Flap failure related to total or partial necrosis is not a rare event. Flap edema could be an important factor on flap losing. Hyaluronidase breaks down the hyaluronic acid existing in the connective tissue, which is involved on water homeostasis of intercellular ground substance, and may be important on increasing flap survival. The aim of this study was to evaluate the effectiveness of hyaluronidase on improving cutaneuos flap survival in rats. Forty-two Wistar rats divided in four groups were included in this study. It was made a 7 x 2 cm random flap in the dorsal aspect of the animal. Three groups received post-operative treatment during four days. Group A (n=11) received 100 UI per day of hyaluronidase, group B (n=11) 50 UI per day and group C (n=10) received distilled water. Group D (n=10) was not treated. It was evaluated the necrosis area and those data were statistically analyzed. Necrosis rates on 7th day were 38,69% (±9,26) in the group A, 38,20% (±15,05) in the group B, 51,97% (±8,37) in the group C and 45,90% (±12,57) in the group D. There was found difference with statistical significance (p<0,05) between group A and B when compared with the group C. There was no statistical difference when compared groups A and B with group D. Hyaluronidase was found effective when the infiltration factor was involved and this suggests a spread effect on edema to be the provable mechanism on increasing of the cutaneous flap survival in rats.
Flap; Hyaluronidase; Rat; Edema; Necrosis
