Testing a device to replace the leech for treating venous congestion.

OBJECTIVE To test the effectiveness of a device designed to promote decongestion and tissue survival of a fasciocutaneous flap during 15 hours of complete venous obstruction. METHODS In a porcine model, a 9 x 7-cm fasciocutaneous flap was elevated and the associated veins were clamped, causing complete venous obstruction for 15 hours in 6 control and 6 treatment animals. Up to 3 devices were used to treat the flap in a predetermined pattern. Control flaps were not treated. Measures of treatment efficacy included blood volumes removed; changes in skin color, surface perfusion, and tissue oxygen tension; and end point histologic findings. RESULTS Control flaps were characterized by progressive darkening of skin color, undetectable surface perfusion, and low levels of oxygen tension. Histologic assessment showed severe congestion and extravasation of blood and distinct signs of necrosis. In contrast, treated flaps had significant improvements in skin color, surface perfusion, and subcutaneous oxygen tension. Histologic analysis showed little, if any, congestion and no signs of necrosis. Mean blood volume removed was 29.5 mL/h. CONCLUSION The device was effective in decongesting a large area of tissue during 15 hours of complete outflow obstruction, based on quantitative measurements of tissue health and viability.