A prosthetic myocardium for repair of localized defects of the left ventricle: Concept and hemodynamic feasibility

Abstract

As an approach to the treatment of patients with large but circumscribed akinetic or dyskinetic regions in the left ventricular myocardium as sequelae of acute myocardial infarction, excision of the defect and implantation of a mechanical functional equivalent of myocardium is suggested. Experimental investigation of this technique is described. Hemodynamic data from a series of dog experiments indicate that activation of the prosthetic myocardium after excision of the left ventricle is followed by improvement in various hemodynamic parametres of interest. Although substantial experimental work must be completed and difficult bioengineering problems solved, preliminary results have encouraged us to continue our investigations of the prosthetic myocardium. An imposing array of treatment methods is now available to the clinician who must deal with the sequelae of acute myocardial infarction. Selecting from pharmacologic, electrophysiologic, and surgical approaches the physician can in many instances design a treatment plan precisely tailored to the clinical problem. Large left ventricular aneurysms and their functional equivalents of ventricular dyskinesis or hypokinesis continue, however, to represent a class of problems in which established techniques have been less than satisfactory. Surgical excision with closure of the defect is regarded as effective for small aneurysms, but such procedures may so compromise cardiac output in patients with large ones as to be unacceptable. Unfortunately, it is just the latter group in which medical palliation is least likely to be effective in managing congestibe failure, angina, and other pathophysiologic manifestations. A relatively unusual approach derived from in-series techniques of mechanical assistance to the failing circulation (1) offers the theoretical possibility of a treatment tailored to the problem of a large ventricular aneurysm. Experimental investigation of this technique in the Surgical Research Laboratory at the Sinai Hospital of Detroit has progressed to the point that a report of our experiences to date may be of interest.