Free flap transfer of the cutaneous maximus muscle in the rat: comparison to the latissimus dorsi muscle flap.

A new rat model of free muscle flap transfer is presented. Microvascular transplantation of the cutaneous maximus muscle flap is performed at the groin site, with anastomosis of the axillary vessels to the appropriate femoral vessels. This muscle flap has many useful attributes for experimental manipulation. It has a high success rate following transplantation, the anatomy is consistent, the dissection is straightforward, the length of pedicle is relatively long (10 mm), the vessels for repair are of sufficient size (1.0-1.35 mm diameter), and the microsurgical procedure can be performed in a relatively short period. The donor site deficit causes minimal impairment to animal mobility, and no evidence of limb ischemia is noted after ligation of the axillary vessels. The cutaneous area adjacent to the muscle is perfused by muscular perforators supplied by the flap pedicle; thus a skin island may be used to monitor the flap or to create a composite myocutaneous transfer. The cutaneous maximus muscle has mixed muscle types and anatomic dimensions similar to those of the latissimus dorsi muscle, and it provides ample tissue for pharmacological and biochemical studies, yet it presents easier dissection and microanastomoses than the latissimus flap, with more potential for versatility in application. The advantages of this muscle flap make it a very useful experimental model for flap transfer research.