Dorsal bipedicled island skin flap: A new flap model in mice

Mice are popular animals for biomedical studies, but few skin flap models have been reported in them. To investigate the ischaemia/reperfusion phenomenon in skin flaps, we first investigated the vascular anatomy of murine dorsal skin and then designed a suitable murine dorsal skin flap model. In 120 mice, six distinct vascular patterns were identified, one being seen in 111 mice (93%). Based on this finding, in Part 2 of the study, 15 mice had flaps (4 x 4 cm) raised based on the two caudal vascular pedicles of the left and right deep circumflex iliac vessels as a bipedicled flap in which the mean (SD) survival was 96 (5)%. In a further 10 mice, flaps were raised based on a single pedicle, the left deep circumflex iliac vessel, as a monopedicled flap, in which the mean (SD) survival was 71 (12)%. The bipedicled flap model was then used to study ischaemia/reperfusion injury. Twenty flaps were subjected to eight hours of ischaemia and subsequent reperfusion, and their mean (SD) survival was 43 (26)%. Histological assessments were also carried out using neutrophil and leucocyte counts, and significant differences between groups were observed.