Novel biliopancreatic duct endoscope combining optical coherence tomography with intraductal US for exploring the bile duct: a diagnostic study in a porcine model.

Background and aims There are many deficiencies of existing biliopancreatic duct endoscopy in the examination of early biliary and pancreatic tumors. This study aimed to evaluate the usefulness and feasibility of a novel ultrafine separable biliopancreatic duct endoscopy device with dual modalities of intraductal ultrasonography (IDUS) and optical coherence tomography (OCT) for the in vivo assessment of biliopancreatic duct system during ERCP. Methods Five Bama miniature pigs were selected to probe their common bile duct and branches by using this novel equipment during ERCP. The feasibility of the procedure was evaluated by clear, clinically interpretable images obtained by using spiral scanning with pull-back method. The clinical usefulness of the novel product was evaluated by postoperative choledochoscopy and assessment of the animal's general condition. Results One hundred forty-one pairs of images from 5 Bama miniature pigs were acquired. Both OCT and IDUS's visualization of the bile duct was characterized by a differentiated 3-layer architecture, whereas IDUS shows with poor clarity than OCT. Postoperative choledochoscopy showed there was no local lesion in the bile duct wall, and the general condition of animals was normal. Conclusions This prospective evaluation indicates the feasibility and potential clinical value of the novel ultrafine separable biliopancreatic duct endoscopy device. The fusion of the 2 imaging modalities can shed light on the early diagnosis of biliary and pancreatic tumors. Further studies shall be carried out to establish the diagnosis criteria with the dual-modality imaging using animal pathological model and human clinic study.