Pneumostatic effect of gelatin-resorcinol formaldehyde-glutaraldehyde glue on thermal injury of the lung: an experimental study on rats

Biomaterials and Advanced Technologies for Hemostatic Management of Bleeding

Bleeding complications arising from trauma, surgery, and as congenital, disease-associated, or drug-induced blood disorders can cause significant morbidities and mortalities in civilian and military populations. Therefore, stoppage of bleeding (hemostasis) is of paramount clinical significance in prophylactic, surgical, and emergency scenarios. For externally accessible injuries, a variety of natural and synthetic biomaterials have undergone robust research, leading to hemostatic technologies including glues, bandages, tamponades, tourniquets, dressings, and procoagulant powders. In contrast, treatment of internal noncompressible hemorrhage still heavily depends on transfusion of whole blood or blood's hemostatic components (platelets, fibrinogen, and coagulation factors). Transfusion of platelets poses significant challenges of limited availability, high cost, contamination risks, short shelf-life, low portability, performance variability, and immunological side effects, while use of fibrinogen or coagulation factors provides only partial mechanisms for hemostasis. With such considerations, significant interdisciplinary research endeavors have been focused on developing materials and technologies that can be manufactured conveniently, sterilized to minimize contamination and enhance shelf-life, and administered intravenously to mimic, leverage, and amplify physiological hemostatic mechanisms. Here, a comprehensive review regarding the various topical, intracavitary, and intravenous hemostatic technologies in terms of materials, mechanisms, and state-of-art is provided, and challenges and opportunities to help advancement of the field are discussed.

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.

Intraoperative techniques to prevent air leaks

Persistent air leaks prolong chest tube duration and hospital stay after lung surgery. Air leaks also may lead to life-threatening empyemas. Preventing postoperative air leaks and BPFs is the best treatment for air-leak complications. Meticulous closure of parenchymal, pleural, and bronchial defects is the mainstay of air-leak control. The reinforcement of parenchymal suture and staple lines, pleural apposition, and well-vascularized tissue-flap coverage of bronchial suture and staple lines further reduce the incidence of prolonged air leaks and BPFs.

In vivo evaluation of a new sealant material on a rat lung air leak model

The ability of an albumin-based hydrogel sealant (ABHS) to prevent air leakage through the suture line after pulmonary surgery was evaluated by comparison with that of a fibrin glue (FG). As an air-leak model, a rat lung was used in which a standard incision was made and the burst pressure for ABHS and FG was measured. The average burst pressures at time 0 for the FG and ABHS groups were 30.8+/-15.2 and 77.5 +/-19.1 mmHg, respectively. At Day 3, the value of ABHS (76.3 +/- 15.8 mmHg) was still significantly higher (P<0.05) than that of FG (60.0 +/- 21.9 mmHg). At Day 7, no statistical difference was observed between the FG group(71.2 +/- 18.6 mmHg) and the ABHS group(88.8 +/- 11.7 mmHg). Histological examination of the incision at Day 14 revealed that neither sealant was not visible at the incision site, and there was no evidence of adverse tissue reaction. It was concluded that ABHS had good sealing properties and is an alternative to FG for air leakage treatment in pulmonary surgery.

The efficacy and side effects of gelatin-resorcinol formaldehyde-glutaraldehyde (GRFG) glue for preventing and sealing pulmonary air leakage

This study was conducted to examine the efficacy and side effects of gelatin-resorcinol formaldehyde-glutaraldehyde (GRFG) glue, when used for preventing or sealing pulmonary air leakage during lung surgery. Formaldehyde-glutaraldehyde (FG) jelly was prepared by mixing FG fluid with 2.5% carboxymethyl cellulose to increase its viscosity. A GRFG glue-spreading stapler was employed to prevent air leakage from the staple line when cutting emphysematous lung tissue in 26 patients, 25 of whom underwent video-assisted thoracoscopic surgery (VATS) and 1, open thoracotomy. A glue-sealing procedure was employed to stop existing pulmonary air leakage in a further 36 patients, 28 of whom underwent VATS and 8, open thoracotomy. The glue-spreading stapler technique prevented air leakage in all 26 patients (100%), while the glue-sealing procedure for pulmonary air leakage stopped air leakage in 31 of the 36 patients (86%). Two patients who underwent glue sealing for air leakage from a deeply cut lung surface suffered massive pulmonary air leakage on postoperative day (POD) 1 and 6, respectively, and required repeat surgery to suture the lung fistula. A transient fever of 38 degrees-39 degrees developed on POD 7 in 6 of the 62 patients (9.7%), but no other complications were observed. These results demonstrated that GRFG is safe and effective in preventing or stopping pulmonary air leakage in the peripheral lung, but not for stopping air leakage from a deeply cut lung.

Experimental study on the in vivo behaviour of a new collagen glue in lung surgery

OBJECTIVE

To study the pneumostatic ability of a collagen polymerised with a polysaccharide (GAO) glue in lung surgery; its influence in pleuro-pulmonary adhesion formation; the pulmonary tissue reaction to it, its biodegradability, and the eventual alterations of pulmonary compliance induced by the glue.

METHODS

Two groups of ten rabbits (controls and treated) were operated under ventilatory assistance by thoracotomy to promote pleural adhesions, and injury to the lung. Repeated chest X-rays were carried out postoperatively. Lungs were examined histologically at day 40. In vitro tests were performed to study glue effects on pulmonary compliance.

RESULTS

Air leaks stopped 2 min after glue application. Persistent pneumothorax were likely seen in treated rabbits (ns). Glue induces a temporary reduction of pulmonary compliance. Glue did not increase adhesion formation, or interfere with the healing process.

CONCLUSIONS

For its properties, GAO seems to be a good and well-tolerated tool to reduce air leaks from the lung, without inducing residual pleural symphysis.

The use of biological glue in aortic surgery

The biologic sealants presently available on the market that are used in cardiovascular surgery and particularly during surgery of the aorta are described in this article. Two of these biological sealants, the gelatin-resorcinol-formaldehyde (GRF) glue and two-component fibrin sealant have been in use for two decades. Their respective properties are described beneficial in modifying the natural history of the disease. Certain pharmacological agents that result in improved aortic function have been identified.

Evaluation of gelatin hydrogel crosslinked with various crosslinking agents as bioadhesives: in vitro study

Bioadhesives are used for tissue adhesion and hemostasis in surgery. A gelatin-resorcinol mixture crosslinked with formaldehyde (GRF glue) and/or glutaraldehyde (GRG) is used for this purpose. Although the bonding strength of the GRF glue to tissue is satisfactory, concerns about the cytotoxicity of formaldehyde are reported in the literature. It was suggested that the cytotoxicity problem of the GRF glue may be overcome by changing its crosslinking method. The study was therefore undertaken to assess the feasibility of using an epoxy compound (GRE glue), a water-soluble carbodiimide (GAC glue), or genipin (GG glue) to crosslink with a gelatin hydrogel as new bioadhesives. GRF glue and GRG glue were used as controls. The results of our cytotoxicity study suggested that the cellular compatibility of the GAC and GG glues was superior to the GRF, GRG, and GRE glues. The gelation time for the GG glue was relatively longer than the GRF and GRG glues, while no gelation time could be determined for the GAC glue. Additionally, it took approximately 17 h for the GRE glue to become adhesive. The GRF and GRG glues had the greatest bonding strengths to tissue among all test adhesives, while the bonding strengths of the GAC and GG glues were comparable. In contrast, there was almost no bonding strength to tissue for the GRE glue. However, the GRF and GRG glues were less flexible than the GAC and GG glues. Subsequent to the bonding strength measurement, each test adhesive was found to adhere firmly to the tissue surface and underwent cohesive failure during the bond breaking. In conclusion, the GRF and GRG glues may be used as tissue adhesives when their ability to bind tissue rapidly and tightly is required; the GAC and GG glues are preferable when the adhesive action must be accompanied with minimal cytotoxicity and stiffness; and the GRE glue is not suitable for bioadhesion in clinical applications.

Gelatin-derived bioadhesives for closing skin wounds: an in vivo study

Bioadhesives have been used in surgery as hemostatic and wound healing agents. GRF (gelatin + resorcinol + formaldehyde) glue, composed of a mixture of gelatin and resorcinol polymerized by the addition of formaldehyde, has been used for this purpose. Widespread acceptance of the GRF glue, however, has been limited by reports of cytotoxicity due to its release of formaldehyde upon degradation. It has been suggested by Wertzel et al. that the cytotoxicity problem of GRF glue may be overcome by changing its cross-linking method. The study was, therefore, undertaken to assess the feasibility of using a water-soluble carbodiimide or genipin to cross-link gelatin as new bioadhesives to close skin wound lesions in a rat model. Formaldehyde-cross-linked counterpart (GRF glue) and a resorbable suture were used as controls. It was noted that the tensile strength of the skin across each wound treated by either application of test glues or suture increased consistently with time during the healing process. Also, the wounds repaired by test glues or suture caused no calcification. The suture used in the study was completely resorbed at the wound area in about 6 days postoperatively. However, the durations required to completely resorb the carbodiimide- or genipin-cross-linked glues were approximately the same (9 days), while it took about 14 days to completely resorb the formaldehyde-cross-linked glue. The healing process for the suture wound repaired was more rapid than those treated by test glues. Of the test glues, the wounds treated by the carbodiimide- or genipin-cross-linked glues induced less inflammatory response and recovered sooner than that treated by the formaldehyde-cross-linked glue. This indicated that the biocompatibility of the carbodiimide- or genipin-cross-linked glues was superior to the formaldehyde-cross-linked glue. The results of this study may serve as a preliminary experimental model for the further investigation of both the carbodiimide- and genipin-cross-linked glues when applied to human skin closure.

Gelatin-resorcinol-formaldehyde-glutaraldehyde glue for sealing pulmonary air leaks during thoracoscopic operation

BACKGROUND

Intraoperative pulmonary air leakage is one of the most troublesome complications in video-assisted thoracoscopic surgical procedures. We developed a sealing procedure using gelatin-resorcinol-formaldehyde-glutaraldehyde (GRFG) glue for pulmonary air leaks during such operations.

METHODS

Formaldehyde-glutaraldehyde (FG) jelly is prepared by mixing FG fluid with 2.5% sodium carboxymethyl cellulose to make the FG fluid viscous. We performed an adhesion-strength test to determine the optimum ratio of gelatin-resorcinol mixture to FG jelly and then conducted an air leakage test on swine lung to compare the sealing effect between fibrin and GRFG glues. To study the histotoxicity of the GRFG glue, the sealant was applied to injured rabbit lung, and the rabbits were followed for 1 day to 188 days. For clinical studies, we developed an endosyringe to apply the GRFG glue on the target site during video-assisted thoracoscopic surgical procedures and used this technique in 21 patients with intraoperative air leaks. In addition, the side effects of GRFG glue application were studied in 52 patients in whom glue was used in several ways during lung operations.

RESULTS

The results of the adhesion-strength test favored a 2:1 gelatin-resorcinol to FG ratio. The mean pressure required to produce air leakage was significantly higher with GRFG glue than with fibrin glue (p<0.001). No critical histologic damage was seen in the rabbit lung, and the glue persisted on the lung surface for 188 days after sealing. Clinical application of the glue in 21 patients resulted in complete stoppage of air leakage during operation and long afterward, except in 1 patient with a late-onset lung fistula. The FG jelly helped prevent glue spillage at the target site, regardless of angle. A transient rise in temperature up to 38.60C was observed as a side effect 7 days after operation in 5 (9.6%) of the 52 patients.

CONCLUSIONS

A GRFG glue using FG jelly seals pulmonary air leaks effectively, simply, and safely during video-assisted thoracoscopic surgical procedures.