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  Hemostatic dressingUSPTO Application #: 20060155234Title: Hemostatic dressing Abstract: The present invention relates to a hemostatic dressing which comprises a plurality of layers that contain resorbable materials and/or coagulation proteins. In particular, the invention includes dressings in which a layer of thrombin is sandwiched between a first and second layer of fibrinogen and wherein the layer of thrombin is not coextensive with the first and/or second layer of fibrinogen. The hemostatic dressings are useful for the treatment of wounded tissue. (end of abstract) Agent: Sterne, Kessler, Goldstein & Fox PLLC - Washington, DC, US Inventors: Martin J Macphee, Dawson Beall, Stanley Friedman USPTO Applicaton #: 20060155234 - Class: 602041000 (USPTO) Related Patent Categories: Surgery: Splint, Brace, Or Bandage, Bandage Structure The Patent Description & Claims data below is from USPTO Patent Application 20060155234. Brief Patent Description - Full Patent Description - Patent Application Claims
FIELD OF THE INVENTION [0001] The present invention relates to a hemostatic dressing that comprises a plurality of layers that contain resorbable materials and/or coagulation proteins. The hemostatic dressing is useful for the treatment of wounded tissue. BACKGROUND OF THE INVENTION [0002] The control of hemorrhage (bleeding) is a critical step in first aid and field trauma care. Unfortunately, the occurrence of excessive bleeding or fatal hemorrhage from an accessible site is not uncommon. J. M. Rocko et al., J. Trauma 22:635 (1982). Mortality data from Vietnam indicates that 10% of combat deaths were due to uncontrolled extremity hemorrhage. SAS/STAT Users Guide, 4th ed. (Cary, N.C.: SAS Institute Inc; 1990). Up to one third of the deaths from exsanguination during the Vietnam War could have been prevented by the use of effective field hemorrhage control methods. SAS/STAT Users Guide, 4th ed. (Cary, N.C.: SAS Institute Inc; 1990). [0003] Although civilian trauma mortality statistics do not provide exact numbers for prehospital deaths from extremity hemorrhage, case and anecdotal reports indicate similar occurrences. J. M. Rocko et al., J. Trauma 22:635 (1982). These data suggest that a substantial increase in survival can be effected by the prehospital use of a simple and effective method of hemorrhage control. [0004] Liquid fibrin sealants have been used as an operating room adjunct to hemorrhage control. J. L. Garza et al., J. Trauma 30:512-513 (1990); H. B. Kram et al., J. Trauma 30:97-101 (1990); M. G. Ochsner et al., J. Trauma 30:884-887 (1990); T. L. Matthew et al., Ann. Thorac. Surg. 50:40-44 (1990); H. Jakob et al., J. Vasc. Surg., 1:171-180 (1984). The widespread use of fibrinogen and thrombin was common in the last year of World War II, but was abandoned because of the transmission of hepatitis. D. B. Kendrick, Blood Program in WW II(Washington, DC: Office of the Surgeon General, Department of Army; 1989), 363-368. [0005] Single donor fibrin sealants have been widely used clinically, not only for hemorrhage control but in various surgical situations. W. D. Spotnitz, Thromb. Haemost. 74:482-485 (1995); R. Lerner et al., J. Surg. Res. 48:165-181 (1990). The American Red Cross and others have developed plasma protein purification methods that seem to eliminate the hepatitis risk. Reiss et al., Trans. Med. Rev. 10:85-92 (1996). [0006] A dry fibrinogen-thrombin dressing (TACHOCOMB.TM., Hafslund Nycomed Pharma, Linz, Austria) is also available for operating room use in many European countries. Schiele et al., Clin. Materials 9:169-177 (1992). Present formulations of this dressing use bovine thrombin. While this fibrinogen-thrombin dressing requires no premixing and is easy to use, its utility is limited by a requirement for storage at 4.degree. C. and the necessity for prewetting with saline solution prior to application to the wound. [0007] A hemostatic sandwich dressing has been described, which contains a layer of thrombin sandwiched between layers of fibrinogen (see, e.g., PCT/US99/10952, which is incorporated herein by reference). Although such dressings can be used in methods for treating wounded tissue, such conventional sandwich dressings can become delaminated, whereby the edges of the layers of the dressing no longer adhere to each other. Such delamination can result in reduced interaction of the dressing components layers, with decreased effectiveness of the dressing in preventing hemorrhage. SUMMARY OF THE INVENTION [0008] The present invention provides a hemostatic dressing (e.g., a bandage) that includes a layer of thrombin sandwiched between a first and a second layer of fibrinogen, wherein the thrombin layer is noncoextensive with the first and/or second fibrinogen layer. Such a hemostatic dressing is useful for treating wounds and offers the unexpected advantage of inhibiting delamination of the layers, as compared with dressings in which the thrombin layer is coextensive with the entire first and second fibrinogen layers. [0009] Thus, the present invention provides a hemostatic dressing which comprises: (i) a first fibrinogen layer; (ii) a thrombin layer adjacent to the first fibrinogen layer; and (iii) a second fibrinogen layer adjacent to the thrombin layer, wherein the thrombin layer is non-coextensive with the first and/or second fibrinogen layers of the hemostatic dressing. [0010] A related dressing of the invention comprises: (i) a resorbable material layer; (ii) a first fibrinogen layer adjacent to the resorbable material layer; (iii) a thrombin layer adjacent to the first fibrinogen layer; and (iv) a second fibrinogen layer adjacent to the thrombin layer, wherein the thrombin layer is noncoextensive with the first and/or second fibrinogen layers of the hemostatic dressing. [0011] In another embodiment, the hemostatic dressing comprises: (i) a first fibrinogen layer; (ii) a resorbable material layer adjacent to the first fibrinogen layer; (iii) a thrombin layer adjacent to the resorbable material layer; and (iv) a second fibrinogen layer adjacent to the thrombin layer, wherein the thrombin layer is non-coextensive with the first and/or second fibrinogen layers of the hemostatic dressing. [0012] The invention also includes methods for treating wounded tissue in a patient, which comprise applying any of the novel hemostatic dressings described herein to wounded tissue. In such methods, the hemostatic dressing can be hydrated with liquids that are exogenous to the wounded tissue, or they can be hydrated with liquids that are endogenous to the wounded tissue. [0013] Also included within the invention are methods for preparing a hemostatic dressing by providing a first layer of fibrinogen, applying a layer of thrombin to the first layer of fibrinogen, and applying a second layer of fibrinogen to the layer of thrombin, wherein the layer of thrombin is noncoextensive with the first fibrinogen layer and/or noncoextensive with the second fibrinogen layer. [0014] Similarly, the invention includes a method for preparing a hemostatic dressing by providing a resorbable or nonresorbable backing layer having attached thereto a first layer of fibrinogen; applying a layer of thrombin to said first layer of fibrinogen on a side of the fibrinogen layer that is opposite of the side to which the resorbable or nonresorbable backing layer is attached; and applying a second layer of fibrinogen to the layer of thrombin, wherein the layer of thrombin is noncoextensive with the first fibrinogen layer and/or noncoextensive with the second fibrinogen layer. [0015] In various embodiments, the thrombin layer is coextensive with 5% to 95% (e.g., 20 to 50%) of the first and second fibrinogen layers, independently. The thrombin layer can be configured in any of a variety of shapes and patterns. For example, and without limitation, the thrombin layer can be configured as an array of spots comprising thrombin, or as a single spot comprising thrombin. Alternatively, the thrombin layer can be configured as a plurality of lines comprising thrombin. [0016] Each layer of the hemostatic dressings can also optionally contain one or more suitable fillers, binding agents and/or solubilizing agents. In addition, each of the hemostatic dressings can also optionally further comprise a release layer which contains a release agent and/or a backing material. [0017] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the invention as claimed. [0018] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which this invention belongs. All patents, patent applications, and publications mentioned herein are incorporated herein by reference. [0019] As used herein, a thrombin layer that is said to be "noncoextensive" with a fibrinogen layer is one in which the spatial boundaries of the thrombin layer in two dimensions are smaller than the spatial boundaries of one or both fibrinogen layers such that the thrombin layer is coextensive with only about 5% to about 95% of the surface area of the first fibrinogen layer of the hemostatic dressing and/or coextensive with only about 5% to about 95% of the surface layer of the second fibrinogen layer of the hemostatic dressing, independently. For example, the thrombin layer can be coextensive with about 10, 20, 30, 40, 50, 60, 70, 75, 80, or 90% of the surface area of each of the first and second fibrinogen layers, independently. A thrombin layer that is "coextensive" with a fibrinogen layer provides full coverage of the fibrinogen layer and is coextensive with 100% of the surface area of the fibrinogen layer. A thrombin layer can be noncoextensive with the first fibrinogen layer and yet be coextensive with the second fibrinogen layer, or vice versa, e.g., by employing fibrinogen layers having different total surface areas or shapes. [0020] "Patient" as used herein refers to human or animal individuals in need of medical care and/or treatment. [0021] "Wound" as used herein refers to any damage to any tissue of a patient that results in the loss of blood from the circulatory system. The tissue can be an internal tissue, such as an organ or blood vessel, or an external tissue, such as the skin. The loss of blood can be internal, such as from a ruptured organ, or external, such as from a laceration. A wound can be in a soft tissue, such as an organ, or in hard tissue, such as bone. The damage may have been caused by any agent or source, including traumatic injury, infection or surgical intervention. The damage can be life-threatening or non-life-threatening. Continue reading... Full patent description for Hemostatic dressing Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Hemostatic dressing patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Hemostatic dressing or other areas of interest. ### Previous Patent Application: Orthopaedic device for correcting abnormal positions of the toes Next Patent Application: Hemostatic compression bandage Industry Class: Surgery: splint, brace, or bandage ### FreshPatents.com Support Thank you for viewing the Hemostatic dressing patent info. IP-related news and info Results in 0.84508 seconds Other interesting Feshpatents.com categories: Tyco , Unilever , Warner-lambert , 3m |
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