Prospective randomized study evaluating an absorbable cyanoacrylate for use in vascular reconstructions

BACKGROUND: An easy-to-use vascular sealant with good safety and efficacy is needed to prevent anastomotic bleeding in vascular surgery. This study evaluated the safety and efficacy of cyanoacrylate surgical sealant in establishing hemostasis of expanded polytetrafluoroethylene to arterial vascular anastomoses in arteriovenous (AV) grafts and femoral bypass grafts. METHODS: This multicenter, randomized, controlled, open-label study was conducted in a hospital setting at 12 sites: 10 in the United States and 2 in Europe. A total of 151 patients undergoing femoral bypass procedures or AV shunt procedures for hemodialysis access using expanded polytetrafluoroethylene grafts were randomized 2:1 to receive cyanoacrylate surgical sealant or the control (oxidized cellulose) between April 26, 2004, and January 18, 2005. Randomization was stratified by clinical site and type of procedure. After the anastomosis, cyanoacrylate surgical sealant or the control was applied to all anastomosis sites for patients undergoing femoral bypass procedures and to only the arterial anastomosis sites for patients undergoing AV shunt procedures. The primary end point was the elapsed time from clamp release to hemostasis. Secondary end points were the proportion of patients achieving hemostasis at t = 0 (immediate), 1, 5, or 10 minutes after clamp release, use of additional adjunctive measures to achieve hemostasis, and occurrence of adverse events. RESULTS: Baseline demographics and clinical characteristics showed that the two treatment groups were similar at baseline. The mean time from clamp release to hemostasis was 119.3 seconds with cyanoacrylate surgical sealant vs 403.8 seconds with the control (P < .001). Immediate hemostasis was achieved in 54.5% of patients receiving cyanoacrylate surgical sealant and in 10% of those receiving the control. The proportion of patients requiring additional adjunctive measures was lower with cyanoacrylate surgical sealant, and the occurrence of adverse events was similar in both groups. CONCLUSIONS: This study demonstrates that cyanoacrylate surgical sealant is effective at reducing the time to hemostasis and achieving immediate hemostasis in AV shunt and femoral bypass procedures and that it is safe for internal use. Cyanoacrylate surgical sealant is an easy-to-use vascular sealant with good safety and efficacy that significantly decreases anastomotic bleeding in vascular surgery.     

A phase 3, randomized, double-blind comparative study of the efficacy and safety of topical recombinant human thrombin and bovine thrombin in surgical hemostasis

BACKGROUND: Plasma-derived bovine thrombin is used as a topical agent to improve surgical hemostasis, but development of antibodies to bovine hemostatic proteins has been associated with increased bleeding and thrombotic complications. Recombinant human thrombin could reduce the risk of these complications. STUDY DESIGN: The objective of this randomized, double-blind, comparative trial was to compare the efficacy, safety, and antigenicity of recombinant human thrombin (rhThrombin) and bovine thrombin as adjuncts to hemostasis in liver resection, spine, peripheral arterial bypass, and dialysis access surgery. Blinded study drug was applied topically to bleeding sites with an absorbable gelatin sponge. The primary efficacy end point was time to hemostasis, summarized as the incidence of hemostasis within 10 minutes. Safety analyses were conducted for 1 month after operation, and the development of antibodies to rhThrombin or to the bovine product was evaluated. RESULTS: Four hundred one patients completed this trial. Hemostasis was achieved at the time-to-hemostasis evaluation site within 10 minutes in 95% of patients in each treatment group. Overall complications, including operative mortality, adverse events, and laboratory abnormalities, were similar between groups. Forty-three (21.5%) patients receiving bovine thrombin developed antibodies to the product; three patients (1.5%; p < 0.0001) in the rhThrombin group developed antibodies to rhThrombin. None of the three patients who developed antirhThrombin antibodies had abnormal coagulation laboratory results or bleeding, thromboembolic, or hypersensitivity events. CONCLUSIONS: Results of this trial suggest that rhThrombin has comparable efficacy, a similar safety profile, and is considerably less immunogenic than bovine thrombin when used for surgical hemostasis.     

Effective control of hepatic bleeding with a novel collagen-based composite combined with autologous plasma: results of a randomized controlled trial

HYPOTHESIS: A novel collagen-based composite of bovine microfibrillar collagen and bovine thrombin combined with autologous plasma is more effective than standard hemostasis (collagen sponge applied with pressure) in controlling diffuse hepatic bleeding after hemihepatectomy or segmental resection of the liver. DESIGN: Randomized controlled trial. SETTING: Seven university-affiliated medical centers. PATIENTS: Sixty-seven adult patients scheduled for hemihepatectomy or segmental resection who received hemostatic intervention with an investigational treatment (n = 38) or control (n = 29). INTERVENTION: Bleeding hepatic tissue was managed in all control subjects with a collagen sponge with manual pressure. Subjects in the experimental group had the sprayable liquid composite intraoperatively applied to the surgical site. The liquid immediately formed a collagen-fibrin gel that was used without concomitant tamponade. MAIN OUTCOME MEASURES: Hemostatic success was defined as the proportion of subjects in each treatment group who achieved complete hemostasis within 10 minutes. Success rates and median times required to achieve controlled bleeding (ie, slight oozing) and complete hemostasis were compared between treatment groups. RESULTS: All 38 subjects in the experimental group achieved complete hemostasis within 10 minutes compared with only 69% (20/29) of control subjects (P<.001). The median time to controlled bleeding was approximately 4 times longer (250 vs 62 seconds) for control subjects than for experimental group subjects (P<.001). The median time required to achieve complete hemostasis also favored the experimental group (150 vs 360 seconds; P<.001). No adverse events related to the use of the experimental hemostatic agent were detected. CONCLUSIONS: The experimental composite is more effective at controlling and stopping diffuse hepatic bleeding than a collagen sponge applied with pressure; it may be a useful hemostatic agent for patients undergoing hemihepatectomy, segmental resection, and related surgical procedures.     

A polymeric sealant inhibits anastomotic suture hole bleeding more rapidly than gelfoam/thrombin: results of a randomized controlled trial

HYPOTHESIS: An experimental polymeric sealant (CoSeal [Cohesion Technologies, Palo Alto, Calif]) provides equivalent anastomotic sealing to Gelfoam (Upjohn, Kalamazoo, Mich)/thrombin during surgical placement of prosthetic vascular grafts. DESIGN: Randomized controlled trial. SETTING: Nine university-affiliated medical centers. PATIENTS: One hundred forty-eight patients scheduled for implantation of polytetrafluoroethylene grafts, mainly for infrainguinal revascularization procedures or the creation of dialysis access shunts, who were treated randomly with either an experimental intervention (n = 74) or control (n = 74). INTERVENTION: Following polytetrafluoroethylene graft placement, anastomotic suture hole bleeding was treated intraoperatively in all control subjects with Gelfoam/thrombin. Subjects in the experimental group had the polymeric sealant applied directly to the suture lines without concomitant manual compression. MAIN OUTCOME MEASURES: Primary treatment success was defined as the proportion of subjects in each group that achieved complete anastomotic sealing within 10 minutes. The proportion of subjects that achieved immediate sealing and the time required to fully inhibit suture hole bleeding also were compared between treatment groups. RESULTS: Overall 10-minute sealing success was equivalent (86% vs 80%; P =.29) between experimental and control subjects, respectively. However, subjects treated with CoSeal achieved immediate anastomotic sealing at more than twice the rate of subjects treated with Gelfoam/thrombin (47% vs 20%; P<.001). Consequently, the median time needed to inhibit bleeding in control subjects was more than 10 times longer than for experimental subjects (16.5 seconds vs 189.0 seconds; P =.01). Strikingly similar findings for all comparisons were observed separately for subgroups of subjects having infrainguinal bypass grafting and for those undergoing placement of dialysis access shunts. CONCLUSIONS: The experimental sealant offers equivalent anastomotic sealing performance compared with Gelfoam/thrombin, but it provides this desired effect in a significantly more rapid time frame.     

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.     

Cryoprecipitate-topical thrombin glue. Initial experience in patients undergoing cardiac operations

The use of fibrin glues as topical hemostatic agents is reported in the European literature. We have composed an analogous compound in our operating rooms using cryoprecipitate and topical thrombin (1000 units/ml) in equal volumes applied directly to the bleeding site. We have used cryoprecipitate-topical thrombin glue in 26 patients undergoing cardiac operations. Severe bleeding not responding to usual methods of control was encountered during or after coronary artery bypass (n = 17), valve replacement (n = 3), bypass plus valve replacement (n = 5), or repair of postinfarction ventricular septal defect (n = 1). Five patients were operated on emergently and four were undergoing their second cardiac operation. The glue was used in four patients while on bypass and fully heparinized and in 17 patients who continued to bleed after separation from bypass and administration of protamine. Hemostasis was achieved in all patients and none required reexploration for bleeding. In five patients undergoing reexploration for postoperative hemorrhage (none having received cryoprecipitate-topical thrombin glue during the initial operation), the glue provided hemostasis when other measures failed, and no additional reexplorations were needed. No patient exhibited hypersensitivity, fibrinolysis, or coagulopathy following the use of this glue. In 16 patients followed for 9 to 12 months postoperatively, no hepatitis has occurred. The highly concentrated fibrinogen in cryoprecipitate is activated by thrombin to form fibrin and bring about rapid hemostasis. Cryoprecipitate-topical thrombin glue is a readily available, reliable, and inexpensive topical hemostatic agent in the patient undergoing a cardiac operation.     

Prospective, randomized, controlled clinical trial of a novel matrix hemostatic sealant in children undergoing adenoidectomy.

PROBLEM ADDRESSED: Floseal is a novel matrix hemostatic sealant composed of collagen-derived particles and topical bovine-derived thrombin. It is applied as a high-viscosity gel for hemostasis and has been clinically proven to control bleeding. This study is a prospective, randomized, controlled clinical trial of Floseal sealant compared to traditional suction cautery hemostasis in children undergoing adenoidectomy. METHODS AND MEASURES: Seventy patients (mean age 7.0 yrs, 45.7% male) with obstructive sleep apnea underwent traditional cold steel adenoidectomy with an adenoid curette and were then randomized to receive the hemostatic sealant (Floseal) or cautery to obtain hemostasis. Patients were crossed over to the other hemostatic technique if hemostasis was not achieved after more than 100 mL of blood loss or 15 minutes elapsed time. Objective data collected included time to hemostasis and blood loss during hemostasis. Visual analog scales (VAS) were used to record subjective data by the operating surgeon including bleeding following adenoid pack removal (0 = none, 3 = brisk) and ease of operation (1 = extremely easy, 6 = extremely difficult). Parents recorded diet on a journal and were contacted by phone at postoperative day 7 and questioned with regard to return to regular diet and use of narcotics. RESULTS: Compared to patients in the cautery group (n = 35), Floseal patients (n = 35) had significantly shorter times to hemostasis (0.6 +/- 1.3 minutes vs 9.5 +/- 5.4 minutes [mean +/- SD], P < 0.001), less blood loss (2.5 +/- 9.2 mL vs 29.4 +/- 27.1 mL, P < 0.001), less subjective bleeding (0.0 +/- 0.6 vs 2.0 +/- 0.7, [median 4-point VAS +/- SD], P < 0.001), and subjectively easier operations (2.6 +/- 1.0 vs 5.2 +/- 1.0 [mean 6-point VAS +/- SD], P < 0.001). Furthermore, Floseal patients returned to regular diet earlier (2.7 +/- 0.7 vs 4.1 +/- 0.5 days [mean +/- SD], P < 0.001) and had less use of narcotics at 7 days postoperatively (40% vs 69%, P < 0.05). Lastly, three patients in the cautery group were crossed over to the Floseal group, but no Floseal subjects were crossed over to the cautery group. The retail cost of Floseal is US 85 dollars. Operating room costs are estimated at US 12 dollars/minute. Reducing the operative length by 8.9 minutes on average produces a cost savings of US 106.80 dollars per operation. There were no complications in either experimental group including postoperative hemorrhage, hospitalization, blood transfusion, or aspiration. CONCLUSIONS: Floseal matrix hemostatic sealant is a safe, efficacious, easy, and cost-effective technique for obtaining hemostasis in children undergoing adenoidectomy. Limitations of the study include the fact that it is nonblinded, which does allow for some bias in the subjective data recorded. However, utilizing 4 different operating surgeons, 3 of whom were not affiliated with the study, minimized this. CLINICAL SIGNIFICANCE OF STUDY: This study demonstrates the safety and efficacy of a novel hemostatic sealant in children undergoing adenoidectomy. Floseal matrix hemostatic sealant can be used as a first-line hemostatic agent, and it is a good tool in the armamentarium of otolaryngologists who encounter significant bleeding following adenoidectomy.     

Fibrin sealant improves hemostasis in peripheral vascular surgery: a randomized prospective trial

OBJECTIVE: To evaluate the efficacy and safety of an investigational fibrin sealant (FS) in a randomized prospective, partially blinded, controlled, multicenter trial. SUMMARY BACKGROUND DATA: Upper extremity vascular access surgery using polytetrafluorethylene (PTFE) graft placement for dialysis was chosen as a reproducible, clinically relevant model for evaluating the usefulness of FS. The FS consisted of pooled human fibrinogen (60 mg/mL) and thrombin (500 NIH U/mL). Time to hemostasis was measured, and adverse events were monitored. METHODS: Consenting adult patients (n = 48) undergoing placement of a standard PTFE graft were randomized in a 2:1:1 ratio to the treatment group using FS (ZLB Bioplasma AG, Bern, Switzerland), oxidized regenerated cellulose (Surgicel, Johnson & Johnson, New Brunswick, NJ), or pressure. Patients received heparin (3,000 IU IVP) before placement of vascular clamps. If the treatment was FS, clamps were left in place for 120 seconds after the application of study material to permit polymerization. If treatment was Surgicel, clamps were left in place until the agent had been applied according to manufacturer's instructions. If the treatment was pressure, clamps were released as soon as the investigator was ready to apply compression. Immediately after release of the last clamp, the arterial and venous suture lines were evaluated for bleeding. The time to hemostasis at both the venous and arterial sites was recorded. RESULTS: Significant (P < or =.005) reduction in time to hemostasis was achieved in the FS group. Thirteen (54.2%) patients randomized to FS experienced immediate hemostasis at both suture lines following clamp removal compared to no patients using Surgicel or pressure. Only one patient (7.1%) in the Surgicel group and no patients in the pressure group experienced hemostasis at 120 seconds from clamp removal, compared to 13 (54.2%) patients for FS. Adverse events were comparable in all groups. There were no seroconversions. CONCLUSIONS: FS achieved more rapid hemostasis than traditional techniques in this peripheral vascular procedure. FS use appeared to be safe for this procedure.     

Controlled clinical trial of a novel hemostatic agent in cardiac surgery. The Fusion Matrix Study Group

BACKGROUND: We performed a prospective randomized trial to compare FloSeal Matrix (Fusion Medical Technologies, Inc, Mountain View, CA), a gelatin-based hemostatic sealant, with Gelfoam-Thrombin (Gelfoam, Pharmacia and Upjohn, Kalamazoo, MI; Thrombin, Gentrac Inc, Middeton, WI) (control group) to control perioperative bleeding. METHODS: A total of 93 patients undergoing cardiac operations were randomized into the FloSeal or control group after standard surgical means to control bleeding had failed. The bleeding site was evaluated at 1, 2, 3, 6, and 10 minutes after applying the hemostatic agent. If bleeding stopped within 10 minutes, the application was considered to be successful. In the case of a failure, the surgeon could use any means preferred (except FloSeal) to achieve hemostasis. All bleeding sites in a patient were treated with the hemostatic agent to which the patient was randomized. Follow-up evaluation was performed at 12 to 36 hours and 6 to 8 weeks after operation. RESULTS: FloSeal stopped bleeding in 94% of the patients (first bleeding site only) within 10 minutes, compared to 60% in the control group (p = 0.001). At 3 minutes, successful hemostasis was achieved in 72% of the FloSeal group compared with 23% in the control group (p = 0.0001). There was no difference in the adverse event profile between the two groups. CONCLUSIONS: FloSeal Matrix demonstrated efficacy superior to that of Gelfoam-Thrombin and had a safety profile similar to that of Gelfoam-Thrombin when used as a topical hemostatic agent during cardiac surgery procedures.     

Absorbable cyanoacrylate as a vascular hemostatic sealant: a preliminary trial

No absorbable cyanoacrylate tissue adhesive for safe internal surgical use is available. This prospective multicenter preliminary study was designed to evaluate the safety and effectiveness of an investigational absorbable cyanoacrylate (IAC) as an adjunct to hemostasis in arteriovenous shunt (AVS) procedures for dialysis access. Consenting adults (10) underwent placement of expanded polytetrafluoroethylene (ePTFE) upper extremity vascular grafts for AVS access using continuous 5-0 or 6-0 polypropylene after heparinization (> or =3000 units i.v.). Arterial anastomoses were evaluated after sealing with IAC followed by 120 seconds of polymerization time. After vascular clamp removal, the mean time to hemostasis was 9.1 +/- 28.8 seconds. Additionally, 90 per cent (9/10) and 100 per cent (10/10) achieved hemostasis by 1 and 5 minutes, respectively. No patients required further adjunctive hemostatic measures. Adverse event safety data analysis through 12 weeks revealed occlusion of graft or vessel in four patients and graft thrombosis in one patient, all thought unrelated to sealant use. Other unrelated adverse events (bleeding, death, deep venous thrombosis, edema, erythema, hematoma, infection, and rash) occurred in single patients. Thus, IAC could be a useful sealant for vascular procedures with a potentially satisfactory safety profile. Larger, randomized, multicenter, prospective trials to further evaluate the use of this material are indicated and appropriate.     

Comparative study of the efficacy of the common topical hemostatic agents with fibrin sealant in a rabbit aortic anastomosis model

OBJECTIVE: The purpose of this study was to compare the hemostatic efficacy of the common surgical hemostatic agents with fibrin sealant (FS) and to assess their functional strength to secure hemostasis in lieu of placing additional sutures. METHODS: End-to-end anastomosis of transected abdominal aorta was performed in moderately anticoagulated rabbits using 4 or 6 interrupted sutures. The suture line was covered either with gauze alone ("untreated") or with gauze plus Gelfoam, Avitene, Surgicel, FloSeal, or FS, following which blood flow was restored. Blood loss was absorbed by gauze and measured. The surviving rabbits were recovered and the repaired vessel was examined histologically 4 weeks after operation. The investigators were blinded to the treatment groups. Aortic anastomoses using 8 or 12 sutures (untreated) were also performed. RESULTS: Untreated 4-suture anastomosis of aorta resulted in a profuse hemorrhage with an average 108.0 +/- 19.2 (mean +/- SD) ml blood loss and 100% mortality (n = 4). FS application sealed the anastomoses, prevented blood loss (P < 0.01 vs untreated) and exsanguination of the rabbits (n = 4). Other hemostatic agents reduced the bleeding to varying degrees compared to the untreated animals (Gelfoam 66.4 +/- 17.6, Avitene 80.6 +/- 34, Surgicel 66.7 +/- 16.7, FloSeal 44.2 +/- 8.5 ml blood loss, n = 4/group), but the changes were not statistically significant. One to three rabbits in each group survived the operation. Six-suture aortic anastomoses, untreated, resulted in 67.7 +/- 21.8 ml blood loss and 100% survival (n = 6). Application of FS produced immediate and sustained hemostasis in all the animals (P < 0.01 vs untreated). Other hemostatic agents also reduced the bleeding (Gelfoam 42.5 +/- 10, Avitene 50.9 +/- 12.4, Surgicel 32.1 +/- 14, FloSeal 33.9 +/- 5.4 ml blood loss, n = 6/group), but the changes were not statistically significant. The 8- and 12-suture aorta repairs resulted in a moderate blood loss (43.9 +/- 19 and 21.3 +/- 14.9 ml, respectively), followed by a stable hemostasis that precluded the need to use any hemostatic agent. The aortic cross-clamping time of the 12-suture and time to hemostasis for both the 8- and the 12-suture techniques were significantly longer than those of the 4-suture plus FS application (P < 0.01, P < 0.01 and P < 0.05, respectively). CONCLUSION: In a moderate coagulopathy, FS was proven to be the most efficacious hemostatic agent, producing immediate and sustained hemostasis at the arterial anastomotic site. This high efficacy is in part attributed to the strong tissue adhesive property of this agent. FS application may potentially ease the anastomosis and shorten the duration of timely critical vascular procedures.     

Prospective randomized study of a protein-based tissue adhesive used as a hemostatic and structural adjunct in cardiac and vascular anastomotic repair procedures

BACKGROUND: The purpose of this study was to determine whether adjunctive use of the bovine serum albumin and glutaraldehyde tissue adhesive BioGlue (BioGlue Surgical Adhesive; CryoLife, Inc) could reduce the rate of anastomotic bleeding in patients undergoing cardiac and vascular repair procedures when compared with a standard repair control. This was a prospective multicenter, randomized, controlled clinical trial conducted in accordance with the IRB at each participating institution. STUDY DESIGN: A total of 151 patients consented to participation and were randomly assigned to standard repair plus BioGlue (n = 76) or standard repair alone (n = 75). These two groups were statistically homogeneous for age, gender, race, procedure, and number of anastomoses. Patients underwent cardiac procedures (n = 49), aortic procedures (n = 105), or peripheral vascular procedures (n = 48). RESULTS: Anastomotic bleeding was significantly reduced in the BioGlue group (18.8% of anastomoses) compared with the control group (42.9% of anastomoses, p < 0.001). Pledget use was reduced in the BioGlue group (26.2%) compared with the control group (35.9%, p = 0.047). Days in the ICU and total days in the hospital were slightly higher in the control group. Adverse event profiles were equivalent between the two groups except for occurrence of neurological defects, which were threefold less in the BioGlue group (p = 0.009). CONCLUSIONS: This study demonstrates that using BioGlue as an adjunct to standard repair methods is safe and significantly reduces the occurrence of intraoperative anastomotic site bleeding in cardiac and vascular repair patients. Using BioGlue along suture lines reinforces anastomoses, thus minimizing pledget use.     

Whole blood thrombin: development of a process for intra-operative production of human thrombin

Thrombin-based clotting agents currently used for topical hemostasis with absorbable sponges, fibrin sealants, and platelet gels are primarily derived from bovine or pooled human plasma sources. Autologous thrombin has important safety advantages in that it does not carry the same safety concerns as pooled plasma-derived products and it avoids exposure to risks associated with bovine-derived proteins. The goal of our research was to develop a rapid, reliable, and simple to perform process to generate autologous human thrombin in the intraoperative setting, from patient whole blood as the starting source material. Using whole blood instead of plasma as the starting material, it is possible to avoid the inherent delay in thrombin availability associated with a primary step of plasma isolation. In this study, we varied several key processing parameters to maximize thrombin production, reproducibility and stability. Autologous thrombin production was generated using a dedicated, single use disposable with a sterile reagent. The disposable consists of a tubular reaction chamber containing glass microsphere beads to activate the alternative pathway of the coagulation cascade. At the end of the process, thrombin-activated serum was harvested from the reaction chamber. The average activity of the thrombin produced at room temperature by this system was 82.8 +/- 15.9 IU/mL. The total processing time was < 30 minutes. The system was compatible with Anticoagulant Citrate Dextrose-Solution A (ACD-A) (8%-12%). The average volume of thrombin harvested from each aliquot of blood was 7.0 +/- 0.3 mL, and the stability of thrombin was observed to be temperature dependent, with cold storage better preserving thrombin activity. Clot times with platelet concentrates at 1:4.3 and 1:11 ratios (thrombin to platelet concentrate) were < 10 and 20 seconds, respectively. A process for the preparation of thrombin from whole blood, under conditions compatible with the resources of an operating room, has been developed. The device is simple to use, requires 30 minutes, and can consistently produce thrombin solutions that achieve rapid clotting of platelet concentrates, plasma, and fibrinogen concentrates even when mixed at thrombin to blood product ratios of 1:11.     

Fibrin sealant facilitates hemostasis in arteriovenous polytetrafluoroethylene grafts for renal dialysis access

A prospective randomized study was performed to evaluate the efficacy of fibrin sealant (FS) in patients undergoing upper-extremity polytetrafluoroethylene (PTFE) graft placement for dialysis. This procedure appears to be a reproducible and clinically relevant model for evaluating FS in vascular surgery. Consenting adult patients (n = 28) undergoing placement of a PTFE graft (6 mm) were randomized to either the treatment group using FS (Hemaseel APR, Haemacure Corp., Sarasota, FL) or control comparator groups (four) of bovine thrombin (T) (Thrombogen, GenTrac Inc., Middleton, WI), pressure (P), bovine thrombin (Thrombogen, GenTrac Inc.) -soaked cellulose sponges (TG) (Gelfoam, Upjohn Co., Kalamazoo, MI), or oxidized regenerated cellulose (S) (Surgicel, Johnson & Johnson, New Brunswick, NJ). All patients received heparin (3000 IU intravenous push) before placement of vascular clamps. The mean time to hemostasis was 29.3 seconds for FS, 147.4 seconds for T, 872.2 seconds for P, 346 seconds for TG, and 1044.5 seconds for S. There were no significant adverse events. FS appeared to be a superior hemostatic agent in these vascular procedures. No complications from FS were noted.     

A multicenter, prospective, randomized trial evaluating a new hemostatic agent for spinal surgery

STUDY DESIGN: A prospective, randomized trial comparing Proceed, a gelatin-based hemostatic sealant (treatment), with Gelfoam-thrombin (control) in stopping intraoperative bleeding during spinal surgery. OBJECTIVES: To determine the effectiveness and safety of Proceed. SUMMARY OF BACKGROUND DATA: Proceed has been tested in animal models to determine its safety and effectiveness as a hemostatic agent. The current study was conducted under a Food and Drug Administration-approved Investigational Device Exemption to evaluate the effectiveness and safety of Proceed in humans. METHODS: For this study, 127 patients undergoing spinal surgery were randomized into either the treatment or control group after standard surgical means to control bleeding had failed. The bleeding site was evaluated at 1, 2, 3, 6, and 10 minutes after the hemostatic agent was applied. The application was considered successful if the bleeding stopped within 10 minutes. Follow-up evaluation was performed at 12 to 36 hours, then at 6 to 8 weeks after surgery. RESULTS: Proceed stopped bleeding in 98% of the patients (first bleeding site only) within 10 minutes, as compared with 90% of the control patients (P = 0.001). At 3 minutes, successful hemostasis had been achieved in 97% of the Proceed group, as compared with 71% of the control group (P = 0.0001). There was no difference in the adverse event profile between the two groups. CONCLUSIONS: A significantly larger number of bleeding sites had achieved hemostasis with Proceed than with Gelfoam-thrombin at 1, 2, and 3 minutes after application. Proceed was as safe as Gelfoam-thrombin when used for hemostasis during spinal surgery procedures.     

Perioperative topical bovine thrombin exposure is not associated with hemodialysis graft thrombosis

Arteriovenous (AV) graft use as hemodialysis access remains highly prevalent, with a consequent high thrombosis rate. The magnitude of this problem requires that all potentially modifiable risk factors for graft thrombosis be thoroughly investigated. During graft surgery, topical bovine thrombin is often administered, which can lead to the development of antibovine thrombin antibodies and subsequent hemostatic changes. A recent study correlated the presence of plasma antibovine thrombin antibodies with graft thrombosis in hemodialysis patients. We therefore hypothesized that perioperative topical bovine thrombin exposure would lead to the development of antibovine thrombin antibodies and graft thrombosis. We screened 314 hemodialysis patients and identified 73 patients who had 74 grafts placed for whom complete data on perioperative topical bovine thrombin exposure and subsequent graft outcomes was available. Sixty-one of these patients were available for retrospective measurement of antibovine thrombin antibodies, antihuman thrombin antibodies, and the thrombin activation markers thrombin activatible fibrinolysis inhibitor (TAFI) and thrombin precursor protein (TpP). In these grafts, there was no significant association between topical bovine thrombin exposure and primary assisted patency (P = 0.37). The presence of antibovine thrombin antibodies (P = 0.13), antihuman thrombin antibodies (P = 0.10), and increased TAFI (P = 0.18) were associated with trends toward reduced primary assisted patency which did not reach significance. There was a correlation between antibovine thrombin antibodies and antihuman thrombin antibodies (r = 0.30, P < 0.0001) and between TAFI and TpP trade mark (r = 0.30, P < 0.0001), but no significant correlation between topical bovine thrombin exposure and elevated levels of antibovine thrombin antibodies, antihuman thrombin antibodies, TAFI or TpP trade mark. We conclude that perioperative topical bovine thrombin exposure is not associated with subsequent graft thrombosis.     

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.     

Hemostatic effect of Vivostat patient-derived fibrin sealant on split-thickness skin graft donor sites

Topical hemostatic agents are used frequently to control bleeding of skin graft donor sites. In this study, the hemostatic properties of Vivostat (Vivolution A/S, Birker?d, Denmark) patient-derived fibrin sealant were compared with a control group of spray thrombin solution, which is considered an industry standard for topical hemostasis. Treatments were applied simultaneously to two randomly chosen halves of a single split-thickness single donor site in patients in five United States surgical centers. The time to achieve satisfactory hemostasis (< or =10 min) was estimated on each half of the wound as the time at which active bleeding had stopped and the wound was suitable for application of a surgical dressing. The time to hemostasis of wounds treated with Vivostat (Vivolution A/S) patient-derived sealant was significantly shorter in comparison with wounds treated with thrombin solution (medians: Vivostat, 31 seconds; thrombin, 58 seconds; p=0.0012). No abnormalities in wound healing were reported for either treatment site 1 week after the operation. Vivostat (Vivolution A/S) sealant is a more rapidly effective topical hemostatic agent than thrombin on split-thickness skin graft donor sites.     

Prospective randomized evaluation of a collagen/thrombin and autologous platelet hemostatic agent during total knee arthroplasty

The purpose of this study was to evaluate the effectiveness of a collagen/thrombin and autologous platelet hemostatic agent in preventing blood loss during primary total knee arthroplasty. This prospective, double-blinded, randomized study was designed to enroll a total of 100 patients. Patients were randomized 1:1 to either the treatment arm (standard hemostasis plus study product) or the control arm (standard hemostasis alone). Transfusion requirements, as determined by a blinded investigator using standardized criteria, were significantly lower in the treatment group (no blood transfusions) compared with the control group (5 transfusions; P = .007). These data support the addition of the study product to prevent blood transfusions after primary total knee arthroplasty.