Impact of different fibrin glue application methods on inguinal hernia mesh fixation capability.

The use of fibrin glue for inguinal hernia mesh fixation has been suggested to be effective in preventing hematomas and reducing postoperative pain compared to tacks and sutures.. The effect of fibrin glue can vary significantly based on the device used. This study assessed the efficacy of fibrin glue based on the type of devices used in an ex vivo system. The rabbit's abdominal wall was trimmed to a size of 3.0 × 6.0 cm and was secured at the edges with metal fixtures. To measure the maximum tensile strength at the point of adhesion failure, the hernia mesh was fixed to the rabbit's abdominal wall using fibrin glue in a 2 cm square area, left for 3 min, and then pulled at a speed of 50 cm/min. The test was conducted 10 times for each group. The median (minimum-maximum) tensile strength values using the spraying, two-liquid mixing, and sequential layering methods were 3.58 (1.99-4.95), 0.51 (0.27-1.89), and 1.32 (0.63-1.66) N, respectively. The spraying method had predominantly higher tensile strength values than the two-liquid mixing and sequential layering methods (P < 0.01). In conclusion, in hernia mesh fixation, the spraying method can be adopted to achieve appropriate adhesive effects.

Investigation of the appropriate viscosity of fibrinogen in repairing pleural defects using ventilation and anchoring in an ex vivo pig model.

OBJECTIVE: Our previous study revealed that the viscosity of fibrinogen could influence the effectiveness of ventilation and anchoring (V/A) methods for controlling air leakages. Here, we examined the association between the viscosity of fibrinogen and effectiveness using an ex vivo pig model. METHODS: The fibrin glue used in this study was BOLHEAL® (KM Biologics Co., Ltd., Kumamoto, Japan). We prepared three types of fibrinogen with different viscosities (higher and lower than normal), including one without additives. Using an ex vivo pig model, a pleural defect was made, and the defect was repaired using three different viscosities of fibrinogen through the V/A method. We measured the rupture pressure at the repair site (N = 10) and histologically evaluated the depth of fibrin infiltration into the lung parenchyma at the repair sites. RESULTS: The median rupture pressure was 51.5 (40-73) cmH2O in Group 1 (lower viscosity), 47.0 (47-88) cmH2O in Group 2 (no change in viscosity), and 35.5 (25-61) cmH2O in Group 3 (higher viscosity). There was no statistically significant difference between Groups 1 and 2 (p = 0.819), but the rupture pressure was significantly higher in Group 2 than in Group 3 (p = 0.0136). Histological evaluation revealed deep infiltration of fibrin into the lung parenchyma in Groups 1 and 2, but no such infiltration was observed in the higher-viscosity group. CONCLUSIONS: The results of this experiment suggested that the V/A method using fibrin glue containing low-viscosity fibrinogen was more effective in controlling air leakage due to pleural defects.

The importance of pH adjustment for preventing fibrin glue dissolution in the stomach: an in vitro study.

Combined use of fibrin glue and polyglycolic acid (PGA) sheets has attracted attention as a preventive measure for complications associated with endoscopic submucosal dissection. However, fibrin glue is a protein that may be dissolved by gastric acid. We evaluated the effect of artificial gastric acid on fibrin clot. The dissolution time of three layers of fibrin glue with PGA sheets was measured in five groups (pH 1.2, 2.0, 4.0, 5.5, and 6.0 with pepsin). Measurements of three samples per group were made. The mean number of the remaining layers at each measurement point was observed for 168 h. The time to complete dissolution of the three layers of fibrin gel in the three samples was 2.5 h at pH 1.2, 5 h at pH 2.0, 24 h at pH 4.0, and 48 h and 6 h at pH 5.5. In order to maintain fibrin glue in the stomach for a long period, there was a need to avoid pepsin activation secondary to acidification of gastric juice. The use of strong antacids is recommended.

Evaluation of the hemostatic effect of a combination of hemostatic agents and fibrin glue in a rabbit venous hemorrhage model.

BACKGROUND: In neurosurgery, it is important to use local hemostatic agents. We have explored a more powerful method of hemostasis by the combination of commercially available hemostatic agents with fibrin glue in the hopes of synergistic effects. METHOD: A bleeding model was constructed by puncturing the rabbit posterior vena cava with a needle. After applying the sample to the bleeding point, compression was performed for 10 s. If temporary hemostasis was achieved after pressure release, a 30 s wash was performed to confirm that ultimate hemostasis was achieved. Up to three hemostasis attempts were performed on the same bleeding point until hemostasis was achieved, and the number of attempts required for hemostasis was counted. If hemostasis was not achieved after three attempts, it was counted as four times. Four groups were evaluated: (1) gelatin sponge alone, (2) gelatin sponge + fibrin glue, (3) oxidized cellulose alone, and (4) oxidized cellulose + fibrin glue; each group was tested 16 times. RESULTS: The median value (range minimum value-maximum value) of the number of hemostatic attempts in Group 1 to Group 4 was 3 (1-4), 1 (1-1), 4 (4-4), and 4 (2-4). In Group 2, there were two test exclusions owing to deviations of the test procedure. CONCLUSIONS: The compatibility of gelatin sponge and fibrin glue was very good, with a very strong and rapid hemostatic effect compared to other methods, showed its usefulness. This combination method may be effective for a variety of venous hemorrhages in neurosurgery.

Fibrin glue: Novel submucosal injection agent for endoscopic submucosal dissection.

Background and study aims Adequate mucosal elevation by submucosal injection is crucial for patient safety and efficiency during endoscopic submucosal dissection (ESD). This study aimed to evaluate the efficacy of fibrin glue (FG) as a long-lasting submucosal injection agent and to evaluate the technical feasibility of FG injection for ESD. Materials and methods To compare the capabilities of different agents in maintaining submucosal evaluation, we injected FG, hyaluronic acid solution, and normal saline into the porcine gastric specimen that was incised into approximately 5 × 5 cm squares. Then, we measured the height of submucosal elevations over time. Moreover, three hypothetical lesions from the resected porcine stomach underwent ESD with FG injection. Thereafter, we conducted macroscopic and histopathologic analyses. Results FG maintained the greatest submucosal elevation among all the injection agents. Three ESD procedures were performed with en bloc resection. Both macroscopic and histopathologic findings showed a thick FG clot on the ulcers. Conclusions The FG solution can be potentially used as an ESD submucosal injection agent in an in vitro model.

Efficacy of the Envelope Method in Applying Polyglycolic Acid Sheets to Post-Endoscopic Submucosal Dissection Ulcers in Living Pigs.

BACKGROUND/AIMS: Application of polyglycolic acid (PGA) sheets using fibrin glue in post-endoscopic submucosal dissection (ESD) ulcers to prevent bleeding has been reported to be difficult with the conventional delivery method because of gravity. This study assessed the usefulness of the envelope-based delivery system with and against gravity in living pigs. METHODS: PGA sheets were applied on post-ESD ulcers with and against gravity six times each using the conventional and envelope methods, respectively. The PGA sheet delivery time and the endoscopic and histological findings of the treated ulcer floors were compared. RESULTS: With gravity, the median PGA sheet application time was 1.00 (0.68-1.30) min/cm2 and 0.32 (0.18-0.52) min/cm2 with the conventional and envelope techniques (p=0.002), respectively, and against gravity, it was 1.20 (1.13-1.63) min/cm2 and 0.50 (0.39-0.58) min/cm2 (p=0.002), respectively. Against gravity, the endoscopic and histological findings revealed that the conventional group had insufficient fixation of the PGA sheets, but the envelope groups had sufficient fixation. The results with gravity were similar between the groups. CONCLUSION: The envelope method makes it possible to deliver PGA sheets to the stomach quickly and cover ulcers appropriately both with and against gravity in living pigs.

Development of an effective method utilizing fibrin glue to repair pleural defects in an ex-vivo pig model.

BACKGROUND: The present study aimed to use an ex-vivo model to investigate whether a new method involving the use of fibrin glue and a polyglycolic acid (PGA) sheet under ventilation enhances the sealing effect after repair of the pleural defect. METHODS: Ex-vivo pig lungs were used in this study. We investigated the maximum pressure tolerance of pleural defects repaired using three methods: 1, directly spraying fibrin glue over a PGA sheet; 2, spreading fibrinogen on the site then sealing with a PGA sheet and spraying with fibrin glue; and 3, spreading fibrinogen while maintaining ventilation then sealing with a PGA sheet and spraying with fibrin glue. RESULTS: The maximum tolerable pressures were as follows (mean ± standard deviation, cmH2O): Method 1, 37.1 ± 13.6, Method 2, 71.4 ± 27.7, Method 3, 111.5 ± 8.8. Histological findings explained the difference in tolerable pressure at the repaired site between methods. Microscopic findings of lungs repaired using Method 3 indicated that the fibrinogen penetrated into deeper tissues to act as an anchor. CONCLUSIONS: Fibrin glue sealing under ventilation increases the anchoring effect of repairing air leakages due to pleural defect in an ex-vivo model. This method may have clinical application. For example, it may be useful to reduce severe air leakage in patients who undergo lung-sparing surgery for a pleural tumor.

A novel and effective delivery method for polyglycolic acid sheets to post-endoscopic submucosal dissection ulcers.

Background and aims Shielding methods for post-endoscopic submucosal dissection (ESD) ulcers have delivery-related problems. We developed an enveloped device for this purpose and evaluated its usefulness. Materials and methods Polyglycolic acid (PGA) sheets were delivered to six 3.0-cm ulcers in two resected porcine stomachs and six 5.0-cm ulcers in another three stomachs. In the regular method group, small PGA sheets were delivered via forceps. In the novel method group, a large PGA sheet was delivered via the new device. The methods were compared in terms of time, and macroscopic and histological findings of the ulcer floor. Results The median time required to cover a 3.0-cm ulcer was 0.39 min/cm2 in the novel method group and 1.03 min/cm2 in the regular method group (P = 0.03), and to cover a 5.0-cm ulcer was 0.38 min/cm2 and 0.85 min/cm2, respectively (P = 0.03). In the novel method group, the PGA sheets were in close contact, fully covering the ulcer floor. In the regular method group, the sheets were partly elevated from the ulcer floor. Conclusions This novel technique seems promising in this preliminary study.

Tissue shielding with polyglycolic acid sheets and fibrin glue on ulcers induced by endoscopic submucosal dissection in a porcine model.

BACKGROUND AND STUDY AIMS: The safety and efficacy of the application of polyglycolic acid (PGA) sheets with fibrin glue to ulcers induced by endoscopic submucosal dissection (ESD) have not been established in the treatment of lesions of the gastrointestinal tract, in which the influence of digestive fluid and peristalsis may affect treatment, and there may also be a risk of infection. The aims of this study were to evaluate the healing process of ESD-induced ulcers in animals treated with the application of a PGA sheet with fibrin glue and to verify experimentally the safety of this treatment procedure. MATERIALS AND METHODS: Gastric ESD was performed in nine pigs under general anesthesia. Two ulcer sites were prepared in each pig; one ulcer was treated by applying a PGA sheet with fibrin glue (treated ulcer site), while the other ulcer was left untreated (control ulcer site). Three pigs were euthanized at week 1, three at week 4, and three at week 8 after ESD, and the ulcer sites were macroscopically and histopathologically evaluated. RESULTS: Of the nine treated ulcer sites, seven ulcer sites, to which a PGA sheet had been applied without exposure to the mucosal fluid, showed no peeling of the sheet despite the influence of peristalsis and gastric acid. Histopathologic examination revealed abundant, newly formed blood vessels in the treated ulcers and good granulation. In the treated ulcers, no excessive inflammation, necrosis, or infection was observed. CONCLUSIONS: Our animal study experimentally demonstrated that this treatment technique can be safely applied to ESD-induced ulcers.

Triple-layer sealing with absorptive mesh and fibrin glue is effective in preventing air leakage after segmentectomy: results from experiments and clinical study.

OBJECTIVES: Fibrin glue in combination with polyglycolic acid (PGA) mesh is effective in preventing air leakage after segmentectomy, but we frequently experienced air leakage with single-layer application. To investigate improved usage, we compared the sealing effect among single-, double- and triple-layer PGA mesh and fibrin glue in both experimental and clinical segmentectomy. METHODS: Ex vivo pig lungs were used for experiments. As a model of segmentectomy, the lateral segment of the left lung was removed using electrocautery. As a model of peripheral lung defect, peripheral lung tissue was resected with scissors. The inter-segmental plane and the peripheral lung defect were sealed using one of the following four methods: (i) fibrin glue alone (Group 1, n = 8), (ii) single-layer with PGA mesh and fibrin glue (Group 2, n = 8), (iii) double-layer (Group 3, n = 8) and (iv) triple-layer (Group 4, n = 8). The seal-breaking pressures among them were compared. In clinical segmentectomy, the periods of chest-tube drainage were compared retrospectively between 17 patients treated by the single-layer and 17 treated by the triple-layer method. RESULTS: In experimental segmentectomy, the seal-breaking pressure in the triple-layer (100 ± 25 cmH2O) was significantly higher than those in the other methods (26 ± 17, 48 ± 12 and 69 ± 19 cmH2O in the Groups 1, 2 and 3, respectively, P < 0.001-0.05), while there were no significant differences among other methods. For peripheral lung defect, the seal-breaking pressures did not differ among the methods. In clinical segmentectomy, the mean chest-drainage period with the triple-layer was 2 ± 0.9 days, which was significantly shorter than 3.6 ± 2.8 days with the single-layer (P = 0.009). CONCLUSIONS: Stronger sealants are required to prevent air leakage from inter-segmental planes than from peripheral lung. To prevent air leakage after segmentectomy, triple-layer PGA mesh and fibrin glue is recommended.