Diagnostic Yield of a Novel 11‐Fr Digital Cholangioscope for Indeterminate Biliary Disease Using Macroscopic‐On‐Site Evaluation: Prospective Comparative Study

ABSTRACT Background and Aim A novel 11‐Fr digital cholangioscope (eyeMAX) has recently become available. However, a prospective comparative study of the diagnostic yield of the eyeMAX and of a conventional cholangioscope (SpyGlass DS II) has not been reported. Therefore, the aim of this study was to prospectively compare the diagnostic yield of the eyeMAX and of the SpyGlass DS II for indeterminate biliary disease. Patients and Method Forceps biopsy was repeated until visible core tissue was obtained. The primary outcome of this study was the diagnostic accuracy of the biopsy specimens obtained by the eyeMAX. The secondary outcomes were comparisons of the diagnostic yield of visual findings, tissue size, number of forceps biopsies until MOSE positivity, and adverse events. Results Fifty patients were prospectively enrolled in the eyeMAX group. And 47 patients in the SpyGlass DS II group were enrolled as a historical control. The number of biopsies was significantly fewer in the eyeMAX group than in the SpyGlass DS II group ( p = 0.001). Tissue size was larger in the eyeMAX group (2.96 ± 0.69 mm 2 ) than in the SpyGlass DS II group (1.80 ± 1.61 mm 2 ). The diagnostic accuracy was also higher in the eyeMAX group (96.0%, 48/50) than in the SpyGlass DS II group (80.9%, 38/47). The diagnostic accuracy for the final diagnosis was slightly higher in the eyeMAX group (93.5%, 47/50) than in the SpyGlass DS II group (89.3%, 42/47). Conclusions The eyeMAX has a favorable diagnostic yield in terms of visual findings and the forceps biopsy specimen. Trial registration: 000049465