Intraductal Optical Coherence Tomography for Investigating Main Pancreatic Duct Strictures

Abstract

Optical coherence tomography (OCT) permits high-resolution imaging of tissue microstructures using a probe that can be inserted into the main pancreatic duct (MPD) through a standard endoscopic retrograde cholangiopancreatography (ERCP) catheter. This prospective study was designed to assess the diagnostic capacity of OCT to differentiate between nonneoplastic and neoplastic lesions in patients with MPD segmental strictures. Twelve consecutive patients with documented MPD segmental stricture were investigated by endoscopic ultrasonography (EUS), with fine-needle aspiration cytology if necessary, and ERCP, followed by brush cytology and OCT scanning. OCT recognized a differentiated three-layer architecture in all cases with normal MPD or chronic pancreatitis, while in all the neoplastic lesions the layer architecture appeared totally subverted, with heterogeneous backscattering of the signal. The accuracy of OCT for detection of neoplastic tissue was 100% compared with 66.7% for brush cytology. In one case, neither OCT scanning nor brush cytology was possible because of the severity of the stricture. This pilot study showed that OCT is feasible during ERCP, in cases of MPD segmental stricture, and was superior to brush cytology in distinguishing nonneoplastic from neoplastic lesions.