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

Existing biliopancreatic duct endoscopy is deficient 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 US (IDUS) and optical coherence tomography (OCT) for the in vivo assessment of the biliopancreatic duct system during ERCP.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 the pull-back method. The clinical usefulness of the novel product was evaluated by postoperative choledochoscopy and assessment of the animal's general condition.One hundred forty-one pairs of images from 5 Bama miniature pigs were acquired. Visualization of the bile duct using both OCT and IDUS was characterized by a differentiated 3-layer architecture, whereas IDUS had poor clarity when compared with OCT. Postoperative choledochoscopy showed no local lesion in the bile duct wall, and the general condition of animals was normal.This prospective evaluation indicated 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 will be carried out to establish diagnosis criteria with the dual-modality imaging using an animal pathologic model and a human clinical study.