CLINICAL PHARMACOLOGY
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GELFOAM Sterile Compressed Sponge has hemostatic
properties. While its mode of action is not fully understood, its effect
appears to be more physical than the result of altering the blood clotting
mechanism.
When not used in excessive amounts, GELFOAM is absorbed
completely, with little tissue reaction. This absorption is dependent on
several factors, including the amount used, degree of saturation with blood or
other fluids, and the site of use. When placed in soft tissues, GELFOAM is
usually absorbed completely within four to six weeks, without inducing
excessive scar tissue. When applied to bleeding nasal, rectal, or vaginal
mucosa, it liquefies within two to five days.
Clinical Studies
GELFOAM Sterile Compressed Sponge is a water-insoluble,
hemostatic device prepared from purified porcine skin gelatin, and capable of
absorbing up to 45 times its weight of whole blood.4 The absorptive
capacity of GELFOAM is a function of its physical size, increasing as the size
of the gelatin sponge increases.5
The mechanism of action of surface-mediated hemostatic
devices is supportive and mechanical.5 Surface-acting devices, when
applied directly to bleeding surfaces, arrest bleeding by the formation of an
artificial clot and by producing a mechanical matrix that facilitates clotting.6
Jenkins et al7 have theorized that the clotting effect of GELFOAM may
be due to release of thromboplastin from platelets, occurring when platelets
entering the sponge become damaged by contact with the walls of its myriad of
interstices. Thromboplastin interacts with prothrombin and calcium to produce
thrombin, and this sequence of events initiates the clotting reaction. The
authors suggest that the physiologic formation of thrombin in the sponge is
sufficient to produce formation of a clot, by its action on the fibrinogen in
blood.7 The spongy physical properties of the gelatin sponge hasten
clot formation and provide structural support for the forming clot.6,8
Several investigators have reported that GELFOAM becomes
liquefied within a week or less and is completely absorbed in four to six
weeks, without inducing excessive scar formation.4,7,9,10,11 Barnes10
reviewed experiences with GELFOAM in gynecologic surgery. No excessive scar
tissue, attributable to the absorption of GELFOAM, could be palpated at
postoperative examination.
Animal Pharmacology
Surface-acting hemostatic devices, when applied directly
to bleeding surfaces, arrest bleeding by providing a mechanical matrix that
facilitates clotting.6,8,13,14 Due to their bulk, surface-acting
hemostatic agents slow the flow of blood, protect the forming clot, and offer a
framework for deposition of the cellular elements of blood.6,7,8,13
MacDonald and Mathews12 studied GELFOAM
implants in canine kidneys and reported that it assisted in healing, with no
marked inflammatory or foreign-body reactions.
Jenkins and Janda13 studied the use of GELFOAM
in canine liver resections and noted that the gelatin sponge appeared to offer
a protective cover and provide structural support for the reparative process.
Correll et al14 studied the histology of
GELFOAM Sterile Compressed Sponge when implanted in rat muscle and reported no
significant tissue reaction.
REFERENCES
4. Council on Pharmacy and Chemistry: Absorbable Gelatin
sponge — new and nonofficial remedies. JAMA 1947; 135:921.
5. Goodman LS, Gilman A: Surface-acting drugs, in The
Pharmacologic Basis of Therapeutics, ed 6. New York, MacMillan Publishing Co. 1980,
p 955.
6. Guralnick W, Berg L: GELFOAM in oral surgery. Oral
Surg 1948; 1:629-632. 7. Jenkins HP, Senz EH, Owen H, et al: Present status of
gelatin sponge for control of hemorrhage. JAMA 1946; 132:614-619.
8. Jenkins HP, Janda R, Clarke J: Clinical and
experimental observations on the use of gelatin sponge or foam. Surg 1946; 20:124-132.
9. Treves N: Prophylaxis of post mammectomy lymphedema by
the use of GELFOAM laminated rolls. Cancer 1952; 5:73-83.
10. Barnes AC: The use of gelatin foam sponges in
obstetrics and gynecology. Am J Obstet Gynecol 1963; 86:105-107.
11. Rarig HR: Successful use of gelatin foam sponge in
surgical restoration of fertility. Am J Obstet Gynecol 1963; 86:136.
12. MacDonald SA, Mathews WH: Fibrin foam and GELFOAM in
experimental kidney wounds. Annual American Urological Association, July 1946.
13. Jenkins HP, Janda R: Studies on the use of gelatin
sponge or foam as a hemostatic agent in experimental liver resections and
injuries to large veins. Ann Surg 1946; 124:952-961.
14. Correll JT, Prentice HR, Wise EC: Biologic
investigations of a new absorbable sponge. Surg Gynecol Obstet 1945; 181:585-589.