Improvement of a long random skin flap survival by application of vascular endothelial growth factor in various ways of local administration in a rat model

Abstract

Background:Vascular endothelial growth factor (VEGF) is a heparin-binding glycoprotein which plays a significant role in angiogenesis and vascular permeability. The effect of various ways of local administration of VEGF on random skin flap survival was studied, using flaps with a relatively high length (L) to width (W) ratio (5:1).Materials and Methods:An 1.5 × 7.5 cm dorsal skin flap with the pedicle orientated, centered, and remaining attached between the lower angles of the scapulae was elevated in 45 Wistar rats in different phases, depending on the group. Rats were divided in five groups of nine. In group A, injections of saline were administered, in equally divided spaces, into flap's fascia and transposed to a created skin defect. In group B, injections of VEGF were applied subdermally, in equally divided spaces, within the limits of a predesigned flap, a week prior to flap dissection and transposition. In group C, injections of VEGF were applied into a recipient bed's fascia just before flap raising and transposition. In group D, injections of VEGF were applied subdermally, only in the distal third of the flap and then the flap was transposed to a recipient area. Finally, in group E, injections of VEGF were applied in the flap intrafascially and in equally divided spaces and then again, the flap was transposed to a recipient area. A week after final flap raising and positioning, rats were euthanatised and flaps were excised. Specimens were photographed, measured, put in formalin 10% and were sent for histological and image analysis.Results:Mean flap survival percentage was 35.4% in group A, and 33.7% in group B. In groups C and D, the mean survival area was 56.3% and 80.4%, respectively. In group E, the mean flap survival percentage was 28.3%. Histological analysis demonstrated increased angiogenesis in groups C and D.Conclusions:VEGF application improved skin flap survival when injected subdermally in the distal third of a random skin flap or into the fascia of a recipient area even though the length-to-width ratio was high.

Locally injected autologous platelet-rich plasma enhanced tissue perfusion and improved survival of long subdermal plexus skin flaps in dogs

“…One major complication of these flaps is necrosis, especially at their distal part, occurring mainly due to insufficient vascularity and thus inadequate blood supply for skin metabolic requirements (1,2,4,5). The length-to-width ratio is considered to be an important factor affecting the survival of this type of flap (2,6). Length-to-width ratios from 1:1 to 3:1 have been suggested in the veterinary literature (2,7).…”

“…Various treatments have been evaluated and recommended to improve skin flap survival, especially when long flaps are needed to cover large defects (1,2,5). Cer-tain growth factors implicated in neovascularisation, including vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF-β), have demonstrated ability to improve the microcirculation and thus the viability of a skin flap (5,6,(8)(9)(10)(11). It has been suggested that the combined use of growth factors may be more effective than the use of a single growth factor for improving wound healing (12,13).…”

VEGF released from a fibrin biomatrix increases VEGFR-2 expression and improves early outcome after ischaemia-reperfusion injury

“…Several experimental studies indicate that the administration of exogenous VEGF can induce regional angiogenesis and improves the survival of skin flaps (Akimoto et al ., ; Vourtsis et al ., ). Therefore, it holds a high potential as a treatment option for chronic limb ischaemia (Ferrara, ).…”

Effect of Natural Hirudin on Random Pattern Skin Flap Survival in a Porcine Model

“…1,2 Causes of necrosis can usually be traced to inadequate venous drainage of the flap, but the pathophysiology of the process is complex. 3,4 Studies aimed at improving the survival of the distal portion of random pattern skin flaps have employed a variety of interventions.…”