We have developed an image-processing algorithm that allows the inspection of small diameter vessels with miniature endoscopes. With this kind of investigation, it is possible to evaluate the lumen after microsurgical anastomosis without the need of the dissection of this vessel. The system was developed with the aid of a 3D-motion simulation model of a mini-endoscope that is moved inside a small diameter blood vessel. The coarse stream of images from the endoscope camera showing the inner surface of the vessel and its corresponding position in the vessel are combined through digital image processing algorithms. The resulting single picture offers a new efficient kind of documentation for the investigation of the anastomoses. It shows in a 2- dimensional image, a map of the inner surface, which allows a quick and easy evaluation of the intervention. With this new endoluminal technique a coarse stream of images can be compressed into a clear projection of the vessels surface.