Microvascular Free Tissue Transfer of the Rectus Abdominis Muscle in Dogs

Objective - To assess donor site morbidity and survival of the rectus abdominis muscle with an overlying skin graft after free tissue transfer to a medial femorotibial defect in dogs.

Study Design - Experimental study

Sample Population: Phase one - six canine cadavers / Phase two - seven adult mixed breed dogs

Methods: Phase one - The rectus abdominis muscle was removed from cadavers, muscular and vascular dimensions were recorded and angiography was performed. Phase two - Muscular transfer was performed through anastomosis of the caudal epigastric vasculature to the saphenous vasculature. Transferred tissues were evaluated on postoperative days three, six, 10, and 13. Animals were examined daily until euthanasia between postoperative days 31 and 42. Postmortem angiograms were performed and tissues collected for histopathologic evaluation.

Results: Phase one - Appropriate vascular dimensions for microvascular anastomosis were confirmed and surgical technique perfected. Phase two – Muscular excision produced minimal donor site morbidity. All muscles survived after microvascular transfer and angiography confirmed vascular patency. All skin grafts survived with one graft undergoing partial necrosis.

Conclusions: The rectus abdominis muscle can be successfully transferred to a medial femorotibial defect and serve as a bed for acute skin grafting. No significant donor site morbidity is associated with its removal.

Clinical Relevance: Microvascular free tissue transfer of the canine rectus abdominis muscle has not been previously described. This technique provides an alternative for repair of appropriate wounds. Additional studies are needed to define its utility in clinical patients.