Invited Review: Avoiding Ischaemic Damage in Latissimus Dorsi Muscles Redeployed as Functional Grafts

The success of cardiomyoplasty and other surgical procedures involving the redeployment of the latissimus dorsi muscle (LDM) depends crucially on preserving the long-term viability of the muscle graft. The need to sacrifice perforating arteries during mobilization renders the grafted muscle vulnerable to ischaemic damage when it is subjected to electrical stimulation, a problem that is not adequately addressed by existing protocols. In this review we show how a more complete understanding of the vascular anatomy of the LDM enables us to propose a new and more effective approach. By injecting fluorescent microspheres we demonstrated the existence of arterial anastomoses connecting the vascular territories of the major arterial supplies: the thoracodorsal and perforating arteries. We went on to show that stimulation of the muscle before it was raised as a graft enhanced flow through these anastomoses, allowing the existing vascular networks to be perfused effectively from the thoracodorsal supply alone. Ischaemic damage was thereby reduced. Under closely comparable conditions this prestimulation procedure proved more effective than the comparatively invasive ‘true vascular delay’ procedure widely used in plastic reconstructive surgery. Protocols based on prestimulation not only offer a solution to the problem of distal graft ischaemia but will also allow cardiac assistance to be introduced at an earlier postoperative stage.