Large-area spectrally encoded confocal endomicroscopy of the human esophagus in vivo.

BACKGROUND AND OBJECTIVE: Diagnosis of esophageal diseases is often hampered by sampling errors that are inherent in endoscopic biopsy, the standard of care. Spectrally encoded confocal microscopy (SECM) is a high-speed reflectance confocal endomicroscopy technology that has the potential to visualize cellular features from large regions of the esophagus, greatly decreasing the likelihood of sampling error. In this paper, we report results from a pilot clinical study imaging the human esophagus in vivo with a prototype SECM endoscopic probe. MATERIALS AND METHODS: In this pilot clinical study, six patients undergoing esophagogastroduodenoscopy (EGD) for surveillance of Barrett's esophagus (BE) were imaged with the SECM endoscopic probe. The device had a diameter of 7 mm, a length of 2 m, and a rapid-exchange guide wire provision for esophageal placement. During EGD, the distal portion of the esophagus of each patient was sprayed with 2.5% acetic acid to enhance nuclear contrast. The SECM endoscopic probe was then introduced over the guide wire to the distal esophagus and large-area confocal images were obtained by helically scanning the optics within the SECM probe. RESULTS: Large area confocal images of the distal esophagus (image length = 4.3-10 cm; image width = 2.2 cm) were rapidly acquired at a rate of ∼9 mm2 /second, resulting in short procedural times (1.8-4 minutes). SECM enabled the visualization of clinically relevant architectural and cellular features of the proximal stomach and normal and diseased esophagus, including squamous cell nuclei, BE glands, and goblet cells. CONCLUSIONS: This study demonstrates that comprehensive spectrally encoded confocal endomicroscopy is feasible and can be used to visualize architectural and cellular microscopic features from large segments of the distal esophagus at the gastroesophageal junction. By providing microscopic images that are less subject to sampling error, this technology may find utility in guiding biopsy and planning and assessing endoscopic therapy. Lasers Surg. Med. 49:233-239, 2017. © 2016 Wiley Periodicals, Inc.

Esophageal-guided biopsy with volumetric laser endomicroscopy and laser cautery marking: a pilot clinical study.

BACKGROUND: Biopsy surveillance protocols for the assessment of Barrett's esophagus can be subject to sampling errors, resulting in diagnostic uncertainty. Optical coherence tomography is a cross-sectional imaging technique that can be used to conduct volumetric laser endomicroscopy (VLE) of the entire distal esophagus. We have developed a biopsy guidance platform that places endoscopically visible marks at VLE-determined biopsy sites. OBJECTIVE: The objective of this study was to demonstrate in human participants the safety and feasibility of VLE-guided biopsy in vivo. DESIGN: A pilot feasibility study. SETTING: Massachusetts General Hospital. PATIENTS: A total of 22 participants were enrolled from January 2011 to June 2012 with a prior diagnosis of Barrett's esophagus. Twelve participants were used to optimize the laser marking parameters and the system platform. A total of 30 target sites were selected and marked in real-time by using the VLE-guided biopsy platform in the remaining 10 participants. INTERVENTION: Volumetric laser endomicroscopy. MAIN OUTCOME MEASUREMENTS: Endoscopic and VLE visibility, and accuracy of VLE diagnosis of the tissue between the laser cautery marks. RESULTS: There were no adverse events of VLE and laser marking. The optimal laser marking parameters were determined to be 2 seconds at 410 mW, with a mark separation of 6 mm. All marks made with these parameters were visible on endoscopy and VLE. The accuracies for diagnosing tissue in between the laser cautery marks by independent blinded readers for endoscopy were 67% (95% confidence interval [CI], 47%-83%), for VLE intent-to-biopsy images 93% (95% CI, 78%-99%), and for corrected VLE post-marking images 100% when compared with histopathology interpretations. LIMITATIONS: This is a single-center feasibility study with a limited number of patients. CONCLUSION: Our results demonstrate that VLE-guided biopsy of the esophagus is safe and can be used to guide biopsy site selection based on the acquired volumetric optical coherence tomography imaging data. ( CLINICAL TRIAL REGISTRATION NUMBER: NCT01439633.).