[Experimental investigation of neovascularisation in large prefabricated flaps after arteriovenous pedicle implantation].

The principle of prefabricated flaps is based on the transformation of a formerly random-pattern vascularized flap, through implantation of a vascular pedicle, into a newly neovascularized axial flap, which can be transferred after a period of neovascularisation from the prepared donor site to the recipient site by using microvascular techniques. In 30 Chinchilla Bastard rabbits weighing from 3700 to 4200 g, a skeletonized arteriovenous pedicle with distal ligation harvested from the femoral and saphena magna artery and vein was implanted beneath an 8 x 15 cm abdominal skin flap to investigate the neovascularisation process in the flap over the course of time. In order to prevent neovascularisation occurring from the underlying vascular bed into the flap, a silicon sheet measuring 8 x 15 cm x 0.25 mm was placed and fixed on the abdominal wall. Flap vitality and neovascularisation process in prefabricated flaps were evaluated by macroscopic observation, blood analysis, selective microangiography, histology and scintigraphy at the various time intervals of 4, 8, 12, 16 and 20 days. The study results showed that newly formed vessels sprouting from the implanted pedicle were seen four days after pedicle implantation. With the retention time of pedicle in the flaps, they continued to grow, became meander and more dense. Respective connections between newly formed vessels and the originally available vasculature of the abdominal flap were markedly observed in the 12- and 16-day groups. Twenty days after prefabrication, the abdominal flap was completely perfused by the blood flow supplied from the newly implanted arteriovenous pedicle through newly formed vessels arising from the implanted pedicle and their rich vascular communications. The neovascularisation in the prefabricated flap consisted of the implanted pedicle, newly formed vessels, the originally available vasculature and their vascular connections. In comparison to the control group (the quantification was determined of 100 %), the vessel quantity in the prefabricated flap of the 20-day group had increased to 98.7 %. As a pre-clinical test, prefabricated flaps through arteriovenous pedicle implantation with special advantages can be a new useful method in plastic and reconstructive surgery.