The effects of VEGF on survival of a random flap in the rat: examination of various routes of administration

The purpose of the present study was to determine the effects of vascular e ndothelial growth factor (VEGF) on survival of a full thickness random patt ern, McFarlane musculocutaneous flap in the rat. In addition, this study ex amined a number of different methods of VEGF delivery in an attempt to dete rmine the most effective route of administration. A 2 x 8 cm full thickness dorsal flap with the pedicle remaining attached at the anterior end was el evated in 72 male Sprague-Dawley rats. The rats were randomised into sis gr oups and immediately received the following treatment: Group I (n = 12): sy stemic VEGF injection into the femoral vein (50 mu g/ml); Group II (n = 10) : multiple systemic VEGF injections at 0, 24 and 48 h post flap elevation ( 50 mu E/ml); Group III(n = 12): subdermal VEGF injection into the flap(1 mu g/ml); Group IV(n = 12): subfascial VEGF injections into the recipient bed (1 mu g/ml); Group V (n = 10): topical VEGF onto the recipient bed(1 mu g/ ml); Group VI (n = 16): control group with no treatment. Following 5 days r ecovery, the area of flap survival was measured. Mean flap survival ranged from 91% in Group II to 78% in Group V, and was significantly greater in al l experimental groups (P < 0.001 for Groups I-IV and P < 0.05 for Group V) as compared to the control group (mean survival of 66%). The only significa nt difference between the experimental groups was between the mean survival in Group TI and Group V (P < 0.05). Histological analysis demonstrated a q ualitatively greater amount of granulation tissue and neovascularisation in the experimental groups. These results support the notion that VEGF rescue s tissue at risk of hypoxic damage by inducing angiogenesis, and the use of growth factors such as VEGF holds promise as a method of increasing skin v iability. (C) 2000 The British Association of Plastic Surgeons.