Blood flow pattern in the thoracodorsal artery after dynamic cardiomyoplasty

To understand if a non invasive determination of blood flow to the Latissimus Dorsi Muscle (LDM) could be used as an indirect index of muscle viability, we postoperatively measured the thoracodorsal artery (TDA) blood flow variations during latissimus dorsi stimulation in 4 patients who had a cardiomyoplasty. The TDA was in all cases identified by a characteristic biphasic blood flow pattern. We measured diameter (mm), mean velocity (cm/sec), systolic/diastolic ratio (SID) and calculated blood flow (ml/min) during 5 minutes of latissimus dorsi stimulation at 2:1 and 1:1 synchronisation ratio while changing the voltage applied to the muscle so to obtain various strength of contraction. Mean blood flow was 33.75 ml/min in basal condition and increased to 42.83 ml/min during a synchronisation rate of 1:2 at a voltage of 150% of clinical setting. There was a further increase up to 50.99 ml/min for a synchronisation rate of 1:1 while, at the same time, a marked reduction of S/D ratio (from 4.29 to 1.97) was detected. In conclusion blood flow in the TDA appears to be directly related to metabolic needs of the stimulated muscle and this non invasive technique can be useful to follow-up patients and control long term muscle viability.