VASCULAR DELAY OF THE LATISSIMUS-DORSI MUSCLE - AN ESSENTIAL COMPONENT OF CARDIOMYOPLASTY

Background. Cardiomyoplasty (CMP) uses the latissimus dorsi muscle (LD M) to assist the heart in cases of cardiac failure. Distal ischemia an d necrosis of the LDM is a recognized complication of CMP that can red uce distal muscle function and the mechanical effectiveness of CMP. Me thods. Canine (n = 9) LDMs were subjected to a 10-day period of vascul ar delay followed by a simulated CMP. Two weeks after simulated CMP (c orresponding to the healing delay between CMP and the onset of LDM sti mulation used in the clinical setting), LDM perfusion was measured in the distal, middle, and proximal segments of the muscle, and circumfer ential (distal and middle squeezing muscle function) and longitudinal (proximal pulling muscle function) force generation and fatigue rates were measured. The results were compared with the contralateral nondel ayed simulated CMP. Results. Muscle perfusion was significantly (p < 0 .05) greater in the distal and middle segments of vascular-delayed LDM s. Circumferential muscle force generation and fatigue rates were sign ificantly (p < 0.05) improved in the vascular-delayed LDMs. Conclusion s. Vascular delay can significantly improve LDM perfusion and function in a model that closely reflects clinical CMP, and the use of vascula r delay may improve clinical outcomes in CMP. (C) 1997 by The Society of Thoracic Surgeons.