Unpreconditioned free revascularized dynamic cardiomyoplasty - Is if feasible?

Background. Cardiomyoplasty is a new ventricular bioassist device for myoca rdial failure. But there are some limitations in standard cardiomyoplasty, such as the orientation of the muscle and fiber and the efficiency of the c ontractile segment of the flap. Free revascularized latissimus dorsi flap m ay be a good idea for solving these problems. Methods. We designed a canine free latissimus dorsi flap by revascularizing the flap with the left internal thoracic vessels by micro-surgical techniq ue. Group I (n=3) as control was performed by standard cardiomyoplasty, and the Group II (n=10) was performed by the revascularized method. The heart was then wrapped by the revacularized flap. Group II was divided into IIa ( n=6, no pre-treatment before revascularization) and IIb, (n=4, normal salin e pre-treatment before revascularization) by the different preservation met hods. Hemodynamic data were recorded. Results. Group I all survived the 8-week training period. But Group II, Gro up IIa and IIb, all died in 3 days, but survived more than 12 hours. The he modynamic analysis in Group I did not show any significant change except le ft ventricular end diastolic pressure. It showed elevated left ventricular pressure when the cardiostimulator was ON. Conclusions. According to the result of this experiment, it seemed impossib le to get a satisfactory result of more than 3 days for free revascularized cardiomyoplasty at present. There were a lot of problems waiting to be sol ved, such as preservation method during ischemia, bulky mass of the flap, a nd the potential problem of neuromuscular atrophy.