Case History. A 54-year-old patient underwent cardiac catheterization following a positive exercise stress test in April of 2006.

Angiography revealed a single vessel chronic total occlusion (CTO) of the right coronary artery (RCA) with collateral circulation feeding the distal vessel. Failed attempts utilizing standard guidewires to open the RCA were made the following day. The patient returned to the cardiac catheterization lab approximately one month later and consented to enroll in the FlowCardia CRosser As the First Therapy (CRAFT) study. CRAFT is a study designed to evaluate use of the CROSSER™ System (FlowCardia, Inc., Sunnyvale, CA) as the primary device to navigate across a CTO prior to a standard guidewire attempt.

Figure 1. Initial angiogram with mid-RCA chronic total occlusion (CTO). Figure 2. Tip of CROSSER catheter advancing through CTO. Figure 3. Post-procedure final angiogram.

Interventional Procedure
A 6 Fr JR 4 was introduced into the ostium of the RCA and then exchanged for a 6 Fr AL2. The initial angiogram (Figure 1) shows a complete occlusion of the mid-RCA with collaterals feeding the distal vasculature. The CROSSER Catheter was advanced into the proximal RCA, activated for 5 minutes (Figure 2) and advanced into the severely calcified lesion. The CROSSER Catheter was removed and a Maverick 3.0mm x 20mm balloon (Boston Scientific, Maple Grove, MN) was introduced over the guidewire and lesion was dilated. Two Taxus stents, a 3.5mm x 32mm and Taxus 4.0mm x 20mm (Boston Scientific), were implanted, with an excellent final result (Figure 3). Total procedure time was 23 minutes. The patient will remain on ticlopidine for 12 months.

Discussion
Use of the CROSSER Catheter for recanalization of chronically occluded arteries, illustrated in this case study, provides operators with an effective and easy-to-use device which can be a useful alternative to the conventional guidewire attempt. The safety profile of the CROSSER Catheter may also prove beneficial in avoiding perforation, dissection and subintimal navigation not infrequently seen

- Glossary Cavitational: 1. A general term used to describe the behavior of voids or bubbles in a liquid. 2. The sudden formation and collapse of low-pressure bubbles in liquids by means of mechanical forces. 3. The pitting of a solid surface. (Sources: en.wikipedia.org; The American Heritage Dictionary)

with the standard guidewire approach to CTOs. The device uses high frequency mechanical energy applied to the plaque using a transducer to transmit from the catheter tip. The pulsed vibration at 21,000 cycles/sec. provides a mechanical impact and cavitational effect. The device represents a valuable adjunct to current devices for recanalization of CTOs.

Laura Minarsch can be contacted at euromed@ix.netcom.com