Growth potential of latissimus dorsi muscle flaps used in the cardiomyoplasty procedure.
Synchronously stimulated latissimus dorsi muscles have been used for cardiomyoplasty in adult patients with heart failure. This procedure has the potential of being used in pediatric patients to enlarge a hypoplastic ventricle or to reinforce the right atrium in the Fontan procedure. The growth potential of such a myograft was studied. Young piglets weighing 18 to 22 kg underwent right latissimus dorsi cardiomyoplasty while the latissimus dorsi weight and myoplasty area were measured. In half of the animals, the myograft was not stimulated and in the others it was continuously stimulated with an atrioventricular sequential pacemaker to contract in synchrony with the heart. Two months later, with doubling of body weight, the hearts were removed for study. In both groups, significant (p less than 0.05) increase in latissimus dorsi weight (+92% +/- 15% nonpaced versus +77% +/- 3% paced) and myoplasty area (+107% +/- 13% nonpaced versus +116% +/- 30% paced) were noted. The results in stimulated versus nonstimulated animals were not significantly different. Thus, not only does cardiomyoplasty offer a contractile tissue to repair or enlarge cardiac chambers, but this tissue can also grow in young patients and avoid subsequent size mismatch.
Brady
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Division of Cardiovascular and Thoracic Surgery, Montreal General Hospital/McGill University, Quebec, Canada.
Dionisopoulos
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T
Desrosiers
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Chiu
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RC
D000818:Animals; D002304:Cardiac Pacing, Artificial; D006348:Cardiac Surgical Procedures / Q000379:methods*; D024510:Muscle Development; D009929:Organ Size; D013524:Surgical Flaps / Q000379:methods*; D013552:Swine