Leeches: controlled trial in venous compromised rat epigastric flaps.

Leeches were studied for their efficacy to improve survival of venous compromised rat skin flaps. In 22 rats, bilateral epigastric island flaps were created and subjected to 6 h of venous occlusion. One flap in each animal was randomised to leech treatment, while the contralateral flap served as its own control. Flap survival, leech feeding time, weight gained by the leech and bleeding time from leech bites were measured. The area of flap survival was significantly increased in leech treated flaps compared to contralateral controls (n = 22 pairs, p = 0.03; Wilcoxon signed rank test). Weight gained in the feeding leech averaged 1.3 +/- 0.2 g (n = 18). Leech feeding time was 107 +/- 13 min (n = 18). Bleeding time from each leech bite averaged 79 +/- 12 min (n = 18). Hence, the extent of flap necrosis resulting from venous impairment can be partly diminished by leech treatment until definitive surgical venous revascularisation.