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Pre-clinical subdural tissue reaction and absorption study of absorbable hemostatic devices.

SURGIFOAM (Absorbable Gelatin Sponge, USP), a new absorbable hemostatic sponge, GELFOAM (Absorbable Gelatin Sponge, USP) or Avitene (microfibrillar collagen hemostat) were evaluated in a three-month tissue reaction and absorption study in rabbits. Bilateral craniotomy was followed by subdural implantation of each hemostatic device. A sham control group was treated in a similar way except that no material was implanted. Implantation of these hemostatic devices for 15, 43, or 92 days did not result in any deaths or clinical neurobehavioral abnormalities, changes in cerebrospinal fluid, or significant macroscopic observations at necropsy. The tissue reaction to SURGIFOAM sponge was characterized by transient granulomatous inflammation that was slightly less intense than that observed for GELFOAM sponge which correlated to slightly longer absorption. In contrast, the tissue reaction to Avitene hemostat was characterized by moderate to marked granulomatous inflammation with an acute inflammatory component indicating a greater degree of tissue irritancy. Sequelae of this reaction were still observed at 92 days post-implantation. The tissue reaction in humans to SURGIFOAM sponge used as a hemostatic agent for neurologic surgical procedures is expected to be comparable to that observed with GELFOAM sponge, resulting in no significant adverse reactions for patients. This animal model was useful to assess the tissue reaction and absorption of biomaterials implanted in contact with the central nervous system, and it was able to differentiate between materials of biologic origin.

Animals↗

[Novel method for calculation of hemostatic potential and its clinical applications. 2].

A formula for calculating the hemostatic potential is proposed: HV = -{Ig[(APTT + PTTIS)/(WBCT.Hct)] + IgPF/PT}, where APTT is activated partial thromboplastin time, sec; PTT prothrombin time, sec; IS index of sensitivity of thromboplastin reagent used; WBCT whole blood clotting time after Lee-White, sec; Het hematocrit; PF probability of liquid blood preservation: and PT probability of thrombotic complications. The aim of the study was to evaluate the probability of practical use of the method and its practical potentialities. Statistical analysis (1014 specimens from 402 patients) confirmed the correctness (plausibility) of our concept and of the model of hemostatic potential. Despite the difficulties of calculation, the resultant hemostatic potential value represents the actual conditions of hemostasis in vivo. The physiological norm is represented as small-positive values of hemostatic potential, reflecting the constant "readiness" of blood to coagulation. Time course of hemostatic potential demonstrates the hemostasis status and its stability during various exposures. The homeostatic potential is a value highly sensitive to hemostatic status and outer exposures. Its changes can be used as a criterion of therapy efficacy.

Adult↗

Hemostatic changes in patients with liver cirrhosis.

BACKGROUND: Hemostatic changes in liver disease are complicated. An overall evaluation of the main hemostatic parameters in patients with different degrees of cirrhosis of the liver has not been reported in Taiwan. METHODS: A series of hemostatic tests and parameters including activated partial thromboplastin time, prothrombin time, thrombin time, bleeding time, factor VIII assay, antithrombin activity, fibrinogen, plasminogen, protamine sulfate test, fibrin(ogen) degradation products, D-dimer, thrombin-antithrombin complex (measured by modified antithrombin), tissue plasminogen activator (tPA), plasminogen activator inhibitor-1, euglobulin lysis test and venous occlusion test were performed in 51 patients with cirrhosis of the liver and 33 healthy controls. Among the cirrhotics, 18 were classified as Child-Pugh group A, 16 were B and 17 were C. RESULTS: Plasminogen, antithrombin and platelet count decreased progressively, starting with group A, then B and then C, relative to the controls. Factor VIII, activated partial thromboplastin time, prothrombin time, bleeding time, D-dimer and fibrin(ogen) degradation products increased progressively starting with group A, to B and then C, relative to controls. Severity of cirrhosis correlated with hemostatic changes. No significant change in the fibrinolytic response after challenge with the venous occlusion test was found in either Child-Pugh groups A, B, C or the controls, though progressive increases in tPA were found starting with group A, to B and then C, relative to controls. CONCLUSIONS: Our study proved a close relationship between the severity of cirrhosis and hemostatic changes. Activated partial thromboplastin time was better than bleeding time or thrombin time to demonstrate the severity of liver damage and hemostatic change in cirrhosis. Because the deterioration of coagulation function and increased fibrinolytic activity paralleled the severity of liver cirrhosis, adequate treatment for cirrhotic bleeding should not only correct the coagulation defects, but should also lower the increasing fibrinolytic activity.

Adult↗

Immunofluorescent localization of factor VIII-related antigen, fibrinogen, and several other plasma proteins in hemostatic plugs in humans.

Factor VIII-related antigen and its low ionic strength subunits were demonstrated in endothelium and hemostatic plugs obtained from punch biopsies of bleeding time wounds according to Mielke. No IgG, IgA, IgM, C4-C3, albumin, or prothrombin was demonstrated in the cryostat sections of hemostatic plugs. Antifibrinogen stained the hemostatic plug and fibrin fibers along the edges of the skin wound. Antiplatelet actomyosin stained the hemostatic plug and the endothelium and pericytes of blood vessels. These results suggest that factor VIII is present in the hemostatic plug not by trapping of plasma but by close association with or presence within the blood platelets. The positive staining of a hemostatic plug in which most platelets have undergone the release reaction indicates that antifactor VIII may be useful for the detection of platelet thrombi in tissue of patients with suspected diffuse intravascular coagulation.

Albumins↗

An intraperitoneal tumorous mass caused by granulomas of microfibrillar collagen hemostat (Avitene).

Microfibrillar collagen hemostat (Avitene) is an absorbable topical hemostatic agent prepared from purified bovine corium collagen. Herein, we report the case of a 56-year-old woman who had undergone an ovariohysterectomy for an ovarian mucinous cystadenocarcinoma 3 months previously and then required a second operation for an intraperitoneal mass associated with microfibrillar collagen hemostat. Microscopically, the resected mass was composed mostly of foreign-body granulomas with microfibrillar collagen hemostat materials. Microfibrillar collagen hemostat was used to control bleeding during the first operation. In a very small portion, however, a recurrent mucinous cystadenocarcinoma was also present. This case is worthy of note in that microfibrillar collagen hemostat may produce huge granulomatous masses that clinically mimic a neoplasm, inducing unnecessary and extensive treatment.

Collagen↗

[Relationship of mitral valve area to hemostatic condition in rheumatic mitral stenosis].

The influence of mitral valve area (MVA) on hemostatic conditions was assessed in patients with rheumatic mitral stenosis (MS) without atrial thrombus who underwent percutaneous mitral valvuloplasty (PMV). The Doppler-derived MVA and hemostatic variables were obtained before and 2-3 months after PMV. Hemostatic tests included measurements of beta-thromboglobulin and platelet factor 4 levels as indexes of platelet activation, fibrinopeptide A and thrombin-antithrombin complex as markers of fibrin generation, and D-dimer and plasmin-alpha 2-plasmin inhibitor complex as indexes of active fibrinolysis. Thirty-three measurements in 17 MS patients were subdivided into three groups: group A, 16 samples when MVA was < 1.5 cm2, group B, 12 samples obtained when MVA was 1.5 - < 2.0 cm2, and group C, 5 samples obtained when MVA was > or = 2.0 cm2. The mean level of beta-thromboglobulin was significantly lower in group C (43.6 +/- 32.4 ng/ml) than in group A (142.5 +/- 132.5 ng/ml) or B (163.8 +/- 179.8 ng/ml) (p < 0.05). The incidence of abnormal beta-thromboglobulin was also significantly lower in group C (20%) than in group A (67%) or B (73%) (p < 0.05). Other mean values or incidence of abnormal values of other hemostatic parameters did not differ between the groups. The hemostatic change induced by PMV was examined in 15 MS patients with no change in cardiac rhythm after PMV therapy. The patients were divided into suboptimal (MVA widening < 0.5 cm2, n = 7) and optimal (> or = 0.5 cm2, n = 8) groups. No favorable hemostatic changes were achieved by PMV in the suboptimal group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

A sprayable hemostat containing fibrillar collagen, bovine thrombin, and autologous plasma.

BACKGROUND: A new sprayable hemostat, CoStasis hemostatic device (Cohesion Technologies Inc, Palo Alto, CA), consisting of collagen, thrombin, and autologous plasma was tested versus fibrin sealant and collagen hemostatic sponges. Performance was also monitored as fibrinogen and platelets were depleted from the plasma. In addition, the strength of the CoStasis gel, its sealing ability, its fibrillar structure, and its platelet-aggregating ability were investigated. METHODS: Hemostatic performance was determined with an in vivo bleeding rabbit kidney and spleen model. Differential scanning calorimetry and electron microscopy were used to analyze collagen structure. Sealing ability was determined with a burst-test apparatus. RESULTS: In the in vivo model, CoStasis was superior to fibrin sealant and collagen sponges in achieving a rapid time to hemostasis. The formulation continued to perform well when either platelets or fibrinogen was depleted. CoStasis formed weaker gels than fibrin sealant and could withstand only modest pressures. The collagen in the formulation had a fibrillar structure that was shown to aggregate human platelets. CONCLUSIONS: CoStasis, with the two platelet activators collagen and thrombin in addition to the thrombin-catalyzed formation of fibrin and the sealing properties of the soft gel, provides an excellent atraumatic hemostat.

Aerosols↗

A pilot study evaluating the efficacy of a fully acetylated poly-N-acetyl glucosamine membrane formulation as a topical hemostatic agent.

BACKGROUND: Topical hemostatic agents are frequently needed for control of intraoperative bleeding. Currently available topical products each have potential drawbacks, making a more effective topical hemostatic agent desirable. This study was performed to evaluate the effectiveness of a particular formulation of a newly available polysaccharide polymer, poly-N-acetyl glucosamine (p-GlcNAc), as a topical hemostatic agent for use in the operating room. Swine splenic incision and splenic capsular stripping hemorrhage models were initially used, with a subsequent pilot human study then performed. METHODS: For the swine splenic incision model, anesthetized immature female Yorkshire white swine had a 3 x 8 mm incision created on the spleen. One of 3 agents (p-GlcNAc membrane, oxidized cellulose, or absorbable collagen) was sequentially applied to individual wounds and digitally compressed for 20 seconds. The wound was observed without pressure for 2 minutes. Up to 8 wounds per animal were created in 7 animals. For the swine splenic capsular stripping model a 2 x 2 cm area of capsular stripping on the surface of the spleen to a depth of 3 mm was created. Either p-GlcNAc membrane or oxidized cellulose was applied and digitally compressed for 60 seconds, followed by observation without pressure for 2 minutes. Six wounds per animal were created in 2 animals. If bleeding persisted in either model, a new cycle of compression was applied. These steps were repeated until hemostasis was achieved. No change in hemodynamics or coagulation factors was observed in either model. Subsequently, 10 consecutive patients undergoing elective small-bowel surgery were enrolled on pilot study. A 5 x 3 x 3 mm cruciate incision was created midway between the mesenteric and antimesenteric borders of the small bowel. Either p-GlcNAc membrane formulation or oxidized cellulose was applied (the sequence alternated per patient) with a 400-mg weight used for even, direct pressure. A second cruciate incision was then created on the contralateral side of the bowel to evaluate the second material. The number of applications required for hemostasis was assessed. Hemodynamics, small-bowel pathologic condition, and hematologic parameters were evaluated. RESULTS: The p-GlcNAc membrane required fewer cycles of compression in the swine splenic incision model to achieve hemostasis than either absorbable collagen or oxidized cellulose (1.25 vs 2.58 and 3.41, respectively; P < .01) and caused more effective immediate cessation of bleeding (79% for p-GlcNAc vs 17% for both absorbable collagen and oxidized cellulose). With the more traumatic splenic capsular stripping model, p-GlcNAc required fewer cycles of compression to achieve hemostasis than oxidized cellulose (average, 2.5 versus 6.8 respectively; P < .01) and was able to achieve hemostasis with greater efficacy (50%) in 2 applications than did oxidized cellulose (0%; P < .01). When used in the human pilot study, p-GlcNAc membranes required fewer cycles of compression than oxidized cellulose (2.5 vs 5.4, respectively; P < .002), was able to stop bleeding with greater efficacy in 1 cycle of compression (50% vs 0%, respectively; P < .01), and ultimately accomplished hemostasis in 80% of the cases as opposed to 20%. CONCLUSIONS: On the basis of its greater hemostatic efficacy as compared with collagen or oxidized cellulose-based products, p-GlcNAc holds promise as an effective topical hemostatic agent and deserves further evaluation.

Acetylation↗

Comparison of a new fibrin sealant with standard topical hemostatic agents.

BACKGROUND: Bleeding following liver resection continues to be a significant morbidity of the procedure. Fibrin sealants represent an improvement over conventional topical hemostatic agents, because they contain components that actively form clot. However, most available agents contain nonhuman protein, which represents an immunologic risk. HYPOTHESIS: An investigational surgical fibrin sealant (Crosseal; American Red Cross, Washington, DC) composed of human clottable proteins and human thrombin is more effective than standard topical hemostatic agents in reducing the time required to achieve hemostasis after liver resection. DESIGN: Prospective, randomized, controlled trial. SETTING: Fifteen major referral centers in the United States and the United Kingdom. METHODS: After liver resection using standard surgical techniques, 121 patients seen between May 1999 and May 2000 were randomized to treatment with a 2-component fibrin sealant (n=58) or to standard topical hemostatic agents, used singly or in combination (n=63). Up to 10 mL of Crosseal was administered by a spray applicator, as recommended by the manufacturer, whereas agents used in the control group were applied according to their instructions for use. MAIN OUTCOME MEASURES: The primary outcome measured was time to hemostasis. Secondary outcomes measured included blood loss between application of the hemostatic agent and closure of the abdomen, duration of postoperative biliary drainage, and the occurrence of complications, defined a priori as reoperation for any reason, development of abdominal fluid collections, or bilious appearance of drained fluid for at least 1 day postoperatively. RESULTS: The mean time to hemostasis was 282 seconds with Crosseal, compared with 468 seconds with standard agents (2-sided; P =.06), for the 116 efficacy-evaluable patients. Hemostasis was achieved within 10 minutes in 53 patients (91.4%) treated with the study fibrin sealant and in 44 control patients (69.8%) (2-sided; P =.003). Intraoperative blood loss was similar in the 2 groups. In the Crosseal group, the percentage of patients developing postoperative complications was 17.2%, compared with 36.5% in the control group (2-sided; P =.02). CONCLUSIONS: Compared with the use of standard topical hemostatic agents, Crosseal fibrin sealant significantly reduced the time to achieve hemostasis following liver resection. Patients treated with the new fibrin sealant also experienced significantly fewer postoperative complications.

Adult↗

Efficacy of a novel hemostatic agent in animal models of impaired hemostasis.

This study evaluated the efficacy of a novel sprayable hemostat under both normal conditions and those of compromised coagulation. CoStasistrade mark Surgical Hemostat ("CoStasis"), containing collagen, thrombin, and autologous plasma, was compared to Instattrade mark collagen sponge, an investigational fibrin sealant, and a no treatment control, for the ability to control bleeding in a rabbit kidney model. Hemostatic performance was determined by time to hemostasis and blood loss in a nonsurvival, randomized, in vivo bleeding rabbit kidney model. Under conditions of normal coagulation, as well as aspirin and heparin treatment, hemostasis was achieved faster with CoStasistrade mark than with Instattrade mark and fibrin sealant. With the exception of the time to hemostasis using Instattrade mark sponge in heparinized rabbits, all differences were statistically significant (p < 0.03, Wilcoxon). Blood loss, where measured, was lower with CoStasistrade mark than with the other hemostats under the three coagulation conditions. Statistical significance, (p < 0.03, Wilcoxon), was achieved with all comparisons except with fibrin sealant in aspirin treated animals. The combination of collagen, thrombin, and autologous plasma used in CoStasis, can achieve significantly faster hemostasis than the conventional atraumatic hemostats, collagen sponge, and fibrin sealant under normal conditions and conditions of impaired hemostasis.

Animals↗

Evaluation of feasibility of hydroxyapatite putty as a local hemostatic agent for bone.

Although bone wax is known to cause an inflammatory reaction in soft tissue and a delay of bone healing, it is usually the first choice to arrest bleeding from bone. Hydroxyapatite (HAP) putty is proposed here. This study evaluated the feasibility of HAP putty with respect to whether or not it has potential value as a hemostatic agent for bone. First, the adhesive strength of HAP putty to bone was evaluated. The adhesive strength of HAP putty to wet bone was much higher when compared with that of bone wax, even though the adhesive strengths of HAP putty and bone wax to dry bone were equivalent. Next, to evaluate the hemostatic ability of HAP putty, bony defects were made in rabbits. HAP putty could arrest bleeding from bone within 3 min. However, when the hemostasis was performed with bone wax, bleeding was arrested within 8 min. Thus, HAP putty showed better hemostatic ability than bone wax. Finally, the tissue response to HAP putty in rabbit subcutaneous tissue was evaluated. Histological observation revealed a slight inflammatory response around HAP putty, whereas bone wax was surrounded by moderate inflammatory tissue. In conclusion, HAP putty has good potential value to be a hemostatic agent for bone because it has strong adhesion, good hemostatic ability, and biocompatibility.

Adhesiveness↗

Development of an animal model for assessment of the hemostatic efficacy of fibrin sealant in vascular surgery.

PURPOSE: Sustained hemostatic function of fibrin sealant (FS) is crucial when it is used in cardiovascular surgery. The purpose of this study was to develop a model that can determine the long-term hemostatic efficacy of tissue sealants in a vascular surgery. METHODS: To determine the ability of the model to detect differences in FS performance, various concentrations of FS were prepared and tested. Tensile strength of FS clots was determined in vitro using a tensiometer. Laparotomy was performed on 49 anesthetized rabbits, and a segment of the aorta was occluded, transected, and then sutured in an end-to-end fashion with four or eight interrupted 9-O sutures. The four-suture repair was covered with FS or placebo, and blood flow restored. Spilled blood was absorbed with gauze and weighed to estimate blood loss. Four weeks after surgery the animals were euthanized and the vessels recovered for histology. RESULTS: Average tensile strength of FS clots at 120, 90, and 60 mg/ml topical fibrinogen complex (TFC) concentration was 0.42 +/- 0.07 N, with no significant difference among them. The lowest TFC concentration, 30 mg/ml, produced weaker clots than either 120 or 90 mg/ml (P < 0.05). All rabbits with four-suture anastomoses that were treated with placebo bled to death after the vessel was unclamped (n = 6). Treatment of suture line with standard FS concentration (120 mg/ml TFC, n = 8) sealed the anastomosis and prevented blood loss. Hemostasis was sustained for 4 weeks, allowing vascular healing. All rabbits with the eight-suture anastomosis survived the operation but lost 42 +/- 9.2 ml blood (n = 5). Hemostatic efficacy of FS was unchanged when TFC was diluted to 90 mg/ml (n = 6) but further dilution to 60 mg/ml with water (n = 8) produced significantly less effective clots, with an average blood loss of 5.5 +/- 7.6 ml (P < 0.05) and two fatal clot failures postoperatively. When FS was diluted to 60 mg/ml TFC with a buffer, it maintained its hemostatic strength (n = 6). Further TFC dilution to 30 mg/ml led to consistent bleeding with an average blood loss of 35.3 +/- 10.3 ml (P < 0.001, n = 6). CONCLUSIONS: The four-suture anastomosis of rabbit aorta offers a consistent and reliable method for evaluating the short- and long-term hemostatic efficacy of FS products. This model is not only able to determine the functional differences in various concentrations of FS, but it is also sensitive to detect the subtle changes in FS preparation (e.g., medium composition) that is not detected by in vitro testing.

Anastomosis, Surgical↗

Prognostic value of hemostatic parameters after liver transplantation.

The prognostic value of hemostatic parameters after orthotopic liver transplantation was evaluated in 37 consecutive patients. Six simple hemostatic parameters (prothrombin time, activated partial thromboplastin time, thrombin time, thrombin coagulase time, plasma fibrinogen and platelet count) were obtained for each patient pre-transplantation and daily post-transplantation for at least 8 days. Using the results of these tests, the degree of hemostatic impairment was arbitrarily scored from 0 to 6. Starting from the first day post-transplantation, hemostatic parameters improved progressively, reaching plateau values on day 7 post-transplantation. On day 8 there were significant differences in the activated partial thromboplastin time, prothrombin time, and in the overall hemostatic scores between patients who survived at least 6 months and those who died. Comparing these hemostasis parameters with such liver function tests as AST, ALT and serum bilirubin, univariate analysis showed that activated partial thromboplastin time, coagulation score and AST were significant predictors of 6-month survival, but by multivariate analysis (Cox proportional hazard rate model) only the activated partial thromboplastin time was an independent predictor. Hence, a simple coagulation test is useful for predicting the survival of patients undergoing liver transplantation.

Adolescent↗

Various local hemostatic agents with different modes of action; an in vivo comparative randomized vascular surgical experimental study.

OBJECTIVES: To evaluate the effects of different local hemostatic agents in a new high flow vascular experimental bleeding model. DESIGN: Bovine thrombin combined with collagen matrix (bTcM), microporous polysaccharide hemospheres (MPH), freeze-dried rFVIIa with and without the combination of MPH were compared to a control group (solely compression) in a randomized fashion (20 animals/group). Primary endpoint was hemostasis, and secondary endpoints were time to hemostasis, blood loss, and blood pressure at hemostasis. METHODS: The common carotid artery of heparinized rats was ligated proximally and transected. Compression was applied for one minute followed by application of the topical hemostatic agent. Compression was maintained for another two minutes followed by re-evaluation of hemostasis: if bleeding continued additional compression was applied and thereafter bleeding was checked every minute until hemostasis. RESULTS: All animals in the bTcM group obtained hemostasis compared to 20% in the control group (p<0.0001). The combination of MPH and rFVIIa (70% hemostasis) also showed a significant hemostatic capacity compared to control group (p<0.001). None of the other active treatment groups differed compared to control group. Animals treated with bTcM had a significantly shorter time to hemostasis compared to animals in the other active treatment groups. No significant difference in blood loss and blood pressure at hemostasis was detected. CONCLUSIONS: The most effective hemostatic agent was bTcM, followed by the combination of rFVIIa and MPH, while neither MPH nor rFVIIa alone displayed any hemostatic capacity compared to compression only.

Animals↗

Training with the compactEASIE biologic endoscopy simulator significantly improves hemostatic technical skill of gastroenterology fellows: a randomized controlled comparison with clinical endoscopy training alone.

BACKGROUND: The Erlangen Active Simulator for Interventional Endoscopy (EASIE) was introduced in 1997 for interventional endoscopy training. compactEASIE developed in 1998 is a modified, light-weight version of the original model. Objective evidence of the benefits of training with these models is limited. A randomized controlled study, therefore, was conducted to compare the effects of intensive 7-month, hands-on training in hemostatic techniques by using the compactEASIE model (in addition to clinical endoscopic training) vs. pure clinical training in endoscopic hemostatic methods. METHODS: Thirty-seven fellows in gastroenterology in New York City area training programs were enrolled. Baseline skills were assessed on the simulator for the following techniques: manual skills, injection and electrocoagulation, hemoclip application, and variceal ligation. Twenty-eight fellows were then randomized into two comparable groups. Those randomized to Group A received purely clinical training in endoscopic hemostatic techniques at their hospitals. Those in Group B, in addition, were trained by experienced tutors in 3 full-day hemostasis workshops over 7 months. Both groups underwent a final evaluation on the compactEASIE simulator conducted by their tutors and additional evaluators who were blinded to the method of training. Initial and final evaluation scores were compared for each group and between groups. Outcomes of actual clinical hemostatic procedures performed during the study period also were analyzed. RESULTS: Ten of 14 fellows randomized to Group A (standard training) and 13 of 14 in Group B (intensive training) returned for the final evaluation. For Group B, scores for all techniques were significantly improved. In Group A, a significant improvement was noted for variceal ligation alone. CONCLUSIONS: compactEASIE simulator training (3 sessions over 7 months), together with clinical endoscopic training resulted in objective improvement in the performance by fellows of all 4 endoscopic hemostatic techniques, whereas significant improvement was noted for variceal ligation alone for fellows who had standard clinical training. In clinical practice, fellows who had intensive simulator/clinical training had a significantly higher success rate and a nonsignificant reduction in the frequency of occurrence of complications.

Animals↗

Relative purity of thrombin-based hemostatic agents used in surgery.

BACKGROUND: Hemostatic agents used in surgery contain thrombin isolated from either a bovine or human source. The use of thrombin derived from a bovine source has been associated with the development of an abnormal immune response, but a study of the immunoreactivity of the various commercially available thrombin preparations has not been conducted. This study determined the relative purity of commercially available thrombin preparations, if humans have natural antibodies that recognize these preparations, and if elicited antibodies against bovine thrombin cross-react with other bovine or human hemostatic agents. STUDY DESIGN: The purity of hemostatic agents was determined by protein and substrate assays, electrophoresis, and immunoblotting. The natural antigenicity and cross-reactivity of elicited antibodies were measured by ELISA using serum samples from 82 donors from the Red Cross and serum collected from patients exposed to bovine thrombin, respectively. RESULTS: All of the bovine thrombin preparations were found to contain the xenogeneic carbohydrate galactosealpha1-3galactose. The natural antigenicity of the bovine thrombin preparations was greater than that of a human thrombin preparation and similar to that of porcine aortic endothelial cells. Antibodies elicited against bovine thrombin were found to cross-react with other bovine preparations and other xenoantigens but not with human hemostatic preparations. CONCLUSIONS: All patients have antibovine thrombin antibodies, even before exposure to bovine thrombin-containing hemostatic agents. The cross-reactivity of elicited antibovine thrombin antibodies indicates that if a patient has been sensitized to a bovine product, it is likely safer to use a human-derived product in lieu of a bovine product.

Disaccharides↗

Oxide hemostatic activity.

The tunable in vitro blood clotting activity of high-surface-area hemostatic bioactive glass is evaluated by Thromboelastograph, a clinical instrument for quantifying changes in blood during coagulation. The hemostatic trends associated with hemostatic bioactive glass and a new preparation of spherical hemostatic bioactive glass, along with similar Si- and Ca-containing oxides, are described and related to Si:Ca ratios, Ca2+ availability and coordination environment, porosity, DeltaHHydration, and surface area. Hemostatic bioactive glass is a new material with an excellent efficacy for inducing hemostasis and is chemically distinct from the traditional bioglass employed for bone growth.

Blood Coagulation↗

Newly designed hemostatic technology based on photocurable gelatin.

In this article, the authors present a novel photochemically driven hemostatic technology using photocurable gelatins partially derivatized with photoreactive xanthene dyes (fluorescein, eosin, and rose bengal) and a hydrophilic difunctional macromer. The developed hemostatic glue consisted of dye derivatized gelatin (20 wt%), poly(ethylene glycol) diacrylate (10 wt%), and ascorbid acid (0.3 wt%), all of which were dissolved in a saline solution. Irradiation of the hemostatic glue by visible light produced a swollen gel within a few tenths of a second due to dye sensitized photo-crosslinking and photograft polymerization. An increase in irradiation time resulted in an increased gel yield and reduced water swellability. A rat liver injured on laparotomy was coated with the hemostatic glue. Upon visible light irradiation through an optical fiber, the coated viscous solution was immediately converted to a swollen gel and, concomitantly, hemostasis was completed. Histologic examination showed that, at 7 days after surgery, little gelatin remained in the injured region, scarring with little necrosis occurred, and inflammatory cells infiltrated from the surrounding tissue and tissue regeneration proceeded well. During laparoscopic surgery, in situ gelation of the hemostatic glue on the liver surface was demonstrated using a specially designed fiberscope.

Animals↗