Fibrin sealants were one of the first modern hemostatic agents, but their initially limited use opened the door for other novel hemostatic products, many of which are now more familiar to most surgeons. Gelatin-based hemostatic agents are abundant in modern operating rooms, and were first introduced in the 1940s as Gelfoam. In their fundamental form, gelatin-based hemostatic agents have undergone very little evolution since their introduction. Gelfoam and Surgifoam are still offered in similar preparations as their initial release. Gelfoam is a purified pork skin gelatin, and its hemostatic properties, although not entirely understood, are felt to be more physical rather than related to direct effects on the clotting cascade. [22] Gelfoam can be used in several ways, either in dry sponge form, moistened with injectable sodium chloride solution, or, commonly, saturated with topical purified thrombin. The combined application with topical thrombin is one of the few advancements made with gelatin-based hemostatic agents. The addition of thrombin can enhance the hemostatic properties of gelatin sponge hemostatics, but plain Gelfoam or Surgifoam is affordable and readily accessible. It is considered a mediocre hemostat by some surgeons, but has been noted to have success when used in its plain form for hemostasis in tubeless percutaneous nephrolithotomy. [23]
A property of gelatin sponge hemostatics is the ability to absorb upwards of 40 times its weight in blood or fluids, and its capacity to expand up to 200% in vivo. [22] This can be construed as a negative property in some settings. Another major advancement in the field of gelatin-based hemostatic agents came in the development of the product Floseal. Approved for commercial use in the US in 1999, Floseal combines human-derived thrombin with bovine-derived gelatin matrix granules which are mixed at the time of use. [24] The major evolution of this product is the liquid nature of Floseal vs gelatin sponge, as well as a novel crosslinking of the gelatin matrix granules that minimizes in vivo expansion of the product. [25] Although this is not an important property of a hemostatic agent in some surgical approaches, the liquid nature of the product does facilitate application, especially in minimally invasive surgery. As with gelatin sponge agents, Floseal is absorbable and well-tolerated. Rare reports of abscess formation or granuloma formation have been reported with the use of gelatin-based agents; however, some of these have been attributed to the radiologic appearance on postoperative imaging of gelatin sponges. [26],[27] Accessibility, ease of use, and effective hemostasis make gelatin-based hemostatic agents a popular tool in reducing surgical morbidity from blood loss.