PERICARDIUM-LINED SKELETAL-MUSCLE VENTRICLES - UP TO 2 YEARS IN-CIRCULATION EXPERIENCE

Background. Skeletal muscle ventricles (Sh?Ns) are autologous pumping chambers constructed from skeletal muscle. Skeletal muscle ventricular rupture and thromboembolism have complicated chronic models of this m ethod of skeletal muscle cardiac assist. Methods. The SMVs were constr ucted from the latissimus dorsi muscle in 10 dogs. The inner surface o f each SMV was lined with autologous pericardium harvested at the time of SMV construction. After a 3-week period of vascular delay and 6 we eks of electrical conditioning to convert the muscle to a fatigue-resi stant state, SMVs were connected to the descending thoracic aorta and stimulated to contract during cardiac diastole. Results. Initial hemod ynamics revealed that SMV contraction at 33 Hz increased diastolic pre ssure 24.7% (60.8 +/- 7.3 mm Hg versus 80.3 +/- 8.8 mm Hg). Skeletal m uscle ventricle relaxation decreased presystolic pressure 14.4% (59.9 +/- 7.7 mm Hg versus 52.3 +/- 7.5 mm Hg) and decreased peak systolic p ressure 4.1% (90.2 +/- 7.3 mm Hg versus 86.5 +/- 5.8 mm Hg). Hemodynam ics were assessed at 1 to 2 weeks, then at 1, 2, 3, and 6 months, and at 6-month intervals thereafter. Hemodynamic performance remained stab le for the duration of this study. After 2 years of pumping continuous ly in circulation, SMV contraction resulted in a 34.8% augmentation of diastolic pressure (63.6 +/- 6.6 mm Hg versus 85.3 +/- 6.4 mm Hg), a 17.2% decrease in presystolic pressure (54.7 +/- 3.73 mm Hg versus 45. 3 +/- 4.1 mm Hg), and a 4.2% decrease in peak systolic pressure (95.3 +/- 10.4 mm Hg versus 91.3 +/- 12.3 mm Hg). Three dogs survived to 2 y ears with the SMVs in circulation. No animal showed evidence of thromb oembolism during serial echocardiography or at autopsy and no SMVs rup tured. Conclusions. These data demonstrate that SMVs can provide effec tive hemodynamic assist over an extended period without specific compl ications related to the SMVs.