Neovascularization in prefabricated flaps using a tissue expander and an implanted arteriovenous pedicle

Abstract

Creating prefabricated flaps using tissue expanders in combination with the implantation of maximal blood flow vascular pedicles into suitable tissue areas represents a new tendency in the reconstruction of large skin defects. In 42 Chinchilla Bastard female rabbits weighing 3,700-4,600 g, skeletonized arteriovenous pedicles with maximal blood flow, dissected from the femoral and saphena magna bundles, were implanted underneath abdominal fasciocutaneous flaps. Oval tissue expanders of 250 ml were placed and fixed on the abdominal wall to expand these prefabricated flaps. The evaluation parameters were macroscopic observation, blood analysis, selective microangiography, histology, and scintigraphy. The study results showed that neovascularization in expanded prefabricated flaps was established from newly formed vessels generated from the implanted pedicles and their vascular connections with the originally available vasculature in the flap. After 20 days of prefabrication, the entirety of the expanded prefabricated flaps was perfused by blood flow supplied from newly implanted arteriovenous pedicles. The study indicated that an expanded prefabricated flap can be successfully created by the simultaneous implantation of a maximal blood flow pedicle in combination with flap expansion.

Influence of Silicone Sheets on Microvascular Anastomosis

“…Experimental investigations indicated increasing blood flow in the implanted vascular pedicle combined with silicone sheet implantation played important roles [10,11,15,21]. Using a silicone sheet and arteriovenous pedicle with microanastomosis, numerous authors have reported 20 days is the minimal time required for neovascularization maturation [10,11,16,15,27,28]. As a result of thrombosis we found delayed neovascularization development in Group 1 compared with Group 2.…”

“…We have experienced flap failure after simultaneous use of silastic implants for wrist and MCP joint reconstruction and free vascularized cutaneous flap transfer owing to skin defects after severe hand and finger contractile burn scars when we performed the vascular microanastomosis at the level of the silicone wrist-spacer implantation. Furthermore, based on previous experimental observations of prefabricated flaps using silicone and pedicles with arteriovenous anastomosis [10,11,28], we found flap transfer was unreliable when the microanastomosis was placed in direct contact with silicone sheets. However, how these sheets influence the microanastomoses is not known nor are the most effective ways to reduce or avoid this undesirable risk.…”

“…The procedure provides the option of creating thin, large, and suitable flaps with minimal morbidity regardless of natural vascular anatomy. This type of flap has been experimentally investigated [5,8,10,11,15,19,21,23,27,28]. The most important requirement for determining successful transfer of prefabricated flaps is maturation of neovascularization.…”

“…Silicone implants are widely used for breast augmentation [3,7,9,29,31], restoration of contour deficiencies [18], scar management [20], and intensifying neovascularization in prefabricated flaps [15,21,28]. They also have been used experimentally and clinically in association with free vascularized flaps to reconstruct tissue defects in the ear and nose [4,12,16], and the trachea [6].…”

Vascularization of engineered cartilage constructs in a mouse model

“…Others have introduced rat models to solve problems concerning prefabrication (Tan et al 2004;Tanaka et al 2003). Staudenmaier et al (2004) and Hoang et al (2005b) demonstrated in a rabbit model that flaps could be well vascularized by an arteriovenous vessel loop. Hoang et al (2009) even simulated a free microsurgical transfer of the prefabricated, prelaminated flaps.…”