In vivo real-time endocytoscopic visualization of blood flow in rectal microvasculature.

Endocytoscopy (ECS) is a new technology that enables endoscopists to visualize gastrointestinal mucosa at the cellular level. This reported case demonstrates the ability to visualize real-time blood flow utilizing ECS. Methylene blue dye was sprayed onto normal rectal mucosa during a routine screening colonoscopy of an asymptomatic patient. High-magnification views of colonic mucosa revealed normal mucosal cellular structure and microvasculature with normal flow of red blood cells. Individual red blood cells were seen circulating through the arterioles. Epithelial colonocytes appeared to be organized in a hexagonal pattern around crypts with borders demarcated by microvasculature. ECS can provide high-magnification views of the gastrointestinal mucosa including microvasculature in real time. This establishes possibilities for future in vivo research in areas such as cancer biology, angiogenesis, and inflammatory bowel disease.