Predictive criteria of response to endoscopic treatment for severe strictures in primary sclerosing cholangitis

Diagnosis of functional strictures in patients with primary sclerosing cholangitis using hepatobiliary contrast-enhanced MRI: a proof-of-concept study

OBJECTIVES

PSC strictures are routinely diagnosed on T2-MRCP as dominant- (DS) or high-grade stricture (HGS). However, high inter-observer variability limits their utility. We introduce the "potential functional stricture" (PFS) on T1-weighted hepatobiliary-phase images of gadoxetic acid-enhanced MR cholangiography (T1-MRC) to assess inter-reader agreement on diagnosis, location, and prognostic value of PFS on T1-MRC vs. DS or HGS on T2-MRCP in PSC patients, using ERCP as the gold standard.

METHODS

Six blinded readers independently reviewed 129 MRIs to diagnose and locate stricture, if present. DS/HGS was determined on T2-MRCP. On T1-MRC, PFS was diagnosed if no GA excretion was seen in the CBD, hilum or distal RHD, or LHD. If excretion was normal, "no functional stricture" (NFS) was diagnosed. T1-MRC diagnoses (NFS = 87; PFS = 42) were correlated with ERCP, clinical scores, labs, splenic volume, and clinical events. Statistical analyses included Kaplan-Meier curves and Cox regression.

RESULTS

Interobserver agreement was almost perfect for NFS vs. PFS diagnosis, but fair to moderate for DS and HGS. Forty-four ERCPs in 129 patients (34.1%) were performed, 39 in PFS (92.9%), and, due to clinical suspicion, five in NFS (5.7%) patients. PFS and NFS diagnoses had 100% PPV and 100% NPV, respectively. Labs and clinical scores were significantly worse for PFS vs. NFS. PFS patients underwent more diagnostic and therapeutic ERCPs, experienced more clinical events, and reached significantly more endpoints (p < 0.001) than those with NFS. Multivariate analysis identified PFS as an independent risk factor for liver-related events.

CONCLUSION

T1-MRC was superior to T2-MRCP for stricture diagnosis, stricture location, and prognostication.

CLINICAL RELEVANCE STATEMENT

Because half of PSC patients will develop clinically-relevant strictures over the course of the disease, earlier more confident diagnosis and correct localization of functional stricture on gadoxetic acid-enhanced MRI may optimize management and improve prognostication.

KEY POINTS

• There is no consensus regarding biliary stricture imaging features in PSC that have clinical relevance. • Twenty-minute T1-weighted MRC images correctly classified PSC patients with potential (PFS) vs with no functional stricture (NFS). • T1-MRC diagnoses may reduce the burden of diagnostic ERCPs.

ERCP-Related Adverse Events in Primary Sclerosing Cholangitis: A Systematic Review and Meta-Analysis

Background and Aims

While endoscopic retrograde cholangiopancreatography (ERCP) is a valuable diagnostic and therapeutic tool in primary sclerosing cholangitis (PSC), there is conflicting data on associated adverse events. The aims of this systematic review and meta-analysis are to (1) compare ERCP-related adverse events in patients with and without PSC and (2) determine risk factors for ERCP-related adverse events in PSC.

Methods

Embase, PubMed, and CENTRAL were searched between January 1, 2000, and May 12, 2021. Eligible studies included adults with PSC undergoing ERCP and reported at least one ERCP-related adverse event (cholangitis, pancreatitis, bleeding, and perforation) or an associated risk factor. The risk of bias was assessed with the Newcastle-Ottawa scale and Cochrane Risk of Bias 2. Raw event rates were used to calculate odds ratios (ORs) and then pooled using random-effects models.

Results

Twenty studies met eligibility criteria, of which four were included in a meta-analysis comparing post-ERCP adverse events in patients with PSC (n = 715) to those without PSC (n = 9979). We found a significant threefold increase in the 30-day odds of cholangitis in PSC compared to those without (OR 3.263, 95% CI 1.076-9.896; p=0.037). However, there were no significant differences in post-ERCP pancreatitis (PEP), bleeding, or perforation. Due to limitations in primary data, only risk factors contributing to PEP could be analyzed. Accidental passage of the guidewire into the pancreatic duct (OR 7.444, 95% CI 3.328-16.651; p < 0.001; I 2 = 65.0%) and biliary sphincterotomy (OR 4.802, 95% CI 1.916-12.033; p=0.001; I 2 = 73.1%) were associated with higher odds of PEP in a second meta-analysis including five studies.

Conclusions

In the context of limited comparative data and heterogeneity, PSC patients undergoing ERCP have higher odds of cholangitis despite the majority receiving antibiotics. Additionally, accidental wire passage and biliary sphincterotomy increased the odds of PEP. Future studies on ERCP-related risks and preventive strategies are needed.

Role of Endoscopic Retrograde Cholangiopancreatography in the Diagnosis and Management of Cholestatic Liver Diseases

Cholestatic liver diseases (CLDs) occur as a result of bile duct injury, emanating into duct obstruction and bile stasis. Advances in radiological imaging in the last decade has replaced endoscopic retrograde cholangiopancreatography (ERCP) as the first diagnostic tool, except in certain groups of patients, such as those with ischemic cholangiopathy (IsC) or early stages of primary sclerosing cholangitis (PSC). ERCP provides an opportunity for targeted tissue acquisition for histopathological evaluation and carries a diverse therapeutic profile to restore bile flow. The aim of this review article is to appraise the diagnostic and therapeutic roles of ERCP in CLDs.

Present and future role of endoscopic retrograde cholangiography in primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a rare, inflammatory cholestatic liver disease that causes biliary strictures which can lead to secondary complications. About 30-50% of PSC patients develop dominant strictures (DS) in the biliary tree, which are both the cause of jaundice and bacterial cholangitis as well as predilection spots for development of neoplastic development. Cancer is the most common cause of death in PSC. A central concern is to distinguish malignant from benign strictures, which eventually is done by invasive methods to obtain a brush cytology or biopsy sample, in most cases via endoscopic retrograde cholangiography-pancreatography (ERCP). Since medical therapies, like ursodesoxycholic acid or immunosuppressive drugs have no proven effect, therapeutic ERCP has become the primary management strategy to improve symptoms and in some patients may slow down disease progression. This article aims at outlining the current and emerging methods in ERCP in PSC patients.

Primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a rare chronic cholestatic liver disease characterized by inflammatory destruction of the intrahepatic and/or extrahepatic bile ducts, leading to bile stasis, fibrosis, and ultimately to cirrhosis, and often requires liver transplantation (LT). PSC occurs more commonly in men, and is typically diagnosed between the ages of 30 and 40. Most cases occur in association with inflammatory bowel disease (IBD), which often precedes the development of PSC. PSC is usually diagnosed after detection of cholestasis during health evaluation or screening of patients with IBD. When symptomatic, the most common presenting symptoms are abdominal pain, pruritus, jaundice or fatigue. The etiology of PSC is poorly understood, but an increasing body of evidence supports the concept of cholangiocyte injury as a result of environmental exposure and an abnormal immune response in genetically susceptible individuals. PSC is a progressive disease, yet no effective medical therapy for halting disease progression has been identified. Management of PSC is mainly focused on treatment of symptoms and addressing complications. PSC can be complicated by bacterial cholangitis, dominant strictures (DSs), gallbladder polyps and adenocarcinoma, cholangiocarcinoma (CCA) and, in patients with IBD, colorectal malignancy. CCA is the most common malignancy in PSC with a cumulative lifetime risk of 10-20%, and accounts for a large proportion of mortality in PSC. LT is currently the only life-extending therapeutic approach for eligible patients with end-stage PSC, ultimately required in approximately 40% of patients. LT secondary to PSC has an excellent outcome compared to other LT indications, although the disease can recur and result in morbidity post-transplant.

Recent advances in the treatment of primary sclerosing cholangitis

Introduction: PSC is a rare liver disease that leads frequently to cirrhosis and need for liver transplantation. No medical treatment is of proven value. Liver transplantation is the only curative therapy available. There is a big medical need to find medical therapy that can alter the natural history of the disease.Areas covered: The authors highlight advances in PSC, based on recent literature retrieved from PubMed until September 2020 regarding both medical and endoscopic biliary therapy.Future possibilities for treatment of PSC are discussed.Expert opinion: Biliary endoscopy is the cornerstone in the treatment of dominant strictures. Single-user peroral cholangioscopy is an emerging modality. Balloon dilatation therapy is the treatment of choice of dominant strictures. The most promising medical therapies showing efficacy in phase II trials are nor-Ursodeoxycholic acid, obethicolic acid, the non-steroidal FXR agonist Cilofexor and Aldafermin, a synthetic analogue of FGF-19. Antibiotics, particularly vancomycin have shown potential benefits, particularly in children but phase III studies are lacking. In observational studies of effects of biological therapy in patients with IBD/PSC adalimumab was associated with reduction in ALP. Results of liver transplantation are favorable but recurrence can be of clinical relevance particularly in patients transplanted before the age of 40.

Gadoxetic acid-enhanced MRI in primary sclerosing cholangitis: added value in assessing liver function and monitoring disease progression

PURPOSE

To investigate the added value of gadoxetic acid-enhanced MRI in monitoring liver function and disease progression in patients with primary sclerosing cholangitis (PSC).

METHODS

We retrospectively identified 104 consecutive patients (75 males; mean age 41.98 ± 12.5 years) with confirmed diagnosis of PSC who underwent 227 gadoxetic acid-enhanced MRI examinations between January 2008 and May 2019. Relative enhancement (RE) of the liver was correlated with the results of liver function tests (LFTs), scoring models (Model for End-Stage Liver Disease (MELD) score, Mayo Risk Score (MRS), Amsterdam-Oxford model (AOM)), and qualitative MRI findings. In addition, results were analyzed separately for excretory MRI examinations (n = 164) and nonexcretory examinations (n = 63) depending on excretion of gadoxetic acid into the common bile duct in the hepatobiliary phase (HBP).

RESULTS

There was a significant correlation of RE with MRS (r = - 0.652), MELD score (r = - 0.474), AOM (r = - 0.468), and LFTs (P < 0.001). RE and albumin were significantly higher in the excretory group whereas scoring models, bilirubin, aspartate aminotransferase, alkaline phosphatase, and international normalized ratio were lower (P < 0.001). RE was lower in segments with absent HBP gadoxetic acid excretion into dilated bile ducts, reduced HBP parenchymal enhancement, atrophy, T2 hyperintensity, and bile duct abnormalities (P < 0.001).

CONCLUSION

Relative enhancement of the liver in gadoxetic acid-enhanced MRI can be used to evaluate global and regional liver function and monitor disease progression in patients with PSC. Hepatobiliary phase gadoxetic acid biliary excretion appears to be a reproducible qualitative parameter for evaluating disease severity that can be easily integrated into routine clinical practice.