Emerging Surgical Techniques

Infarct Exclusion Surgery. Primary indications for surgical treatment of LV aneurysm consist of LV failure, angina pectoris, thromboembolism, and tachyarrhythmias. It has been well recognized for decades that, after ventricular aneurysmectomy, patients can experience improved HF symptoms.33 This concept recently has been expanded from dyskinetic (aneurysmal) ventricles to include akinetic ventricles, which previously were considered unlikely to improve following ventricular reconstruction. Linear aneurysmectomy has been widely performed as a standard procedure for post-infarction LV aneurysm. However, this technique remains unsatisfactory because LV distortion occurs postoperatively and an akinetic or dyskinetic area persists in the ventricular septum, resulting in limited improvement of cardiac function.34 To overcome these problems, Dor and associates excluded all akinetic or dyskinetic myocardium from the left ventricle, including the septum, and placed a tight circumferential suture around the aneurysmal base to reduce the LV volume and return the LV contour to near normal (endoventricular circular patch plasty, or EVCPP). Recently, EVCPP has attracted interest as a treatment for post-infarction large akinetic scars. Dor's group has reported on the use of this technique on more than 750 patients.35 Results were clinically satisfactory and in more than 90% of cases with ventricular aneurysm, the 1-year left ventricular ejection fraction was superior to the preoperative function. More recently, the same group reported on 44 patients treated with EVCPP with previous transmural anterior myocardial infarction.36 They found that LV shape became more elliptical in systole than it was in diastole (eccentricity index closer to 1), but new onset mitral regurgitation occurred in 25% of patients.

A minor modification of the procedure described by Dor is referred to as the surgical anterior ventricular endocardial restoration (SAVER) operation. A large, multicenter prospective registry reported on 439 consecutive patients who received this operation with impressive medium-term survival. Based on this, the Surgical Treatment for Ischemic Heart Failure (STICH) trial, a large, National Institutes of Health-funded study of both CABG and ventricular reconstruction has been initiated. Still, the limited experience with this procedure and the concern that mitral valvular disease could be worsened leaves insufficient grounds for a recommendation of this technique at this time. The STICH trial demonstrated that surgical ventricular reconstruction did not offer significant benefit over coronary bypass surgery alone. The addition of surgical ventricular reconstruction to CABG reduced the LV volume, as compared with CABG alone, but this anatomical change was not associated with a reduction in the rate of death or hospitalization for cardiac causes.37

Passive Restraint. Another technique uses passive containment of the ventricles with a surgically placed epicardial prosthetic wrap constructed of either preformed knitted material38 or nitinol.39 The Acorn trial examined outcomes in 300 patients randomized to receive a cardiac restraint device or standard therapy.40 More patients who received the cardiac support device achieved the primary end-point (alive, free of major cardiac procedures and >=1 NYHA functional class improvement) than the patients treated with standard therapies, however there was no difference in mortality between groups. Early and sustained improvements in LV remodeling indices were also noted.41 The Paracor HeartNet device has more limited observational data supporting its use, but preliminary studies suggest improvements in exercise performance, quality of life and cardiac structure with use of this device.39