Percutaneous Coronary Revascularization of an Occluded Ostial
Circumflex Artery Arising from the Right Coronary Cusp
Utilizing

Approximately 30% of patients with significant coronary artery disease (CAD) have a chronically occluded vessel ( CTO).¹ Due to frequent difficulty in crossing the CTO lesion by standard wire techniques, novel approaches have been created to improve success rates. One such innovative strategy is to cross the lesion in a retrograde approach utilizing collateral vessels.
This approach was born out of the peripheral angioplasty experience that frequently demonstrated success in crossing CTOs in a distal-to-proximal lesion progression, consistent with the histological realization that the proximal cap is frequently thicker, less tapered and more calcified than the proximal cap.² Retrograde percutaneous coronary intervention (PCI) has evolved since its initial use in saphenous vein grafts first reported in 1990.³ Interventional cardiologists in Japan have been particularly instrumental in the development and advancement of CTO techniques which include sophisticated guidewire manipulation of septal collateral vessels,^2,4 including wiring of anomalous native coronary vessels recently reported in the Journal.⁵ Furthermore, Lane et al described the first published account of retrograde PCI through an epicardial collateral vessel.⁶
We report the use of a retrograde epicardial collateral approach to successfully revascularize an ostial occluded anomalous circumflex artery arising off the right coronary cusp.

Case Report. A 56-year-old male with a history of hyperlipidemia presented with unstable angina of 2 weeks’ duration. Init ially precipitated by moderate exertion, his symptoms progressed to rest angina. The patient was taken to the cardiac catheterization laboratory. Left coronary angiography revealed nonobstructive disease in his left anterior descending (LAD) and an absence of left main (LM) and circumflex (LCX) coronary arteries (Figure 1). No collateral circulation was visible.
Selective angiography of the right coronary artery (RCA) demonstrated a small-caliber, nondominant and nonobstructive vessel with a short, straight epicardial collateral feeding a large, dominant LCX. Injection of the RCA resulted in retrograde filling of the LCX to its mid portion (Figure 2).
Despite multiple angulations during selective LAD and RCA angiography, no LCX ostium could be identified. Furthermore, aortic root angiography (LAO projection, 40 cc over 2 seconds utilizing 600 psi with a Medrad^© automatic injector) was unrevealing. It was felt that the patient’s symptoms were consistent with an occluded ostial LCX. In order to identify the location of the LCX ostium as well as to attempt PCI of the lesion, the decision was made to approach the lesion via the epicardial collateral originating from the RCA.
A 100 cm 6 Fr Judkins right 4 (JR4) guiding catheter (Cordis Corp., Miami Lakes, Florida) was used to selectively engage the RCA ostium. A 100 cm 6 Fr Judkins short left 4 (SL4) guiding catheter (Medtronic Inc., Minneapolis, Minnesota) was intubated (via the contralateral left common femoral artery) into the left coronary artery for left coronary angiography. A 300 cm Asahi Prowater Flexwire (Asahi Intecc Co. Ltd., Japan) was successfully navigated to the proximal LCX in a retrograde fashion through the epicardial collateral bridging the distal RCA and distal LCX arteries. A 1.5 x 12 mm x 135 cm over-the-wire (OTW) Voyager balloon (Guidant Corp., Santa Clara, California) was delivered to the proximal LCX for optimal guidewire support. The wire was advanced proximally into the ascending aorta and into the left subclavian artery for optimal purchase (Figures 3 and 4). At this point, the balloon was easily advanced to the aorta. Contrast was injected directly through the balloon catheter, although opacification was suboptimal.

To adequately confirm the intraluminal position of the guidewire and balloon, repeat ascending aortography was performed (LAO projection, 40 cc contrast over 2 seconds at 600 psi by Medrad injector). This angiographic image confirmed the wire and balloon’s intraluminal position and it revealed the ostial occlusion of an anomalous LCX arising from the right coronary cusp (Figure 5). The SL4 guiding catheter was removed. The JR4 guiding catheter was slightly withdrawn proximally for optimal antegrade nonselective angiography of the LCX. Adequate opacification now facilitated the accurate placement of the 1.5 x 12 mm balloon, which was subsequently inflated, thereby restoring antegrade TIMI 3 flow in the LCX. Additional balloon angioplasty was performed with a Maverick 2.5 x 20 mm x 135 cm OTW balloon (Boston Scientific Corp., Natick, Massachusetts).
To optimize the delivery of a 2.5 x 18 mm x 137 cm Cypher^™ Rx stent (Cordis) to the proximal LCX, an antegrade approach was felt to be necessary. A second shorter wire (AsahiProwater 180 cm length) was advanced into the distal LCX in an antegrade fashion alongside the first (retrograde) Prowater Flex wire (“buddy wires”), thereby facilitating delivery of the stent. When adequately positioned, the 300 cm retrograde wire was removed and the stent was deployed at 18 atm. Multiple angiographic views post PCI revealed 0% residual stenosis, TIMI 3 antegrade flow, absence of collateral (LCX-to-RCA) opacification and no dissections or perforations (Figure 6).

A small, nonocclusive filling defect consistent with mild residual thrombus remained. A 12-hour intravenous infusion of eptifibatide was therefore initiated. The patient returned for office follow up 2 weeks later and he denied further angina at rest or with activity.

Discussion. We believe that this is the first reported case of successful PCI of an anomalous ostial LCX occlusion utilizing a retrograde epicardial collateral approach. This case isunique in demonstrating the utility of such an approach when the ostium of an occluded vessel cannot be adequately localized. In this case, this challenge was compounded by virtue of the artery’s anomalous origin. Without identifying the vessel’s origin, successful antegrade percutaneous revascularization would have been very unlikely.
The success of this case adds to the growing body of literature demonstrating the utility of retrograde epicardial and intramyocardial collateral CTO intervention. The first reported case of retrograde PCI for a CTO through an epicardial collateral was by Lane and colleagues.⁶ Kaneda et al recently reported the first case of retrograde PCI for an anomalous RCA arising from the LCX in the Journal.⁵ This latest contribution highlights the continued significant impact that interventional cardiologists have made in this field.
In contrast to septal collateral vessels, the wiring of epicardial collaterals carries an increased risk of pericardial effusion. Fortunately, the epicardial collateral in this patient was very favorable for crossing due to its short, nontortuous length and relatively large diameter. Still, we employed a soft, floppytipped wire (Asahi Prowater Flex) as our initial retrograde crossing guidewire in order to minimize this risk.
The importance of CTO revascularization is evidenced by multiple studies reporting improved outcomes including, symptomatic angina relief, increased exercise capacity, reduction in myocardial ischemia, improvement in left ventricular function, reduction in coronary artery bypass graft surgery referral and improved survival.^7–10 For these reasons, we felt that a percutaneous revascularization attempt in this patient was warranted.
As demonstrated in this case, successful intervention is enhanced by advanced guidewire techniques. Such approaches, coupled with specialty wires and dedicated CTO crossing devices, give the interventionalist a plethora of tools to tackle such challenging lesions. This armamentarium supports the safety and efficacy of CTO PCI, thereby promoting ongoing innovation in this field.