Are leeches effective in local/regional skin flap salvage?

BACKGROUND Leeches have been used clinically to help salvage venous-congested skin flaps since 1960. Numerous articles have described their success in benefitting the survival of local, regional, and free flaps. However, the clinical application remains imprecise. The theory behind leech therapy is that leech bites decrease venous congestion in compromised skin flaps. Venous congestion is detrimental to skin flap survival, because it leads to microcirculatory thrombosis and blood stasis. The active enzyme in leech saliva, hirudin, is a powerful anticoagulant. This allows blood to flow more freely at the bite site. The objective of leech therapy is to establish temporary venous outflow until further neovascularization has taken place. Typically, leeches are applied to the compromised area of the flap every several hours and are removed once they are no longer biting the tissue. Patients must have antibiotic coverage (such as fluoroquinolones, sulfamethoxazoletrimethoprim, or a secondor third-generation cephalosporin) during leech therapy to reduce the risk of infection (commonly caused by Aeromonas hydrophilia). Hemoglobin should be monitored daily, because treatment can lead to sudden anemia requiring blood transfusions. This article reviews the evidence surrounding the use of leeches to salvage failing local and regional skin flaps to the head and neck area.