What is the recommended endoscopic therapy for primary sclerosing cholangitis (PSC) with dominant bile duct strictures?

Endoscopic Therapy for Primary Sclerosing Cholangitis with Dominant Bile Duct Strictures

Balloon dilation should be the first-line endoscopic therapy for dominant bile duct strictures in primary sclerosing cholangitis (PSC), with stenting reserved only for strictures refractory to dilation. 1

Definition and Significance of Dominant Strictures

• Dominant strictures in PSC are defined as stenoses with a diameter of ≤1.5 mm in the common bile duct or ≤1 mm in the hepatic duct, occurring in 45-58% of PSC patients during follow-up 1
• These strictures can lead to biliary obstruction, causing symptoms and liver function deterioration, and are associated with worse prognosis compared to PSC without dominant strictures 2
• Dominant strictures should be suspected in patients with increasing serum bilirubin levels, worsening pruritus, progressive bile duct dilation on imaging, cholangitis, or deteriorating liver biochemical indices 1

Diagnostic Approach

• Magnetic resonance cholangiography (MRC) should be the primary diagnostic modality for PSC rather than ERCP 3
• ERCP should be considered before therapeutic intervention to confirm dominant strictures and perform ductal sampling (brush cytology, endobiliary biopsies) to exclude cholangiocarcinoma 3, 1
• Cholangiocarcinoma should be suspected in any patient with worsening cholestasis, weight loss, raised serum CA19-9, and/or new or progressive dominant stricture 3

Recommended Endoscopic Treatment Algorithm

First-Line Therapy: Balloon Dilation

• Balloon dilation alone should be the preferred initial treatment for dominant strictures in PSC 3, 1
• Select a balloon caliber up to the maximum caliber of the ducts delimiting the stricture (typically 6-8 mm for hepatic ducts and up to 8 mm for common bile duct) 3
• Balloon dilations are usually repeated at intervals of 1-4 weeks until technical success, typically requiring 2-3 sessions 3
• Technical success is defined as complete balloon inflation with no waist observed fluoroscopically, followed by unobstructed passage of contrast medium 3
• This approach has shown lower complication rates (15% vs 54%) compared to stenting 3

Second-Line Therapy: Stenting

• Stenting should be reserved for strictures refractory to balloon dilation 1
• If stenting is required, short-term stenting is preferred over long-term stenting to reduce complications 3
• Long-term stenting (mean 3 months) is associated with higher risk of stent clogging and cholangitis 3
• The European multicenter randomized DILSTENT trial was prematurely stopped due to significantly higher serious adverse event rates in the stent group compared to balloon dilation 3

Role of Biliary Sphincterotomy

• Biliary sphincterotomy should not be performed routinely but considered on a case-by-case basis 3
• Sphincterotomy is particularly indicated after difficult cannulation in patients likely to require multiple ERCPs 3
• In PSC, sphincterotomy has been associated with increased risk of short-term adverse events (odds ratios: 4.7-5.0) but may be protective for subsequent ERCPs 3

Management of Recurrent Strictures

• Repeat dilation of relapsing dominant strictures should be performed if: 3
  1. The dominant stricture is causing recurrent symptoms (cholangitis, pruritus) or significant increase in cholestasis
  2. The patient's response to previous dilations has been satisfactory

Outcomes and Prognosis

• Scheduled endoscopic treatment of dominant strictures has been associated with improved transplantation-free survival compared to on-demand treatment (median: 17.9 vs 15.2 years) 4
• Regular endoscopic balloon dilation benefits patients with dominant strictures even if asymptomatic 4
• Endoscopic treatment has shown improved survival compared to that predicted by prognostic models 5
• However, patients with dominant strictures still have worse prognosis than those without (mean survival 13.7 vs 23 years) 2
• Dominant strictures are associated with 26% risk of developing cholangiocarcinoma 2

Complications and Safety Considerations

• Prophylactic antibiotics should be administered routinely before ERCP in patients with PSC 3
• Bile duct perforation rates are lower with balloon dilation (0.2% of procedures) compared to stenting 3
• Overall complication rates for endoscopic treatment of PSC are approximately 7.3% with no procedure-related deaths reported in large series 5
• Patients should be monitored for bacterial cholangitis, which requires prompt treatment with antibiotics and biliary decompression 1

Special Considerations

• New dominant strictures, especially at initial PSC diagnosis, require thorough evaluation to exclude cholangiocarcinoma, as half of cholangiocarcinoma cases may present within 4 months of PSC diagnosis 2
• Refractory bacterial cholangitis or strictures unresponsive to endoscopic management should prompt evaluation for liver transplantation 1