HYBRID ASSISTED CIRCULATION DEVICE DRIVEN BY AUTOSKELETAL MUSCLE

1994 Fiscal Year Final Research Report Summary

• Project/Area Number: 04670833
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: Thoracic surgery
• Research Institution: Yokohama City Univ.
• Principal Investigator: KONDO Jiro Yokohama City Univ., School of med, Assist.Prof., 医学部, 助教授 (00046038)
• Co-Investigator(Kenkyū-buntansha): MATSUMOTO Akihiko Yokohama City Univ., School of med, Prof., 医学部, 教授 (20045975) ; MATSUMOTO Akihiko Yokohama City Univ., School of med, Prof. (20045975) ; MATSUMOTO Akihiko Yokohama City Univ., School of med, Prof. (20045975) ; MATSUMOTO Akihiko Yokohama City Univ., School of med, Prof. (20045975) ; MATSUMOTO Akihiko Yokohama City Univ., School of med, Prof. (20045975)
• Project Period (FY): 1992 – 1994
• Keywords: cardiomyoplasty / skeletal muscle / muscle contraction / assisted circulation device

Research Abstract

Since the initiation of our basic research in 1987 relating to cardiomyoplasty, fundamental data concerning acquisition of resistance to fatigue by skeletal muscle, including transformation, improvement in hemodynamics, and output, have been accumulated.
Based on this information, experiments were performed to elucidate the basic capacity of skeletal muscle and to develop an experimental assisted circulation device driven by skeletal muscle.
Using a method of vascular template, changes in blood circulation in the latissimus dorsi which were devascularized except for the thoracodorsal vessels were analyzed in dogs. Development of arterioles from the region in control of the thoracodorsal vessels to the devascularized region led to restoration of blood circulation. This finding may be important to overcome the problem of muscular fatigue.
In an acute experiment using adult dogs, an assisted circulation device driven by the latissimus dorsi was produced, and its output characteristics were determined. The results suggest that the latissimus dorsi has sufficient output to assist cardiac function for a short period of time, while sustained supply of sufficient output was impossible because of fatigue. Although the number of dogs used was too small to obtain valid results, the latissimus dorsi may have sufficient output to drive a pump for assistance of cardiac function.
Future studies are needed to study the following : 1) What type of pump is required for efficient utilization of the output from the latissimus dorsi? ; and 2) Does the pretreated latissimus dorsi (vascular delay and preconditioning) results in fatigue resistance leading to prolonged operation of the pump?