Research project developing a biological energy pump with rectus abdominis muscle : potential to clinical application

使用自体骨骼肌作为心脏辅助的生物能量泵是消除感染和免疫抑制问题的有前途的方法之一，这些问题有时发生在使用机械辅助装置和移植的患者中。我们开发了一个系统的生物泵使用腹直肌和检查的潜力，将其应用于病人。腹直肌的调节：为了获得抗疲劳的肌肉，在杂种狗中进行持续8周的慢性电刺激。调节后，注意到肌肉的纤维类型从II型转变为1型（抗疲劳）。与非条件肌肉相比，条件肌肉产生压力的能力降低到约70%。心包肌成形术的心脏辅助效果：取8只杂种犬未经条件的左侧腹直肌，制备带蒂移植物，保留胸廓内动、静脉。将移植物缝合到从前面切除的心包残端上，以便带心包的移植物挤压整个心脏。该系统的刺激使主动脉收缩压增加8.6%，右心室压力增加53.6%，主动脉血流量增加18.1%。心衰诱导后，上述增加幅度进一步增大.这些结果表明，使用腹直肌的生物能量泵可能适用于作为心脏辅助系统，然而，在8周的调节后，调节肌肉的功率不可避免地降低。这种方法的另一个问题是肋间神经的保存困难，这在未来必须克服。

A biological energy pump which uses autologous skeletal muscle as a cardiac assist is one of the promising method that eliminates the problems of infection and immunosuppression which sometimes occur in patients with mechanical assist devices and transplantation. We developed a system of the biological pump using rectus abdominis muscle and examined the potential to apply it for patients.1. Conditioning of rectus abdominis muscle : To obtain fatigue resistant muscle, chronic electrical stimulation for 8 weeks was performed in mongrel dogs. After conditioning, transformation of fiber types of the muscle was noted from type II to type 1 (fatigue resistant). Capability of generating presure by the conditioned muscle was reduced to about 70% compared to unconditioned muscle.2. Efficacy of cardiac assistance by pericardiomyoplasty : The left rectus abdominis muscle unconditioned was harvested in 8 mongrel dogs, and a pedicled graft was prepared with internal thoracic artery and vein preserved. The graft was sutured to the pericardial stump which was resected anteriorly so that the graft with the pericardium should squeeze the entire heart. The stimulation of the system increased the systolic aortic pressure by 8.6%, the right ventricular pressure by 53.6%, and the aortic blood flow by 18.1%, respectively. These increment were augmented after induction of heart failure.3. These results suggest that the biological energy pump using the rectus abdominis muscle might be applicable as a cardiac assist system, and yet that the power of the conditioned muscle is inevitably reduced after 8 weeks conditioning. The other problem of this method is difficulty of preservation of the intercostal nerves, which has to be overcome in future.