Abstract
Background: Thoracic aortomyoplasty is one of the surgical treatment for heart failure and has advantages over artificial heart or intraaortic balloon pumps. It uses autogenous skeletal muscles and solves problems such as energy source. However its use in clinical settings has been limited. This preliminary study was designed to develop surgical technique and to determine the effect of acute descending thoracic aortomyoplsty. Material and Method: Thirteen adult Mongrel dogs were used. The left latissimus dorsi muscle was wrapped around the descending aorta under general anesthesis. Swan-Ganz and microtipped Millar catheter were used for the hemodynamics and endocaridial viability ratio. Data were collected with myostimulator on and off in normal hearts and the ischemic hearts. Result: In normal hearts, the mean aortic diastolic pressure increased from 72$\pm$15mmHg at baseline to 78$\pm$13mmHg with stimulator on. Coronary perfusion pressure increased from 61$\pm$11mmHg to 65$\pm$9mmHg. Diastolic time increased from 0.288$\pm$0.003 msec to 0.290$\pm$0.003msec. Systolic time decreased from 0.164$\pm$0.002msec to 0.160$\pm$0.002 msec. Endocardial viability ratio increased from 1.21$\pm$0.22 to 1.40$\pm$0.18. In ischemic hearts, mean aortic diastolic pressure incrased from 56$\pm$21mmHg at baseline to 61$\pm$15mmHg with stimulator on. Coronary perfusion pressure increased from 48$\pm$17mmHg to 52$\pm$15mmHg. Diastolic time increased from 0.290$\pm$0.003 msec to 0.313$\pm$0.004msec. Systolic time decreased from 0.180$\pm$0.002 msec to 0.177$\pm$0.003 msec. Endovascular viability ratio increased from 0.9$\pm$0.31 to 1.1$\pm$0.31. The limited number of cases ruled out the statistic significance. Conclusion: Descending thoracic aortomyoplasty is a simple operation designed to use patient's own skeletal muscles. It trends to increase diastolic augmentation and coronary perfusion pressure. Modification of surgical technique and stimulator protocol would maximize the effect to assist the heart.
