Preservation of the latissimus dorsi muscle during cardiomyoplasty surgery

Background: Cardiomyoplasty surgery has been shown to be associated with damage and degeneration of the assisting skeletal muscle. The purpose of this study was to use ischemic (short-term) and thermal (long-term) preconditioning to protect the muscle during surgery and the subsequent ischemia. Methods: Three 10-minute cycles of ischemia-reperfusion were accomplished noninvasively on goat latissimus dorsi muscle (LDM) immediately prior to surgery. In another experiment, LDM was noninvasively heat shocked for 20 minutes at 42 degrees C 24 hours prior to surgery. LDM damage was evaluated 5 days postsurgery using enzyme activities (beta-glucuronidase, beta-GLN; citrate synthase), hydroxyproline, morphology, and blood flow. Results: The lysosomal enzyme, beta-GLN, was significantly increased (43%, p < 0.05) by surgical dissection and remained high in the ischemic preconditioned LDM (58%, p < 0.05) and in the heat shocked LDM (57%, p < 0.05). Conclusion: These findings show that these two protective protocols do not reduce the muscle damage that occurs during surgical preparation of the LDM for cardiomyoplasty.