Christopher R. Forrest

Abstract

The rabbit island and peninsular axial pattern latissimus dorsi musculocutaneous (LDM) flaps were assessed for their appropriate use as experimental musculocutaneous flap models. Contralateral island and peninsular LDM flaps (10 X 20 cm) were constructed on rabbits, and their vascular anatomy, hemodynamics, and viability were compared. Anatomical dissections and fluorescein dye studies revealed that the skin overlying the latissimus dorsi muscle received its blood supply mainly from a direct cutaneous branch of the thoracodorsal artery before its entry to the latissimus dorsi muscle. A few small musculocutaneous arteries (perforators) were seen in the proximal portion of the latissimus dorsi muscle, but these perforators provided very little blood supply to the overlying skin. Results from hemodynamic and viability studies with rabbit peninsular and island LDM flaps also indicated that the blood supply from the musculocutaneous arteries to the overlying skin paddle was small and could not reliably support the survival of the cutaneous portion of these musculocutaneous flaps. We conclude that rabbit LDM flaps are different in vascular structure and blood supply compared with the human LDM flaps. Thus, discretion should be advised in applying the rabbit peninsular or island LDM flaps as experimental flap models for the study of the pathophysiology and pharmacology of the musculocutaneous flaps relevant to the clinical situation.