Previous studies have suggested that topically applied platelet-derived wound healing factors (PDWHF) accelerate wound healing by stimulating angiogenesis, fibroblast proliferation, and collagen synthesis. To assess the ability of platelet factors to facilitate healing of chronic cutaneous ulcers we performed a randomized, prospective, double-blind, placebo-controlled study of topical PDWHF in 18 patients with 26 lower extremity wounds refractory to conventional therapy. Wounds were present for at least 8 weeks (mean, 5.5 +/- 4.3 months). They were extensively debrided initially and were measured and photographed at weekly intervals for 12 weeks. Eight patients with nine wounds were treated with placebo solution (controls), and 10 patients with 17 wounds were treated with PDWHF (treatment group). Seventy-eight percent of patients had diabetes mellitus, 72% had occlusive peripheral vascular disease, and 28% had venous disease; distribution of these disorders was equivalent in both groups. Ankle-brachial indexes, which were often spuriously elevated, averaged 0.93 +/- 0.54 in controls and 1.04 +/- 0.56 in patients treated with PDWHF (p greater than 0.5). Mean transcutaneous oxygen tension was 37.8 +/- 11.9 mmHg in controls and 37.1 +/- 9.1 mmHg in patients treated with PDWHF. Initial wound area was larger in controls than in the patients treated with PDWHF (28.9 +/- 45.2 cm2 vs 13.0 +/- 4.4 cm2), but this difference was not statistically significant (p = 0.19). Three (33%) wounds (in two patients) healed in controls, and four (24%) wounds (in three patients) healed in the PDWHF group (p greater than 0.5). The rate of healing in controls was 1.9 +/- 2.7 cm2/week.(ABSTRACT TRUNCATED AT 250 WORDS)