A Comparison of a Cyanaocrylate Glue (Glubran) vs. Fibrin Sealant (Tisseel) in Experimental Models of Partial Pulmonary Resection and Lung Incison in Rabbits

THE USE OF FIBRIN GLUE IN THE TREATMENT OF BRONCHIAL STUMP FAILURE AFTER LOWER LOBECTOMY ON THE RIGHT (A CLINICAL CASE)

Despite the constantly improving technique of operations, the use of modern suture materials and stitching-cutting devices, the problem of the occurrence of the failure of the bronchial stump remains unresolved. Many methods have been proposed for the treatment of bronchial stump failure, ranging from endoscopic mucosal coagulation and the installation of various types of occluders and ending with repeated surgical interventions. There are a huge number of publications devoted to the use of fibrin glue in various fields of medicine, for example, in neurosurgery, maxillofacial surgery, orthopedics, dentistry and thoracic surgery, fibrin glue is successfully used, including in the development of bronchial stump failure. This article presents a clinical observation of the use of fibrin glue in the treatment of bronchial stump failure after lower lobectomy on the right.

Rational engineering and applications of functional bioadhesives in biomedical engineering

For the past decades, several bioadhesives have been developed to replace conventional wound closure medical tools such as sutures, staples, and clips. The bioadhesives are easy to use and can minimize tissue damage. They are designed to provide strong adhesion with stable mechanical support on tissue surfaces. However, this monofunctionality of the bioadhesives hinders their practical applications. In particular, a bioadhesive can lose its intended function under harsh tissue environments or delay tissue regeneration during wound healing. Based on several natural and synthetic biomaterials, functional bioadhesives have been developed to overcome the aforementioned limitations. The functional bioadhesives are designed to have specific characteristics such as antimicrobial, cell infiltrative, stimuli-responsive, electrically conductive, and self-healing to ensure stability under harsh tissue conditions, facilitate tissue regeneration, and effectively monitor biosignals. Herein, we thoroughly review the functional bioadhesives from their fundamental background to recent progress with their practical applications for the enhancement of tissue healing and effective biosignal sensing. Furthermore, the future perspectives on the applications of functional bioadhesives and current challenges in their commercialization are also discussed.

Tissue Adhesives: From Research to Clinical Translation

Sutures, staples, clips and skin closure strips are used as the gold standard to close wounds after an injury. In spite of being the present standard of care, the utilization of these conventional methods is precarious amid complicated and sensitive surgeries such as vascular anastomosis, ocular surgeries, nerve repair, or due to the high-risk components included. Tissue adhesives function as an interface to connect the surfaces of wound edges and prevent them from separation. They are fluid or semi-fluid mixtures that can be easily used to seal any wound of any morphology - uniform or irregular. As such, they provide alternatives to new and novel platforms for wound closure methods. In this review, we offer a background on the improvement of distinctive tissue adhesives focusing on the chemistry of some of these products that have been a commercial success from the clinical application perspective. This review is aimed to provide a guide toward innovation of tissue bioadhesive materials and their associated biomedical applications.

The Impact of Fibrin Sealant Volume on Skin Graft Contraction in a Full-Thickness Skin Graft Model

BACKGROUND

Fibrin sealant has been used for skin grafting in anatomically difficult facial areas. Although biodegradable, an excess of fibrin sealant may inhibit skin graft healing by inhibiting diffusion at the graft-recipient bed interface. The impact of fibrin sealant volume on graft healing was examined in a rat full-thickness skin graft model.

METHODS

Seventy-two full-thickness 2.5 × 2.5-cm skin grafts were used on the dorsum of male Sprague-Dawley rats. The grafts were treated with three different volumes of fibrin sealant placed onto the recipient bed: 0.0 mL or normal saline (group 1), 0.1 mL (group 2), and 0.4 mL (group 3). Graft healing and complications were assessed using digital photographs and necropsies on postoperative days 3, 7, and 21.

RESULTS

Group 3 showed the greatest graft contraction on days 3 and 21, while group 2 showed the least contraction on all 3 postoperative days (P = 0.002, 0.004, and <0.001, respectively). Histopathologic analysis showed inflammatory foreign body reactions in group 3 on days 3 and 7, and less vascular density on day 21 (P = 0.003). Group 1 showed the highest incidence of hematoma (P = 0.004).

CONCLUSION

An excess volume of fibrin sealant may produce pathologic wound contraction in skin grafting because a skin graft lacks a vascular pedicle and is highly dependent on diffusion from the host environment. Before using fibrin sealant for skin grafting in facial areas where the aesthetic outcome is important, the appropriate volume to use can be determined.

Local and systemic effects of fibrin and cyanoacrylate adhesives on lung lesions in rabbits

OBJECTIVES

Tissue adhesives can be used to prevent pulmonary air leaks, which frequently occur after lung interventions. The objective of this study is to evaluate local and systemic effects of fibrin and cyanoacrylate tissue adhesives on lung lesions in rabbits.

METHODS

Eighteen rabbits were submitted to videothoracoscopy + lung incision alone (control) or videothoracoscopy + lung incision + local application of fibrin or cyanoacrylate adhesive. Blood samples were collected and assessed for leukocyte, neutrophil and lymphocyte counts and interleukin-8 levels preoperatively and at 48 hours and 28 days post-operatively. After 28 days, the animals were euthanized for gross examination of the lung surface, and lung fragments were excised for histopathological analysis.

RESULTS

Fibrin and cyanoacrylate produced similar adhesion scores of the lung to the parietal pleura. Microscopic analysis revealed uniform low-cellular tissue infiltration in the fibrin group and an intense tissue reaction characterized by dense inflammatory infiltration of granulocytes, giant cells and necrosis in the cyanoacrylate group. No changes were detected in the leukocyte, neutrophil or lymphocyte count at any time-point, while the interleukin-8 levels were increased in the fibrin and cyanoacrylate groups after 48 hours compared with the pre-operative control levels (p<0.01).

CONCLUSION

Both adhesive agents promoted normal tissue healing, with a more pronounced local inflammatory reaction observed for cyanoacrylate. Among the serum markers of inflammation, only the interleukin-8 levels changed post-operatively, increasing after 48 hours and decreasing after 28 days to levels similar to those of the control group in both the fibrin and cyanoacrylate groups.

Application of COMPONT Medical Adhesive Glue for Tension-Reduced Duraplasty in Decompressive Craniotomy

BACKGROUND The aim of this study was to evaluate the application of medical adhesive glue for tension-reduced duraplasty in decompressive craniotomy. MATERIAL AND METHODS A total of 56 cases were enrolled for this study from Jan 2013 to May 2015. All patients underwent decompressive craniotomy and the dura was repaired in all of them with tension-reduced duraplasty using the COMPONT medical adhesive to glue artificial dura together. The postoperative complications and the healing of dura mater were observed and recorded. RESULTS No wound infection, epidural or subdural hematoma, cerebrospinal fluid leakage, or other complications associated with the procedure occurred, and there were no allergic reactions to the COMPONT medical adhesive glue. The second-phase surgery of cranioplasty was performed at 3 to 6 months after the decompressive craniotomy in 32 out of the 56 cases. During the cranioplasty we observed no adherence of the artificial dura mater patch to the skin flap, no residual COMPONT glue, or hydropic or contracture change of tissue at the surgical sites. Additionally, no defect or weakening of the adherence between the artificial dura mater patch and the self dura matter occurred. CONCLUSIONS COMPONT medical adhesive glue is a safe and reliable tool for tension-reduced duraplasty in decompressive craniotomy.

Histopathological Effects of Fibrin Glue and Cyanoacrylate on the Maxillary Sinus

Objective

To compare the histopathological effects of fibrin glue (FbGl) and cyanoacrylate (CyAc) on the maxillary sinus mucosa.

Methods

Twenty rabbits were divided into two groups of 10, and surgical defects were created in the maxillary sinuses. The right maxillary sinus was treated with FbGl in one group and with CyAc in the other group. As a control, the left maxillary sinuses of all rabbits were treated with sterile saline solution. One rabbit treated with CyAc died during the study and was excluded. On postoperative day 21, all animals were sacrificed. Maxillary sinus mucosa samples were studied to determine the extent of inflammation and fibrosis, foreign body reaction, cilia loss, increased osteogenesis in bony structures under the mucosa, and loss of serous glands.

Results

The FbGl group differed significantly from the CyAc and control groups in terms of a high degree of inflammation (p<0.001), fibrosis (p<0.001), foreign body reaction (p<0.001), cilia loss (p<0.001), and serous gland loss (p<0.001). In terms of osteogenesis, there were no significant differences between the FbGl and CyAc groups (p=0.650), while there was a significant (p=0.002) difference between these two groups and the control group.

Conclusion

Histopathologically, CyAc had fewer side effects than FbGl. Further clinical studies are needed to demonstrate the validity of these results in humans.

In Vitro Lung Model Assessing the Efficacy of Surgical Sealants in Treating Alveolar Air Leaks

PURPOSE

The lack of reliable testing methods limits the evidence-based practice of surgical sealants in treating alveolar air leak (AAL). We developed an in vitro lung model to evaluate sealants' efficacy and tested the widely used human thrombin-fibrinogen sponge, TachoSil as an example.

MATERIALS AND METHODS

The caudal lobe of freshly excised swine lung (n = 10) was intubated and ventilated. A focal superficial parenchymal defect (40 × 25 mm) was created in the inflated lung. AAL was assessed with increasing inspired tidal volume (TVi). After sealant application, AAL was assessed in the same way until burst failure, defined as an AAL exceeding 20 mL. To evaluate the elasticity of the sealant, the length of defect was recorded in the inflated lung.

RESULTS

Superficial parenchymal defects resulted in AAL increasing with ascending TVi. Multiple linear regression analysis revealed strong correlation between AAL and maximal inspiratory pressure, compliance and resistance. At TVi = 400, 500, and 600 mL, TachoSil achieved sealing in ten, eight, and seven tests, respectively. As TVi increased, superficial defects were still sealed in four, two, and two tests at TVi = 700, 800, and 900 mL, respectively. The burst pressure was 42 ± 5 cmH2O. Adhesive failures were found at the burst pressure in all tests. Concerning elasticity, TachoSil allowed an expansion of the covered lung defect of 7 ± 6 mm.

CONCLUSIONS

TachoSil demonstrated a strong sealing efficiency and marked elasticity in treating AAL. These results are consistent to that of the previously published animal experiment, suggesting the reliability of the presented in vitro model.

Hydrogels to modulate lentivirus delivery in vivo from microporous tissue engineering scaffolds

Numerous strategies to induce tissue regeneration employ scaffolds to create space and present biological cues that promote development. In this report, microporous scaffolds that provide structural support were filled with hydrogels to regulate cell adhesion and migration and were investigated as delivery vehicles for gene therapy vectors in vivo. Porous scaffolds were filled with either lentivirus-entrapped collagen or fibrin hydrogels, both of which support cell adhesion yet have varied rates for degradation and cell infiltration. Empty scaffolds and alginate hydrogels were employed as controls, with the latter not supporting cell infiltration. Hydrogel-filled scaffolds retained the lentivirus more effectively than empty scaffolds, and transgene expression was observed for all scaffold conditions. Empty and fibrin-filled scaffolds had maximal transgene expression in vivo, followed by collagen and alginate, with similar levels. Transduced macrophages and dendritic cells were initially present at the scaffold boundary and adjacent tissue and within the scaffold at later time points for all but the alginate condition. At days 3 and 7, expression was also imaged throughout the spleen and thymus, which may result from cell migration from the implant. These studies demonstrate that hydrogels can modulate gene delivery from scaffolds used in cell transplantation and regenerative medicine.

Pulmonary alveolar and vascular morphometry after gel plug occlusion of the trachea in a fetal rabbit model of CDH

PURPOSE

Tracheal occlusion (TO) induces lung growth in congenital diaphragmatic hernia (CDH) but is also associated with drawbacks. We devised a temporary gel plug that induced lung growth when placed in the fetal trachea. This study evaluates the effects of temporary versus permanent TO on histologic radial alveolar count (RAC) and vascular morphometrics.

METHODS

Experimental CDH was created surgically in 64 New Zealand White rabbit fetuses on gestational day (GD) 24. On GD 27, these fetuses were randomized to intratracheal instillation of a fibrin gel plug (GP), tracheal suture ligation (SL), intratracheal instillation of normal saline (NS), or sham amniotomy (SH). Non-manipulated fetuses served as controls (NM). Histologic lung sections were assessed blindly for RAC and relative arterial adventitial thickness (%AT) as a variable for vascular remodelling. Results were statistically compared.

RESULTS

RAC was significantly lower in the ipsilateral lung of SH fetuses than in the contralateral lung (p = 0.011). Mean RAC was higher after SL (p < 0.001) and GP (p = 0.03) compared to SH. Furthermore, %AT was higher in GP (50 ± 28, p < 0.001) and SL (45 ±2 6, p = 0.003) fetuses than in controls (36 ± 19).

CONCLUSION

Temporary and permanent TO leads to increased RAC; this effect was more pronounced with permanent TO. Both interventions were associated with an increased %AT. These findings may explain the adverse clinical effects of TO, despite causing accelerated lung growth.

Management of haemostasis in surgery: sealant and glue applications

Blood loss has always been a sensitive issue in surgery. Traditional techniques, such as suturing and electrocautery, have drastically reduced operatory bleeding. Unfortunately, wound edges and point application devices are frequently characterized by bleeding and infections. Over the past 20 years, haemostatic agents and tissue sealants have been developed and now are currently used, along with classic suture in various surgical specialties. Their fluid nature allows management of blood loss along any point of the wound and tissue repair. This review presents an overview of the most diffused haemostatic sealants, focusing on their main use in surgery and their adverse effects.

Comparative study of lung sealants in a porcine ex vivo model

BACKGROUND

Lung sealants are often used to prevent alveolar air leaks after lung resection surgery. Some sealants have shown to be effective in clinical studies, but extensive comparative evaluation has not yet been conducted. We aimed to evaluate different sealant burst pressures in an ex vivo model mimicking air leakage after lung resection.

METHODS

Fifty-four porcine lungs comprised the study material. Six different sealants were evaluated: Bioglue (V-Tech, Roskilde, Denmark), TachoSil (Nycomed, Roskilde, Denmark), Tisseel (Baxter, Allerød, Denmark), Evicel (OMRIX biopharmaceuticals S.A, Rhode-St-Genèse, Belgium), TissuePatchDural (Vingmed, Roskilde, Denmark), and Pleuraseal (Covidien, Copenhagen, Denmark). After creating a standardized pleural defect, each lung was randomized into 1 of the 6 treatment groups (n= 9). Each lung was ventilated with incremental airway pressure. Air leakage was assessed after each increment. If leakage occurred, the burst pressure was recorded.

RESULTS

The Evicel fibrin sealant and Tisseel fibrin sealant exhibited significantly lower burst pressures compared with the Bioglue, TachoSil, and Pleuraseal (p < 0.05). Bioglue had the highest median burst pressure (55 cm H(2)O) followed by TachoSil (35 cm H(2)O), PleuraSeal (35 cm H(2)O), TissuePatchDural (25 cm H(2)O), Evicel (15 cm H(2)O), and Tisseel (15 cm H(2)O).

CONCLUSIONS

This model has shown to be feasible in determining and comparing the burst pressures of different lung sealants. Further studies are needed to determine responses in living tissue and burst pressure over time in vivo.

Ethyl 2-cyanoacrylate tissue adhesive in partial lobectomy in rats

OBJECTIVE

To determine the efficacy of ethyl 2-cyanoacrylate adhesive in repairing the lung parenchyma after partial lobectomy in rats, in terms of hemostasis/aerostasis, scarring, and surgical time.

METHODS

The study involved 30 Wistar rats, randomly divided into five groups (one control group and four study groups). In the study groups, the lung parenchyma was repaired with either cyanoacrylate adhesive or surgical suture following resection of a small or large fragment (25% or 50%, respectively) of the left caudal lung lobe.

RESULTS

Surgical time and hemostasis time were shorter in the two groups treated with the adhesive than in the two submitted to suture. There were no significant differences among the groups regarding specific lung compliance. Adherences and inflammatory reactions were more severe in the groups submitted to suture.

CONCLUSIONS

In this study, the use of cyanoacrylate adhesive helped reduce the surgical time and the intensity of inflammatory reactions, as well as preserving lung compliance. Cyanoacrylate adhesives should be considered an option for lung parenchyma repair, decreasing the risk of complications after partial lobectomy in humans.