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To deal with the problem of restenosis after PTCA, several new methods and devices for treating atheromatous lesions have been developed. Among the promising techniques, is the opportunity to remove atheromatous material with the directional coronary atherectomy catheter designed by J.B. Simpson. The atherectomy catheter consists of a housing at the catheter tip with a concave cutting device which is rotated at a speed of 2000 r.p.m. The housing is positioned at the stenosis by means of a central guidewire; the material to be removed protrudes into the housing. With an inflatable balloon on the opposite side, the position of the housing is fixed in the coronary artery, the plaque is pressed further into the orifice and severed by the rotating blade. The material removed remains in the tip of the housing and can be used for morphologic examination as well as for functional studies with individual cell cultures. Experience published to date encompasses the results of 1032 treated stenoses. The majority of the treated lesions, 53%, were localized in the left anterior descending coronary artery; in 22% the lesion were located in the right coronary artery, in 17% in an aorto-coronary venous bypass graft. Due to the difficulty in positioning the relatively rigid atherectomy catheter, the method has only been employed in the circumflex artery in 6%. In a substantial number of patients, the stenoses had already been subjected to PTCA; in 57% of 963 patients treated with atherectomy, angioplasty had been performed previously, in 25% bypass grafting had been carried out. The primary success rate was 93%.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulse oximetry has been recently introduced into anesthetic practice as an additional monitoring technique. In contrast to other methods (ECG, inspection, auscultation, blood gas analysis), it immediately detects an impending lack of oxygen, whatever its cause. Therefore, especially in pediatric risk patients, precious time can be saved. This is illustrated during the perioperative period for correction of gastroschisis. Even with a critical look at the mishaps of this method - overestimation of true O2 saturation (sO2) and partial O2 saturation (psO2) and overestimation of hemoglobin derivatives--pulse oximetry seems superior to the established monitoring techniques in the perioperative period. Therefore, we believe pulse oximetry to be an useful tool for additional monitoring, especially in pediatric risk patients. It is a suitable continuous and noninvasive in vivo technique for the early detection of hypooxygenation. Due to the special disadvantages of the method, we consider it advisable to perform control measurements with a CO-oximeter from time to time.