IMPROVED SURVIVAL RATES OF RANDOM FLAPS IN RABBITS WITH A MONOCLONAL-ANTIBODY THAT BLOCKS LEUKOCYTE ADHERENCE

To examine the role of neutrophil adhesiveness in the tissue injury in volving the ischemic ''at risk'' area of random flaps, we used the mon oclonal antibody 60.3, which binds selectively to the primary neutroph il adherence-mediating glycoprotein CD18 in a random cutaneous flap mo del. Control animals that had flaps elevated and replaced (n = 12) had a mean distal necrosis of 31.9 +/- 9.3 percent of the total flap surf ace area. Treatment with monoclonal antibody 60.3 (n = 12) reduced dis tal necrosis to 10.6 +/-7.5 percent (p < 0.005). Inhibiting inosculati on by interposing a thin silicone sheet decreased distal flap survival ; however, the protective effect of monoclonal antibody 60.3 on improv ing flap survival was unchanged. Control isolated flaps (n = 13) had a mean distal necrosis of 49.0 +/- 15. 5 percent compared with 22.2 +/- 5.6 percent for the antibody-treated (n = 8) isolated flaps (p < 0.05 ). We conclude that increased neutrophil adhesiveness plays an importa nt role in the tissue injury involving the ischemic ''at risk'' area o f random flaps and that transient, specific inhibition of leukocyte ad herence by monoclonal antibody 60.3 improves the distal survival of ra ndom flaps in this model. Moreover, we conclude that ''graft inosculat ion'' contributes to ''flap'' survival in this model; however, conclus ions regarding the effect of treatment are not altered by blocking ino sculation.