Diameter that defines a dominant biliary stricture

What is known

• This cholangiographic diameter threshold (≤1.5 mm CBD, ≤1.0 mm hepatic duct) is applied consistently across cohort studies and reviews to define dominant strictures at ERCP. ^1–5
• The hepatic duct measurement is specified within 2 cm of the bifurcation in some protocols. ^1,2
• The International PSC Study Group has proposed a newer definition combining symptoms, laboratory parameters, cholangiographic imaging, and endoscopic therapy rather than diameter alone. ⁵

What is unknown / caveats

• The purely diameter-based definition does not account for upstream/downstream duct caliber or biochemical/clinical consequences
• A newer symptom- and laboratory-inclusive definition has been proposed and yields different prevalence estimates
• The diameter threshold is the traditional definition, but a revised composite definition is now being adopted.

References

1. Färkkilä M, Åberg F, Alfthan H, Jokelainen K, Puustinen L, Kautiainen H, Tenca A. Surrogate markers of bile duct disease progression in primary sclerosing cholangitis - A prospective study with repeated ERCP examinations. JHEP Rep. 2024. PMID: 39290402.

2. Rupp C, Hippchen T, Bruckner T, Klöters-Plachky P, Schaible A, Koschny R, Stiehl A, Gotthardt DN, Sauer P. Effect of scheduled endoscopic dilatation of dominant strictures on outcome in patients with primary sclerosing cholangitis. Gut. 2019. PMID: 30910856.

3. Malik A, Kardashian AA, Zakharia K, Bowlus CL, Tabibian JH. Preventative care in cholestatic liver disease: Pearls for the specialist and subspecialist. Liver Res. 2019. PMID: 32042471.

4. Gidwaney NG, Pawa S, Das KM. Pathogenesis and clinical spectrum of primary sclerosing cholangitis. World J Gastroenterol. 2017. PMID: 28465630.

5. Jalan-Sakrikar N, Anwar AA, Ali A, Nasser-Ghodsi N, Felzen A, Huebert RC, LaRusso NF, O'Hara SP. Cholangiocyte biology in primary sclerosing cholangitis and other cholangiopathies: pathogenesis, clinical insights, and experimental tools. Physiol Rev. 2026. PMID: 41973609.

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Draft, generated by the IBDology RAG and not yet clinician-reviewed. Answers are grounded in the retrieved literature listed above; a high faithfulness score means the answer matches its sources, not that the sources are correct.