G. Willemart et al., Dexamethasone treatment prior to reperfusion improves the survival of skinflaps subjected to secondary venous ischaemia, BR J PL SUR, 51(8), 1998, pp. 624-628
The potential use of the anti-inflammatory glucocorticoid, dexamethasone, t
o treat ischaemic skin flaps prior to reperfusion was investigated. Island
flaps were raised in rats, subjected to arteriovenous ischaemia for 2 h, no
rmal blood flow for 24 h, secondary venous ischaemia for 4 h and secondary
reperfusion for 7 days. This sequence mimics the clinical sequence of free
flap transfer followed by a subsequent venous thrombosis. Groups of 10 rats
were administered with an intraperitoneal dose of either saline (controls)
or dexamethasone (2.5 mg/kg) 30 min before the end of the venous ischaemia
. Compared with viability of 70.0% in controls, dexamethasone treatment inc
reased viability significantly to 92.0% (P < 0.01). In skin flap tissue har
vested at 24 h reperfusion, dexamethasone treatment resulted in significant
attenuation of tissue water content, tissue myeloperoxidase activity and t
issue hydroperoxide levels. Thus the protective effect of this agent may be
explained by the combined reduction of oedema formation, neutrophil infilt
ration and free radical production, respectively. We conclude that a single
systemic dose of dexamethasone prior to reperfusion may be beneficial in t
reating skin flaps that have undergone secondary venous ischaemia.