Intraductal cryobiopsy via percutaneous cholangioscopy for biliary strictures: a multicenter feasibility study.

Background: Tissue diagnosis of biliary strictures is challenging and often requires multiple methods. Cryobiopsy, which is well established in bronchoscopy with high tissue yield, is presented here for the first time as a proof-of-principle feasibility study performed via the percutaneous route for biliary strictures. Methods: Patients undergoing percutaneous cholangioscopy for intraductal diagnosis of biliary strictures underwent six forceps biopsies and three cryobiopsies in a randomized order. The main objective was to assess feasibility, defined as the retrieval of at least one adequate sample per method per patient. Results: Among 15 patients (53% women; mean age 60.2 years), all had at least one adequate sample obtained by each method. Cryobiopsy yielded significantly larger (8.54 vs. 1.87 mm2; P < 0.001) and more representative specimens (97.6% vs. 74.7%; P = 0.001). It also scored higher on overall histologic quality on a Likert scale of 0–6 (5 vs. 4; P < 0.001) and had more artifact-free areas (93.5% vs. 85.5%; P = 0.01). No bleeding or perforations occurred; only minor adverse events were reported and these resolved with standard treatment. Conclusions: This feasibility study showed that intraductal cryobiopsy via percutaneous cholangioscopy yielded larger samples and may enable more detailed histologic assessment than forceps biopsies. Further studies will evaluate its accuracy, safety, and potential for use with peroral cholangioscopy during endoscopic retrograde cholangiopancreatography.