A clamp for direct transfusion of blood. A demonstration

Abstract

The clamp is similar in its construction to an artery forceps without the grooves. At the tip of each blade there is attached a small cannula with a smooth bore. At the inner edge of each cannula four small pin points are attached, and on the outer surface of the cannula four grooves are cut. When the clamp is closed, the pins of one cannula lie in the grooves of the other. The pins are bent outward and therefore the cannulas have a pyramidal form, so that each pin can lie snugly in its groove. At the beginning of the operation, both halves of the clamp are separated. The vein is pushed through one cannula and its wall is hooked on the pins. The same is done with the artery and the other half of the clamp. Then both halves of the clamp are united and clamped. I believe that when we deal with small blood vessels it is easier to hook the walls on the pins than to turn them back like a cuff as is done in Crile's cannula. When the clamp is closed, both blood vessels are connected with the endothelial surfaces.

I have performed several operations on dogs, uniting the femoral or cervical vein of one dog to the femoral artery of another. The transfusion was kept up for over half an hour, until the donor was practically exsanguinated. There was no clotting, leakage, or any other defect in the clamp.