The authors present a case of post-myocardial infarction ventricular pseudoaneurysm repair with mitral valve replacement and coronary revascularization performed through a minimally invasive left anterior minithoracotomy via the fourth intercostal space.
Patient Information
This case presents a 69-year-old male with a history of myocardial infarction. Ten months prior, he underwent urgent stenting of the circumflex branch of the left coronary artery. The right coronary artery had total occlusion, and angiographic revascularization was deemed unfeasible. Six months later, transthoracic echocardiography revealed a large left ventricular pseudoaneurysm and thrombus formation in the left ventricle. The patient presented to the authors’ hospital with severe dyspnea at rest and weakness.
Echocardiography revealed left ventricular dilation with reduced contractility, external rupture of the posterolateral wall of the left ventricle with subsequent pseudoaneurysm formation, and severe mitral regurgitation due to significant restriction of the posterior mitral leaflet.
Contrast-enhanced computed tomography (CT) confirmed a large posterolateral left ventricular aneurysm. Severe atherosclerotic involvement of the infrarenal segment of the descending aorta as well as the iliac and femoral arteries was identified. In view of these CT findings, the right axillary artery was selected as the optimal site for arterial cannulation for cardiopulmonary bypass.
New coronary angiography demonstrated diffuse stenotic involvement of the left anterior descending artery (LAD) and left circumflex artery (LCx) ranging from 70 percent to 90 percent, and total occlusion of the right coronary artery.
Surgery
After cardiopulmonary bypass was initiated and the pericardium was opened, severe adhesions were detected and partially dissected. With the arrested heart using an aortic transthoracic cross-clamp and antegrade cold blood cardiaplegia, pseudoaneurysm was identified and dissected.
After exposure, a ventriculotomy was performed through the posterior wall of the left ventricular (LV) pseudoaneurysm. Massive thrombotic masses at various stages of organization were visualized within the left ventricular cavity. A careful thrombectomy was performed. Inspection of the mitral valve revealed marked restriction of the posterior leaflet. A decision was made to proceed with mitral valve replacement using a mechanical prosthesis. To preserve left ventricular geometry, the posterior mitral leaflet was preserved and incorporated as additional tissue during suture placement on the mitral annulus. A bovine pericardium patch was prepared and implanted over the healthy myocardial tissue using a one-layer continuous suture with 3-0 polypropylene.
Additionally, linear reconstruction of the LV aneurysm was performed with a three-layer suture with 3-0 polypropylene.
The distal anastomosis of the saphenous vein graft (SVG) to the obtuse marginal (OM) and the left internal mammary artery (LIMA) to the LAD was performed. After deairing, the aortic cross-clamp was removed. Using a side-biting clamp, the proximal anastomosis of the SVG to the aorta was completed. Hemostasis of the graft anastomosis and ventriculotomy site was cheeked.
The total operative time was 480 minutes, with the cross-clamp time accounting for 191 minutes.
Postoperative Course
The patient was discharged from the hospital on postoperative day eight, including a one-day stay in the intensive care unit. No complications were observed during the treatment period.
Discussion
Complex cardiac surgery procedures in patients with heart failure and reduced ejection fraction (EF) present several challenges for both the surgeon and the patient.
Although these procedures are technically feasible with a minimally invasive approach, this video briefly discusses the pros and cons of this surgical strategy.
Pros
The anterior, anterolateral, and posterior walls of the left ventricle are readily accessible through the left anterior thoracotomy and are located closer to the operative field than with a median sternotomy. As demonstrated in the video, most of the procedure can be performed using conventional, nonminimally invasive surgical instruments.
Exposure of the mitral valve through a left ventriculotomy and left anterior thoracotomy is more anatomical than through a left atriotomy and median sternotomy because the mitral valve is naturally oriented toward the LV apex, while the surgeon remains on the left side of the operating table.
Any coronary targets for coronary grafting can easily be accessed and grafted using the technique of totally coronary revascularization via left anterior thoracotomy (TCRAT). The excellent visualization of virtually any region of the left ventricle can be consistently achieved.
The surgical assistant is actively involved in all parts of this procedure through the left anterior minithoracotomy and was able to assist with two instruments, as in conventional cardiac surgery performed through a median sternotomy.
The main pros of this technique are minimal trauma to patients while achieving expected quality of surgical repair. Minimizing the surgical trauma may facilitate a smoother and faster recovery of severely exhausted patients compared to surgery performed through the median sternotomy.
Cons
Concomitant surgery is technically more difficult to perform using the minithoracotomy approach due to narrow wounds. Despite continuous assistance, the incision remains narrow, and the surgical technique should be adjusted to these conditions.
Not all parts of the heart are constantly in the view, which requires additional surgical training to perform multiobject surgery. Experience with minimally invasive coronary artery bypass grafting through a left anterior thoracotomy and the experience with concomitant valve procedures are needed to safely perform combined coronary-valve-aneurysm cases.
Rib damage and postoperative pain have also been reported as drawbacks of the thoracotomy approach. However, surgical experience and dedicated minimally invasive cardiac surgical minithoracotomy retractors eliminate this problem in the vast majority of cases.
The following conditions remain contraindications to complex concomitant minimally invasive cardiac surgery (MICS):
- Extensive calcification of the ascending aorta (porcelain aorta)
- Inability to establish peripheral cardiopulmonary bypass through femoral or axillary access
- Previous cardiac surgery (relative contraindication)
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