Anaphylaxis to aprotinin in fibrin sealant

A Phase 3, Randomized, Active-controlled, Single-blind Clinical Trial to Evaluate the Efficacy of Fibrin Sealant Grifols in Achieving Hemostasis in Pediatric Surgery

BACKGROUND

In this study, two fibrin sealant products, Fibrin Sealant Grifols (FS Grifols 80 mg/mL fibrinogen; 500 IU/mL thrombin) and Evicel (fibrinogen 55-85 mg/mL; thrombin 800-1200 IU/mL) were studied for efficacy in achieving hemostasis at a targeted bleeding site (TBS) on parenchymous or soft tissue in pediatric surgeries.

METHODS

This phase 3, single-blind, active comparator, non-inferiority trial compared the number of patients achieving hemostasis at a TBS at four (T4 - primary endpoint), seven (T7) and 10 (T10) minutes after application, Safety and tolerability were assessed by recording adverse events during and after procedures. Eligible patients were <18 years old undergoing elective, open, non-cardiac thoracic, abdominal or pelvic surgeries. Preterm (<37 weeks gestation) and newborn (0-27 days) infants were eligible.

RESULTS

At T4, 98.7% of FS Grifols group (n = 91) and 95.4% of the Evicel group (n = 87) achieved hemostasis. All patients with residual bleeding at T4 were undergoing soft tissue surgery. All patients achieved hemostasis by T7. At T10, all patients achieved hemostasis except one (FS Grifols (no observation recorded)). There were no incidents of persistent bleeding. For FS Grifols, 26.5% of patients had treatment-emergent adverse events (TEAEs) and 18.4% for Evicel. One TEAE (moderate procedural pain - FS Grifols group) was considered possibly related to study treatment. Three patients died for reasons unrelated to the study medications.

CONCLUSIONS

FS Grifols was safe and effective at achieving hemostasis in pediatric patients having parenchymous or soft tissue surgeries. The efficacy of FS Grifols was non-inferior to Evicel.

LEVEL OF EVIDENCE

I.

Leukocyte- and platelet-rich fibrin in endoscopic endonasal skull base reconstruction: study protocol for a multicenter prospective, parallel-group, single-blinded randomized controlled non-inferiority trial

BACKGROUND

Recent advances in endoscopic endonasal transsphenoidal approaches (EETA) for skull base lesions have resulted in a significant increase in extent and complexity of skull base defects, demanding more elaborate and novel reconstruction techniques to prevent cerebrospinal fluid (CSF) leakage and to improve healing. Currently, commercially available fibrin sealants are often used to reinforce the skull base reconstruction. However, problems have been reported regarding hypersensitivity reactions, efficacy, and costs. This trial aims to investigate autologous leukocyte- and platelet-rich fibrin (L-PRF) membranes as an alternative for commercially available fibrin glues in EETA-related skull base reconstruction reinforcement.

METHODS/DESIGN

This multicenter, prospective randomized controlled trial aims to demonstrate non-inferiority of L-PRF membranes compared to commercially available fibrin sealants in EETA cases (1) without intra-operative CSF-leak as dural or sellar floor closure reinforcement and (2) in EETA cases with intra-operative CSF-leak (or very large defects) in which a classic multilayer reconstruction has been made, as an additional sealing. The trial includes patients undergoing EETA in three different centers in Belgium. Patients are randomized in a 1:1 fashion comparing L-PRF with commercially available fibrin sealants. The primary endpoint is postoperative CSF leakage. Secondary endpoints are identification of risk factors for reconstruction failure, assessment of rhinological symptoms, and interference with postoperative imaging. Additionally, a cost-effectiveness analysis is performed.

DISCUSSION

With this trial, we will evaluate the safety and efficacy of L-PRF compared to commercially available fibrin sealants.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03910374. Registered on 10 April 2019.

Fibrin Sealants: Challenges and Solutions

Intraoperative bleeding and postoperative bleeding are major surgical complications. Tissue sealants, hemostats, and adhesives provide the armamentarium for establishing hemostatic balance, including the tissue sealant fibrin. Fibrin sealants combine advantages including instantaneous effect, biocompatibility, and biodegradability. However, several challenges remain. This review summarizes current fibrin product generations and highlights new trends and potential strategies for future improvement.

Intraoperative anaphylaxis due to aprotinin after local application of fibrin sealant diagnosed by skin tests and basophil activation tests: a case report

Background

There are few cases of anaphylaxis after local application of fibrin sealant diagnosed by skin tests.

Case presentation

A 49-year-old woman underwent partial lung resection under general anesthesia. Anesthesia was induced uneventfully. Shortly after applying absorbable suture reinforcement felt that contained fibrin sealant, her systolic blood pressure fell to approximately 70 mmHg, along with facial flushing. Anaphylaxis was diagnosed based on the clinical symptoms and high serum tryptase levels. Three months after the event, skin tests were performed with all agents and were positive only for fibrin sealant vial no. 2, whose main component is aprotinin. Subsequently, basophil activation tests using fibrin sealant vial no. 2 and pure aprotinin demonstrated that the causative agent was likely aprotinin.

Conclusions

We diagnosed aprotinin-induced anaphylaxis using skin tests and basophil activation tests. The occurrence of anaphylaxis should be considered when changes in vital signs are observed after the use of fibrin sealant.

Fibrin glue-induced eosinophilic pleural effusion after pulmonary resection: A case report

INTRODUCTION AND IMPORTANCE

Prolonged air leakage after pulmonary resection is a common complication, and fibrin glue is used as a sealant to reduce this. Fibrin glue-induced adverse events are generally rare. Herein, we describe a rare case of fibrin glue-induced eosinophilic pleural effusion (EPE).

CASE PRESENTATION

A 77-year-old man underwent partial pulmonary resection for right lower lobe lung cancer, and the pulmonary staple stump was subsequently covered with fibrin glue. Antibacterial drugs were administered for the treatment of postoperative pneumonia. However, re-elevation of the inflammatory cell number was observed, and computed tomography revealed an increase in right pleural effusion. Although thoracoscopy was performed based on a possibility of empyema, no empyema was observed. The eosinophil count in the pleural effusion was 11%; thus, the patient was diagnosed with EPE, which was resolved after thoracic drainage, without corticosteroid administration. Fibrin glue was identified as the causative agent, using a drug-induced lymphocyte stimulation test.

CLINICAL DISCUSSION

EPE is defined as an eosinophil count of ≥10% in the pleural effusion. If pleural effusion on the surgical side, with fever or an elevated inflammatory cell number, is observed in the early postoperative period after pulmonary resection, empyema should be considered foremost. In this case, the administration of antibacterial drugs was ineffective, and the patient was eventually diagnosed with EPE.

CONCLUSION

EPE should be considered as a rare fibrin glue-induced adverse event after pulmonary resection. It is recommended that the leukocyte fraction be examined, if pleural effusion is collected for postoperative pleural effusion.

Comparison and application of commercially available fibrin sealants in ophthalmology

Fibrin glues carry many advantages over traditional suture as a tissue adhesive and have been increasingly used in a variety of ophthalmic procedures over the past 15 years. Several fibrin sealants are commercially available worldwide, each of which differs slightly in its composition and mechanism of delivery. The focus of our review is to briefly discuss the reported uses of fibrin in ophthalmic surgery and provide a broad overview of the properties associated with each commercially available fibrin sealant.

Novel synthetic adhesive as an effective alternative to Fibrin based adhesives

AIM

To compare a novel, fully synthetic, polyurethane based glue (MAR-1) to fibrin sealant in a partial liver resection rat model.

METHODS

After 50% resection of the lateral left liver lobe in male Wistar rats (n = 7/group/time point), MAR-1, Fibrin or NaCl was applied. After 14, 21 and 90 postoperative days, sealant degradation, intra-abdominal adhesions were scored, and histological examination of liver tissue was performed.

RESULTS

(Mean ± SEM) (MAR-1 vs Fibrin vs NaCl). Bleeding mass was significantly higher in NaCl (3.36 ± 0.51 g) compared to MAR-1 (1.44 ± 0.40 g) and Fibrin (1.16 ± 0.32 g). At 14 and 90 d, bleeding time was significantly lower in MAR-1 (6.00 ± 0.9 s; 13.57 ± 3.22 s) and Fibrin (3.00 ± 0.44 s; 22.2 ± 9.75 s) compared to NaCl (158.16 ± 11.36 s; 127.5 ± 23.3 s). ALT levels were significantly higher in MAR-1 (27.66 ± 1 U/L) compared to Fibrin (24.16 ± 0.98 U/L) and NaCl (23.85 ± 0.80 U/L). Intrabdominal adhesions were significantly lower in MAR-1 (11.22% ± 5.5%) compared to NaCl (58.57% ± 11.83%). Degradation of the glue was observed and MAR-1 showed almost no traces of glue in the abdominal cavity as compared to the Fibrin (10% ± 5% 14 d; 7% ± 3% 21 d). Survival showed no significant differences between the groups.

CONCLUSION

Compared to Fibrin, MAR-1 showed similar hemostatic properties, no adverse effects, and is biocompatible. Further studies on adhesion strength and biodegradability of synthetic sealants are warranted.

Comparison of TachoSil and TachoComb in patients undergoing liver resection-a randomized, double-blind, non-inferiority trial

Background

This study aimed to demonstrate the noninferior efficacy of TachoSil vs. TachoComb in Japanese patients undergoing liver resection and to assess the safety of TachoSil vs. TachoComb in these patients.

Methods

This randomized, double-blind, noninferiority study (JapicCTI-090684) involved participants scheduled for liver resection/living donors (age ≥ 20 years). TachoSil or TachoComb (1:1 allocation ratio) was applied to control persistent exudative bleeding after primary hemostasis during liver resection/removal for donation. The primary outcome was hemostasis 5 min after study treatment application. The 95% confidence interval (CI) for the difference in the proportion of participants with hemostasis 5 min after application of TachoSil/TachoComb was determined; noninferiority of TachoSil was indicated if the lower limit of the CI was ≥−14%. Adverse events (AEs) were recorded.

Results

All participants in the efficacy analysis (TachoSil: 54/54, 100%; TachoComb: 54/54, 100%) achieved hemostasis 5 min after study treatment application. Therefore, TachoSil was noninferior to TachoComb. All participants experienced ≥1 AE; however, none discontinued because of an AE. Most (≥97.8%) AEs were mild or moderate in severity.

Conclusions

These findings confirm the safety profile and noninferior hemostatic efficacy of TachoSil compared with TachoComb.

Ophthalmic use of blood-derived products

There is a wide spectrum of blood-derived products that have been used in many different medical and surgical specialties with success. Blood-derived products for clinical use can be extracted from autologous or allogeneic specimens of blood, but recombinant products are also commonly used. A number of blood derivatives have been used for a wide range of ocular conditions, from the ocular surface to the retina. With stringent preparation guidelines, the potential risk of transmission of blood-borne diseases is minimized. We review blood-derived products and how they are improving the management of ocular disease.

Use of a fibrin adhesive for conjunctival closure in trabeculectomy

PURPOSE

To assess the safety and efficacy of a fibrin tissue adhesive (Tissucol Duo(®) ) used to close the conjunctiva in trabeculectomy.

METHODS

A nonrandomized prospective study including 57 patients with chronic simple glaucoma who underwent trabeculectomy surgery. All the trabeculectomies were conducted by the same surgeon using the same surgical technique with the exception that conjunctival closure was achieved by either running Nylon 10/0 suture (n = 29) or using the fibrin glue (n = 28). Preoperative and postoperative data were obtained on intraocular pressure (IOP), number of hypotensive medications used, self-reported discomfort and complications arising during and after surgery.

RESULTS

No differences were detected between the two patient groups regarding the intraocular pressure reduction achieved during follow-up. In the first 2 weeks of follow-up, reported discomfort assessed using a visual analogue scale was significantly lower in the Tissucol Duo(®) group. Two patients in the Tissucol Duo(®) group suffered conjunctival dehiscence and suturing was required at 24 hours postsurgery. Remaining complications were similar in the two groups.

CONCLUSION

The use of Tissucol Duo(®) seems to be a safe and efficient option for conjunctival closure in trabeculectomy that simplifies the surgical procedure and reduces patient discomfort in the immediate postoperative period.

Use of fibrin sealants in cardiovascular surgery: a systematic review

BACKGROUND

Fibrin sealants are used for hemostasis and tissue adherence.

AIM OF STUDY

This systematic review summarizes published clinical data for fibrin sealant use in cardiovascular surgery.

METHODS

A literature search for the following terms was conducted using PubMed and EMBASE: (TISSEEL or Tissucol or Beriplast P or Evicel or Quixil or Crosseal or Reliseal or Fibringluraas or Bolheal or Tachosil or Vivostat or Vitagel or Artiss or "fibrin glue" or "fibrin sealant" or "fibrin tissue adhesive") and (cardiac or cardiovascular or vascular or heart or coronary or surgery). Case reports and series were excluded; although reports of controlled trials were preferred, uncontrolled trial data were also considered.

RESULTS

Clinical trials and chart review analyses of fibrin sealants were identified and summarized. Although clinical trial data were available for other agents, the majority of published studies examined TISSEEL. Overall, TISSEEL and other fibrin sealants showed improvements over standard of care or control groups for a variety of predefined endpoints. Safety findings are also summarized.

CONCLUSIONS

Data from these studies showed that fibrin sealants were well tolerated and provided effective hemostasis in a range of cardiac and aortic surgeries.

Adverse effects of fibrin sealants in thoracic surgery: the safety of a new fibrin sealant: multicentre, randomized, controlled, clinical trial

OBJECTIVES

The safety of fibrin sealants (FS) has been questioned in the light of recent reports of adverse effects. We evaluated the safety of a new FS in a randomized controlled trial (RCT).

METHODS

Multicentre, open-label Phase II/III RCT to evaluate the safety of the new FS. The trial was approved by the Ethic Committee of each three participating Centre. FS includes two components (component 1: fibrinogen; component 2: thrombin), each of them subjected to two viral inactivation procedures. Out of 200 screened patients, 185 eligible patients (49 females, 136 males), aged between 18 and 75 years, undergoing major thoracic surgery were randomized to receive FS (#91 patients) as an adjuvant for air leak control or no treatment (#94 patients, control group). Safety variables were: percentage of subjects with adverse events associated with the therapy; formation of antibodies against bovine aprotinin; vital signs (blood pressure, body temperature, heart and respiratory rate); laboratory parameters.

RESULTS

Overall operative mortality was 3.2% (6/185), 1.1% in the FS group and 5.3% in the control group, respectively. Twenty patients (22%) had adverse events in the FS group and 22 (23.4%) in the control group. Atrial fibrillation (five patients in the FS group and four in the control group) and hyperpyrexia (five and seven patients, respectively, in the two groups) were the most common adverse events. No patient reported thromboembolic events (pulmonary embolism or deep vein thrombosis) during the in hospital stay or within 1 month from discharge. None of the adverse events was considered as treatment related. The formation of bovine aprotinin antibodies was reported in a total of 34 patients (37.4%) in the FS group and was not related to any adverse effect.

CONCLUSIONS

The present RCT did not show any increased risk of adverse events, and of surgical complications, related to the use of the new FS.

The potential for salmon fibrin and thrombin to mitigate pain subsequent to cervical nerve root injury

Nerve root compression is a common cause of radiculopathy and induces persistent pain. Mammalian fibrin is used clinically as a coagulant but presents a variety of risks. Fish fibrin is a potential biomaterial for neural injury treatment because it promotes neurite outgrowth, is non-toxic, and clots readily at lower temperatures. This study administered salmon fibrin and thrombin following nerve root compression and measured behavioral sensitivity and glial activation in a rat pain model. Fibrin and thrombin each significantly reduced mechanical allodynia compared to injury alone (p < 0.02). Painful compression with fibrin exhibited allodynia that was not different from sham for any day using stimulation by a 2 g filament; allodynia was only significantly different (p < 0.043) from sham using the 4 g filament on days 1 and 3. By day 5, responses for fibrin treatment decreased to sham levels. Allodynia following compression with thrombin treatment were unchanged from sham at any time point. Macrophage infiltration at the nerve root and spinal microglial activation were only mildly modified by salmon treatments. Spinal astrocytic expression decreased significantly with fibrin (p < 0.0001) but was unchanged from injury responses for thrombin treatment. Results suggest that salmon fibrin and thrombin may be suitable biomaterials to mitigate pain.

Application of energy-based technologies and topical hemostatic agents in the management of surgical hemostasis

Achieving intraoperative hemostasis is essential for excellent surgical outcomes. A variety of methods, ranging from mechanical tools and energy-based technologies to topical hemostatic agents, are available to the modern surgeon. Given that bleeding develops from different origins, from small discrete bleeding or venous oozing to arterial hemorrhage, different tools and agents have different efficacy in specific situations. In this article, we review the mechanism by which currently available hemostatic tools and agents stop bleeding and give recommendations for their use during surgery. Furthermore, the costs of the various methods are presented, allowing the provider to choose not only the most potent but also the most cost-effective treatment modality in each situation.

The use of fibrin glue in surgery of the knee

Fibrin glue, also known as fibrin sealant, is now established as a haemostatic agent in surgery, but its role in orthopaedic surgery is neither well known nor clearly defined. Although it was originally used over 100 years ago, concerns about transmission of disease meant that it fell from favour. It is also available as a slow-release drug delivery system and as a substrate for cellular growth and tissue engineering. Consequently, it has the potential to be used in a number of ways in orthopaedic surgery. The purpose of this review is to address its use in surgery of the knee in which it appears to offer great promise.

Comparison between TachoComb and TachoSil for surgical hemostasis in arterial bleeding: an animal experimental study

BACKGROUND

TachoComb has frequently been used for the treatment of both venous and arterial bleeding. However, anaphylactic reactions have been reported after repeated use of hemostatic agents containing aprotinin such as TachoComb. Because aprotinin is also associated with risk of renal failure, manufacturing of a new product--TachoSil--which lacks aprotinin seems a logic evolvement. Furthermore, thrombin on the TachoSil material has been changed from bovine in TachoComb to human origin. These changes in the biochemical composition could lead to changes in the hemostatic performance. Therefore, we aimed to disclose any difference in hemostatic efficacy of the two products.

METHODS

Twelve 70-kg pigs had controlled insults to the thoracic aorta with and without heparin administration. The iatrogenic lesion was randomly covered with either TachoComb or TachoSil and the time to hemostasis was measured.

RESULTS

Time to hemostasis when using TachoSil compared with TachoComb was increased 14% (-13% to 48%) with heparin and 10% (-26% to 66%) without heparin (mean +/- 95% confidence interval; p > 0.05 in both). Time to hemostasis with heparin administration increased significantly in both treatments: TachoComb 80% (26%-156%) (p = 0.001) and TachoSil 75% (18%-158%) (p = 0.005).

CONCLUSION

We found neither statistical nor clinical evidence that TachoComb should have better hemostatic properties than does TachoSil in arterial bleeding. Both TachoSil and TachoComb can be used with heparin administration, but significant prolongation of the time to hemostasis is to be expected for both products. TachoSil should be preferred to TachoComb due to the potential lower risk of side effects when using the former.

Fibrin glue in ophthalmology

Suturing is a time consuming task in ophthalmology and suture induced irritation and redness are frequent problems. Postoperative wound infection and corneal graft rejection are examples of possible suture related complications. To prevent these complications, ophthalmic surgeons are switching to sutureless surgery. A number of recent developments have established tissue adhesives like cyanoacrylate glue and fibrin glue as attractive alternatives to sutures. A possible and promising new application for tissue adhesives is to provide a platform for tissue engineering. Currently, tissue glue is being used for conjunctival closure following pterygium and strabismus surgery, forniceal reconstruction surgery, amniotic membrane transplantation, lamellar corneal grafting, closure of corneal perforations and descematoceles, management of conjunctival wound leaks after trabeculectomy, lid surgery, adnexal surgery and as a hemostat to minimise bleeding. The purpose of this review is to discuss the currently available information on fibrin glue.

Soft materials to treat central nervous system injuries: evaluation of the suitability of non-mammalian fibrin gels

Polymeric scaffolds formed from synthetic or natural materials have many applications in tissue engineering and medicine, and multiple material properties need to be optimized for specific applications. Recent studies have emphasized the importance of the scaffolds' mechanical properties to support specific cellular responses in addition to considerations of biochemical interactions, material transport, immunogenicity, and other factors that determine biocompatibility. Fibrin gels formed from purified fibrinogen and thrombin, the final two reactants in the blood coagulation cascade, have long been shown to be effective in wound healing and supporting the growth of cells in vitro and in vivo. Fibrin, even without additional growth factors or other components has potential for use in neuronal wound healing in part because of its mechanical compliance that supports the growth of neurons without activation of glial proliferation. This review summarizes issues related to the use of fibrin gels in neuronal cell contexts, with an emphasis on issues of immunogenicity, and considers the potential advantages and disadvantages of fibrin prepared from non-mammalian sources.

Fibrin glue application in the management of refractory chylous ascites in children

The purpose of this retrospective review of the charts of 6 children who underwent surgical treatment of chylous ascites refractory to conservative measures between 1993 and 2006 was to evaluate the efficiency of fibrin glue application for control of lymph leakage. Five children had postoperative chylous ascites (neuroblastoma, 4; cystic lymphangioma, 1) and 1 had a congenital malformation. Surgical exploration revealed large areas of diffuse lymphatic leakage in all of the patients. Lymphatic fistula was not identified intraoperatively in any patient. Ingestion of lipophilic dye in a concentrated fatty meal was not helpful in locating a lymph fistula. Absorbable mesh was used in association with glue application in the last 3 patients treated. Control of ascites was achieved immediately in 2 patients and within 3 weeks in 2 patients. Repeat surgery was required in the remaining 2 patients. The mean follow-up time was 4.3 years. One patient died of tumor recurrence 12 months after surgical treatment without relapse of the ascites. Two mild late recurrences were observed at 6 and 11 months after surgery and were managed conservatively. The findings of this study show that fibrin glue application on absorbable mesh after dissection of the leakage zones is easy, safe, and effective. We recommend that surgery with glue application be repeated until control of ascites is achieved. We suggest fibrin glue application as a preventive measure against postoperative chylous ascites.

Delay of 6 weeks between aprotinin injections for tendinopathy reduces risk of allergic reaction

Aprotinin is a collagenase inhibitor previously shown to be effective for treating tendinopathies but associated with systemic allergic reactions. This historical cohort study aimed to determine whether or not the injection regime used affected the risk of allergic reaction and outcome. It compared 223 tendinopathy cases (group R) generally treated with a rapid series of aprotinin injections spaced one to two weekly and 158 cases (group D) generally given a single injection or a delay in their repeat injection(s) of over 6 weeks. Side effects and outcome measures were documented by questionnaire with a response rate of 75%. Systemic allergic reactions occurred in 7% of group R cases compared with 2% in group D (NS). Injections given 2-4 weeks after a previous injection were significantly more likely to lead to allergic reactions (6%) than initial injections (0.3%) and injections given >6 weeks after a previous injection (0.9%) (P<0.05). Overall patient rated satisfaction and outcome measures were similar between groups. In summary the current published regime of multiple aprotinin injections over a period of a few weeks has a fairly high rate of systemic allergic reactions. This can be reduced by minimising repeat injections and recommending a delay of at least 6 weeks between injections. Practitioners using aprotinin must have available facilities to treat anaphylaxis.

Anaphylaxis during anaesthesia: diagnostic approach

Correct management of anaphylaxis during anaesthesia requires a multidisciplinary approach with prompt recognition and treatment of the acute event by the attending anaesthesiologist, and subsequent determination of the responsible agent(s) with strict avoidance of subsequent administration of all incriminated and/or cross-reacting compounds. However, correct identification of the causative compound(s) and safe alternatives is not always straightforward and, too often, not done. This review is not intended to discuss acute management of anaesthesia-related anaphylaxis but summarizes the major causes of anaphylaxis during anaesthesia and the diagnostic approach of this rare but potentially life-threatening complication. Apart from general principles about the diagnostic approach, history taking and importance of tryptase quantification, more specific confirmatory diagnostic procedures are organized on the basis of the major causes of perioperative anaphylactic reactions.

Stability, sterility, coagulation, and immunologic studies of salmon coagulation proteins with potential use for mammalian wound healing and cell engineering

Fibrin sealants made by polymerization of fibrinogen activated by the protease thrombin have many applications in hemostasis and wound healing. In treatments of acute injury or surgical wounds, concentrated fibrin preparations mimic the initial matrix that normally prevents bleeding and acts as a scaffold for cells that initiate tissue repair. However risks of infectious disease, immunogenic reaction, and the high cost of purified human or other mammalian blood proteins limit widespread use of these materials. Purified coagulation proteins from Atlantic salmon represent a potentially safer, equally effective, and less costly alternative in part because of the low ambient temperature of these farmed animals and the absence of endogenous agents known to be infectious in mammalian hosts. This study reports rheologic measurements of lyophilized salmon fibrinogen and thrombin that demonstrate stability to prolonged storage and gamma irradiation sufficient to reduce viral loads by over five orders of magnitude. Coagulation and immunologic studies in rats and rabbits treated intraperitoneally with salmon fibrin show no deleterious effects on coagulation profiles and no cross reactivity with host fibrinogen or thrombin. The results support the potential of salmon fibrin as an alternative to mammalian proteins in clinical applications.