Harvesting of the latissimus dorsi muscle: a small animal model for seroma formation.

A common complication of soft tissue dissection and muscle harvesting is seroma formation. In order to manage and understand the formation of seromas, we developed a small animal model for seromas in the Sprague Dawley rat. Skin flaps and subcutaneous tissue were elevated and the latissimus dorsi muscle was harvested in 20 animals. Eighteen of the 20 rats (90%) formed clinically significant seromas. Sixteen animals had associated skin flap necrosis and 12 required serial drainage for recurrent seromas. At necropsy, gross capsular formation occurred in all animals who developed seromas. Microscopically, a fibrous capsule enveloping the seroma was seen associated with a local chronic inflammatory cell infiltrate. We conclude: (1) Elevation of the latissimus dorsi muscle in the rat is a reliable and practical animal model for seroma formation; (2) Sequelae of clinically significant seromas are often as severe as skin flap necrosis; (3) An inflammatory reaction may be associated with seromas.