This case report describes a 36-year-old male with acute complete occlusion of his dominant left circumflex coronary artery after mechanical mitral valve replacement. The patient was successfully treated with percutaneous catheter intervention using drug-eluting coronary stents.

       Coronary artery compression can occur during mitral valve replacement with a mechanical prosthesis due to the proximity of the dominant artery to the posterior mitral annulus and the propensity for distortion during anchoring the

Figure 1

Left anterior oblique view showing the complete occlusion of the proximal mid left circumflex artery.

prosthesis sewing ring. This can result in irreversible myocardial ischemia, infarction and even death post-operatively if there is complete vessel occlusion.1–6 Very few articles have mentioned the treatment of such an injury. We previously reported the first successful treatment of coronary artery compression after mitral valve replacement in a child using a coronary stent.7 We now report the first adult case of complete dominant left circumflex artery occlusion discovered immediately post mitral valve mechanical prosthesis and treated using three drug-eluting stents with excellent results. We propose to consider this less invasive percutaneous bailout approach as an alternative (or hybrid) treatment for such surgical complications in order to avoid exposing the patient to the risk of redo surgery.

Figure 2

Right anterior oblique view showing the complete occlusion of the proximal mid left circumflex artery.

       Case report. Our patient was a 36-year-old man with history of rheumatic heart disease. He underwent aortic valve replacement with mechanical St. Jude prosthesis 20 years prior. Recently, he became symptomatic with severe rheumatic mitral regurgitation and underwent mitral valve replacement with a 29 mm CarboMedicics mechanical prosthesis (Sulzer medica prosthetic heart valve, Carbomedics Inc., Austin, Texas). Immediately post-operatively, his 12-lead electrocardiogram showed

Figure 3

Left anterior oblique view showing balloon inflation in mid left circumflex after successful double wire crossing.

significant acute ST elevation (acute injury pattern) involving the inferior and posterior leads. Echocardiogram showed severe hypokinesis of the inferior and posterior walls. Thus, the patient was taken emergently to the cardiac catheterization laboratory, where coronary angiography was performed. This revealed normal coronary origins, a left dominant coronary circulation, total occlusion of the middle circumflex artery around the mitral mechanical prosthesis with no flow to the distal area, and normal vessels elsewhere (Figures 1 and 2).

Figure 4

Right anterior oblique view clearly showing left circumflex phasic compression around the mitral valve prosthetic ring.

       After group discussion of the management options, risks and benefits, we opted to proceed with percutaneous transcatheter intervention to treat this complication. Using a 7 French Left Judkins guiding catheter, 0.014" ACS Hi-Torque Cross-It and 0.014´´ ACS Hi-Torque floppy II wires with MICROGLIDE coating, we successfully crossed the totally occluded segment of the dominant left circumflex coronary artery after several attempts, then passed a 2.5 x 20 mm Tacker balloon (Cordis Corporation, Miami, Florida) dilated up to 12 atmospheres. We established distal flow, but still had phasic compression of the artery around the mitral valve prosthetic ring (Figures 3 and 4). We decided to overcome this mechanical compression using metal scaffolding with coronary stents. We successfully deployed 3 sirolimus-eluting Cypher™ stents (Cordis Corporation). First, we deployed a 2.5 x 18 mm

Figure 5

Right anterior oblique view showing deployment of the drug-eluting stent in the left circumflex artery.

Cypher stent distally at 12 atm, followed by a 2.5 x 18 mm Cypher stent in the mid segment deployed at 12 atm and a 3.0 x 8 mm Cypher stent in the proximal segment deployed at 12 atm. All were deployed with excellent results, with no residual lesions or compression and TIMI 3 flow with normal myocardial blush (Figures 5 and 6). Post-procedure, the patient had complete resolution of his ST elevation and mild elevation of troponin T and

Figure 6

Right anterior oblique view after successful angioplasty and stenting of the left circumflex artery.

Figure 7

Right anterior oblique view 1 year later showing widely patent stents in the left circumflex artery.

CK-MB levels. He was extubated on the following day, remained hemodynamically stable, and was maintained on anticoagulation, antiplatelet therapy, beta-blocker and ACE inhibitor. Repeat echocardiogram a few days later showed near normal wall motion and normal function of both mitral and aortic mechanical prostheses. The patient was seen regularly in the clinic; repeat coronary angiography was done 1 year later and revealed a widely patent left circumflex artery (Figure 7).

       Discussion. Coronary artery injury during valve surgery may occur with occlusion of the artery by the prosthetic ring, or by laceration, dissection or suture of the artery.1 The close proximity of the dominant left circumflex artery to the mitral annulus (average, 3–7.5 mm)2 contributes to the risk of iatrogenic injury, especially to the proximal mid segment of the artery during anchoring the prosthetic ring in place. Early recognition and management is crucial to maintain myocardial viability and function. Immediate saphenous vein bypass grafting to the distal left circumflex was the common treatment for such complication (especially for those who could not be weaned from bypass machine).2 We now report a successful new treatment approach via percutaneous catheter intervention and using drug-eluting stents for consideration as an alternative (or hybrid) technique to treat such surgical complications.

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