Comparison of a collagen membrane versus a fibrin sealant after a peroneal nerve section and repair: a functional and histological study

DOTAGEL: a hydrogen and amide bonded, gelatin based, tunable, antibacterial, and high strength adhesive synthesized in an unoxidized environment

The development of bioadhesives that concurrently exhibit high adhesion strength, biocompatibility, and tunable properties and involve simple fabrication processes continues to be a significant challenge. In this study, a novel bioadhesive named DOTAGEL is synthesized by crosslinking gelatin (GA), dopamine (DA), and tannic acid (TA) in an unoxidized environment due to the advantage of controlling the degree of protonation in GA and TA, as well as controlling the degree of intermolecular amide and hydrogen bonding in the acidic medium. DOTAGEL (DA + TA + GA) shows superior adhesion strengths of 104.6 ± 46 kPa on dry skin and 35.6 ± 4.5 kPa on wet skin, up to 13 attachment-detachment cycles, retains adhesion strength under water for up to 10 days and is capable of joining two cut parts of internal organs of mice. Moreover, DOTAGEL shows strong antibacterial properties, self-healing, and biocompatibility since it contains TA, a natural and antibacterial cross-linker with abundant hydroxyl groups and the capability of forming non-covalent bonds in an unoxidized environment, and dopamine hydrochloride, a mussel inspired biomaterial containing both the amine and catechol groups for amide bonding and hydrogen bonding with TA and GA. The cross-linking among 20% (w/v) GA, 0.2% (w/v) DA, and 20% (w/v) TA is done by the centrifugation process at room temperature. Two different acids, hydrochloric acid and acetic acid, were used for tuning the pH of the medium, which led to two different samples named DOTAGEL/AA and DOTAGEL/HCL. The degree of cross-linking and mechanical and biochemical properties, like adhesion strength, degradation rate, antibacterial properties, stickiness, etc., are tuned by adjusting the pH of the medium. DOTAGEL/HCL showed 6.5 times faster degradation in 10 days, a faster release rate in the antibacterial study, 2 times adhesion strength in a dry medium, and more stickiness. The novelty lies not only in increased adhesion strength but also in the single-step fabrication process of the adhesive in the acidic medium. This research proposes the formation of a tunable antibacterial adhesive that is capable of working on wet surfaces within the body and that has the potential to become a successful tissue adhesive with a wide range of possibilities in controlled drug delivery at wound sites and other biomedical applications.

Comparison of Fibrin Glue With Conventional Suturing in Peripheral Nerve Repairs: A Study of Sensory and Motor Outcomes

BACKGROUND

Nerve injuries have traditionally been repaired with sutures, and this method is considered the gold standard technique in the management of nerve injuries. However, fibrin glue has recently become a promising tool for repairing nerve injuries and has advantages including ease of usability, atraumatic application technique, and decreased co-optation time of the nerves. This study aims to clinically evaluate the efficacy of nerve repair with fibrin glue compared with the usual suture technique in terms of sensory and motor outcomes.

METHODS

A total of 80 patients were included in the study; 50 patients underwent primary nerve repair, and 30 patients underwent Oberlin's repair. These subsets were randomly divided into two groups in which the nerves were repaired with microsutures in one group and fibrin glue in the other group.

RESULTS

In the comparison of fibrin glue with microsutures, there were no significant differences between the two groups in the 2-point discrimination (2PD) test, Semmes-Weinstein test, motor function, and Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire scores. However, the co-optation times were significantly shorter with fibrin glue than with microsutures.

CONCLUSION

Based on our findings, nerve repair with fibrin glue is as effective as microsutures in terms of sensory and motor recovery and has added advantages of ease of usability and shorter repair times. Therefore, fibrin glue may be an effective alternative to sutures in nerve repair.

History of peripheral nerve injuries

This article reviews the history of peripheral nerve (PN) injuries and successive advances in their management by notable pioneers, an interesting topic that I chose for my Doctoral Thesis in 1990 in Madrid. Mentioning all their names and contributions is an obligatory tribute, and I offer my sincere apologies for inevitably leaving a few out. For half a century I have witnessed microsurgery advances, and also experienced frequent failures in my practice with the use of new techniques; a testimony that we are very far from achieving the 'Holy Grail' of complete PN recovery for these injuries. Our experience is often like a pendulum, from nihilism to optimism and vice versa. Many factors influence the results of PN repair. Fortunately, microsurgery has been a breakthrough but, too often, emergency surgery is carried out by surgeons without enough tools and experience, both very important factors in this field.

Ultra-sounding out a technique that sticks

Ultrasound can be used to promote the physical interlocking of adhesives and tissues.

Current Concepts on Tissue Adhesive Use for Meniscal Repair-We Are Not There Yet: A Systematic Review of the Literature

BACKGROUND

Tissue adhesives (TAs) represent a promising alternative or augmentation method to conventional tissue repair techniques. In sports medicine, TA use has been suggested and implemented in the treatment of meniscal tears. The aim of this review was to present and discuss the current evidence and base of knowledge regarding the clinical usage of TAs for meniscal repair.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic literature search was performed using the PubMed, Embase, and Cochrane Library databases for studies reporting on clinical outcomes of TA usage for meniscal repair in humans in the English language published before January 2020.

RESULTS

Ten studies were eligible for review and included 352 meniscal repairs: 94 (27%) were TA-based repairs and 258 (73%) were combined suture and TA repairs. Concomitant anterior cruciate ligament reconstruction was performed in 224 repairs (64%). All included studies utilized fibrin-based TA. Of the 10 studies, 9 were evidence level 4 (case series), and 8 reported on a cohort of ≤40 meniscal repairs. Rates of meniscal healing were evaluated in 9 of 10 studies, with repair failure seen in 39 repairs (11%).

CONCLUSION

The use of TAs, specifically fibrin-based TAs, for meniscal repair shows good results as either an augmentation or primary repair of various configurations of meniscal tears. However, this review reveals an absence of comparative high-quality evidence supporting the routine use of TAs for meniscal repair and emphasizes the lack of an ideal TA designed for that purpose. Further high-quality research, basic science and clinical, will facilitate the development of new materials and enable testing their suitability for use in meniscal repair.

Emerging Biopolymer-Based Bioadhesives

Bioadhesives have been widely used in healthcare and biomedical applications due to their ease-of-operation for wound closure and repair compared to conventional suturing and stapling. However, several challenges remain for developing ideal bioadhesives, such as unsatisfied mechanical properties, non-tunable biodegradability, and limited biological functions. Considering these concerns, naturally derived biopolymers have been considered good candidates for making bioadhesives owing to their ready availability, facile modification, tunable mechanical properties, and desired biocompatibility and biodegradability. Over the past several years, remarkable progress has been made on biopolymer-based adhesives, covering topics from novel materials designs and advanced processing to clinical translation. The developed bioadhesives have been applied for diverse applications, including tissue adhesion, hemostasis, antimicrobial, wound repair/tissue regeneration, and skin-interfaced bioelectronics. Here in this comprehensive review, recent progress on biopolymer-based bioadhesives is summarized with focuses on clinical translations and multifunctional bioadhesives. Furthermore, challenges and opportunities such as weak adhesion strength at the hydrated state, mechanical mismatch with tissues, and unfavorable immune responses are discussed with an aim to facilitate the future development of high-performance biopolymer-based bioadhesives.

Use of Erythropoietin and Fibrin Glue Mixture for Peripheral Nerve Repair

BACKGROUND

Erythropoietin has neuroregenerative effects. Fibrin glue may be used for nerve repair and controlled release of substances. In this study, the authors investigated the effects of erythropoietin-containing fibrin glue on nerve repair, based on the hypothesis that erythropoietin-containing fibrin glue would positively affect nerve regeneration.

METHODS

Thirty-six Long-Evans rats were used. The animals were divided into six groups. Their left sciatic nerves were isolated, transected, and repaired with saline-containing fibrin glue in group 1, with erythropoietin-containing fibrin glue in group 2, with saline-containing fibrin glue and two sutures in group 3, with erythropoietin-containing fibrin glue and two sutures in group 4, with two sutures in group 5, and with four sutures in group 6. Sciatic Functional Index calculation, pin-prick test, and toe-spread test were performed on days 21, 42, and 63. All animals were killed on day 63. The nerve sections were analyzed histologically.

RESULTS

The Sciatic Functional Index, pin-prick test, and toe-spread test results were the best in group 4 and the worst in group 5. Group 4 showed superior Schwann cell proliferation (p < 0.05). Groups with epineural suture use (groups 3, 4, 5, and 6) had higher endoneurial collagen synthesis scores than the groups without suture use (groups 1 and 2) (p < 0.05). The myelin protein zero immunostaining results were significantly higher in the erythropoietin-treated groups (groups 2 and 4) (p < 0.05).

CONCLUSION

The combined use of erythropoietin-containing fibrin glue and two epineural sutures (group 4) showed a statistically significant improvement in many parameters.

CLINICAL RELEVANCE STATEMENT

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Healing through the lens of immunothrombosis: Biology-inspired, evolution-tailored, and human-engineered biomimetic therapies

Evolution, from invertebrates to mammals, has yielded and shaped immunoclotting as a defense and repair response against trauma and infection. This mosaic of immediate and local wound-sealing and pathogen-killing mechanisms results in survival, restoration of homeostasis, and tissue repair. In mammals, immunoclotting has been complemented with the neuroendocrine system, platelets, and contact system among other embellishments, adding layers of complexity through interconnecting blood-born proteolytic cascades, blood cells, and the neuroendocrine system. In doing so, immunothrombosis endows humans with survival advantages, but entails vulnerabilities in the current unprecedented and increasingly challenging environment. Immunothrombosis and tissue repair appear to go hand in hand with common mechanisms mediating both processes, a fact that is underlined by recent advances that are deciphering the mechanisms of the repair process and of the biochemical pathways that underpins coagulation, hemostasis and thrombosis. This review is intended to frame both the universal aspects of tissue repair and the therapeutic use of autologous fibrin matrix as a biology-as-a-drug approach in the context of the evolutionary changes in coagulation and hemostasis. In addition, we will try to shed some light on the molecular mechanisms underlying the use of the autologous fibrin matrix as a biology-inspired, evolution-tailored, and human-engineered biomimetic therapy.

Emerging bioadhesives: from traditional bioactive and bioinert to a new biomimetic protein-based approach

Bioadhesives have reached significant milestones over the past two decades. Research has shown not only to produce adhesives capable of adhering to dry tissue but recently wet tissue as well. However, most bioadhesives developed have exhibited high adhesion strength yet lack other properties required for versatility in application, such as elasticity, biocompatibility and biodegradability. Adapting from limitations met from early bioadhesives and meeting the current demand allows novel bioadhesives to reach new milestones for the future. In this review, we overview the progression and variations of bioadhesives, current trends, characterisation techniques and conclude with future perspectives for bioadhesives for tissue engineering applications.

Engineering Hydrogel Adhesion for Biomedical Applications via Chemical Design of the Junction

Hydrogel adhesion inherently relies on engineering the contact surface at soft and hydrated interfaces. Upon contact, adhesion normally occurs through the formation of chemical or physical interactions between the disparate surfaces. The ability to form these adhesion junctions is challenging for hydrogels as the interfaces are wet and deformable and often contain low densities of functional groups. In this Review, we link the design of the binding chemistries or adhesion junctions, whether covalent, dynamic covalent, supramolecular, or physical, to the emergent adhesive properties of soft and hydrated interfaces. Wet adhesion is useful for bonding to or between tissues and implants for a range of biomedical applications. We highlight several recent and emerging adhesive hydrogels for use in biomedicine in the context of efficient junction design. The main focus is on engineering hydrogel adhesion through molecular design of the junctions to tailor the adhesion strength, reversibility, stability, and response to environmental stimuli.

Enzyme Catalyzed Hydrogel as Versatile Bioadhesive for Tissue Wound Hemostasis, Bonding, and Continuous Repair

Developing a versatile bioadhesive which is biocompatible, adhesive, hemostatic, and therapeutic is of great significance to promote wound sealing and healing. Herein, an adhesive (GTT-3 hydrogel) is fabricated by catalysis of tannic acid modified gelatin (Gel-TA) with transglutaminase (TG). The hydrogen bonding, imine linking, and acyl-transfer reaction between GTT-3 hydrogel and tissue enable efficient hydrogel integration and adhesion to tissue instantly, so as to seal the wound and stop bleeding. Moreover, the intrinsic wound healing ability of gelatin and the antibacterial properties of TA provide favorable conditions for wound healing after adhesion. In vitro mechanical property testing and cell experimental results determine the elasticity, adhesion, and biocompatibility of the GTT-3 hydrogel. The wound operation in mouse models and pathological sectioning results indicate that GTT-3 adhesive obviously accelerates hemostasis, wound bonding, and healing. With the special property of instant adhesion and excellent hemostatic and therapeutic repair effects, GTT-3 hydrogel may provide a new option for surgical operation.

Polymeric Tissue Adhesives

Polymeric tissue adhesives provide versatile materials for wound management and are widely used in a variety of medical settings ranging from minor to life-threatening tissue injuries. Compared to the traditional methods of wound closure (i.e., suturing and stapling), they are relatively easy to use, enable rapid application, and introduce minimal tissue damage. Furthermore, they can act as hemostats to control bleeding and provide a tissue-healing environment at the wound site. Despite their numerous current applications, tissue adhesives still face several limitations and unresolved challenges (e.g., weak adhesion strength and poor mechanical properties) that limit their use, leaving ample room for future improvements. Successful development of next-generation adhesives will likely require a holistic understanding of the chemical and physical properties of the tissue-adhesive interface, fundamental mechanisms of tissue adhesion, and requirements for specific clinical applications. In this review, we discuss a set of rational guidelines for design of adhesives, recent progress in the field along with examples of commercially available adhesives and those under development, tissue-specific considerations, and finally potential functions for future adhesives. Advances in tissue adhesives will open new avenues for wound care and potentially provide potent therapeutics for various medical applications.

Unusually rare occurrence and recurrence of temporomandibular joint ankylosis and oral submucous fibrosis simultaneously in a patient: A surgeon's dilemma

We here present a rare case of simultaneous occurrence and recurrence of TMJ ankylosis and submucous fibrosis in the same patient. Patient presented with limited mouth opening at both occasions. However, the diagnosis of submucous fibrosis was overlooked at the first presentation. The patient reported with recurrence of both the conditions after a period of 15 years. We presume that noncompliance of jaw exercises aggravated both the conditions as one led to the other. Since fibrosis sets in earlier than bony fusion, we theorized that the patient had acquired OSMF before TMJ ankyloses recurrence. The case was managed with release of fibrous bands intraorally followed by release of TMJ ankylosis and interposition with dermis fat graft. Physiotherapy is extremely essential when either pathology is treated in patients, especially when both are present in a single patient.

Unique heterologous fibrin biopolymer with hemostatic, adhesive, sealant, scaffold and drug delivery properties: a systematic review

Fibrin biopolymers, previously referred as "fibrin glue" or "fibrin sealants", are natural biomaterials with diverse applications on health. They have hemostatic, adhesive, sealant, scaffold and drug delivery properties and have become widely used in medical and dental procedures. Historically, these biomaterials are produced from human fibrinogen and human or animal thrombin, and the possibility of transmission of infectious diseases by human blood is not ruled out. In the 1990s, to overcome this problem, a new heterologous biomaterial composed of a thrombin-like enzyme purified from Crotalus durissus terrificus venom and a cryoprecipitate rich in fibrinogen extracted from buffaloes Bubalus bubalis blood has been proposed. Therefore, a systematic review of studies on exclusively heterologous fibrin sealants published between 1989 and 2018 was carried out using the following databases: PubMed, SciELO and Google Scholar. The keyword used was "heterologous fibrin sealant". The search resulted in 35 scientific papers in PubMed, four in SciELO and 674 in Google Scholar. After applying the inclusion/exclusion criteria and complete reading of the articles, 30 studies were selected, which formed the basis of this systematic review. It has been observed that the only completely heterologous sealant is the one produced by CEVAP/UNESP. This heterologous biopolymer is proven effective by several studies published in refereed scientific journals. In addition, clinical trials phase I/II for the treatment of chronic venous ulcers authorized by the Brazilian Health Regulatory Agency (ANVISA) were completed. Preliminary results have indicated a safe and promising effective product. Phase III clinical trials will be proposed and required to validate these preliminary findings.

History of Hemostasis in Neurosurgery

Control of bleeding in the confined area of the skull is imperative for successful neurosurgery and the prevention of devastating complications such as postoperative hemorrhage. This paper reviews the historical evolution of methods to achieve successful hemostasis in neurosurgery from the early1800s to today. The major categories of hemostatic agents (mechanical, chemical and thermal) are delineated and discussed in chronological order. The significance of this article is in its detailed history of the kinds of hemostatic methods that have evolved with our accumulating medical and surgical knowledge, which may inform future innovations and improvements.

A Prospective, Single-Blind, Randomized, Phase III Study to Evaluate the Safety and Efficacy of Fibrin Sealant Grifols as an Adjunct to Hemostasis During Soft Tissue Open Surgery

BACKGROUND/PURPOSE

Rapid hemostasis, an essential prerequisite of good surgical practice during surgical bleeding, including soft tissue open surgery, often requires adjunctive treatment. We evaluated the safety and hemostatic effectiveness of a human plasma-derived fibrin sealant (FS Grifols) in soft tissue open surgery.

METHODS

Patients with moderate soft tissue bleeding during open, urologic, gynecologic or general surgery were studied. The trial consisted of a preliminary phase (to familiarize investigators with the technique for FS Grifols application and the intraoperative procedures required by the clinical protocol) and a primary phase: in both phases, patients were randomized 1:1 to FS Grifols or Surgicel^®. The primary efficacy endpoint, based on analysis of subjects in the primary phase of the study, was to evaluate whether FS Grifols was non-inferior to Surgicel^® in achieving hemostasis, based on the proportion of subjects in both treatment groups who achieved hemostasis at the target bleeding site (TBS) by 4 min (T₄) following the start of treatment application. Safety assessments included adverse events (AEs), vital signs, physical assessments, common clinical laboratory tests, viral markers, and immunogenicity.

RESULTS

A total of 224 subjects were randomized (primary phase): FS Grifols (N = 116), Surgicel^® (N = 108). The 95% CI at T₄ for the ratio of the proportion of patients achieving hemostasis in the two treatment groups was 1.064 (0.934, 1.213), indicating non-inferiority for FS Grifols vs. Surgicel^®. The rate of hemostasis at the TBS by T₄ in both phases of the study was higher in the FS Grifols treatment group (preliminary phase: 90.2%; primary phase: 82.8%) than in the Surgicel^® treatment group (preliminary phase: 78.8%; primary phase: 77.8%). Overall, reported AEs were as expected in surgical patients and were similar between the two treatment groups.

CONCLUSIONS

This study shows the non-inferiority in time to hemostasis of FS Grifols vs. Surgicel as an adjunct to hemostasis in patients undergoing soft tissue open surgery, and a similar rate of AEs.

Beyond the Cyst: The Many Contributions of Isadore Tarlov (1905-1977) to Contemporary Neurosurgical Practice

: Isadore Max Tarlov (1905-1977) is primarily remembered for his 1938 description of the eponymous perineural "Tarlov cyst." However, during his long career as a neurosurgeon and researcher, he was responsible for many other observations and inventions that influenced the development of neurosurgery in the 20th century. While studying at Johns Hopkins Medical School he was acquainted with Walter Dandy, and he became the first resident to study under Wilder Penfield at the newly formed Montreal Neurological Institute. He made many novel observations about peripheral and cranial nerve anatomy, pioneered nerve anastomosis and grafting techniques, and introduced the concept of fibrin glue. He developed an animal model of spinal cord injury and used it to establish for the first time that functional neurological reserve is proportional to rapidity of injury, because gradual onset of compression is better tolerated by neural tissue than acute compression. He was the first to describe the use of the knee-chest position for lumbar spine surgery to minimize increases in epidural venous pressure due to abdominal compression. Finally, near the end of his career, he published a collection of thoughtful, philosophical essays entitled The Principle of Parsimony in Medicine and Other Essays, in which he advocated for a humanistic and restrained approach to medical practice. In this article, we discuss the contributions of Tarlov to the field of neurosurgery, including many of his lesser-known accomplishments that have become part of neurosurgery's collective legacy.

Fibrin, the preferred scaffold for cell transplantation after myocardial infarction? An old molecule with a new life

Fibrin is a topical haemostat, sealant and tissue glue, which consists of concentrated fibrinogen and thrombin. It has broad medical and research uses. Recently, several studies have shown that engineered patches comprising mixtures of biological or synthetic materials and progenitor cells showed therapeutic promise for regenerating damaged tissues. In that context, fibrin maintains cell adherence at the site of injury, where cells are required for tissue repair, and offers a nurturing environment that protects implanted cells without interfering with their expected benefit. Here we review the past, present and future uses of fibrin, with a focus on its use as a scaffold material for cardiac repair. Fibrin patches filled with regenerative cells can be placed over the scarring myocardium; this methodology avoids many of the drawbacks of conventional cell-infusion systems. Advantages of using fibrin also include extraction from the patient's blood, an easy readjustment and implantation procedure, increase in viability and early proliferation of delivered cells, and benefits even with the patch alone. In line with this, we discuss the numerous preclinical studies that have used fibrin-cell patches, the practical issues inherent in their generation, and the necessary process of scaling-up from animal models to patients. In the light of the data presented, fibrin stands out as a valuable biomaterial for delivering cells to damaged tissue and for promoting beneficial effects. However, before the fibrin scaffold can be translated from bench to bedside, many issues must be explored further, including suboptimal survival and limited migration of the implanted cells to underlying ischaemic myocardium. Copyright © 2016 John Wiley & Sons, Ltd.

Fibrin sealant use in pilonidal sinus: Systematic review

AIM: To review the current data about the success rates of fibrin sealant use in pilonidal disease.

METHODS: Fibrin sealant can be used for different purposes in pilonidal sinus treatment, such as filling in the sinus tracts, covering the open wound after excision and lay-open treatment, or obliterating the subcutaneous dead space before skin closure. We searched Pubmed, Google-Scholar, Ebsco-Host, clinicaltrials, and Cochrane databases and found nine studies eligible for analysis; these studies included a total of 217 patients (84% male, mean age 24.2 ± 7.8).

RESULTS: In cases where fibrin sealant was used to obliterate the subcutaneous dead space, there was no reduction in wound complication rates (9.8% vs 14.6%, P = 0.48). In cases where sealant was used to cover the laid-open area, the wound healing time and patient comfort were reported better than in previous studies (mean 17 d, 88% satisfaction). When fibrin sealant was used to fill the sinus tracts, the recurrence rate was around 20%, despite the highly selected grouping of patients.

CONCLUSION: Consequently, using fibrin sealant to decrease the risk of seroma formation was determined to be an ineffective course of action. It was not advisable to fill the sinus tracts with fibrin sealant because it was not superior to other cost-effective and minimally invasive treatments. New comparative studies can be conducted to confirm the results of sealant use in covering the laid-open area.

Light-Activated Sealing of Nerve Graft Coaptation Sites Improves Outcome following Large Gap Peripheral Nerve Injury

BACKGROUND

Nerve repair using photochemically bonded human amnion nerve wraps can result in superior outcomes in comparison with standard suture. When applied to nerve grafts, efficacy has been limited by proteolytic degradation of bonded amnion during extended periods of recovery. Chemical cross-linking of amnion before bonding may improve wrap durability and efficacy.

METHODS

Three nerve wraps (amnion, cross-linked amnion, and cross-linked swine intestinal submucosa) and three fixation methods (suture, fibrin glue, and photochemical bonding) were investigated. One hundred ten Lewis rats had 15-mm left sciatic nerve gaps repaired with isografts. Nine groups (n = 10) had isografts secured by one of the aforementioned wrap/fixation combinations. Positive and negative control groups (n = 10) were repaired with graft and suture and no repair, respectively. Outcomes were assessed using sciatic function index, muscle mass retention, and histomorphometry. Statistical analysis was performed using analysis of variance and the post hoc Bonferroni test (p < 0.05).

RESULTS

Cross-linking improved amnion durability. Photochemically bonded cross-linked amnion recovered the greatest sciatic function index, although this was not significant in comparison with graft and suture. Photochemically bonded cross-linked amnion recovered significantly greater muscle mass (67.3 ± 4.4 percent versus 60.0 ± 5.2 percent; p = 0.02), fiber diameter, axon diameter, and myelin thickness (6.87 ± 2.23 μm versus 5.47 ± 1.70 μm; 4.51 ± 1.83 μm versus 3.50 ± 1.44 μm; and 2.35 ± 0.64 μm versus 1.96 ± 0.47 μm, respectively) in comparison with graft and suture.

CONCLUSION

Light-activated sealing of cross-linked human amnion results in superior outcomes when compared with conventional suture.

Use of Monsel solution to treat obstetrical hemorrhage: a review and comparison to other topical hemostatic agents

Peripartum hemorrhage accounts for 8% of maternal deaths in the United States, and nearly 27% worldwide. A growing need exists for tactics to spare morbidity given a rise of abnormal placentation that contributes to excessive blood loss at the time of delivery. Approaches such as compression sutures, balloon tamponade, and pelvic artery embolization are not without side effects and potential implications for future fertility. The use of topical hemostatic agents has become widespread in gynecologic and obstetric surgery despite a paucity of distinct studies in the field, and may allow providers to increasingly avoid cesarean hysterectomy. A variety of topical hemostatic agents exist along a wide cost continuum, each characterized by specific efficacy, advantages, drawbacks, and often gaps in long-term data to support safety and impact on future fertility. Herein, we comprehensively review these agents and illustrate a nontraditional use of Monsel solution applied directly to the placental bed in a case of focal placenta accreta. This ultimately contributed to successful uterine preservation with no known adverse sequelae. Monsel solution may have a role in establishing hemostasis in the setting of abnormal placentation, and may be a particularly attractive alternative in resource-poor nations.

Fibrin Sealant: A Review of Its Applications in Periodontal Surgery

Aim

Fibrin sealant is a biological tissue adhesive mimicking the final stage of coagulation. It has a wide variety of application in the field of periodontics. The aim of this article was to review current applications and identify potential use of fibrin sealant in periodontal surgical procedures on an evidence-based conclusion.

Materials and methods

An online search was performed in PubMed, Google Scholar and Cochrane Library databases using keywords fibrin sealant, fibrin glue, fibrin, regeneration, wound healing, tissue adhesive, gingival recession/therapy, surgical therapy, periodontal, and periodontitis in a mutually inclusive manner. The studies were evaluated by two independent reviewers for inclusion in this literature review.

Results

Out of 196 research papers identified, 59 articles were selected by the authors for this literature review, giving preference to clinical trials related to periodontal application.

Conclusion

Use of fibrin sealant is a simple, safe, costeffective, and rapid way to fix flaps and grafts avoiding any postoperative bleeding. Fibrin sealant has the property for regeneration when used in conjunction with a barrier membrane for formation of new connective tissue attachment. It is effective in microsurgical procedures and closing flaps around implant site. They initiate early wound healing through collagen synthesis and fibroblast proliferation. Fibrin sealant may be an alternate biomaterial for periodontal surgery which may stimulate periodontal wound healing and regeneration.

How to cite this article

Jacob S, Nath S. Fibrin Sealant: A Review of Its Applications in Periodontal Surgery. Int J Experiment Dent Sci 2015;4(1):40-46.

Biocompatibility and Efficacy of Five-Channel and Eight-Channel Crosslinked Urethane-Doped Polyester Elastomers (CUPEs) as Nerve Guidance Conduit for Reconstruction of Segmental Peripheral Nerve Defect Using Rat Model

Introduction: Peripheral nerve injury is common in clinical practice. Nerve defect is a challenging scenario. The current gold standard of managing a nerve defect is autologous nerve graft. However, due to the selection of nerve graft and donor site morbidity, artificial nerve conduits are gaining popularity. However, there are drawbacks of single hollow conduit such as lack of internal support to prevent conduit collapse and inability so as to recreate the proper native spatial arrangement of cells and extracellular matrix within the conduit. In this study, the biocompatibility and efficacy of five-channel and eight-channel Crosslinked Urethane-doped Polyester Elastomers (CUPEs) as nerve guidance conduit will be evaluated through a rat model with reconstruction of segmental peripheral nerve defect. Material and Method: Eighteen adult Sprague-Dawley rats were used. They were randomly allocated to three groups: autograft group, five-channel conduit group and eight-channel conduit group with each consisted of six rats. A 10mm nerve defects were created at the right sciatic nerve. They were bridged with reverse autograft, 5-channel conduit and 8-channel conduit. After eight weeks the rats were euthanized and the reconstructed nerves were harvested for histomorphometric analysis. Result: All conduits showed regenerated nerve tissue inside. There was no collapse of the conduits. There were no severe tissue reaction or scarring near the reconstructed nerve. No neuroma was formed. Histomorphometric analysis showed nerve regeneration was enhanced with increasing number of channels inside conduit. There was overall drop in fiber density between proximal and distal segment among all groups. Conclusion: CUPE nerve guidance conduit is biocompatible and shows good nerve regeneration in reconstructing nerve defect.

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.

Composition of fibrin glues significantly influences axial vascularization and degradation in isolation chamber model

In this study, different fibrin sealants with varying concentrations of the fibrin components were evaluated in terms of matrix degradation and vascularization in the arteriovenous loop (AVL) model of the rat. An AVL was placed in a Teflon isolation chamber filled with 500 μl fibrin gel. The matrix was composed of commercially available fibrin gels, namely Beriplast (Behring GmbH, Marburg, Germany) (group A), Evicel (Omrix Biopharmaceuticals S.A., Somerville, New Jersey, USA) (group B), Tisseel VH S/D (Baxter, Vienna, Austria) with a thrombin concentration of 4 IU/ml and a fibrinogen concentration of 80 mg/ml [Tisseel S F80 (Baxter), group C] and with an fibrinogen concentration of 20 mg/ml [Tisseel S F20 (Baxter), group D]. After 2 and 4 weeks, five constructs per group and time point were investigated using micro-computed tomography, and histological and morphometrical analysis techniques. The aprotinin, factor XIII and thrombin concentration did not affect the degree of clot degradation. An inverse relationship was found between fibrin matrix degradation and sprouting of blood vessels. By reducing the fibrinogen concentration in group D, a significantly decreased construct weight and an increased generation of vascularized connective tissue were detected. There was an inverse relationship between matrix degradation and vascularization detectable. Fibrinogen as the major matrix component showed a significant impact on the matrix properties. Alteration of fibrin gel properties might optimize formation of blood vessels.

The embracing end-to-side neurorrhaphy in rats

PURPOSE

Compare two new methods with the traditional end-to-side neurorrhaphy.

METHODS

Rats were divided into four groups. In A-L group the peroneal nerve was sectioned and the distal stump was connected to the lateral of the tibial nerve (donor) with two 10-0 nylon points. In A-R group two perineurium flaps embraced the donor nerve. In the B-R group a suture embraced the donor nerve. Group B-L was the control. After six months tibial cranial muscle mass and morphometry of the distal stump of the peroneal nerve were evaluated.

RESULTS

Muscle mass in groups A-R, A-L and B-R were lower than B-L group (p<0.0001) an equal between themselves (p>0.05). Groups A-R, B-R and A-L had a lower number of nerve fibers when compared with B-L (p=0.0155, p=0.016, p=0.0021).

CONCLUSION

The three types of neurorrhaphy showed no differences related to muscle mass and number of nerve fibers suggesting that the embracing with a single suture has great potential due its simplicity and usefulness in deep areas.

Effectiveness of fibrin adhesive in facial nerve anastomosis in dogs compared with standard microsuturing technique

PURPOSE

Epineural suturing is the most common technique used for peripheral nerve anastomosis. In addition to the foreign body reaction to the suture material, the surgical duration and difficulty of suturing in confined anatomic locations are major problems. We evaluated the effectiveness of fibrin glue as an acceptable alternative for nerve anastomosis in dogs.

METHODS

Eight adult female dogs weighing 18 to 24 kg were used in the present study. The facial nerve was transected bilaterally. On the right side, the facial nerve was subjected to epineural suturing; and on the left side, the nerve was anastomosed using fibrin adhesive. After 16 weeks, the nerve conduction velocity and proportion of the nerve fibers that crossed the anastomosis site were evaluated and compared for the epineural suture (right side) and fibrin glue (left side). The data were analyzed using the paired t test and univariate analysis of variance.

RESULTS

The mean postoperative nerve conduction velocity was 29.87 ± 7.65 m/s and 26.75 ± 3.97 m/s on the right and left side, respectively. No statistically significant difference was found in the postoperative nerve conduction velocity between the 2 techniques (P = .444). The proportion of nerve fibers that crossed the anastomotic site was 71.25% ± 7.59% and 72.25% ± 8.31% on the right and left side, respectively. The histologic evaluation showed no statistically significant difference in the proportion of the nerve fibers that crossed the anastomotic site between the 2 techniques (P = .598).

CONCLUSIONS

The results suggest that the efficacies of epineural suturing and fibrin gluing in peripheral nerve anastomosis are similar.

Combination of guided osteogenesis with autologous platelet-rich fibrin glue and mesenchymal stem cell for mandibular reconstruction

BACKGROUND

This study examined whether a combination of autologous platelet-rich fibrin glue (PRFG) with mesenchymal stem cells (MSCs) and MEDPOR as guided tissue regeneration (GTR) could act as an osteogenic substitute and whether this treatment yields faster new bone formation than MEDPOR alone or PRFG plus MSC.

MATERIAL

MSCs were harvested and isolated from the bone marrow of dog ilium. Full-thickness bony defects (1.5×1.5 cm) were created in the bilateral mandible angles of the dog. Treatments for bone defect in each group were as follows: group I (n=4), MEDPOR sheet as GTR and autologous PRFG/MSCs admixtures; group II (n=4), autologous PRFG/MSCs admixtures; group III (n=4), MEDPOR sheet as GTR; and group IV (n=4), control (empty defect). The percentage of new bone regeneration in computerized tomography at 2 months and 4 months was calculated by Analyze version 7.0 software. The mandibles were harvested from all specimens at 4 months, and the grafted sites were evaluated by gross, histologic, and X-ray examination.

RESULTS

By radiographic analysis at 16 weeks posttransplantation, it was shown that an average of 72.8%±8.02% new bone formation in group I, 53.34%±6.87% in group II, 26.58%±6.41% in group III, and 15.14%±2.37% in group IV. Histologic examination revealed that the defect was repaired by typical bone tissue in groups I and II, whereas only minimal bone formation with fibrous connection was observed in the groups III and IV group. Besides, muscle incarceration was found in groups II and IV without MEDPOR as GTR.

CONCLUSION

Autologous PRFG plus osteoinduced MSCs have good potential for bone regeneration. In combination with MEDPOR as GTR, bone regeneration is enhanced by preventing soft tissue ingrowth hindering bone regeneration.

Initial experience with hemostatic fibrin glue as adjuvant during drainless parotidectomy

OBJECTIVES

To evaluate the use of Hemostatic Fibrin Glue in parotidectomy without the use of surgical drains.

STUDY DESIGN

Prospective cohort study of 10 patients undergoing parotidectomy. Surgery as a one day admission without the use of surgical drains was planned. The complication and duration of the hospital stay were obtained.

METHODS

Parotidectomy was undertaken by one surgeon. Prior to wound closure, the skin flap and wound bed were approximated using Tisseel tissue sealant. Data regarding the incidence of any complication and the duration of the hospital stay were obtained. Patients were followed to assess surgical outcome and document any complications. The mean follow-up period was 8 months (range 4-12 months).

RESULTS

There were no major surgical complications. Two patients had facial nerve weakness due to adherence of the tumour in the facial nerve, in there was which complete recovery after few months. All patients were discharged the next day. None of the patients felt that the discharge had been premature.

CONCLUSIONS

Parotidectomy can be undertaken safely without the need for surgical drains, therefore, allowing the patients to leave the hospital on the first postoperative day.

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.

A review on endogenous regenerative technology in periodontal regenerative medicine

Periodontitis is a globally prevalent inflammatory disease that causes the destruction of the tooth-supporting apparatus and potentially leads to tooth loss. Currently, the methods to reconstitute lost periodontal structures (i.e. alveolar bone, periodontal ligament, and root cementum) have relied on conventional mechanical, anti-infective modalities followed by a range of regenerative procedures such as guided tissue regeneration, the use of bone replacement grafts and exogenous growth factors (GFs), and recently developed tissue engineering technologies. However, all current or emerging paradigms have either been shown to have limited and variable outcomes or have yet to be developed for clinical use. To accelerate clinical translation, there is an ongoing need to develop therapeutics based on endogenous regenerative technology (ERT), which can stimulate latent self-repair mechanisms in patients and harness the host's innate capacity for regeneration. ERT in periodontics applies the patient's own regenerative 'tools', i.e. patient-derived GFs and fibrin scaffolds, sometimes in association with commercialized products (e.g. Emdogain and Bio-Oss), to create a material niche in an injured site where the progenitor/stem cells from neighboring tissues can be recruited for in situ periodontal regeneration. The choice of materials and the design of implantable devices influence therapeutic potential and the number and invasiveness of the associated clinical procedures. The interplay and optimization of each niche component involved in ERT are particularly important to comprehend how to make the desired cell response safe and effective for therapeutics. In this review, the emerging opportunities and challenges of ERT that avoid the ex vivo culture of autologous cells are addressed in the context of new approaches for engineering or regeneration of functional periodontal tissues by exploiting the use of platelet-rich products and its associated formulations as key endogenous resources for future clinical management of periodontal tissue defects.

Fibrin sealant: past, present, and future: a brief review

BACKGROUND

Fibrin sealant is a two-component topical hemostat, sealant, and tissue adhesive consisting of fibrinogen and thrombin that has been used in the United States as a blood bank- or laboratory-derived product since the 1980s and has been commercially available since 1998.

METHODS/RESULTS

Initially, surgeons employed hospital-based materials because of the lack of availability of a commercially produced agent. At present, there are five U.S. Food and Drug Administration (FDA)-approved forms including products derived from pooled or autologous human plasma as well as bovine plasma. On-label indications include hemostasis, colonic sealing, and skin graft attachment. Recent clinical and experimental uses include tissue or mesh attachment, fistula closure, lymphatic sealing, adhesion prevention, drug delivery, and tissue engineering.

CONCLUSIONS

The modern literature on fibrin sealant now exceeds 3000 articles and continues to expand. This brief review presents the history of this material, its present clinical use, and its future applications.

Immediate anti-tumor necrosis factor-alpha (etanercept) therapy enhances axonal regeneration after sciatic nerve crush

Peripheral nerve regeneration begins immediately after injury. Understanding the mechanisms by which early modulators of axonal degeneration regulate neurite outgrowth may affect the development of new strategies to promote nerve repair. Tumor necrosis factor-alpha (TNF-alpha) plays a crucial role in the initiation of degenerative cascades after peripheral nerve injury. Here we demonstrate using real-time Taqman quantitative RT-PCR that, during the time course (days 1-60) of sciatic nerve crush, TNF-alpha mRNA expression is induced at 1 day and returned to baseline at 5 days after injury in nerve and the corresponding dorsal root ganglia (DRG). Immediate therapy with the TNF-alpha antagonist etanercept (fusion protein of TNFRII and human IgG), administered systemically (i.p.) and locally (epineurially) after nerve crush injury, enhanced the rate of axonal regeneration, as determined by nerve pinch test and increased number of characteristic clusters of regenerating nerve fibers distal to nerve crush segments. These fibers were immunoreactive for growth associated protein-43 (GAP-43) and etanercept, detected by anti-human IgG immunofluorescence. Increased GAP-43 expression was found in the injured nerve and in the corresponding DRG and ventral spinal cord after systemic etanercept compared with vehicle treatments. This study established that immediate therapy with TNF-alpha antagonist supports axonal regeneration after peripheral nerve injury.

An eclectic review of the history of peripheral nerve surgery

We take our present concepts of nerve repair for granted. In fact, the pioneers who established these principles traveled a road filled with erroneous dogma, bad advice, and misleading data. The lessons learned from a review of the history of peripheral nerve surgery are applicable to all neurosurgical disciplines. In honor of Dr. David Kline's distinguished career, we will review 3 aspects of the history of peripheral nerve surgery: Can an injured nerve regain function? How do peripheral nerves regenerate? When should a neuroma in continuity be resected?

A new fibrin sealant from Crotalus durissus terrificus venom: applications in medicine

Fibrin sealant, a widely available tissue adhesive, has been used since 1940 in a variety of clinical applications. Commercially available fibrin sealant products are synthesized from bovine thrombin and human fibrinogen, which may transmit infectious diseases, and recipients may also develop antibodies against bovine thrombin. Bearing these disadvantages in mind, a new fibrin sealant was developed in 1989 by a group of researchers from the Center for the Study of Venoms and Venomous Animals, in Sao Paulo State, Brazil. The main purpose was to produce an adhesive fibrin without using human blood, to avoid transmitting infectious diseases. The components of this novel sealant were extracted from large animals and a serine proteinase extracted from Crotalus durissus terrificus snake venom. The applicability of this sealant was tested in animals and humans with beneficial results. The new fibrin sealant can be a useful tool clinically due to its flexibility and diversity of applications. This sealant is a biological and biodegradable product that (1) does not produce adverse reactions, (1) contains no human blood, (3) has a good adhesive capacity, (4) gives no transmission of infectious diseases, and (5) may be used as an adjuvant in conventional suture procedures. The effectiveness of this new fibrin sealant is reviewed and its development and employment are described.

Treatment of acute Achilles tendon rupture: fibrin glue versus fibrin glue augmented with the plantaris longus tendon

In the surgical repair of Achilles tendon ruptures, suturing is standard, although fibrin glue also has been used for repair since the 1980s. Augmentation with the plantaris longus tendon is also a popular technique; however, no study has yet compared the outcome of augmented versus only glued repair of ruptured Achilles tendons. This study compares the long-term results of surgical repair of Achilles tendon rupture with fibrin glue versus fibrin glue augmented with the plantaris longus tendon. Forty patients who had undergone Achilles tendon repair with fibrin glue took part in a follow-up examination after an average of 11.5 years. The fibrin group consisted of 16 patients and the fibrin glue augmented with plantaris longus tendon group consisted of 15 patients. The modified Thermann score (adapted from Weber) and results of an isokinetic force measurement were the same in both groups, whereas complications in the 2 groups also did not differ. We conclude that augmentation with the plantaris longus tendon is not necessary when operatively treating acute ruptured Achilles tendons with fibrin glue.

LEVEL OF CLINICAL EVIDENCE

2.