Iontophoretic delivery of nitric oxide donor improves local skin flap viability

Abstract

The dimensions of local flaps are often limited by the vascular supply to the distal aspect of the flap. Distal flap necrosis occurs if the vascular supply is inadequate. The purpose of this study was to investigate the use of iontophoretic delivery of nitric oxide (NO) donors to a local skin flap model to improve the survival area of the flap. Thirty-two male Sprague-Dawley rats (300 g) were divided into seven experimental groups to determine the effect of iontophoretic delivery of NO on surface perfusion and flap survival area. A caudally based 3 x 11 cm dorsal skin flap was used to measure the effect of iontophoretic delivery of NO donors to a local skin flap to improve survival area of the flap. Iontophoretic delivery of the NO donors sodium nitroprusside (SNP) and diethylenetriamine NONOate (DETA-NO) resulted in a significant increase in survival area and surface perfusion when compared with sham controls. Iontophoretic delivery of saline was associated with a 13% improvement in flap survival when compared with nontreated controls. Iontophoretic delivery and subcutaneous injection of NO donors (SNP and DETA-NO) increased skin flap viability by demonstrating improved flap survival areas. The results of this study suggest that NO may serve as a postoperative treatment of skin flaps to encourage skin flap survival and prevent distal necrosis.

Figure 1

Representative photo of increased tissue survival is noted following injection of the NO donor DETA-NO. Arrows designate line of necrosis. (A) Photo of control flap. (B) DETA-NO treated flap. DETA-NO=diethyltriamine NONOate.

Figure 2

(A) Average percentage increase in survival via injection treatment with and without NO donors. (B) Flap perfusion of the different nitric oxide treatments and control. SNP=sodium nitroprusside; DETA-NO=diethyltriamine NONOate. N=4 per group. Values are means ± SD. † P<.05 vs. Sham control, * P<.05 vs INJ control.

Figure 3

(A) Average percentage increase in survival area via TID treatment with and without NO donors.(B) Flap perfusion of the different nitric oxide treatments via TID treatment and control. SNP=sodium nitroprusside; DETA-NO= diethyltriamine NONOate. N=4 per group. Values are means ± SD.. † P<.05 vs. SHAM, * p<.05 vs. INJ Control, # P< .05 vs. SNP 1.25 mg (TID).