In vivo imaging of enteric neuronal networks in humans using confocal laser endomicroscopy.

Neurons and glia comprise the enteric nervous system (ENS), which is an essential part of the gut. Changes of the enteric glia cell function are associated with functional diseases and motility disorders.1 The neurons of the ENS are collected into 2 types of ganglia: myenteric (Auerbach’s) and submucosal (Meissner’s) plexuses. Myenteric plexuses are located between the inner and outer layers of the muscularis externa, and submucosal plexuses are located in the submucosal layer.1 Thus, direct, in vivo imaging of the ENS in humans is not possible with conventional white light endoscopy. Confocal laser endomicroscopy (CLE) is a new established endoscopic method providing in vivo histology at subcellular resolution during ongoing endoscopy.2 Preceding porcine model studies demonstrated that use of CLE at levels of the submucosa or superficial muscularis might enable the ENS to be visualized in vivo.3,4 Two ypes of endomicroscopic systems are available. Probeased endomicroscopy (Mauna Kea Technologies, Paris, okyo, France) allows real-time cellular imaging with igh frame rates at a distinct depth,5 whereas embedded ype of endomicroscopy (Pentax, Tokyo, Japan) allows ndomicroscopy with high-resolution and variable imagng plane depth (0 –250 m).6 Endomicroscopy requires contrast agents for fluorescence imaging. Commonly used dyes are fluorescein and Acriflavine. The aim of the current study was to evaluate, whether and how endomicroscopy might be able to visualize the enteric nervous system of the submucosal layer of the colon in humans.