Cholangioscopy- versus fluoroscopy-guided transpapillary mapping biopsy for preoperative evaluation of extrahepatic cholangiocarcinoma: a prospective randomized crossover study

Background To evaluate the lateral extent of extrahepatic cholangiocarcinoma, the value of cholangioscopy-guided mapping biopsy (CMB) compared with that of fluoroscopy-guided mapping biopsy (FMB) remains unknown. The aim of this study was to compare these two techniques. Methods In this prospective, randomized, crossover study, both CMB and FMB techniques were performed for all patients in a randomized order. Target sites for the mapping biopsy were determined based on resection lines of possible surgical procedures. At least two biopsy strokes were attempted at each target site. The primary outcome was the rate of site-based successful biopsies, which was defined as acquisition of epithelium-containing material appropriate for diagnosing benignancy/malignancy from each site, regardless of amount of materials obtained from the same site. Results Between September 2016 and October 2018, 28 patients (16 distal bile duct cancer and 12 perihilar bile duct cancer) were enrolled and divided into two groups of 14 patients: CMB first and FMB first. Although all 118 target sites could be approached using CMB, FMB forceps reached only 71% of them with significantly poor accessibility to the B2/3 confluence. Since several materials were too small and did not contain epithelium, the overall rates of site-based successful biopsies were 78% (92/118) using CMB and 64% (76/118) using FMB ( P = 0.031). Conclusions The rate of site-based successful biopsies using CMB was significantly higher than that using FMB when evaluated using specimens obtained from several biopsy strokes.