Randomized clinical trial of fibrin sealant in patients undergoing resternotomy or reoperation after cardiac operations

Effect of topical application of autologous platelet gel on sternal wound infection after cardiac surgery: A meta-analysis

Following heart operation, a severe life-threatening complication has been identified by investigators who have recently discovered that local application of platelet-rich plasma (PRP) can lower the rate of wound infection in heart surgery. Nevertheless, due to the low quality of these trials, we have tried to perform high-quality meta-analyses to prove the efficacy of PRP in heart surgery for post-operative wound infections. In this study, five randomised controlled trials (RCTs) were chosen from three databases, and there were 1005 studies to analyse the data. Among 181 cases, PRP was applied to the surgical site, and 205 in the control group. Both the CI and the OR or the average difference (MD) were computed with either a fixed or random-effect model. A meta-analysis of the data was carried out with RevMan 5.3. The results showed that there were no statistically significant differences in the incidence of post-operative surgical site infection (SSI) in control group compared to those treated with PRP gel (OR, 0.97; 95% CI, 0.38, 2.47; p = 0.95); In the heart operation, the local application of PRP gel decreased the rate of drainage after operation (MD, -217.82; 95% CI, -335.38, -100.26; p = 0.0003); The operation time of the PRP gel was not significantly different from that of the control group (MD, 12.65; 95% CI, -2.95, 28.24; p = 0.11). Contrary to earlier research, the application of autoplatelet gel in heart surgery did not seem to decrease operative site infections after the operation, but it did decrease the amount of postoperative drainage. Nevertheless, because of the limited number of RCTs in this meta-analysis, caution should be exercised in their treatment. More high-quality randomised, large-sample trials are required to further confirm the findings.

Principles of minimize bleeding and the transfusion of blood and its components in operated patients - surgical aspects

One of the target of perioperative tratment in surgery is decreasing intraoperative bleeding, which increases the number of perioperative procedures, mortality and treatment costs, and also causes the risk of transfusion of blood and its components. Trying to minimize the blood loss(mainly during the operation) as well as the need to transfuse blood and its components (broadly understood perioperative period) should be standard treatment for a patient undergoing a procedure. In the case of this method, the following steps should be taken: 1) in the preoperative period: identyfication of risk groups as quickly as possible, detecting and treating anemia, applying prehabilitation, modyfying anticoagulant treatment, considering donating one's own blood in some patients and in selected cases erythropoietin preparations; 2) in the perioperative period: aim for normothermia, normovolemia and normoglycemia, use of surgical methods that reduce bleeding, such as minimally invasive surgery, high-energy coagulation, local hemostatics, prevention of surgical site infection, proper transfusion of blood and its components if it occurs; 3) in the postoperative period: monitor the condition of patients, primarily for the detection of bleeding, rapid reoperation if required, suplementation (oral administration preferred) nutrition with microelements (iron) and vitamins, updating its general condition. All these activities, comprehensively and in surgical cooperation with the anesthesiologist, should reduce the blood loss and transfusion of blood and its components.

Composition, host responses and clinical applications of bioadhesives

Bioadhesives are medical devices used to join or seal tissues that have been injured or incised. They have been classified into tissue adhesives, sealants, and hemostatic agents. Bioadhesives such as FloSeal®, CoSeal®, BioGlue®, Evicel®, Tisseel®, Progel™ PALS, and TissuGlu® have been commercialized and used in clinical setting. They can be formulated with natural or synthetic components or a combination of both including albumin, glutaraldehyde, chitosan, cyanoacrylate, fibrin and thrombin, gelatin, polyethylene glycol (PEG), along with urethanes. Each formulation has intrinsic properties and has been developed and validated for a specific application. This review article briefs the mechanisms by which bioadhesives forms adhesion to tissues and highlights the correlation between bioadhesives composition and their potential host responses. Furthermore, clinical applications of bioadhesives and their application-driven requirements are outlined.

Novel autologous, high concentrated fibrin as advanced hemostatic agent for coronary surgery

BACKGROUND

Variability in transfusion outcomes and excessive postoperative bleeding represents a significant problem in cardiac surgery. The effort to reduce bleeding complications and transfusion outcomes is desirable. Our study investigated the feasibility of reducing bleeding complications and transfusion requirements by applying perioperatively prepared autologous bio-regenerative fibrin sealant.

METHODS

A prospective, case-control study enrolled 74 patients undergoing coronary artery bypass grafting by a single surgeon. Patients in the control group (N = 43), received traditional methods of hemostasis, while patients in the experimental group (N = 31) were treated additionally with autologous bio-regenerative fibrin.

RESULTS

Patients were well-matched with regard to basic demographic, laboratory and procedural data. Allogeneic blood transfusion requirement in control group was 39.5 % (17 of 43 patients), compared to 6.5 % (2 of 31 patients) in treated group (p < 0,001). The lower infection rate in the experimental group was also noted. No safety issues were identified during the preparation and application process.

CONCLUSION

Autologous bio-regenerative fibrin can be safely prepared, with no time consuming, and was demonstrated to be a useful tool to decrease allogeneic blood transfusion requirements following elective coronary artery bypass grafting surgery. A prospective randomized trial is needed to confirm these findings.

Evaluation of the Safety and Efficacy of a Novel Thrombin Containing Combination Hemostatic Powder Using a Historical Control

This clinical study compares 2 hemostatic agents, a novel combination powder (CP) (HEMOBLAST^™ Bellows) and an established polysaccharide starch powder (PP) (Arista^™ AH) to assess the usefulness of CP. Retrospective comparative analysis of CP (July 2018 to July 2019, 68 patients) to PP (January 2011 to January 2013, 94 patients) in cardiothoracic patients was performed using linear regression models adjusting for age, sex, and procedure type for the endpoints: blood loss; protamine to skin closure time (hemostasis time); chest tube output and blood products required 48 hours postoperatively; ICU stay; postoperative comorbidities; and 30 day mortality. 162 patients (108 M: 54 F) underwent 162 cardiothoracic surgical procedures including: transplantation (n = 44), placement of ventricular assist device (n = 87), and others (n = 31). Use of CP compared to PP (Estimated Mean Difference [95% CI], P-value) produced significant reductions: blood loss (mL) (-886.51 [-1457.76, -312.26], P = 0.003); protamine to skin closure time (min) (-16.81 [-28.03, -5.59], P = 0.004); chest tube output (48 hrs, mL) (-445.76 [-669.38, -222.14], P < 0.001); packed red blood cell transfusions (units) (-0.98 [-1.56, -0.4], P = 0.001); and postoperative comorbidities (-0.31 [-0.55, -0.07], P = 0.012). There were no differences in the ICU stay (4.07 [-2.01, 10.15], P = 0.188) or 30-day mortality (0.57 [0.20, 1.63], P = 0.291). The use of CP in complex cardiothoracic operations resulted in improved hemostasis and significant clinical benefits in blood loss, transfusion requirements, morbidity, and time in operating room.

Early Chest Re-Exploration for Excessive Bleeding in Post Cardiac Surgery Patients: Does It Matter?

Introduction Re-explorations after open-heart surgery are often required if the patient is bleeding or shows features of cardiovascular instability and does not improve with conservative measures. Our study aims to determine whether timely re-exploration of patients who are bleeding has an impact on the morbidity and mortality of the patients. Methods A retrospective analysis of 75 patients that underwent open-heart surgery and subsequently underwent chest re-exploration for excessive bleeding between March 2018 and March 2020. Patients who were reopened post-op for indications other than excessive bleeding were excluded. Results A total number of cases were 700, out of which 75 (9.3%) patients were reopened, as compared to the literature, which shows worldwide 2-11% being reopened. Post-operative drain output was 1000ml to 1500ml in 47 (62.7%) and more than 1500ml in 28 (37.3%) patients before they were reopened. In 67 (89.3%) patients, three to five units of blood were transfused, and in eight (10.7%) patients, more than five units of blood were transfused. We believe our mortality in the reopened patients was low, because of timely intervention and early re-exploration, and is probably the reason why our figures land in a higher range (2-11%) of reopened cases (9.3%). Reopening time was less than five hours in 49 (65.3%) patients and less than 10 hours in 26 (34.7%) patients in our study. We tried to minimize the loss of blood and re-explored the patients before they lose excessive blood, the average time for reopening in our study was less than 10 hours. The average intensive care unit (ICU) stay was 4.2 days (range three to six days). Wound infections were reported in one of three patients. There was no mortality in these patients. Surgical site of bleeding was identified in 54 (72%) patients and no particular site was found in 21 (28%) patients. Suggesting that it is common to have a surgical bleeder than coagulopathy induced bleeding in post-cardiac surgery patients Conclusions We believe our low mortality (0%) is due to early reopening in patients who are bleeding excessively after cardiac surgery.

Management of Physeal Fractures: A Review Article

BACKGROUND

Physis is the weakest structure in the skeleton of a child and a frequent site of an injury or fracture. A physeal fracture presents a unique challenge in the management as the sequalae of such an injury could lead to growth disturbances.

METHODS

In this review, mainly focussing on traumatic physeal injuries, the authors discuss the applied anatomy, different fracture patterns, clinical assessment and management of physeal fractures in children.

RESULTS

Discussion on acute physeal injuries as well as physeal arrest and approach to its management is presented. Past attempts for treatment of physeal injuries and recent advances in their management is also discussed.

CONCLUSION

The ideal approach to treat physeal injuries should take into account the location of injury, age of the patient, fracture type and growth potential of the involved physis. Prompt diagnosis and physeal-respecting treatment techniques are important.

Topical Hemostatic Agents at Time of Obstetric and Gynecologic Surgery: ACOG Committee Opinion, Number 812

There are three broad categories of hemostatic agents: 1) caustic, 2) physical, and 3) biologic. Because of the paucity of data on the use of topical hemostatic agents in gynecologic and obstetric surgery, indications for use are extrapolated from data on the use of these agents in other types of surgeries and are based on expert opinion. Topical hemostatic agents can be a useful adjunct to assist in the management of intraoperative bleeding in select circumstances. Topical hemostatic agents most commonly are used in situations where the use of electrocautery or sutures for hemostatic control of surgical bleeding is not ideal or safe, including bleeding in areas with nearby vulnerable structures or in the presence of diffuse bleeding from peritoneal surfaces or cut surfaces of solid organs. When managing intraoperative bleeding, there is no substitute for meticulous surgical technique. When possible, the surgeon should attempt to control intraoperative bleeding with sutures, clips, or electrosurgery before the use of hemostatic agents. It is essential for surgeons to understand the appropriate use, contraindications, and cost of these agents in order to make the most informed decision for patient care.

Autologous cartilage and fibrin sealant may be superior to conventional fat grafting in preventing physeal bone bridge formation - a pilot study in porcines

PURPOSE

The article compares physeal recovery after insertion of autologous cartilage and a conventional fat graft in a standardized porcine physeal gap model. Presence of a bone bridge was the primary outcome.

METHODS

Ten porcines in two groups of five were included in a paired design. A standardized physeal gap in the distal femur was made in all animals. One group (n = 5) was randomized for deposition of autologous cartilage and a Tisseel^® or Tisseel^® alone. The autologous cartilage was harvested from the femoral articular surface. The other group was randomized for fat grafting or no grafts at all. All animals were housed for 14 weeks. Magnetic resonance imaging (MRI) was performed at 14 weeks prior to euthanasia. The physis was harvested for histology.

RESULTS

MRI - Three bone bridges were seen in the fat grafted gaps. All empty gaps formed a bone bridge. No gaps filled with autologous cartilage and Tisseel^® resulted in bone bridges. One gap filled with Tisseel^® only caused a bone bridge. Histology - The cartilage grafted gaps recovered with physeal-like cartilaginous tissue in histological analysis.

CONCLUSIONS

Fat grafts seems ineffective in preventing bone bridges. The use of autologous cartilage may be superior to the current treatment. However, donor site complications were not investigated. The study serves as a proof of concept study and requires further investigation.

LEVEL OF EVIDENCE

III.

SPOT GRADE II: Clinical Validation of a New Method for Reproducibly Quantifying Surgical Wound Bleeding: Prospective, Multicenter, Multispecialty, Single-Arm Study

The SPOT GRADE (SG), a Surface Bleeding Severity Scale, is a unique visual method for assessing bleeding severity based on quantitative determinations of blood flow. This study assessed the reliability of the SG scale in a clinical setting and collected initial data on the safety and efficacy of HEMOBLAST Bellows (HB), a hemostatic agent, in abdominal and orthopedic operations. Twenty-seven patients were enrolled across 3 centers and received the investigational device. Bleeding severity and hemostasis were independently assessed by 2 surgical investigators at baseline and at 3, 6, and 10 minutes after application of HB and compared for agreement. The mean paired κ statistic for assignment of SG scores was .7754. The mean paired κ statistics for determining eligibility for participation in the trial based on bleeding severity and the mean paired κ statistics determining the presence of hemostasis were .9301 and .9301, respectively. The proportion of patients achieving hemostasis within 3, 6, and 10 minutes of HB application were 50.0%, 79.2%, and 91.7%, respectively. There were no unanticipated adverse device effects and one possible serious adverse device effect, as determined by the Independent Data Monitoring Committee (IDMC). The reliability of the SG scale was validated in a clinical setting. Initial data on the safety and efficacy of HB in abdominal and orthopedic operations were collected, and there were no concerns raised by the investigators or the IDMC.

Fibrin and Thrombin Sealants in Vascular and Cardiac Surgery: A Systematic Review and Meta-analysis

OBJECTIVE

In vascular and cardiac surgery, the ability to maintain haemostasis and seal haemorrhagic tissues is key. Fibrin and thrombin based sealants were introduced as a means to prevent or halt bleeding during surgery. Whether fibrin and thrombin sealants affect surgical outcomes is poorly established. A systematic review and meta-analysis was performed to examine the impact of fibrin or thrombin sealants on patient outcomes in vascular and cardiac surgery.

DATA SOURCES

Cochrane CENTRAL, Embase, and MEDLINE, as well as trial registries, conference abstracts, and reference lists of included articles were searched from inception to December 2019.

REVIEW METHODS

Studies comparing the use of fibrin or thrombin sealant with either an active (other haemostatic methods) or standard surgical haemostatic control in vascular and cardiac surgery were searched for. The Cochrane risk of bias tool and the ROBINS-I tool (Risk Of Bias In Non-randomised Studies - of Interventions) were used to assess the risk of bias of the included randomised and non-randomised studies; quality of evidence was assessed by the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. Two reviewers screened studies, assessed risk of bias, and extracted data independently and in duplicate. Data from included trials were pooled using a random effects model.

RESULTS

Twenty-one studies (n = 7 622 patients) were included: 13 randomised controlled trials (RCTs), five retrospective, and three prospective cohort studies. Meta-analysis of the RCTs showed a statistically significant decrease in the volume of blood lost (mean difference 120.7 mL, in favour of sealant use [95% confidence interval {CI} -150.6 - -90.7; p < .001], moderate quality). Time to haemostasis was also shown to be reduced in patients receiving sealant (mean difference -2.5 minutes [95% CI -4.0 - -1.1; p < .001], low quality). Post-operative blood transfusions, re-operation due to bleeding, and 30 day mortality were not significantly different for either RCTs or observational data.

CONCLUSION

The use of fibrin and thrombin sealants confers a statistically significant but clinically small reduction in blood loss and time to haemostasis; it does not reduce blood transfusion. These Results may support selective rather than routine use of fibrin and thrombin sealants in vascular and cardiac surgery.

Article Commentary: Hemostats, Sealants, and Adhesives: A Practical Guide for the Surgeon

Hemostats, sealants, and adhesives are useful adjuncts to modern surgical procedures. To maximize their benefit, a surgeon needs to understand the safety, efficacy, usability, and cost of these agents. To be truly added to a surgeon's own toolbox, the operator must also have knowledge of when and how to best use these materials. This commentary is designed to succinctly facilitate this understanding and knowledge. A nomenclature and classification system based on group, category, and class has been created to help with this process and is provided here. By using this system, materials consisting of similar design and for common indications can be compared. For example, in this system, the three functional groups are hemostats, sealants, and adhesives. The hemostats may be divided into four categories: mechanical, active, flowable, and fibrin sealant. These hemostat categories are further subdivided into generic classes based on the composition of the approved materials. Similarly, categories and classes are provided for sealants and adhesives. In this commentary, the salient points with respect to the characteristics of these agents are presented. A discussion of when these agents can be used in specific indications and how they may be applied to achieve the best results is also provided.

Surgical applications of intracorporal tissue adhesive agents: current evidence and future development

Introduction: Traditional mechanical closure techniques pose many challenges including the risk of infection, tissue reaction, and injury to both patients and clinicians. There is an urgent need to develop tissue adhesive agents to reform closure technique. This review examined a variety of tissue adhesive agents available in the market in an attempt to gain a better understanding of intracorporal tissue adhesive agents as medical devices.Areas covered: Fundamental principles and clinical determinants of the tissue adhesives were summarized. The available tissue adhesives for intracorporal use and their relevant clinical evidence were then presented. Lastly, the perspective of future development for intracorporal tissue adhesive were discussed. Clinical evidence shows current agents are efficacious as adjunctive measures to mechanical closure and these agents have been trialed outside of clinical indications with varied results.Expert opinion: Despite some advancements in the development of tissue adhesives, there is still a demand to develop novel technologies in order to address unmet clinical needs, including low tensile strength in wet conditions, non-controllable polimerization and sub-optimal biocompatibility. Research trends focus on producing novel adhesive agents to remit these challenges. Examples include the development of biomimetic adhesives, externally activated adhesives, and multiple crosslinking strategies. Economic feasibility and biosafety are limiting factors for clinical implementation.

The Use of Fibrin-based Tissue Adhesives for Breast in Reconstructive and Plastic Surgery

Background:

Breast plastic surgery is a rapidly evolving field of medicine. The modern view of surgical trends reflects the desire to minimize complications and introduce advanced technologies. These always will be priorities for surgeons. Reconstructive surgery, a branch of plastic surgery focusing on restoration of lost functional and aesthetic component, seeks to enhance psychological rehabilitation and improves the quality of life, as well as aesthetic recovery.

Objective:

This review addresses the action of fibrin agents and their effect on the quality of surgical hemostasis.

Discussion and Conclusion:

The fundamental goals for the surgeon are to perform a minimally traumatic intervention and to prevent any form of complication. Achieving complete hemostasis is an intraoperative necessity. Timely prevention of bleeding and hemorrhagic phenomena can affect not only the outcome of the operation, but also the incidence of postoperative complications. Topics include the integrity of microvascular anastomoses, tissue adhesion, and the incidence of seromas and hematomas associated with fibrin glue usage. The literature on fibrin adhesives with respect to prevention of postoperative complications, and the effectiveness with active drainage also are analyzed.

Contribution of fibrin glue in the surgery of cyanogenic and non-cyanogenic congenital cardiopathies: retrospective cohort study

Background

Postoperative bleeding in cardiovascular surgery is a frequent and complicated situation for the surgical team, and may also be responsible for significant hospital expenditures. Fibrin glue are indicated in surgery to improve hemostasis when conventional techniques such as compression, sutures or electrocoagulation are insufficient. Through this study, we tried to study the contribution of fibrin glue to the improvement of the clinical parameters (volume of postoperative bleeding, length of stay in intensive care, volume of blood transfusion ...) in two populations having undergone cardiac surgery, one in which we used the fibrin glue and one without fibrin glue.

Methods

This was a retrospective cohort study conducted in the cardiovascular surgery department of our Hospital in Rabat between June 2012 and June 2015. Fibrin glue (Tissucol® of BAXTER) was used in one group with an haemostatic aim. The pre and post-operative clinical data of the patients were analyzed and compared with data from patients who were operated without the use of fibrin glue because it was not yet available in the hospital. The clinical parameters were collected analyzed using the SPSS 13.0 software.

Results

One hundred ten patients were included in this study. The fibrin glue was used intraoperatively in 55 patients and not used in 55 patients. 43 (39.1%) had cyanogenic diseases and 67 (60.9%) had non-cyanogenic pathologies. The volume of transfused red blood cells was lower in patients in whom we used biological glue (p = 0.005), as well as the number of days spent in intensive care (p = 0.02). However, the difference was not significant between the two groups for other parameters such as bleeding volume per kg, the number of units of fresh frozen plasma and the platelet units count transfused.

Conclusions

The results we found show that fibrin glue reduces the duration of hospitalization in resuscitation and reduces the number of units of transfused red blood cells to patients after surgery. However, it does not reduce significantly the total postoperative bleeding volume per weight, the number of fresh frozen plasma units or platelets units transfused. The fibrin glue could therefore be of moderate benefit in pediatric cardiac surgery.

Evaluation of the safety and efficacy of a new hemostatic powder using a quantitative surface bleeding severity scale

AIMS OF THE STUDY

The safety and efficacy of a hemostatic powder (HP) versus a control agent, absorbable gelatin sponge and thrombin (G + T), were assessed, using a validated, quantitative bleeding severity scale.

METHODS

Subjects were randomized to receive HP (256 subjects) or G + T (132 subjects) for treatment of minimal, mild, or moderate bleeding at 20 investigational sites. The primary efficacy endpoint was non-inferiority of HP relative to G + T for success at achieving hemostasis within 6 minutes. Secondary endpoints in rank order included: superiority of HP relative to G + T in mean preparation time; non-inferiority of HP relative to G + T for achieving hemostasis within 3 min; superiority of HP relative to G + T for achieving hemostasis within 6 min; and superiority of HP relative to G + T for success for achieving hemostasis within 3 min.

RESULTS

A total of 388 subjects were included in the primary efficacy analysis. At 6 min, hemostasis was achieved in 93.0% (238/256) of the HP group compared to 77.3% (102/132) of the G + T group (non-inferiority P < 0.0001, superiority P < 0.0001). All secondary endpoints were met. Complications were comparable between treatment groups.

CONCLUSIONS

HP had superior rates of hemostasis, shorter preparation time, and a similar safety profile compared to G + T in this prospective, randomized trial using quantitative bleeding severity criteria.

Cytocompatibility and mechanical properties of surgical sealants for cardiovascular applications

OBJECTIVES

The present study compared physical, mechanical, and biologic characteristics of 4 clinically available surgical sealants for cardiovascular repair.

METHODS

BioGlue (Cryolife Inc, Kennesaw, Ga), PreveLeak (Mallinckrodt Pharmaceuticals, St Louis, Mo), Tridyne VS (BD, Franklin Lakes, NJ), and Coseal (Baxter Healthcare Corporation, Westlake Village, Calif) were compared for the following properties: hydrated swelling, cytocompatibility, burst strength, biaxial stretching (elasticity), and in vitro degradation.

RESULTS

Sealants showed a wide range of swelling upon hydration. By gravimetric and volumetric measurement, swelling was greatest for Coseal followed by Tridyne VS, BioGlue, and PreveLeak. Tridyne VS was the most cytocompatible based on Alamar Blue assay results, supporting 85% cell survival compared with 36% to 39% survival with the other sealants. All sealants withstood pressure above mean arterial pressure (70-110 mm Hg) and physiologic systolic blood pressure (90-140 mm Hg) in an ex vivo arterial flow burst model; lowest peak pressure at failure was PreveLeak at 235 ± 48 mm Hg, and highest peak pressure at failure was BioGlue at 596 ± 72 mm Hg. Biaxial tensile testing showed no differences in elasticity between ex vivo porcine aorta and carotid arteries and Tridyne VS or Coseal, and BioGlue and PreveLeak were significantly stiffer. In vitro degradation time for Coseal was 6 days and 21 days for Tridyne VS. No degradation was observed in BioGlue or PreveLeak for 30 days.

CONCLUSIONS

Although all sealants withstood supraphysiologic arterial pressure, there were differences in characteristics that may be important in clinical outcome. Coseal degradation time was short compared with other sealants, whereas BioGlue and PreveLeak showed a significant compliance mismatch with native porcine carotid artery. Tridyne VS was significantly more cytocompatible than the other 3 sealants.

Fibrin-based delivery strategies for acute and chronic wound healing

Fibrin, a natural hydrogel, is the end product of the physiological blood coagulation cascade and naturally involved in wound healing. Beyond its role in hemostasis, it acts as a local reservoir for growth factors and as a provisional matrix for invading cells that drive the regenerative process. Its unique intrinsic features do not only promote wound healing directly via modulation of cell behavior but it can also be fine-tuned to evolve into a delivery system for sustained release of therapeutic biomolecules, cells and gene vectors. To further augment tissue regeneration potential, current strategies exploit and modify the chemical and physical characteristics of fibrin to employ combined incorporation of several factors and their timed release. In this work we show advanced therapeutic approaches employing fibrin matrices in wound healing and cover the many possibilities fibrin offers to the field of regenerative medicine.

An in vitro study of fibrin sealant as a carrier system for recombinant human bone morphogenetic protein (rhBMP)-9 for bone tissue engineering

In the craniofacial bone field, fibrin sealants are used as coagulant and adhesive tools to stabilize grafts during surgery. Despite this, their exact role in osteogenesis is poorly characterized. In the present study, we aimed to characterize the osteogenic potential of TISSEEL fibrin sealant and used its technology to incorporate growth factors within its matrix. We focused on recombinant human bone morphogenetic protein (rhBMP)-9, which has previously been characterized as one of the strongest osteogenetic inducers in the BMP family. TISSEEL displayed an excellent ability to retain rhBMP9, which was gradually released over a 10-day period. Although TISSEEL decreased bone stromal ST2 cell attachment at 8 h, it displayed normal cell proliferation at 1, 3, and 5 days when compared to tissue culture plastic. Interestingly, TISSEEL had little influence on osteoblast differentiation; however its combination with rhBMP9 significantly increased ALP activity at 7 days, Alizarin Red staining at 14 days, and mRNA levels of osteoblast differentiation markers ALP, bone sialoprotein, and osteocalcin. In summary, although fibrin sealants were shown to have little influence on osteogenesis, their combination with bone-inducing growth factors such as rhBMP9 may serve as an attractive carrier/scaffold for future bone regenerative strategies. Future animal studies are now necessary.

IGF-1-containing multi-layered collagen-fibrin hybrid scaffolds for bladder tissue engineering

Clinical success of bladder reconstructive procedures could be promoted by the availability of functional biomaterials. In this study, we have developed a multi-layered scaffold consisting of a bioactive fibrin layer laminated between two collagen sheets all having undergone plastic compression. With this construct we performed bladder augmentation in a nude rat model after partial bladder excision and evaluated the morphological and functional behavior of the implant. The fibrin was functionalized with a recombinant human insulin-like growth factor-1 (IGF-1) variant that covalently binds fibrin during polymerization and has a matrix metalloproteinase-cleavage insert to enable cell-mediated release. The purified IGF-1 variant showed similar bioactivity in vitro compared to commercially available wild type (wt) IGF-1, inducing receptor phosphorylation and induction of human smooth muscle cell proliferation. In vivo, the multi-layered bioactive collagen-fibrin scaffolds loaded with the IGF-1 variant triggered dose-dependent functional host smooth muscle cell invasion and bundle formation with re-urothelialization 4weeks after surgery in a rat model.

STATEMENT OF SIGNIFICANCE

The design of new bio-functional scaffolds that can be employed for bladder reconstructive procedures is a growing focus in the field of tissue engineering. In this study, a fibrin binding form of human insulin-like growth factor-1 (IGF-1) was produced and used to functionalize a multi-layered collagen-fibrin scaffold consisting of bioactive fibrin layer, sandwiched between two collagen gels. An effective dosage of our IGF-1 variant was successfully determined via a nude rat bladder model, which may play a critical role in estimating its therapeutic dosage in clinical trials. Thus, this new bioactive scaffold may offer an advanced approach to accelerate bladder regeneration.

Autologous Fibrin Glue—Clinical Use and Sealing of High-Porosity Vascular Prostheses

Autologous fibrin glue was prepared in a new way by means of ethanol. From 42 patients 44 mL of blood with a mean plasma fibrinogen concentration of 3.7 mg/mL was drawn. The product of the preparation was a mean of 2.5 mL of fibrinogen concentrate with a concentration of 28 mg/mL. After addition of 0.3 part of thrombin solution containing calcium chloride and aprotinin, an antifibrinolytic agent, the total volume of two-component fibrin glue was 3.3 mL. The preparation was done in a closed system to ensure sterility and com pleted within ninety minutes. Twenty high-porosity double-velour vascular prostheses were sealed with autologous fibrin glue in the laboratory. The pro stheses were tight for blood up to a pressure higher than 300 mmHg, which was comparable to vascular prostheses impregnated with collagen, but to more than twice the pressure of 130 mmHg, where vascular prostheses preclotted with blood started leaking. Autologous fibrin glue imparts a nice white vascular graft with superior handling characteristics, since it is nonsticky compared with blood-clotted grafts and softer and more pliable than the vascular prostheses impregnated with collagen from the manufacturer. In addition autologous fi brin glue has the obvious advantages of safety from transmission of viral dis eases and from immunologic reactions.

Practice guidelines for perioperative blood management: an updated report by the American Society of Anesthesiologists Task Force on Perioperative Blood Management*

The American Society of Anesthesiologists Committee on Standards and Practice Parameters and the Task Force on Perioperative Blood Management presents an updated report of the Practice Guidelines for Perioperative Blood Management.

Supplemental Digital Content is available in the text.

In vivo study of novelly formulated porcine-derived fibrinogen as an efficient sealant

Fibrinogen has been used as surgical sealant in the clinical setting for decades. The application of human plasma-derived fibrinogen is limited due to high cost and the risk of prion and virus infection. We developed a novel arginine-formulated fibrinogen from cryoprecipitates of porcine plasma. This porcine-derived fibrinogen exhibited excellent stability during sterilization and better hemostatic efficacy than a leading commercial hemostatic product in a nonlethal hemorrhage model. Therefore, it has the potential to be more economical and readily available while having a decreased risk of human blood-borne pathogen transmission.

The FINISH-3 trial: a phase 3, international, randomized, single-blind, controlled trial of topical fibrocaps in intraoperative surgical hemostasis

BACKGROUND

This Phase 3, international, randomized, single-blind, controlled trial (FINISH-3) compared the efficacy and safety of Fibrocaps, a ready-to-use, dry-powder fibrin sealant containing human plasma-derived thrombin and fibrinogen, vs gelatin sponge alone for use as a hemostat for surgical bleeding in 4 indications (ie, spinal, hepatic, vascular, soft tissue dissection).

STUDY DESIGN

Adults with mild to moderate surgical bleeding (randomized 2:1; Fibrocaps vs gelatin sponge) were treated at a single bleeding site (day 1). Time to hemostasis (TTH) during 5 minutes was compared (log-rank statistic) within each indication. Safety follow-up continued to day 29.

RESULTS

Patients were treated (Fibrocaps, n = 480; gelatin sponge, n = 239) when undergoing spinal (n = 183), vascular (n = 175), hepatic (n = 180), or soft-tissue (n = 181) procedures. Fibrocaps was applied by spray device in 53% of all procedures (94% of hepatic and soft-tissue procedures). Fibrocaps significantly reduced TTH compared with gelatin sponge; estimated hazard ratios were 3.3, 2.1, 2.3, and 3.4 for the 4 surgical indications, respectively (each p < 0.001; primary end point). Fibrocaps significantly reduced median TTH for each indication (p < 0.001) and was superior for secondary efficacy end points of restricted mean TTH (p < 0.001) and probability of hemostasis at 3 (p < 0.001) and 5 (p ≤ 0.002) minutes. Adverse event incidences were generally similar between treatment arms. Non-neutralizing, anti-thrombin antibodies developed in 2% of Fibrocaps-treated and 3% of gelatin sponge-treated patients.

CONCLUSIONS

Fibrocaps was well tolerated and significantly reduced TTH relative to gelatin sponge alone in all 4 surgical indications. These findings demonstrate the broad utility of Fibrocaps as a hemostatic agent for mild to moderate surgical bleeding.

Hemostatic efficacy of latest-generation fibrin sealant after hepatic resection: a randomized controlled clinical study

PURPOSE

This randomized, controlled, single-blinded multicenter study evaluated the efficacy of latest-generation fibrin sealant containing synthetic aprotinin as fibrinolysis inhibitor as supportive treatment for hemostasis after elective partial hepatectomy.

METHODS

Adult subjects undergoing resection of at least one liver segment were assigned to treatment with fibrin sealant or manual compression with a surgical gauze swab if persistent oozing necessitated additional hemostatic measures after primary control of arterial and venous bleeding. The primary outcome measure was the proportion of subjects with intraoperative hemostasis at 4 min after start of randomized treatment application. Secondary efficacy outcome measures included intraoperative hemostasis at 6, 8, and 10 min, intra- and postoperative rebleedings, transfusion requirements, and drainage volume.

RESULTS

Seventy subjects were randomized. Hemostasis at 4 min was achieved in 29/35 (82.9 %) fibrin sealant subjects compared with 13/35 (37.1 %) control subjects (p < 0.001). Significantly more fibrin sealant subjects achieved hemostasis at 6 (p < 0.001), 8 (p = 0.028), and 10 min (p = 0.017). The number of rebleedings was low in both study arms. Transfusion requirements and 48-h drainage volumes were similar between the study arms. No adverse events related to study treatment were reported.

CONCLUSIONS

Fibrin sealant was shown to be safe and superior to manual compression in the control of parenchymal bleeding after hepatic resection. The use of synthetic aprotinin as fibrinolysis inhibitor further improves the safety margin of fibrin sealant by eliminating the risk of transmission of bovine spongiform encephalopathy and other bovine pathogens.

Fibrin sealants: surgical hemostat, sealant and adhesive

INTRODUCTION

Fibrin sealants (FS) have been approved for use in the United States since 1998. Since approval, they have been used in a wide variety of clinical settings and new products continue to be introduced.

AREAS COVERED

This review covers the literature supporting the USA FDA-approved indications for FS products produced by Baxter Corp. Literature review of PubMed, the Cochrane Library, FDA approval documents and product websites yielded information contained in this article. Mechanism of action, efficacy and safety of these products are covered.

EXPERT OPINION

FS are generally safe, popular and are used for a wide variety of off-label indications. Their use appears to be expanding rapidly. For many uses, including approved ones, large well-controlled trials are still needed. Additionally, cost-effectiveness data for these products would be a great benefit in guiding their future use.

Fibrin Sealant: The Only Approved Hemostat, Sealant, and Adhesive-a Laboratory and Clinical Perspective

Background. Fibrin sealant became the first modern era material approved as a hemostat in the United States in 1998. It is the only agent presently approved as a hemostat, sealant, and adhesive by the Food and Drug Administration (FDA). The product is now supplied as patches in addition to the original liquid formulations. Both laboratory and clinical uses of fibrin sealant continue to grow. The new literature on this material also continues to proliferate rapidly (approximately 200 papers/year). Methods. An overview of current fibrin sealant products and their approved uses and a comprehensive PubMed based review of the recent literature (February 2012, through March 2013) on the laboratory and clinical use of fibrin sealant are provided. Product information is organized into sections based on a classification system for commercially available materials. Publications are presented in sections based on both laboratory research and clinical topics are listed in order of decreasing frequency. Results. Fibrin sealant remains useful hemostat, sealant, and adhesive. New formulations and applications continue to be developed. Conclusions. This agent remains clinically important with the recent introduction of new commercially available products. Fibrin sealant has multiple new uses that should result in further improvements in patient care.

Armentarium of topical hemostatic products in cardiovascular surgery: an update

Within Canada, 2.6 million in-hospital surgical procedures are completed annually. Significant bleeding following is the most common surgical complication, occurring in up to 25% of all surgeries. Bleeding causes increased mortality and morbidity, by increasing the number of transfusions required, secondary to increased cumulative blood loss, and by causing hemodynamic instability. A solution to this issue encountered during surgery is the use of hemostatic products. The objectives of this manuscript are (1) to review the spectrum of hemostatic products available in cardiovascular surgery and (2) to provide an update on new topical products soon available, or in development, for optimizing hemostasis during surgical procedures.

A totally recombinant human fibrin sealant

BACKGROUND

Applications of plasma-derived human fibrin sealants (pdhFS) have been limited because of cost, limited supply of pathogen-screened plasma, the need for bioengineering improvements, and regulatory issues associated with federal approval. We describe a totally recombinant human fibrin sealant (rhFS), which may engender an abundant, safe, and cost-effective supply of efficacious fibrin sealant.

MATERIALS AND METHODS

A first-generation rhFS made from recombinant human fibrinogen (rhFI; produced in the milk of transgenic cows), activated recombinant human factor XIII (rhFXIIIa; produced in yeast), and recombinant human thrombin (rhFIIa; purchased, made in animal cell culture) was formulated using thromboelastography (TEG). The hemostatic efficacy of rhFS versus commercial pdhFS was compared in a nonlethal porcine hepatic wedge excision model.

RESULTS

The maximal clot strength of rhFS measured in vitro by TEG was not statistically different than that of pdhFS. TEG analysis also showed that the rhFS gained strength more quickly as reflected by a steeper α angle; however, the rhFS achieved this clot strength with a 5-fold lower factor I content than the pdhFS. When these fibrin sealants were studied in a porcine hepatic wedge excision model, the hemostatic scores of the rhFS were equivalent or better than that of the pdhFS.

CONCLUSIONS

The bioengineered rhFS had equivalent or better hemostatic efficacy than the pdhFS in a nonlethal hemorrhage model, despite the factor I concentration in the rhFS being about one-fifth that in the pdhFS. Because the rhFS is amenable to large-scale production, the rhFS has the potential to be more economical and abundant than the pdhFS, while having a decreased risk of blood-borne pathogen transmission.

Autologous uncultured bone marrow-derived mononuclear cells and modified cannulated screw in repair of femoral neck fracture

The purpose of this study was to assess whether autologous uncultured bone marrow-derived mononuclear cells (BMMNCs) combined with modified cannulated screw would accelerate the healing of canine femoral neck fracture. BMMNCs were encapsulated within fibrin glue (FG) and implanted into the fractured femoral neck via modified cannulated screw in experiment group, and the control group was treated by modified cannulated screw. Gross observation, radiological examination, histological analysis, and blood vessel microdensity counting were used to compare bone healing of each group at 1, 2, and 3 months. FG was confirmed as an ideal cell-delivery vehicle for BMMNCs proliferation and differentiation in vitro testing. In vivo animal testing, faster new bone formation and fracture healing were confirmed by gross observation, radiological examination, histological analysis in experimental group than in control group at all times points. The blood vessel microdensity counting increased gradually both in the experimental group and control group, but was more obviously in experimental group at 3 months (p < 0.01). These data suggest that autologous BMMNCs combined with modified cannulated screw treatment is an effective therapy for femoral neck fracture and thus, may be an option for clinical applications.

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.

Optimizing hemostatic practices: matching the appropriate hemostat to the clinical situation

Achieving hemostasis is a critical focus of clinicians working in the surgical setting, given that uncontrolled surgical bleeding is associated with increased mortality rates and higher costs of care. As principal members of the surgical team, perioperative nurses are in an optimal position to plan and direct care during a bleeding event and throughout a patient's surgical stay. This supplement includes an assessment of the clinical and economic effects of surgical bleeding, a thorough review of available therapies, and a detailed comparison of these products to demonstrate which agents are best suited for a given clinical situation. By understanding the basic science of coagulation and hemostasis and current advances in topical hemostatic agents, including their safety, efficacy, and judicious use, perioperative nurses will be empowered to better assist the surgeon in optimizing patient outcomes.

Formulation and characterization of poloxamine-based hydrogels as tissue sealants

In situ cross linkable polyethylene glycol (PEG)-based polymers play an increasing role in surgical practice as sealants that provide a barrier to fluid/gas leakage and adhesion formation. This study investigated the gelation behavior and physical properties of hydrogels formed from homogeneous and blended solutions of two acrylated poloxamines (Tetronics® T1107 and T904) of various molecular weights and hydrophilic/lipophilic balances relative to a PEG control. Hydrogels were formed by reverse thermal gelation at physiological temperature (T1107-containing formulations) and covalent crosslinking by Michael-type addition with dithiothreitol. All poloxamine-based hydrogels exhibited thermosensitive behavior and achieved significantly reduced swelling, increased tensile properties and increased tissue bond strength relative to the PEG hydrogel at physiological temperature. Swelling and tensile properties of all poloxamine-based hydrogels were significantly greater at 37°C relative to 4°C, suggesting that their improved physical properties derive from cooperative crosslinking by both noncovalent and covalent mechanisms. Poloxamine-based hydrogels were cytocompatible and underwent hydrolytic degradation over 2-5weeks, depending on their T1107/T904 composition. In conclusion, select poloxamine-based hydrogels possess a number of properties potentially beneficial to tissue sealant applications, including a substantial increase in viscosity between room/physiological temperatures, resistance to cell adhesion and maintenance of a stable volume during equilibration.