

This single-center, prospective, nonrandomized tandem study compared the diagnostic accuracy of EUS-SWE and VCTE in consecutive patients undergoing liver biopsy sampling because of unreliable noninvasive testing. EUS-SWE of the left and right lobes were separately performed and then compared with VCTE. Liver elasticity cutoffs for different stages of fibrosis were estimated in 3 ways: optimized sensitivity and specificity using the Youden index; and with sensitivity and specificity fixed at 90% each, Diagnostic accuracy for fibrosis was compared with liver histology using the area under the receiver-operating characteristic curve (AUROC). The primary outcome was the diagnostic accuracy of EUS-SWE for advanced fibrosis. Secondary outcomes were diagnostic accuracy of VCTE, EUS-SWE for left and right hepatic lobes for significant/advanced fibrosis, and cirrhosis.

RESULTS

Forty-two patients (39 men, aged 54.5 ± 12.1 years) underwent EUS-SWE, VCTE, and liver biopsy sampling. The cross-validated AUROCs for advanced fibrosis were as follows: VCTE, .87 (95% confidence interval [CI], .76-.97); EUS-SWE left lobe, .8 (95% CI, .64-.96); and EUS-SWE right lobe, .78 (95% CI, .62-.95). The corresponding AUROCs for cirrhosis were as follows: VCTE, .9 (95% CI, .83-.97); EUS-SWE left lobe, .96 (95% CI, .9-1); and EUS-SWE right lobe, .9 (95% CI, .8-1). VCTE was unreliable in 8 patients who successfully underwent EUS-SWE. There was no statistically significant difference in the AUROCs for EUS-SWE and VCTE.

CONCLUSIONS

EUS-SWE correlates well with liver histology and is a safe and reliable diagnostic test for assessing liver fibrosis with accuracy comparable with VCTE. (Clinical trial registration number: NCT04533932.).

Post-transplant biliary complications: advances in pathophysiology, diagnosis, and treatment

Liver transplantation (LT) is the only curative therapy in patients with end-stage liver disease. Long-term survival is excellent, yet LT recipients are at risk of significant complications. Biliary complications are an important source of morbidity after LT, with an estimated incidence of 5%-32%. Post-LT biliary complications include strictures (anastomotic and non-anastomotic), bile leaks, stones, and sphincter of Oddi dysfunction. Prompt recognition and management is critical as these complications are associated with mortality rates up to 20% and retransplantation rates up to 13%. This review aims to summarise our current understanding of risk factors, natural history, diagnostic testing, and treatment options for post-transplant biliary complications.

Post-Transplant Biliary Strictures: An Updated Review

Liver transplantation (LT) is the only curative therapy in patients with end-stage liver disease with excellent long-term survival; however, LT recipients are at risk of significant complications. Among these complications are biliary complications with an incidence ranging from 5 to 32% and associated with significant post-LT morbidity and mortality. Prompt recognition and management are critical as these complications have been associated with mortality rates up to 19% and retransplantation rates up to 13%. An important limitation of published studies is that a large proportion does not discriminate between anastomotic strictures and nonanastomotic strictures. This review aims to summarize our current understanding of risk factors and natural history, diagnostic testing, and treatment options for post-LT biliary strictures.

Early laboratory values after liver transplantation are associated with anastomotic biliary strictures

Backgrounds/Aims

The aim of this study was to evaluate longitudinal changes of post-liver transplantation (LT) biliary anatomy and to assess the association of increased laboratory values after LT with the development of post-LT anastomotic biliary stricture (ABS).

Methods

Adult deceased donor LT recipients from 2008 and 2019 were evaluated. ABS was defined after blinded review of endoscopic cholangiograms. Controls were patients who underwent LT for hepatocellular carcinoma who did not have any clinical or biochemical concerns for ABS.

Results

Of 534 patients who underwent LT, 57 patients had ABS and 57 patients served as controls. On MRI, ABS patients had a narrower anastomosis (2.47 ± 1.32 mm vs. 3.38 ± 1.05 mm; p < 0.01) and wider bile duct at 1-cm proximal to the anastomosis (6.73 ± 2.45 mm vs. 5.66 ± 1.95 mm; p = 0.01) than controls. Association between labs at day 7 and ABS formation was as follows: aspartate aminotransferase hazard ratio (HR): 1.014; 95% confidence interval (CI): 1.008–1.020, p = 0.001; total bilirubin HR: 1.292, 95% CI: 1.100–1.517, p = 0.002; and conjugated bilirubin HR: 1.467, 95% CI: 1.216–1.768, p = 0.001. Corresponding analysis results for day 28 were alanine aminotransferase HR: 1.004, 95% CI: 1.002–1.006, p = 0.001; alkaline phosphatase HR: 1.005, 95% CI: 1.003–1.007, p = 0.001; total bilirubin HR: 1.233, 95% CI: 1.110–1.369, p = 0.001; and conjugated bilirubin HR: 1.272, 95% CI: 1.126–1.437, p = 0.001.

Conclusions

Elevation of laboratory values early after LT is associated with ABS formation.

Beyond the Liver Function Tests: A Radiologist's Guide to the Liver Blood Tests

Liver blood tests (often also known as liver chemistries, liver tests, or the common misnomer liver function tests) are routinely used in diagnosis and management of hepatobiliary disease. Abnormal liver blood test results are often the first indicator of hepatobiliary disease and a common indication for abdominal imaging with US, CT, or MRI. Most of the disease entities can be categorized into hepatocellular or cholestatic patterns, with characteristic traits on liver blood tests. Each pattern has a specific differential, which can help narrow the differential diagnosis when combined with the clinical history and imaging findings. This article reviews the major liver blood tests as well as a general approach to recognizing common patterns of hepatobiliary disease within these tests (hepatocellular, cholestatic, acute liver failure, isolated hyperbilirubinemia). Examples of hepatobiliary disease with hepatocellular or cholestatic patterns are presented with characteristic test abnormalities and imaging findings. The commonly encountered scenario of chronic hepatitis with possible fibrosis is also reviewed, with discussion of potential further imaging such as elastography. The role of liver blood tests and imaging in evaluating complications of hepatic transplant is also discussed. Overall, integrating liver blood test patterns with imaging findings can help the radiologist accurately diagnose hepatobiliary disease, especially in cases where imaging findings may not allow differentiation between different entities. ^©RSNA, 2021.

Patients with post-transplant biliary strictures have significantly higher rates of liver transplant failure and rejection: A nationwide inpatient analysis

BACKGROUND AND AIM

Biliary strictures are a common complication of liver transplantation. We assess the impact of post-transplant biliary strictures and describe the outcomes of endoscopic retrograde cholangiopancreatography (ERCP), interventional radiology (IR), and surgical therapies.

METHODS

Using the Nationwide Readmissions Database (NRD), hospitalized liver transplant recipients were identified using the International Classification of Diseases 10th Revision codes. Patients with post-transplant biliary strictures were identified, and outcomes (inpatient mortality, 30-day readmission, transplant rejection/infection/failure, and disposition) were compared with transplant recipients without strictures. Among transplant patients with biliary strictures who underwent therapeutic intervention, corresponding outcomes were compared between IR, surgical interventions, and ERCP.

RESULTS

Of the 8300 liver transplant recipients meeting selection criteria, 554 patients (age 48.9 ± 18.2 years, mean ± SD; 39.5% women) had biliary strictures. Compared with patients without strictures, the adjusted odds ratio (OR) for various outcomes in patients with biliary strictures were as follows: 1.46 (1.20, 1.77; P < 0.001) for 30-day non-elective readmission, 2.71 (2.04, 3.59; P < 0.001) allograft rejection, 2.32 (1.61, 3.37; P < 0.001) liver transplant failure, 3.05 (1.39, 6.73; P < 0.01) infection, and 1.41 (1.08, 1.82; P = 0.01) disposition to skilled nursing or intermediate care facility. Therapeutic interventions during index hospitalization were performed in 350 patients: ERCP 46.6% (n = 163), surgery 41% (n = 144), and IR 12.3% (n = 43) patients. Compared with ERCP, the adjusted odds for various outcomes were disposition to skilled nursing or intermediate care facility 2.72 (1.08, 6.87; P = 0.03) and 2.09 (1.05, 4.15; P = 0.036), prolongation of hospitalization 14.4 (3.7, 25.1; P = 0.008) and 15.0 (7.4, 22.7; P < 0.001), and failure of liver allograft 8.47 (1.47, 48.6; P = 0.017) and 12.23 (2.74, 54.4; P = 0.001) for IR and surgical interventions, respectively.

CONCLUSION

Post-liver transplant biliary strictures are associated with increased rates of allograft rejection, allograft failure/infections, and readmissions. Compared with ERCP, management of these patients with IR or surgical interventions is associated with significantly higher rates of allograft failure and hospital stay.

Interobserver Agreement for Classifying Post-liver Transplant Biliary Strictures in Donation After Circulatory Death Donors

INTRODUCTION

Biliary strictures are a common complication of donation after circulatory death (DCD) liver transplantation (LT) and require multiple endoscopic retrograde cholangiopancreatography (ERCP) procedures. Three classification systems, based on cholangiograms, have been proposed for categorizing post-LT biliary strictures. We examined the interobserver agreement for each of the three classifications.

METHODS

DCD LT recipients from 2012 through March 2017 undergoing ERCP for biliary strictures were included in the study. Initial cholangiograms delineating the entire biliary tree prior to endoscopic intervention were selected. One representative cholangiogram was selected from each ERCP. Five interventional endoscopists independently viewed each anonymized cholangiogram and classified the post-LT stricture according to each of the three classification systems. The Ling classification proposes four types of post-LT strictures based on their location. The Lee classification proposes four classes based on location and number of intrahepatic strictures. The binary system classifies strictures into anastomotic or non-anastomotic types. The Krippendorff's alpha reliability estimate was used to grade the strength of agreement as "poor," "fair," "moderate," "good," or "excellent" for values between 0-0.20, 0.21-0.4, 0.41-0.6, 0.61-0.08, and 0.81-1, respectively.

RESULTS

One hundred DCD LT recipients (age 57.07 ± 8.8 years; 71 males) were initially evaluated. Of these, 49 patients who underwent 206 ERCP procedures for biliary strictures were included in the analysis. One hundred thirty-nine cholangiograms were selected and subsequently classified by five endoscopists. Interobserver agreement for post-LT biliary strictures was 0.354 for Ling classification (fair agreement), 0.405 for Lee classification (fair agreement), and 0.421 for the binary classification (moderate agreement). The binary classification provided the least amount of detail regarding the location and number of biliary strictures.

DISCUSSION

The currently available classification systems for assessing post-LT biliary strictures have sub-optimal interobserver agreement. A better-designed classification system is needed for categorizing post-LT biliary strictures.

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.

Outcomes of endoscopic therapy in donation after cardiac death liver transplant biliary strictures

BACKGROUND

Biliary strictures after donation-after-cardiac-death (DCD) liver transplantation (LT) require multiple endoscopic retrograde cholangiopancreatographies (ERCP). The outcomes of endoscopic dilation and maximal stenting are not well-characterized in this high-risk population.

METHODS

DCD LT recipients who underwent LT and ERCP from 2012-2018 were selected. Anastomotic and non-anastomotic strictures were treated with balloon dilation and maximal stenting. A successful stent-free trial was defined as absence of biochemical, clinical or imaging evidence of strictures on follow-up exceeding 6 months. Adverse events were defined as unplanned admission or inpatient evaluation within 7 days of ERCP.

RESULTS

Forty-nine DCD LT recipients underwent ERCP and 34 patients were diagnosed with strictures (20 anastomotic). Stent-free trial was successful in 27 patients. Adverse events occurred after 20 ERCPs. Patients with anastomotic strictures required fewer stents (1.43 ± 1.37 vs 2.63 ± 1.66; P < 0.001), shorter procedure and fluoroscopy times (34.15 ± 20.9 vs 59.6 ± 30.7 minutes, P < 0.001; 5.99 ± 7.4 vs 14.73 ± 10.74 minutes, P < 0.001), fewer relapses (10% vs 57%, P = 0.003), shorter intervals between initial ERCP and stent-free success (136.9 ± 118.3 vs 399.56 ± 234.7; P = 0.003), and between LT and stent-free success (227.8 ± 171.9 vs 464.1 ± 224.6 days; P = 0.005) compared to non-anastomotic strictures.

CONCLUSION

Endoscopic dilation and maximal stenting resolves biliary strictures in DCD LT recipients with sustained success and relatively few adverse events.

Predictors of Biliary Strictures After Liver Transplantation Among Recipients of DCD (Donation After Cardiac Death) Grafts

INTRODUCTION

Biliary strictures are a common complication among donation after cardiac death (DCD) liver transplantation (LT) recipients and may require multiple endoscopic retrograde cholangiopancreatography (ERCP) procedures. We evaluated the risk factors associated with development of biliary strictures in DCD LT recipients.

METHODS

DCD LT recipients who underwent transplantation from 2012 to 2017 were divided into 2 groups: (a) those with anastomotic or non-anastomotic biliary strictures who required ERCP ("stricture group") and (b) those who did not require ERCP or had cholangiograms without evidence of biliary strictures ("non-stricture group"). Clinical data, cholangiograms and laboratory values at day 0 and day 7 after LT were compared between the two groups.

RESULTS

Forty-nine of the 100 DCD LT recipients underwent ERCP. Thirty-four of these 49 LT recipients had evidence of anastomotic or non-anastomotic biliary strictures (stricture group), while the remaining 66 LT recipients comprised the non-stricture group. Donor age was significantly higher in stricture group compared to non-stricture group (49.2 ± 1.8 vs 42.8 ± 1.57 years, respectively; p = 0.01). The stricture group had a significantly higher total bilirubin at day 0 (3.5 ± 0.37 vs 2.6 ± 0.21 mg/dL; p = 0.02) and INR at day 7 (1.24 ± 0.06 vs 1.13 ± 0.01; p = 0.048) compared to the non-stricture group. Multi-variate analysis demonstrated significant association between biliary strictures and total bilirubin at day 0 of LT and age of donor.

CONCLUSION

Biliary strictures occur frequently in DCD LT recipients and may be associated with older age of donor. Hyperbilirubinemia immediately after transplant and higher INR in the first 7 days after transplant may predict subsequent development of biliary strictures.

Significant infections in liver transplant recipients undergoing endoscopic retrograde cholangiography are few and unaffected by prophylactic antibiotics

INTRODUCTION

Current practice guidelines recommend prophylactic antibiotics prior to endoscopic retrograde cholangiopancreatography (ERCP) in liver transplant recipients (LTR). This study evaluated the risk of clinically significant infections after ERCP in LTR who received antibiotic prophylaxis compared to those who did not.

METHODS

This retrospective case-cohort study evaluated all LTR who underwent elective, outpatient ERCP from 2008 to 2015. Hospitalized patients, pediatric allograft recipients and patients with cholangitis or incomplete biliary drainage were excluded. The primary outcome was unanticipated hospitalization from procedure-related clinically significant infection occurring within 3 days of ERCP.

RESULTS

Sixty-nine patients (48 males; mean age 60.5 ± 7.4 years) underwent 191 ERCPs after liver transplantation. Prophylactic antibiotics were administered during 82 ERCPs and not administered for 109 ERCPs. Unscheduled admissions for fever within 3 days occurred in 4 patients. Only 2 patients had documented bacteremia, of which only 1 patient received prophylactic antibiotics and also met primary outcome. Interventions during ERCP, patient demographics, and time from transplantation were not associated with increased risk of hospitalization from infections or bacteremia.

CONCLUSIONS

The risk of infectious complications after ERCP in LTR is low and not affected by administration of prophylactic antibiotics. A tailored approach to antibiotic prophylaxis may be more appropriate than universal prophylaxis in selected LTR at low risk of infections.

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.