In addition to currently available, low risk procedures for reestablishment of patency in arteriosclerotic vascular segments with bougier techniques as described by Dotter and the balloon dilatation modification according to Grüntzig, as necessary together with local thrombolysis, important new developments based on mechanical principles are the atherectomy according to Simpson as well as the rotation atherotomy with a flexible catheter and slowly rotating milling head or rapidly rotating head as used by Kensey. To provide a larger lumen of recanalization, we developed an atherotomy lathing catheter with a rapidly rotating head and various diameters which is now available for intraoperative use. The thrombendarterectomy as described by Vollmar with the "ring stripper" is used only intraoperatively and can only be performed retrograde. The effect of laser systems encompasses disintegration and ablation of occlusive material. The rotation atherotomy is based on the capability of discrimination between hard occlusive material and elastic vascular wall through suitable construction of the lathe head (Figures 1 a to 1 e). Since, in passive catheters, the capability of lathing at the tip is associated with a high risk of perforation and a lateral possibility for lathing is not achievable, the lathing performance should be small, at the center of rotation and orthogonal to the axis of rotation at the outer radius. Through combination with a spherical disc face perpendicular to the axis of rotation, which protrudes only slightly from the hemispherical catheter tip, with a maximum at the center and minimum at the lateral borders, the lathing head has only a slight risk of perforation and no undesired sheering forces (Figures 2a to 2d).(ABSTRACT TRUNCATED AT 250 WORDS)

Kensey was the first to present a fast-rotating tip catheter for percutaneous recanalization of arterial obstructions. A cam rotating at high speed is used to reduce the thrombotic material to medium-sized pieces less than 7 µm in diameter, thus causing only clinically insignificant microembolizations (K. R. Kensey 1986, personal communication) [3]. Fluid jets from a round the base of the cam are designed to dilate the artery and to keep the cam centered in the vessel lumen [1].

Balloon angioplasty and bypass graft surgery are common procedures for treating vascular occlusive disease. The purpose of this preliminary investigation was to evaluate the effectiveness and the safety of a new catheter system, first introduced by KR Kensey. The system involves a flexible catheter with a high speed rotating tip, driven by an electrical motor. The tip is cooled by a continuous flow of sterile saline containing dextran 40, heparin and urokinase. Radiopaque contrast medium may be infused through the catheter to allow the device to be guided and to detect lesions and to evaluate the efficacy of treatment. The system was applied in three patients with occlusive vascular disease (Stage IIb) and segmental or total occlusion of the superficial femoral artery (SFA). The milling catheter was introduced percutaneously into the common femoral artery and guided to the area of occlusion under DSA control. In two patients total recanalisation was achieved after passage of the milling catheter. In one patient the totally occluded SFA could not be cannulated and a femoro-popliteal bypass was performed one week later. Complications such as perforation of the vessel or peripheral embolisation were not observed. Pedal pulses were improved significantly in one patient. Further investigations will be necessary to demonstrate whether the milling catheter can be safely used to revascularise patients with limb threatening peripheral vascular disease.