[Vascular endoscopy using a flexible fiberscope with a thin external diameter; experimental and clinical studies]

The purpose of this study is to evaluate capability of a fiberscope with a thin external diameter (2. 5mm, Olympus PF25-L) in observing the inner surface of blood vessels in animals and humans. Vascular endoscopy was firstly performed in three living dogs. The inner surface of canine abdominal aorta was not be fully inspected because of retrograde blood flow from the renal and lumbal arteries, but by blocking the proximal and distal blood flow using Fogarty catheters that of canine iliac artery including a flap of intima of 1mm diameter could be successfully observed. As clinical application of this endoscope the inspection of intravascular structures of Dardik's Biografts obliterated after peripheral bypass surgery were performed. In every case, bellows-like inner surface of this graft and several shapes of stenosis could be clearly recognized. Thus this endoscope presented the good optical quality, but due to lack of an angulating system visualization of anastomotic site was not achieved in most cases. No patient incurred complications of any sort. We conclude that vascular endoscopy using this type of endoscope can be performed safely, and provide useful information to the field of peripheral vascular surgery, but for the widespread clinical use of this vascular endoscopy, efforts should be made to improve the endoscope system itself and the method of effective interruption of blood flow.