New US capsule endoscopy for superficial and submucosal imaging of the esophagus: the first-in-human study

Abstract

Endoscopic ultrasound (EUS) is essential in diagnosis and staging of esophageal subepithelial lesions and tumors. However, EUS is invasive, relies on high-trained endoscopists, and typically requires sedation. The newly developed ultrasound capsule endoscopy (USCE), which incorporates both white-light and ultrasound imaging modalities into a tethered capsule, is a minimally-invasive method for obtaining superficial and submucosal information of the esophagus. This study aimed to assess the feasibility and safety of this USCE system. A total of 20 participants were enrolled: 10 healthy volunteers and 10 patients with esophageal lesions indicated for EUS. Participants first underwent USCE, and subsequently EUS within 48 hours. The primary outcome was the technical success rate of USCE. The secondary outcomes included safety, visualization of the esophagus and comfort assessment. The technical success rate of USCE was 95% as one patient failed to swallow the capsule. None adverse event was observed. The esophagus was well visualized and all lesions were detected under USCE optical mode in 19 participants. For healthy volunteers, the ultrasound images of normal esophageal walls were all characterized by differentiated 7-layer architecture under both USCE and EUS. For the 9 patients, the features of esophageal lesions were recognized clearly under USCE ultrasound mode, and presumptive diagnoses derived from USCE were all consistent with those from EUS. Most participants preferred USCE compared to EUS. The novel USCE is feasible and safe to observe the esophageal mucosa and acquire submucosal information, which has the potential to be widely used in clinic.