Dynamic Ventriculoplasty with Electrically Stimulated Sleletal Muscle Graft For Complex Cardiac Anomaly.

1998 Fiscal Year Final Research Report Summary

• Project/Area Number: 09470286
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Thoracic surgery
• Research Institution: Jikei University School of Medicine
• Principal Investigator: MORITA Kiyozo Jikei University School of Medicine, Cardiac Surgery, Assistant Professor, 心臓外科, 講師 (70174422)
• Co-Investigator(Kenkyū-buntansha): NOMURA Kouji Jikei University School of Medicine, Cardiac Surgery, Assistant, 医学部, 助手 (40246434) ; KOYANAGI Katsushi Jikei University School of Medicine, Cardiac Surgery, Assistant, 医学部, 助手 (60225589) ; KUROSAWA Hiromi Jikei University School of Medicine, Cardiac Surgery, Professor, 医学部, 教授 (50075511)
• Project Period (FY): 1997 – 1998
• Keywords: hypoplastic right ventricle / univentricular heart / electrical preconditioning / skeletal muscle graft

Research Abstract

PURPOSE : The purpose of this experimental study is to establish new surgical procedures of dynamic ventriculoplasty with an electrically stimulated skeletal muscle graft for complex cardiac anomaly.
METHODS : In 12 mongrel dogs, a resected RV free wall was reconstructed with a extended pericardial patch, simulating patch enlargement of the hypoplastic right ventricle (RV). A chronically preconditioned latissimus dorsi graft was placed onto the patch, and was electrically driven with a trained-pulse (20 Hz) . In the other 16 dogs, RV cavity was completely obliterated during a cardiopulmonary bypass (CPB) to simulate univentricular hearts. A modified-Fontan circulation was established with the aortic homograft anastomosed between RA and PA, incorporated with a pericardial pouch as a compression chamber. After a termination of CPB, A latissimus dorsi graft was applied to wrap the pericardial pouch and was stimulated with a trained-pulse (20 Hz).
Results : Graft pacing showed significant augmentation of pulmonary flow and pressure (158*21%, 156*14%, respectively), contributing to restoring normal RV function in the hypoplastic RV model. Similar augmentation of the right heart performance was confirmed in a setting of the modified Fontan procedure for univentricular heart.
Continuous pacing was performed in some animals for 7 hours without evidence of muscle fatigue, thromboembolism and muscle degenaration..
Conclusions : Myo-Ventriculoplasty with electrically stimulated skeletal muscle can restore normal RV performance at a physiological preload, and may provide a surgical option for some types of cardiac anomaly.