Abstract
We present a case of a gentleman who presented with acute myocardial infarction and cardiac arrest 6 days after undergoing mitral valve replacement surgery. Immediate coronary angiography revealed perforation of the left circumflex artery which was successfully treated with a covered stent. This report details the successful percutaneous treatment of an exceedingly rare complication of mitral valve surgery.
1
Introduction
Mitral valve repair and replacement surgeries have become common and safe procedures. Recent trends indicate that there is a fundamental shift towards repair and away from replacements due to lower complication and mortality rates and improved clinical outcomes, especially in cases of redo operations. Patients who are symptomatic from their mitral valve disease have a higher rate of mortality than those who are asymptomatic . We present a case of an elderly male who underwent redo mitral valve replacement for symptomatic mitral stenosis and whose postoperative course was complicated by acute myocardial infarction and ventricular tachycardia arrest due to coronary perforation which was successfully treated with a covered coronary stent.
2
Case presentation
An 82-year-old male with a past medical history consisting of mitral valve replacement with a 27-mm bioprosthetic Carpentier-Edwards Pericardial Valve in 2002 due to infective endocarditis, metastatic prostate cancer, and chronic kidney disease presented to clinic with worsening dyspnea on exertion. A transthoracic echocardiogram revealed severe mitral stenosis, with a gradient of 26 mmHg, as well as severe mitral regurgitation. The patient was agreeable to a redo mitral valve replacement operation.
Preoperative coronary angiography revealed a 50%–60% stenosis of the midportion of the nondominant right coronary artery (not shown); the other coronary arteries were free of significant disease ( Fig. 1 ). The operation was performed via a right minithoracotomy approach. The previous prosthetic valve was removed, and in its place was implanted a 29-mm St. Jude porcine bioprosthesis with maintenance of chordal supports. It was secured with multiple pledgeted 2-0 Tycron sutures placed on the ventricular side of the annulus. The patient was weaned off cardiopulmonary bypass easily and decannulated without complication, and the total bypass time was 170 min.
His postoperative course was unremarkable until day 6 when he suffered a ventricular tachycardia-mediated cardiac arrest. The patient received a 200-J biphasic shock which terminated the ventricular tachycardia, and a subsequent electrocardiogram revealed sinus tachycardia with 2-mm ST segment elevations in leads II, III, and aVF and tall R waves with 2-mm ST segment depressions in V1-V3, consistent with an acute inferoposterior infarction. In addition, a stat creatinine kinase MB fraction was 15.2 ng/ml (normal 0–9.9 ng/ml). After discussion with the cardiac surgeons and family, the patient was emergently taken to the cardiac catheterization lab for further investigation.
Coronary angiography was performed using standard 6-Fr JL 4.5 and JR 4 catheters. Diagnostic angiography revealed a free perforation of the proximal left circumflex artery ( Fig. 2 ). After placement of an intraaortic balloon pump (Maquet Medical, Fairfield, NJ, USA), the decision was made to proceed with percutaneous coronary intervention to seal the perforation with a covered stent.
A 7000-U bolus of heparin was given for anticoagulation, and a 7-Fr sheath was exchanged for the 6-Fr sheath in the right common femoral artery. A 7-Fr EBU 4 guide (Medtronic Cardiovascular, Minneapolis, MN, USA) and a 0.014×300-cm Asahi Prowater wire (Abbot Vascular/Asahi, Temecula, CA, USA) were used. The 7-Fr system was chosen because it provided the minimum diameter necessary for passage of the covered stent. Given the nontortuous, noncalcified vessel, the Prowater was chosen because of the balance and support it could provide. Heparin was chosen as anticoagulation, and the desired activated clotting time was 250 s in order to balance the need for anticoagulation during wire placement and the free perforation. Despite the fact that the patient had a free perforation, performing the procedure without anticoagulation could have resulted in the thrombosis of other, nonaffected vessels. The wire was placed distally into the obtuse marginal artery, and a 3.0-mm×12-mm Apex balloon (Boston Scientific, Natick, MA, USA) was advanced across the site of the perforation. The balloon was inflated to 12 atm, and the perforation was temporarily sealed ( Fig. 3 ). Next, the balloon was removed from the body, and a 3.0-mm×19-mm JoStent GraftMaster (Abbott Vascular, Temecula, CA, USA) was deployed at 10 atm. It was inflated to a maximum of 10 atm and deployed ( Fig. 4 ). Intracoronary nitroglycerin (200 µg) was administered. Angiography then revealed appropriate apposition of the covered stent with no residual perforation.
All catheters and wires were then removed from the body, and final angiography showed improved flow into the left circumflex and obtuse marginal arteries and no evidence of residual extravasation ( Fig. 5 ). Transthoracic echocardiogram was also performed during the case and revealed no evidence of pericardial effusion prior to stent placement.
