ENOXAPARIN DOES NOT CONTRIBUTE TO RANDOM PATTERN FLAP VIABILITY: AN EXPERIMENTAL STUDY IN THE RAT DORSAL SKIN FLAP

Introduction: In this experimental study, the effect of different dosages of subcutaneously injected enoxaparin over the viability of random pattern skin flaps was investigated. Material and Methods: Four groups were studied using 32 male Sprague-Dawley rats (300-450 grams). Group I (n=8): control group, no agent was given. In Group II (n=8): Enoxaparin (Clexane, Sanofi Aventis) 2 mg/kg, in Group III (n=8): Enoxaparin 4 mg/kg, in Group IV (n=8): Enoxaparin 8 mg/kg were injected subcutaneously to rats 2 hours before the dissection of random pattern skin flaps (3x10 cm). Flaps were elevated with sharp dissection and sutured back to their original places. Enoxaparin doses were repeated postoperatively twice a day for 1 week. On the 7th postoperative day, necrotic and viable parts of flaps were copied over transparent papers. Copies were then transported over squared paper in millimeter and necrotic and viable areas of flaps were counted in square units. The ratio of necrotic areas in flaps to the total flap areas was calculated. The difference among groups was examined by Kruskal-Wallis test. Statistical significance was presumed at p <= 0.05. Results: Necrotic area wideness was found 150 +/- 14.82 square unit in Group I, 140.71 +/- 25.8 square units in Group II, 146.75 +/- 10,27 square units in Group III and 154,37 +/- 13,59 square units in Group IV. The difference among groups was not significant (p >= 0.05). The ratio of necrotic area to total flap area was found % 44.98 +/- 5.5 in Group I, % 42.84 +/- 6.45 in Group II, % 44.36 +/- 3.93 in Group III, and % 47.26 +/- 6.95 in Group IV. Statistical significance was not determined in terms of necrotic area ratio (p >= 0.05). Conclusion: Subcutaneous enoxaparin injection does not have an increasing effect over viability of random patern rat dorsal skin flap.