Biliary cryobiopsy via percutaneous cholangioscopy in indeterminate biliary strictures: a clinical multicenter feasibility study

Aims The differential diagnosis of indeterminate biliary strictures can be challenging. Forceps biopsy and brush cytology via ERCP and/or cholangioscopy are limited in sensitivity. Cryobiopsy has been established for bronchoscopy and has shown promising results in ex vivo bile duct tissue, with regards to volume of samples and histologic assessment (Wirsing et al. Endosc Int Open, 2022,10:E809-E814). Our aim was to evaluate the feasibility of this new technique in human indeterminate biliary strictures, using the percutaneous route for this proof-of-principle study [1].

Methods Patients with indications for percutaneous drainage and intraductal tissue diagnosis via percutaneous cholangioscopy underwent 6 standard forceps biopsies and 3 cryobiopsies with the flexible cryoprobe in randomized order. Primary endpoint was feasibility, defined as percentage of at least one adequate sample per patient in both study groups. Secondary endpoints included size of biopsy, quality and representativeness of each sample, and complications.

Results 15 patients were included (male:female 7:8, mean age 60.2 years). Adequate samples could be obtained in all patients in the cryo and the forceps biopsy groups. With regards to individual samples, there were 42/45 (93%) successful attempts for cryobiopsy and 87/90 (96.6%) for forceps biopsy. Cryobiopsy provided significantly larger specimens (mean of 8.45mm² vs. 1.87mm², p<0.0001), higher percentage of artefact free areas in histology (93.5% vs. 85.5%; p=0.011), higher histopathological assessment score (Likert Scale 0-6; 4.71 vs. 3.63; p=0.0005) and higher percentage ofrepresentative specimens (97.6% vs. 74.7%; p=0.001). Over both groups, three patients reported abdominal pain after the procedures, two developed fever, one developed cholangitis and in one case, wound infection occurred at the percutaneous access site. No bleeding or perforation was reported. All adverse events resolved after treatment with analgesia and/or antibiotics.

Conclusions Cholangioscopy guided intraductal cryobiopsy is a safe method for the evaluation of indeterminate biliary strictures; samples obtained are substantially larger and provide better histologic assessment compared to cholangioscopic biopsy forceps sampling. Further studies will assess comparative clinical accuracy

Publication History

Article published online:
27 March 2025

• References

• 1 Wirsing L. et al. Endosc Int Open 2022; 10: E809-E814