An apparatus and method are disclosed for release of a tendon sheath using a rasp tool and an endoscopic cutting tool. The rasp tool has a body supporting a probe with a rasp surface at one end of the probe for removing soft tissue adhering to the tendon sheath after insertion of the probe into a pocket formed above the tendon sheath. The body, rasp probe and rasp surface are formed in one piece and may be mounted removably on an endoscope. The endoscopic cutting tool has a probe with a blade at one end, the blade being extendable by operation of a trigger after insertion of the probe into the pocket, the blade being operable to cut the tendon sheath by pulling the tool out of the pocket with the blade extended. The trigger is part of a pistol grip assembly that is mounted on the cutting blade probe and endoscope so that it can be rotated about the axis of the cutting blade probe. The endoscope illumination can be provided with ultraviolet light to make visible objects not visible otherwise.