DESCENDING THORACIC AORTOMYOPLASTY - A TECHNIQUE FOR CLINICAL-APPLICATION

Background. Descending thoracic aortomyoplasty is a form of skeletal m uscle-powered cardiac assistance. Its use in clinical settings has bee n limited by the ligation of intercostal arteries necessary to complet e a circumferential wrap of the aorta with the latissimus dorsi. Metho ds. This study assessed the feasibility and the efficacy of aortomyopl asty constructed with a modified latissimus dorsi. A pericardial patch was attached to the latissimus dorsi and divided around the preserved intercostal arteries. Nine alpine goats (37 +/- 2 kg) underwent desce nding aortomyoplasty using this technique. All intercostal arteries we re preserved. After a 6-week recovery period, the animals underwent a 6-week, incremental electrical conditioning program. After 90 postoper ative days, animals were examined under anesthesia with the myostimula tor on and off. Results. Aortomyoplasty activation resulted in augment ation of mean diastolic aortic pressure by 16.0 +/- 0.9 mm Hg (23%). S ignificant improvements in cardiac index (40%), stroke volume index (3 7%), left ventricular stroke work index (49%), and mean arterial press ure (19%) were noted. An intravascular sonographic probe placed in the descending aorta revealed circumferential compression of the aorta du ring counterpulsation. Mean cross-sectional aortic area was reduced by 51.8%, from 210.1 +/- 7.1 to 108.9 +/- 6.7 mm(2) during aortomyoplast y activation (p < 0.05). Histologic analysis confirmed the long-term p atency of intercostal arteries. Conclusions. Descending aortomyoplasty , modified with an interposing patch of pericardium, effectively trans fers skeletal muscle force across the aortic wall and assists cardiac function. This technique allows preservation of all aortic branches, a nd with this novel approach, the clinical utility of aortomyoplasty ca n now be explored.