ABSTRACT
The usefulness of combining antithrombotic agents and radical scavengers in the treatment
of reperfusion injury (an almost ideal approach) was substantiated using an ischemic
flap model. The cause(s) of reperfusion injury was hypothesized on the basis of differences
in effects between antithrombotic agents and radical scavengers in the experimental
groups. Flap specimens were also obtained regularly for histologic examination.
The experiment was conducted in nine rabbit groups. For continuous treatment with
intraarterial antithrombotic agents, both heparin and urokinase were continuously
injected at respective administration rates of 20 U/kg/hr and 200 IU/kg/hr for seven
consecutive days immediately before reperfusion. For intraarterial radical scavenger
treatment, a solution of both 30,000 U/kg SOD and 30,000 U/kgcatalase in 5 ml of a
lactated Ringer's solution was injected over a period of about 30 min immediately
before reperfusion.
The ischemic time of the flaps was 10 hr for Group 1 and 12 hr for Group II. Each
group was comprised of subgroups a, b, c, and d: a = control; b = continuous intraarterial
antithrombotic agent injection; c = intraarterial lactated Ringer's solution alone;
and d = intraarterial radical scavenger injection. For Group II, an additional subgroup
e was established, which received continuous injection of both intraarterial antithrombotic
agents and injected intraarterial radical scavenger.
In the 10-hr ischemic treatment group, an effect was obtained by continuous intraarterial
antithrombotic agents alone. In the 12-hr ischemic treatment group, a significant
improvement in flap-take ratio was obtained using intraarterial radical scavenger,
in combination with antithrombotic agents. Observation of the flaps that survived
in subgroups Ib and lie revealed skin thinning, vascular wall thickening, and muscular
tissue degeneration, although the skin architecture was well preserved.
