Keep-Out Wire: An Approach to Percutaneous Coronary Intervention of an Aorto-Ostial Lesion

Percutaneous coronary intervention of aorto-ostial lesions presents a unique problem — to precisely locate the ostium of a vessel using 2-dimensional fluoroscopy.1 We present a case demonstrating a “keep-out wire” technique to assist with the precise positioning of aorto-ostial stents.  

Case report

A 68-year-old man presented with exertional throat pain during usual activity on a background of hypertension, hyperlipidemia, previous cigarette smoking and a family history of ischemic heart disease. Exercise stress testing was submaximal due to claudication and was not diagnostic. Computed tomography coronary angiography revealed a calcium score of 353, consistent with a moderate atherosclerotic plaque burden, and significant stenoses of the right coronary artery. Invasive coronary angiography confirmed an ostial 90% stenosis (Figures 1-2) and a 70% distal stenosis in the right coronary artery. The limitation of 2-dimensional fluoroscopy can be seen in the presence of calcified plaque in the aortic cusp, which appeared 2 mm deep to the ostium due to the angle of image acquisition (Figure 1). 

A Judkins right 4 (JR4) guide catheter was used to pass a Rinato coronary guide wire (Asahi Intecc) through the artery. The ostial and distal lesions were predilated with 2.25 x 10 mm Tazuna balloon (Terumo). The distal stenosis was stented, with an excellent result. The ostial lesion was technically difficult, as the guide catheter was either engaged past the ostium or disengaged altogether. Deployment of a 3.0 x 12 mm Synergy stent (Boston Scientific) at the ostium was attempted, but even after post dilatation, a residual 50% stenosis proximal to the stent remained.

At this point, a “keep-out wire” (Balance Middleweight [BMW], Abbott Vascular) was inserted and the tip was curled in the aortic root (Figure 3), permitting the guide catheter to be positioned and anchored at the ostium without engaging the right coronary artery. A 3.0 x 8 mm Synergy stent (Boston Scientific) was deployed at the ostium, ensuring that the ostium was covered, but without overhang of stent into the aorta (Figure 4). The patient’s symptoms abated.

Discussion

Ostial stents are often difficult to position accurately. It is not uncommon for the stent to be deployed too far into the artery (necessitating a second stent) or to protrude out into the aorta, which can potentially complicate future intervention should restenosis occur.¹ Pressure dampening on catheter engagement of ostial lesions can also occur. The use of a “keep-out wire” prevents catheter engagement and allows accurate localizing of the ostium by reducing movement during the cardiac cycle of the stent during deployment. Care should be taken to keep the tip of the keep-out wire free so that it does not get caught under a plaque, a rare possibility that we have never experienced. Herein, we describe a case demonstrating the use of the “keep-out wire” technique to assist in accurate positioning of ostial stents. 

¹Department of Cardiology, Gosford Hospital, Holden Street, Gosford, NSW, Australia; ²Department of Cardiology, Sydney Adventist Hospital, 185 Fox Valley Rd, Wahroonga, NSW, Australia

Disclosures: Dr. Calvin Phang and Dr. George Lau report no financial or relationship conflicts regarding the content herein.

Dr. Calvin Phang can be contacted at calvinphang@yahoo.com.

Reference

1. Chetcuti SJ, Moscucci M. Double-wire technique for access into a protruding aorto-ostial stent for treatment of in-stent restenosis. Catheter Cardiovasc Interv. 2004; 62: 214-217.