A comparison of pretreatment with a topical combination of nonivamide and nicoboxil and surgical delay in a random pattern skin flap model.

Delay procedures are intended to increase flap safety in otherwise risky flaps. In general they are of surgical nature, making an additional operation necessary. To overcome this drawback, non-surgical alternatives that may be as effective as the surgical procedure are constantly sought. We have previously shown an effective postoperative method to augment flap viability by topical application of a combination of nicoboxil and nonivamide. The goal of this study was to investigate whether this combination is also effective in inducing a delay effect in experimental skin flaps. Thirty male Wistar rats were randomised into three groups (n=10), and a standardised dorsal random pattern (6x2 cm) skin flap was raised on each animal. In rats of group 1, a surgical delay procedure was carried out 1 week prior to full flap harvest by incising the two longitudinal borders of the flap. In group 2 rats, the whole flap area was treated by the topical ointment once a day in order to induce a chemical delay effect for 7 days prior to flap harvest. In group 3 rats, the flap was harvested without any prior intervention and this group served as a control. Skin flap viability was assessed on postoperative day 7, and the extent of the viable skin flap area was compared between the three groups. The surgical delay procedure resulted in a significant increase in the viable area of the skin flaps compared to the chemical delay group and the control group. Additionally, there was a significant increase in skin flap viability between the chemical group and the control group (mean percentage of viable skin flap area in surgical delay group, 80.9+/-15.6; nonivamide/nicoboxil pre-treated group, 71.8+/-4.9; control group, 60.7+/-2.1; p<0.05). Although not as effective as the surgical delay procedure, the topical combination of nicoboxil and nonivamide proved to be of significant value in order to ameliorate ischemic necrosis in experimental skin flaps. Due to its ease and safety in application, this ointment may prove clinically useful in selected situations, especially when combined with an additional postoperative treatment.