[Experimental concept of periprosthetic membrane neo-flap with axial vascular pedicle]

This study was designed to demonstrate that progressive inflation of an expansion prosthesis placed under the epigastric pedicle of the rat induced the formation of vascular connections between this vessel and the periprosthetic membrane. 17 Wistar rats were operated under general anaesthesia. The 7 cc prosthesis was implanted into the inguinal fold and the valve was placed in a dorsal position via limited incisions. 11 rats were studied, divided into 3 series: 3 control rats (non-inflated prosthesis), a series in which the prosthesis was inflated up to 20 cc (at a rate of 5 cc per week) and a series in which the fate of the capsular flap isolated as a vascular island flap in a prefabricated silicone block was studied. The assessment was threefold: clinical, microradiographic after injection of lipiodol into the epigastric artery and histological. The clinical and microradiographic studies demonstrated the reality of the blood supply of part of the periprosthetic membrane and its connections with the epigastric axial pedicle. This membrane surface, constituting a real biological flap prefabricated by expansion, corresponds to the peripedicular zone (2 x 1 cm). The viability of the island flaps was confirmed after 8, 14 and 21 days. Histological studies confirmed the hypervascularisation and richness of the collagen fibres as a result of expansion.