Evaluation of a temporary arteriovenous shunt to establish neovascularization in a musculocutaneous flap: an...

On the dorsum of adult Sprague-Dawley rats, 3 x 7 cm pedicle flaps were raised and a temporary arteriovenous shunt (AVS) from anastomosis of the tail artery and vein was placed beneath. Fourteen, 21 and 28 days later, the pedicle flaps were converted to island flaps leaving only the AVS attachment. The degree of subsequent flap viability was directly related to the amount of time before flap conversion. At 14, 21 and 28 day intervals, there was 33.4%, 73.5% and 98% flap viability, respectively. Long-term AVS patency was found not to be required for flap survival. Normal hair growth, quantity and quality, occurred in only the 28 day delay group. Microangiography and histologic examination revealed extensive neovascularization from both the AVS artery and vein extending into the muscle, subcutaneous tissue and skin layers of each island flap. In summary, neovascularization of a large random pattern musculocutaneous island flap is possible using a temporary arteriovenous shunt. Flap survival is directly related to the length of time between AVS placement and cutaneous pedicle division, although long-term AVS patency is not required for continued flap viability. Hair growth may directly reflect the degree of underlying neovascular maturation. This AVS neovascularization technique could be applied to create new donor sites for free tissue transfer.