The problem of bleeding has caused complications in surgery or after traumatic damage for generations. Different techniques have been used to control the flow of blood, such as the application of hot tar during a more barbaric age, or the use of sutures or ligatures to tie off bleeding vessels or a small cautery being used to burn bleeders, or assorted clamps, adapted for particular surgical techniques. Various forms of dressings have been used to encourage clotting or otherwise control the flow of blood. Various forms of absorbable elements for contact with the wound surface have been suggested, including such materials as foamed gelatin or knitted oxidized regenerated cellulose. The history of surgery shows many other materials have been used to control bleeding.
In general, the desirable aspects of hemostats are recognized, but new and improved hemostats are in demand.