Arteriovenous cross-flow flap in rats: a novel skin flap

Angiosomes are blocks of tissues, composed of the integument and underlying deep structures, supplied and drained by a named artery and its accompanying vein. The purpose of the current study is to describe a new principle, which allows extension of the territory of an angiosome into the adjacent angiosome, thus enabling the creation of a large skin flap (arteriovenous cross-flow flap). Epigastric skin flaps, measuring 8 x 8 cm, were raised in 30 Sprague-Dawley male rats. In group A (single-pedicle flap), the flaps were based on the epigastric artery and vein on the ipsilateral side, and the contralateral pedicle was divided. In group B (cross-flow flap), the epigastric vein on the ipsilateral side and the epigastric artery on the contralateral side of the flap were divided. In group C (skin graft), the vascular pedicles were divided bilaterally. A definitive assessment was made on the seventh day. Digital images of the flaps were analyzed using an imaging software and the areas of skin survival and necrosis were determined. Lead oxide microangiogram was performed in another set of flaps both acutely and 1 week after flap elevation. The percent survival flap area in group A was 69.94, in group B was 89.07, and in group C was 13.00. All the groups are statistically different, with a p value < 0.001. The microangiograms showed striking differences in the vascular pattern in the cross-flow and the single-pedicle flaps. It is clearly demonstrated that the arteriovenous cross-flow flaps have increased survival of skin when compared with the conventional axial-pattern flaps.