Four skin grafting procedures were performed on both sides of the chests of 12 dogs to evaluate the effect of wound drainage on the survival and cosmetic appearance of the grafts. The techniques evaluated were a sheet graft, (control), continuous low level suction, piecrust incisions, and nonexpanded mesh graft. Graft viability was assessed on the 10th postoperative day by visual inspection. The mean survival rate for all grafts was 90%. No significant difference between graft types was observed.Hair growth on each graft was assessed 3 months postoperatively as "normal" (resembled that on the surrounding skin), "moderate" (thickness of hair growth was less than normal but would nearly conceal the underlying skin), "sparse" (a few hairs were present and the skin below was easily visible), and "none" (no hair growth). No statistical differences in categories of hair growth were detected within types or between types of grafts. Hair growth also was assessed as "acceptable" (those areas having normal and moderate hair growth) and "nonacceptable" (hair growth sparse or none). No difference between graft types was noted. All types exhibited a significantly greater area of acceptable than nonacceptable hair growth. KIN GRAFTING IN DOGS and cats is performed to S provide a durable and cosmetic covering. The cosmetic appearance, which encompasses both the quality of hair regrowth as well as the color and texture of the skin, is reported to be more acceptable with fullthickness grafting than with split-thickness grafting.lP3 Full-thickness skin grafting frequently results in a hairy skin indistinguishable from the surrounding area when the donor site is matched with the local color and direction of hair g r o~t h .~,~ Skin graft survival is dependent on the rapid reestablishment of an adequate circulation to provide nutrition and to dispose of metabolic waste products.6-8 The formation of a hematoma or seroma under a graft is reported to be the most common cause of graft failure .9-13Factors affecting hair regrowth have not been studied extensively. The purposes of this study were to determine the effects of wound drainage on skin graft survival and cosmetic appearance of full-thickness skin grafts.
Materials and MethodsFour full-thickness skin grafting procedures were performed on 12 adult Beagle dogs. The surgical technique is described in part I of this study.'* For the first 3 weeks after surgery, wire basket type muzzles were kept on the dogs, and the grafts were bandaged to prevent molestation. The following graft types were evaluated:1. Sheet-The sheet graft was not modified and served as a control.2. Drain-Continuous low level suction was provided by placing a fenestrated 19 gauge butterfly catheter* under the graft and attaching it to a 5 ml evacuated glass tube. t * Miniset Vein Infusion Set,