Microporous Polysaccharide Hemospheres Potentiate Ischemia-Induced Skin Flap Necrosis in a Murine Model

Background: Microporous polysaccharide hemospheres are an increasingly used adjunctive measure for obtaining operative field hemostasis. However, the impact of these agents on survival of vascularly challenged tissues is unknown. The aim of this study was to investigate the effect, if any, of microporous hemospheres on tissue survival in a murine model. Methods: Eighteen Sprague-Dawley rats underwent creation of two flanking dorsal, modified McFarlane-style flaps using a length-to-width ratio of 4:1. Microporous polysaccharide hemospheres were applied to the underside of only one flap in each animal. In a subset of five rats, tissue malondialdehyde activity was measured at 24 hours. The remaining 13 animals were killed after 7 days, and the area of flap necrosis was measured photographically. Histopathologic analysis was also performed on the margins of the necrotic area. Results: Size comparison showed a significantly larger area of necrosis in the microporous polysaccharide hemosphere-treated flaps relative to controls (1.69 +/- 1.21 cm(2) versus 0.28 +/- 0.28 cm(2); p = 0.00135). Higher malondialdehyde levels were also found in the microporous polysaccharide hemosphere-treated flaps at 24 hours (0.462 +/- 0.098 versus 0.315 +/- 0.065; p = 0.047). The areas of skin necrosis were noted to be partial thickness on histologic examination. Conclusions: Microporous polysaccharide hemospheres are associated with an increased incidence of distal tip necrosis in dorsal rat skin flaps. Despite their efficacy in surgical hemostasis, their use should be judicious, especially with marginally perfused tissues such as mastectomy skin flaps.