Therapeutic Ultrasound in Percutaneous Coronary Angioplasty: Sheffield Experience

Our clinical peripheral artery experience with therapeutic ultrasound, confirming its safety and feasibility and suggesting some areas of potential use, gave us confidence to attempt its use during percutaneous coronary angioplasty, when a sufficiently flexible waveguide had been developed [1,2]. Our coronary experience started in 1993 [3] using the Baxter system, which is composed of a 20 kHz generator with a 4.6 Fr diameter catheter ensheathing a nickel-titanium waveguide (see Chapter 14). This waveguide terminates in a probe tip, which was initially of 1.7 mm diameter. The catheter is of rapid exchange design, with the guide wire lumen accommodating a 0.018 inch wire, though in practice we have used 0.014 inch wires to ensure free movement of the probe. During ultrasound energy application, a saline flush is used at a rate of 10ml/min. We have routinely used guiding catheters of 8 Fr diameter; although standard Judkins shapes are often used, for better support and stability other configurations, such as Amplatz and Voda, are more often used than in conventional percutaneous transluminal coronary angioplasty (PTCA).