Abstract: In order to remove a lesion constricting a vascular channel, such as arteries (1), a cutter (10) of oblong, and preferably ellipsoidal shape is provided by a plurality of flexible segments (15). The segments have cutting elements (20) in the form of cusps and mounds (25) distributed over their outwardly facing surfaces. The cutter is shortened axially between its distal (D) and proximal ends to radially expand it and present the cutting elements and mounds to the lesion. The mounds help to smoothen the inside of the vascular channel following cutting of the lesion material by the cutting elements. Reaming (reciprocal movement of the cutter) along the axis (11) of the channel or rotation of the cutter may be effected from a control unit (100) via a drive shaft 40 which encases a coaxial fluid/suction supply via pipes (60, 70) to the vicinity of the cutter. A guidewire (30), which may be in a sleeve (90) is also used for axial retraction of the segments to expand the cutter.

Abstract: A drainage catheter system, for draining fluids from body organs such as a kidney or a liver in patients whose natural drainage pathways are blocked, has a main drainage lumen and an obturator channel which may be integral with each other. This system can be easily exchanged for a new catheter system when the main drainage lumen of the initially placed catheter system becomes obstructed or occluded by encrusted deposits or tumor ingrowth. Catheter system exchange is initiated by withdrawal of a pre-installed obturator from the obturator channel of the catheter systems. Obturator withdrawal can be used to actuate release of a catheter loop-retaining thread or drawstring from its loop-retaining state in catheter systems which have pigtail loops. Once the obturator has been completely removed, a conventional flexible-tip guidewire is inserted through the now open or un-obturated, obturator channel.

Abstract: The tip of a stylet which is received in a needle cannula is automatically capped in a guard body when the stylet is withdrawn from the cannula. The stylet may be reassembled in the cannula and put into working position, with the point of the tip extending from the cannula shaft, by reinserting the stylet and guard into the cannula hub. The guard contains an arm which moves into blocking position with respect to the tip of the stylet when it is withdrawn from the cannula by following a cam surface on the cannula hub (either inside or outside the hub for different styles of needle cannulas). The arm may be spring biased, across a hole in the guard in which the stylet is slidably disposed into interfering relationship with the arm. The cam surface urges the arm to bring a portion thereof which protects the point of the tip of the stylet and captures it inside the guard.