Augmented blood removal after medicinal leech feeding in congested tissue flaps.

Reconstructive microsurgery is performed to reattach, transfer, or transplant body tissues. Venous congestion is a complication that threatens the viability of the affected tissue and is often treated with medicinal leeches. Leech therapy has two phases: active bloodletting and passive bleeding from the leech wound after detachment, which can last for several hours. Unfortunately, the small blood volumes removed by medicinal leeches are generally ineffective in decongesting tissue. Our goal was to develop a device to augment blood removal during the passive-bleeding phase of leech therapy with the use of a porcine model of venous congestion. Results indicated that the use of the device resulted in significant increases in blood retrieval relative to reports of passive bleeding alone (141%, 156%, and 155% in 1, 2, and 3 hours, respectively). These results are an encouraging first step toward development of a mechanical device that completely replaces the use of medicinal leeches in modern medicine.