Doppler-guided retrograde catheterization system

摘要

Abstract: The purpose of this study was to investigate a Dopplerguided catheterization system as an adjunctive oralternative methodology to overcome the disadvantagesof left heart catheterization and angiography. Thesedisadvantages include the biological effects ofradiation and the toxic and volume effects of iodinecontrast. Doppler retrograde guidance uses a 20 MHzcircular pulsed Doppler crystal incorporated into thetip of a triple lumen multipurpose catheter and isadvanced retrogradely using the directional flowinformation provided by the Doppler waveform. Thevelocity detection limits are either 1 m/second or 4m/second depending upon the instrumentation. In aphysiologic flow model of the human aortic arch,multiple data points revealed a positive wave form whenflow was traveling toward the catheter tip indicatingproper alignment for retrograde advancement. There wasa negative wave form when flow was traveling away fromthe catheter tip if the catheter was in a branch orbent upon itself indicating improper catheter tipposition for retrograde advancement. In a series of sixdogs, the catheter was able to be accurately advancedfrom the femoral artery to the left ventricular chamberunder Doppler signal guidance without the use of x-ray.The potential applications of a Doppler guidedretrograde catheterization system include decreasingtime requirements and allowing safer catheter guidancein patients with atherosclerotic vascular disease andsuspected aortic dissection. The Doppler system mayallow left ventricular pressure monitoring in theintensive care unit without the need for x-ray and itmay allow left sided contrast echocardiography. Withpulse velocity detection limits of 4 m/second, thissystem may allow catheter direction and passage intothe aortic root and left ventricle in patients withaortic stenosis. A modification of the Doppler cathetermay include transponder technology which would allowprecise catheter tip localization once the catheter tipis placed in the aortic root. Such technology mayconceivably assist in allowing selective coronarycatheterization. These studies have demonstrated thatDoppler guided retrograde catheterization provides anaccurate method to catheterization the aortic root andleft ventricular chamber without x-ray. In humans, itmay prove useful in a variety of settings including thedevelopment of invasive ultrasonic diagnostic andtherapeutic technology.!