Topic: Chemistry
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Effect of a Chitosan-Based Hemostatic Dressing on Blood Loss and Survival ina Model of Severe Venous Hemorrhage and Hepatic Injury in Swine
Effect of a Chitosan-Based Hemostatic Dressing on Blood Loss and Survival ina Model of Severe Venous Hemorrhage and Hepatic Injury in Swine AnthonyE.
Chitosan is the deacetylatedform of chitin. In general, the generic term chitosan is applied when the extent ofdeacetylation is above 70%andthegeneric term chitin is used when the extent of deacetylationis insignificant, or below 20%. With less than 100%deacetylation, the chitosan polysaccharide is a linear block copolymer containing both N -acetyl- D -glucosamine and D -glucosamine monomer units. In its acid salt form, chitosan demonstratesmucoadhesive activity,7 which makes it an ideal candidate for consideration as a hemostatic agent. A variety of forms of chitins and chitosans have been used to enhance hemostasis in experimental studies involving bleed- ingfromsmall parenchymal defects and similar experimental insults. Liquid chitosans improved hemostasis in several an- imalstudies. 8-11 Hemostatic activity of thin membranes of chitosan have been demonstrated in models involving peri- tonealabrasions in rabbits.12 Thin membranes of chitin have been effective for surface splenic incisions and isolated splenic capsular stripping 13,14 in animal models, and in 3-mm-deep intestinal wall incisions inhuman subjects.
Most reported mortality rates for these injuries are greater than 60%.16 Currently, the most effective method for treating grade V liver injuries appears to be packing the abdomen with gauze sponges to achievetamponade followed by reoperation for pack removal at a later time. 17-19 An effective hemostatic dressing could augment current methods for control of this severe form of hemorrhage. Recently, a freeze-dried chitosan-based dressing has been developed. This chitosan dressing20 was designed to optimize the muco- adhesive surface density and structural integrity of chitosan at the site of injury. Using a model of severe hepatic trauma and vascular injury in swine, we examined the effects of afreeze- dried chitosan-based dressing on blood loss and short-term survival.
Source: www.hemcon.com
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