Intrathoracic and extrathoracic skeletal muscle ventricles in circulation: left ventricular apex-to-aorta configuration.
Skeletal muscle ventricles (SMVs) were constructed from the latissimus dorsi muscle in 12 dogs. In group I (n = 6), SMVs were placed intrathoracic, in the apex of the left hemithorax. In group II (n = 6), SMVs were positioned extrathoracic between the chest wall and subcutaneous tissue. After a 3-week vascular delay period, SMVs were electrically pre-conditioned with 2-Hz continuous stimulation for 6 weeks. At a second procedure, a valved conduit was placed between the left ventricular (LV) apex and the SMV, and a second valved conduit between the SMV and the thoracic aorta. The SMVs were stimulated to contract during diastole at a 1:2 ratio with the heart. In group I, SMVs generated peak pressures of 91 +/- 10 mmHg, pumped 47% of the systemic blood flow (0.73 +/- 0.25 vs 1.54 +/- 0.42 L/min; p < 0.05), and produced a 25% decrease in the LV systolic tension-time index (TTI) (16.9 +/- 2.7 vs 12.5 +/- 3.3 mmHg.sec; p < 0.05). In group II, SMV peak pressure was 93 +/- 10 mmHg, SMVs pumped 51% of the systemic blood flow (0.78 +/- 0.10 vs 1.53 +/- 0.42 L/min; p < 0.05), and the LV systolic TTI decreased 29% (14.0 +/- 0.8 vs 9.9 +/- 2.0 mmHg.sec; p < 0.05). There was no significant difference between group I and II. These data indicate that the SMV:LV apex-to-aorta configuration is the most effective method reported to date for skeletal muscle cardiac assist. Extrathoracic and intrathoracic SMVs functioned equally well after connection to the circulation.
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Department of Surgery, Wayne State University, Detroit, Michigan 48225.
Thomas
G A
GA
Hammond
R L
RL
Fietsam
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R
Nakajima
H
H
Isoda
S
S
Nakajima
H
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Colson
M
M
Stephenson
L W
LW
D000714:Anastomosis, Surgical; D000818:Animals; D001013:Aorta, Thoracic / Q000601:surgery*; D001243:Assisted Circulation / Q000379:methods*; D001794:Blood Pressure / Q000502:physiology; D001807:Blood Vessel Prosthesis; D002302:Cardiac Output / Q000502:physiology; D004285:Dogs; D004567:Electrodes, Implanted; D005500:Follow-Up Studies; D006352:Heart Ventricles / Q000601:surgery*; D006439:Hemodynamics; D009119:Muscle Contraction / Q000502:physiology; D009132:Muscles / Q000502:physiology / Q000637:transplantation*; D011093:Polyethylene Terephthalates; D011138:Polytetrafluoroethylene; D011651:Pulmonary Artery / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology; D013318:Stroke Volume / Q000502:physiology; D013524:Surgical Flaps / Q000379:methods*; D013903:Thoracic Surgery; D017725:Ventricular Pressure / Q000502:physiology
D011093:Polyethylene Terephthalates; D011138:Polytetrafluoroethylene