In vivo histologic imaging of the muscularis propria and myenteric neurons with probe-based confocal laser endomicroscopy in porcine models (with videos).

BACKGROUND The submucosal tunneling technique enables us to endoscopically access deeper tissue layers. Use of probe-based confocal laser endomicroscopy (pCLE) provides optical histologic imaging on the site. OBJECTIVE To determine the technical feasibility of ex vivo and in vivo pCLE imaging of the muscularis propria and myenteric neurons by using submucosal endoscopy with a mucosal flap safety valve (SEMF). DESIGN Acute porcine model study. SETTING Animal laboratory. INTERVENTION Two ex vivo and 6 in vivo porcine models were used. A submucosal space was created with SEMF, and a neuronal molecular probe was topically applied onto the muscularis. Confocal imaging of the stained muscularis was performed by using pCLE. The selected sites were sampled, and the histopathology of the sites was analyzed. MAIN OUTCOME MEASUREMENTS The two main outcome measures were the procedural success rate of submucosal access and the correlation between pCLE and histologic images. RESULTS Submucosal access to the pCLE study site was successful in all attempts (100%; 17/17 sites). The muscularis propria was visualized with pCLE in the ex vivo and in vivo porcine models in 83.3% of sites (20/24), and the neuron-like cells were identified in 41.7% of sites (10/24). LIMITATIONS Animal experiment. CONCLUSION The muscularis propria and myenteric neurons could be selectively visualized with pCLE in vivo.