Autologous fibrin glue: the last step in operative hemostasis

Platelets, Protean Cells with All-Around Functions and Multifaceted Pharmacological Applications

Platelets, traditionally known for their roles in hemostasis and coagulation, are the most prevalent blood component after erythrocytes (150,000-400,000 platelets/μL in healthy humans). However, only 10,000 platelets/μL are needed for vessel wall repair and wound healing. Increased knowledge of the platelet's role in hemostasis has led to many advances in understanding that they are crucial mediators in many other physiological processes, such as innate and adaptive immunity. Due to their multiple functions, platelet dysfunction is involved not only in thrombosis, mediating myocardial infarction, stroke, and venous thromboembolism, but also in several other disorders, such as tumors, autoimmune diseases, and neurodegenerative diseases. On the other hand, thanks to their multiple functions, nowadays platelets are therapeutic targets in different pathologies, in addition to atherothrombotic diseases; they can be used as an innovative drug delivery system, and their derivatives, such as platelet lysates and platelet extracellular vesicles (pEVs), can be useful in regenerative medicine and many other fields. The protean role of platelets, from the name of Proteus, a Greek mythological divinity who could take on different shapes or aspects, is precisely the focus of this review.

Safety and efficacy of sFilm-FS, a novel biodegradable fibrin sealant, in Göttingen minipigs

Bleeding during surgical procedures is a common complication. Therefore, hemostatic agents have been developed to control bleeding, and fibrin sealants have several benefits. sFilm-FS is a novel fibrin sealant that comprises a biodegradable co-polymeric film embedded with human fibrinogen and thrombin. Herein, the safety and efficacy of sFilm-FS were compared using a liver and spleen puncture model of Göttingen minipigs with those of the standard hemostatic techniques (control animals) and EVARREST^®, a reference fibrin sealant. Hemostasis and reduced blood loss were more effectively achieved with sFilm-FS than with the standard techniques in the control animals and comparable to those achieved with EVARREST^®. No treatment-related adverse effects were observed in any of the groups. Histopathological evaluation indicated that sFilm-FS was slightly and moderately reactive at the liver puncture site and spleen, respectively, compared with the standard techniques in the control animals. These changes are expected degradation reactions of the co-polymeric film and are not considered as adverse events. No treatment-related abnormalities were noted in the other evaluated organs. Additionally, no evidence of local or systemic thromboses was noted. These results support the use of sFilm-FS for hemostasis in humans.

Utility of autologous fibrin glue in the donor site of free abdominal flap for breast reconstruction: A randomized controlled study

BACKGROUND

Seroma formation at the donor site is a common complication of breast reconstruction using free abdominal flap. In this study, we assessed the benefits of use of autologous fibrin glue (AFG) at the donor site.

METHODS

This randomized controlled study compared AFG group (n = 61) with commercial fibrin glue (CFG) group (n = 79). Owing to the high volume of AFG (10 mL), AFG group received fibrin glue at both the anastomosis and the donor sites, whereas CFG group received fibrin glue only at the anastomosis site. Operative protocols and the criteria for postoperative drain removal were identical in both groups. Patient characteristics and abdominal discharge were compared between the two groups.

RESULTS

Since anemia was a contraindication for use of AFG, preoperative Hb in CFG group was significantly lower than that in AFG group; other factors were comparable in the two groups. The mean total abdominal drain volumes on first postoperative day (POD1) and POD2 was (AFG vs. CFG) 130.9 vs. 169.4 mL (P < 0.001) and 131.0 vs. 162.8 mL (P = 0.03), respectively. On POD3, there was no significant difference in this respect (116.2 vs. 128.4 mL, P = 0.19). The mean time for removal of all abdominal drains was significantly lower in AFG group (7.4 vs. 8.4 days; P = 0.01).

CONCLUSIONS

AFG reduced the discharge at the donor site of free abdominal flap, especially in the early postoperative period. AFG helped to reduce the abdominal drainage period.

Comparison of fibrin sealants in peripheral vascular surgery: A systematic review and network meta-analysis

Background

Evidence comparing fibrin sealants (FSs) in surgery are limited. This study evaluated the efficacy and safety of FSs, and manual compression in peripheral vascular surgery.

Methods

A systematic review of randomized trials was conducted in Medline, Embase, and Cochrane databases within the last 15 years. Data were available to conduct a network meta-analysis (NMA) in peripheral vascular surgery. Fibrin sealant treatment arms were further broken-down and assessed by clotting time (i.e., 2-min [2C] or 1-min [1C]). The primary efficacy outcome was the proportion of patients achieving hemostasis by 4 min (T4). Treatment-related serious and non-serious adverse events (AEs) were qualitatively assessed.

Results

Five studies (n = 693), were included in the NMA. Results predicted VISTASEAL 2C, followed by EVICEL 1C, had the highest probability of achieving T4. Compared with manual compression, significant improvements in T4 were found with VISTASEAL 2C (relative risk [RR] = 2.67, 95% CrI: 2.13–3.34), EVICEL 1C (RR = 2.58, 95% CrI: 2.04–3.23), VISTASEAL 1C (RR = 2.00, 95% CrI: 1.45–2.65), and TISSEEL 2C (RR = 1.99, 95% CrI: 1.48–2.60). TISSEEL 1C was not significantly different than manual compression (RR = 1.40, 95% CrI: 0.70–2.33). Among FSs, VISTASEAL 2C was associated with a significant improvements in T4 compared with VISTASEAL 1C (RR = 1.33, 95% CrI: 1.02–1.82), TISSEEL 2C (RR = 1.34, 95% CrI: 1.05–1.77), and TISSEEL 1C (RR = 1.90, 95% CrI: 1.18–3.74). Treatment-related serious and non-serious AE rates were typically lower than 2%.

Conclusions

In peripheral vascular surgeries, VISTASEAL 2C and EVICEL 1C were shown to have the highest probabilities for achieving rapid hemostasis among the treatments compared. Future studies should expand networks across surgery types as data become available.

•

Fibrin sealants can control perioperative bleeding, yet comparative evidence is limited.

•

This network meta-analysis compared fibrin sealants and compression in peripheral vascular surgery.

•

VISTASEAL and EVICEL had the highest probability of achieving hemostasis by 4 min.

•

These results show differences exist between fibrin sealants in peripheral vascular surgery.

Neuroprotection and immunomodulation by dimethyl fumarate and a heterologous fibrin biopolymer after ventral root avulsion and reimplantation

Background:

Ventral root avulsion (VRA) is an experimental approach in which there is an abrupt separation of the motor roots from the surface of the spinal cord. As a result, most of the axotomized motoneurons degenerate by the second week after injury, and the significant loss of synapses and increased glial reaction triggers a chronic inflammatory state. Pharmacological treatment associated with root reimplantation is thought to overcome the degenerative effects of VRA. Therefore, treatment with dimethyl fumarate (DMF), a drug with neuroprotective and immunomodulatory effects, in combination with a heterologous fibrin sealant/biopolymer (FS), a biological glue, may improve the regenerative response.

Methods:

Adult female Lewis rats were subjected to VRA of L4-L6 roots followed by reimplantation and daily treatment with DMF for four weeks. Survival times were evaluated 1, 4 or 12 weeks after surgery. Neuronal survival assessed by Nissl staining, glial reactivity (anti-GFAP for astrocytes and anti-Iba-1 for microglia) and synapse preservation (anti-VGLUT1 for glutamatergic inputs and anti-GAD65 for GABAergic inputs) evaluated by immunofluorescence, gene expression (pro- and anti-inflammatory molecules) and motor function recovery were measured.

Results:

Treatment with DMF at a dose of 15 mg/kg was found to be neuroprotective and immunomodulatory because it preserved motoneurons and synapses and decreased astrogliosis and microglial reactions, as well as downregulated the expression of pro-inflammatory gene transcripts.

Conclusion:

The pharmacological benefit was further enhanced when associated with root reimplantation with FS, in which animals recovered at least 50% of motor function, showing the efficacy of employing multiple regenerative approaches following spinal cord root injury.

Fibrin Tissue Sealant as an Adjunct to Cleft Palate Repair

PURPOSE

Fibrin glue is a common tissue sealant used to promote hemostasis, adhere tissues, and accelerate healing. Cleft palate repair can be technically challenging, creating dead space between tissue planes, and can be prone to complications such as would dehiscence or bleeding. The purpose of this study is to assess the role of fibrin glue as an adjunct to cleft palate repair. The authors hypothesize a beneficial impact on complication rates, including bleeding, dehiscence, and fistula formation, among others.

METHODS

Primary cleft palate repairs using fibrin glue were retrospectively analyzed. Demographic, intraoperative, perioperative, and postoperative data were combed for outcome variables. Complication rates were calculated in percentages and the results were compared to the published literature. Z-test statistics were performed for comparison.

RESULTS

A total of 45 patients, 21 females and 24 males, who underwent primary cleft palate repair with fibrin glue between 2011 and 2014, had sufficient data to be reviewed. There were no instances of bleeding, dehiscence, airway obstruction, infection, oronasal fistula, or return to the operating room in any patients. One patient exhibited mild postoperative coughing and secretions that resolved with conservative measures. Another patient displayed postoperative seizure activity due to a pre-existing condition. All complication rates in our fibrin glue series were lower than those reported without the use of fibrin glue. Overall complication rates with fibrin sealant are significantly lower than overall complication rates without.

CONCLUSION

Our data suggest that fibrin sealant is a beneficial adjunct to cleft palate repair. Its application is well-tolerated and the complication profile in our cohort was much less than the reported rates. The results of this preliminary study should be vetted with a prospective analysis involving a control group.

Diffusion-Reaction Models of Genipin Incorporation into Fibrin Networks

Genipin is a naturally derived small molecule that crosslinks compounds containing primary amines including many natural biopolymers. A diffusion-reaction model to predict the rates of delivery and incorporation of genipin into fibrin networks is presented. Genipin crosslink formation within fibrin hydrogels is a multi-step process that requires genipin diffusion and reaction with primary amines in hydrated networks. The reaction rate of genipin into fibrin gels was measured via spectroscopy while the rate of marginal crosslink formation was measured by rheology. Covalent coupling between genipin and primary amines in fibrin gels obeys second-order kinetics in genipin concentration with an effective activation energy of -71.9 ± 3.2 kJ-mol^-1. Genipin diffusion-reaction within fibrin gels exhibits Thiele moduli between 0.02-0.28, which suggests that the systems studied herein are reaction-limited. Genipin-crosslinked fibrin clots are resistant to fibrinolytic degradation as measured by rheology. Finally, active genipin can be delivered from poly(D,L-lactide-co-glycolide) matrices to gels at rates that are comparable to the characteristic rate of incorporation in fibrin networks. Taken together, this work establishes a quantitative framework to engineer controlled release systems for genipin delivery into protein-based hydrogel networks.

Influence of sealant fibrin on the wound healing of the pigs vocal folds

Fibrin sealants or fibrin glue are products made from human plasma proteins, which mimic the final pathway of the coagulation cascade. Its application to stimulate the healing process has been a topic of debate in the literature. The use of fibrin sealants in phonosurgery has been empirical; there have been no studies that investigate the action of fibrin sealant in Reinke's space.

Aim

To evaluate the effect of fibrin glue in healing of the vocal folds of pigs after surgical manipulation.

Materials and Methods

This was a prospective and experimental study. Six animals had both vocal folds incised. Sealant was applied in one of them; the other served as a control. After three months, the animals were sacrificed and a collagen count was carried out.

Results

The side on which glue was applied had an average of 27.8% against 20.4% of the side without glue.

Conclusion

The collagen concentration in the samples where the fibrin sealant was applied was significantly higher compared to samples without glue. Thus, the presence of a fibrin sealant stimulates fibrogenesis in this tissue.

The use of autologous platelet-leukocyte-enriched plasma to minimize drain burden and prevent seroma formation in latissimus dorsi breast reconstruction

INTRODUCTION

Seromas and drains are major sources of morbidity associated with latissimus dorsi breast reconstruction. Our goal was to look at an autologous platelet-leukocyte-enriched plasma spray and to assess its efficacy in reducing drain burden and seroma formation.

METHODS

We performed a single surgeon, patient-controlled, blinded study on bilateral latissimus dorsi breast reconstruction patients in which we applied autologous platelet-leukocyte-enriched plasma to one side and measured drain amounts, time to drain removal, and seroma rate.

RESULTS

Twelve patients were included in this study. The average age was 41.1 years, and the average body mass index was 21.6 kg/m. Average volume of drain output showed neither difference (789 mL spray side vs. 790 mL control side) nor average time to drain removal (11.83 days spray side vs. 11.5 days control side). There were 2 complications reported: 1 hematoma (8.33%) and 1 seroma (8.33%) that required aspiration in a postoperative visit.

CONCLUSIONS

It appears after 12 patients that there is no demonstrable difference regarding drain output, time to drain removal, or seroma incidence between the study and the control group. We feel a larger study population would add power and confirm these findings.

A novel autologous scaffold for diced-cartilage grafts in dorsal augmentation rhinoplasty

BACKGROUND

Diced-cartilage grafts have been used for dorsal nasal augmentation for several years with good results. However, compounds such as Surgicel and temporalis fascia used as a wrap have inherent problems associated with them, predominantly inflammation and graft resorption. An autologous carrier could provide stabilization of cartilage grafts while avoiding the complications seen with earlier techniques.

METHODS

In our patients, a malleable construct was used for dorsal nasal augmentation in which autologous diced-cartilage grafts were stabilized with autologous tissue glue (ATG) created from platelet-rich plasma (platelet gel) and platelet-poor plasma (fibrin glue).

RESULTS

A prospective analysis of 68 patients, who underwent dorsal nasal augmentation utilizing ATG and diced-cartilage grafts between 2005 and 2008, were included in the study. Although there was notable maintenance of the dorsal height, no complications occurred that required explantation over a mean follow-up of 15 months.

CONCLUSION

The use of ATG to stabilize diced-cartilage grafts is a safe, reliable technique for dorsal nasal augmentation. The platelet gel provides growth factors while the fibrin glue creates a scaffold that allows stabilization and diffusion of nutrients to the cartilage graft.

The hemodynamic behavior of arterial anastomosis using fibrin sealant: experimental study in swine

The wide use of biological sealants as a reinforcement for arterial sutures and the small experimental base in literature motivated this study. Our aim was to evaluate the flow, tear pressure, and the need of reinforcement stitches in sutured arteries after a cross-section. This research project complied with the Helsinki convention. The Tissucol (Baxter) fibrin sealant was used in all experiments. The femoral and carotid arteries of 17 swine from the same breed (weighing from 15 to 20 kg) were cross-sectioned after heparinization and subjected to anastomoses using a single continuous plane of 7-0 prolene. We worked with 68 artery samples, 34 in the treatment group and 34 in the control group. For each animal, one carotid and one femoral artery randomly received fibrin sealant with the contralateral side being used as a control. The need and the number of reinforcement stitches were recorded. Ten minutes after protamine infusion, the animals were sacrificed and the arteries were catheterized respecting 1 cm proximal and distal. The arteries were measured and placed on a flow meter to evaluate the flow rate of 10 mL of 0.9% NaCl in a 50 cm high column. The arteries were then subjected to air infusion at increasingly higher pressures (stepwise increases of 25 mm Hg), the grafts were dipped in 0.9% NaCl solution, the first air leakage was observed, and the tear pressure recorded. Data was analyzed with EpiInfo 6 data manager. The external diameters and thickness of the arteries were similar in both the treatment and control group. There was no significant difference between the groups regarding the tear pressure (P = 0.329), flow rate (P = 0.943), and the number of samples with a tear pressure above 200 mm Hg. However, the sealant reduced the number of reinforcement stitches necessary (P = 0.029). We conclude that fibrin sealant reduces the need of additional stitches; however, it does not change the tear pressure nor significantly reduces the flow.

Autologous platelet gel and fibrin sealant enhance the efficacy of total knee arthroplasty: improved range of motion, decreased length of stay and a reduced incidence of arthrofibrosis

In this study we describe the potential role of autologous platelet gel and fibrin sealant in unilateral total knee arthroplasty to improve the postoperative range of motion and to reduce the incidence of arthrofibrosis. Total knee arthroplasty is often associated with a considerable amount of post-operative blood loss. Persistent limited motion directly after surgery may ultimately result in arthrofibrosis. To counteract these effects we investigated whether the use of autologous derived platelet gel and fibrin sealant would reduce postoperative blood loss, decrease the impaired range of motion and the incidence of arthrofibrosis. All patients were consecutively operated and assigned to the study or control groups. Study group patients (n = 85) were treated with the application of autologous platelet gel and fibrin sealant at the end of surgery. Eighty patients were operated without the use of platelet gel and fibrin sealant, and served as the control group. The postoperative hemoglobin decrease, range of motion and length of hospitalization were recorded. During a 5-month postoperative period patients were followed to observe the incidence of arthrofibrosis. In patients in the treatment group the hemoglobin concentration in blood decreased significantly less when compared to the control group. They also showed a superior postoperative range of motion when compared to those of the control group (P < 0.001). The incidence of arthrofibrosis and subsequent forced manipulation was significantly less (P < 0.001) in patients managed with platelet gel and fibrin sealant. We conclude that peri-operatively applied platelet gel and fibrin sealant may improve the range of motion after total knee arthroplasty, decreases the length of stay and may reduce the incidence of arthrofibrosis.

Platelet-Rich and Platelet-Poor Plasma

Hemostasis is important for any surgical procedure. One method uses autologous platelet-rich and/or platelet-poor plasma sprayed on the wound site. Although effective, there are little quantitative data available to fully document the extent to which these autologous products function as hemostats. Also, limitations in current animal models make quantitative study of topical hemostats difficult. A porcine partial-thickness skin wound model was developed to compare the hemostatic ability of these treatments with untreated control wounds. Rectangular partial-thickness dermal wounds were created in the back of a pig, which was then sprayed with activated platelet-rich plasma, activated platelet-poor plasma, or left untreated. Bleeding was quantified by two methods: 1) gravimetric measurement of exudate transfer to a sponge over a 15-minute interval, and 2) iron assay of the exudate over this same interval. Values for treated wounds were normalized to those of control wounds to minimize interanimal variability. Both gravimetric and iron assay measurements demonstrated that platelet-rich plasma was effective within 5 minutes after application with normalized bleeding values of approximately 35% and 20%, respectively, of the untreated controls. Corresponding values for platelet-poor plasma were approximately 90% and 65%, respectively, with differences only significant for the iron assay method measured on 10- and 15-minute wound exudate. Although both platelet-rich and platelet-poor plasma demonstrated hemostatic potential, the effect was more robust with the former. Iron assay was a more accurate method of measuring bleeding than gravimetric analysis.

The effect of platelet-enriched fibrin glue on bone regeneration in autogenous bone grafts

OBJECTIVE

The aim of this study was to examine the ability of platelet-enriched fibrin glue to enhance bone formation in critically sized defects in the dog mandible.

STUDY DESIGN

Seven adult female mongrel dogs underwent continuity resections on both sides of the mandible; 1 defect was reconstructed with the original particulate bone mixed with platelet-enriched fibrin glue, and as a control the contralateral defect was reconstructed with the original particulate bone alone.

RESULTS

Biopsies after 6 weeks showed that the addition of platelet-enriched fibrin glue enhanced new bone formation in the autogenous bone grafts.

CONCLUSION

Our data suggest that fibrin nets formed by fibrinogen, in combination with growth factors present in platelet-enriched fibrin glue, might effectively promote bone healing at bone graft sites.

Comparison of the topical haemostatic agents for the prevention of suture hole bleeding. An experimental study

OBJECTIVE

using a rabbit vascular graft model we investigated the use of fibrin glue (FG), gelatin-resorcinol-formaldehyde (GRF), and collagen (C) as a means of reducing suture hole bleeding.

MATERIALS AND METHODS

twenty-eight rabbits were divided into four groups: fibrin glue, gelatin-resorcinol-formaldehyde, collagen and control. A 1 cm incision was made in the abdominal aortic wall of each animal. Incisions were covered with a polytetrafluoroethylene patch sutured with a 7-0 polypropylene. Fibrin Glue, GRF, and C were applied to cover suture holes in the groups 1, 2 and 3, respectively, but nothing in controls (group 4). The fibrin clot was allowed to achieve strength for 3 minutes before the clamps were reopened. After reopening the clamps, blood was collected from the surgical site using a syringe for a total of 2 min.

RESULTS

mean blood loss was significantly lower in the FG, GRF, and C compared with control group (p=0.0022, p=0.0022, and p=0.0017, respectively). The volume of blood lost and the time of haemostasis in the group 1 (FG) was less than those in groups 2 and 3 (GRF and C, respectively) (p=0.001). The haemostasis (defined 2 min later) was achieved only in group 1 (FG) (p=0.00067).

CONCLUSIONS

FG, GRF and C all reduce blood loss. Fibrin glue containing factor XIII was the most effective.

The use of autologous platelet-rich plasma (platelet gel) and autologous platelet-poor plasma (fibrin glue) in cosmetic surgery

The purpose of this study was to evaluate a new technique of harvesting and preparing autologous platelet gel and autologous fibrin glue (body glue) and to evaluate their effectiveness in stopping capillary bleeding in the surgical flaps of patients undergoing cosmetic surgery. A convenience sample of 20 patients ranging from 25 to 76 years of age undergoing cosmetic surgery involving the creation of a surgical flap were included in the study. The types of surgical procedures included face lifts, breast augmentations, breast reductions, and neck lifts. Platelet-poor and platelet-rich plasma were prepared during the procedure from autologous blood using a compact, tabletop, automated autologous platelet concentrate system (SmartPReP, Harvest Autologous Hemobiologics, Norwell, Mass.). The platelet-poor and platelet-rich plasma were combined with a thrombin-calcium chloride solution to produce autologous fibrin glue and autologous platelet gel, respectively. Capillary bed bleeding was present in all cases and effectively sealed within 3 minutes following the application of platelet gel and fibrin glue. The technique for making the solution and for evaluating its effectiveness in achieving and maintaining hemostasis during cosmetic surgical procedures is described. Autologous platelet gel and fibrin glue prepared by the automated concentrate system are compared with autotransfusor-prepared platelet gel and Tisseel (Baxter Healthcare Corp.), a commercially prepared fibrin sealant preparation.

Fibrin glue and clinical impact on haemophilia care

Fibrin glues, a kind of biological sealant, have been used for enhancement of local haemostasis, tissue sealing and wound healing for haemophilia and similar disorders. Commercial viral-inactivated fibrin glue products are available in Europe and have recently been approved in the USA. Using fibrin glue, hospitalization, medical cost, viral transmission risk and factor supplementation will be reduced. In the near future, the role of fibrin glues will be increased in the haemophilia field.

Safer circumcision in patients with haemophilia: the use of fibrin glue for local haemostasis

OBJECTIVE

To evaluate the efficacy and the reduced costs of factor concentrates in circumcision by using fibrin glue in patients with haemophilia.

PATIENTS AND METHODS

Eleven patients with haemophilia (age range 6-14 years, 10 with haemophilia A, one with haemophilia B) were circumcised using fibrin glue for local haemostasis and to reduce the duration of clotting factor replacement after surgery. Circumcision was carried out under general anaesthesia; the prepuce was incised circumferentially and excised using the Gomco clamp technique. Haemophiliac patients were divided into two groups: in group 1 (four patients, three with haemophilia A and one with haemophilia B) the factor levels were assessed every 8 h and bolus injections of factor repeated during the first 4 days after surgery; in group 2, the seven remaining haemophilia A patients received a postoperative bolus injection and approximately 4 U/kg per hour of factor substitution for the first 2 days after surgery by continuous infusion. Eleven other patients with haemophilia A underwent circumcision using same surgical procedure but were given only factor substitution without fibrin glue, and served as a control group (group 3).

RESULTS

None of the patients had significant bleeding or complications. The total costs were significantly reduced, to $8898 per patient in group 1 and $4866 per patient in group 2, when compared with $12875 per patient in group 3 (both P<0.05).

CONCLUSION

Fibrin glue is a useful treatment for circumcision in patients with haemophilia; it lessens the need for factor substitution after circumcision and thus reduces the high cost of treatment.

The management of peripheral arterial aneurysms using percutaneous injection of fibrin adhesive

Most peripheral arterial aneurysms are pseudoaneurysms and are iatrogenic or related to trauma. They can be treated by several techniques that can be performed by the radiologist, negating the need for surgery. Ultrasound guided compression repair is usually the treatment of choice, but is not always successful. The number of available treatment options reflects the varying site and nature of pseudoaneurysms and perhaps the lack of a consistently reliable method. We have successfully treated 13 patients with peripheral aneurysms (11 femoral, 1 popliteal and 1 posterior tibial aneurysm) using a commercial fibrin tissue adhesive. The method involves percutaneous injection of the adhesive components using ultrasound and screening control, following successful occlusion of the aneurysm neck by angioplasty balloon.

Comparative study of different biological glues in an experimental model of surgical bleeding in anesthetized rats: platelet-rich and -poor plasma-based glue with and without aprotinin versus commercial fibrinogen-based glue

The use of fibrin glue in cardiovascular surgery has been associated with decreased operative time, effective control of localized bleeding, and reduced postoperative blood loss. All preparations of fibrin glue mimic the final common pathway of the coagulation cascade in which fibrinogen is converted to fibrin in the presence of thrombin and calcium. The goal of the study was to compare five different types of fibrin glue, with or without aprotinin, on a surgical bleeding model in the rat. In 70 anesthetized Wistar rats, after laparotomy, a 3 cm liver incision was performed. After randomization, seven groups were studied. In the first group, Biocol was used as a pinpoint application to the bleeding site. Four groups received a fibrin glue obtained from a single human donor plasma using Cell Saver V (Haemonetics). The sealant was applied as a two-component system. The first component of the glue was either platelet-rich-plasma (PRP) or platelet-poor-plasma (PPP). The second component consisted of a mixture of 0.5 ml CaCl 10% with 1000 U of human thrombin, with or without 400KUI of aprotinin (AP). The last two groups, control and aprotinin were treated using saline solution or topical aprotinin respectively. Hemoglobin and hematocrit were measured before surgery and 30 min after application of the glue. The decrease in hemoglobin (Hb) and hematocrit (Hct) was the primary efficacy variable. Before surgery, there was no difference regarding Hb and Hct values between groups. Thirty min after the application of the glue, the decrease in hemoglobin expressed as percent of the control values is only significantly lower in the Biocol group when compared to control. No significant difference was observed with the other groups in comparison to control. The commercial fibrin glue (Biocol) is more efficient than other preparations. This efficacy is likely due to a higher fibrinogen concentration.

Fibrin-film stenting in a porcine coronary injury model: efficacy and safety compared with uncoated stents

OBJECTIVES

This study was designed to test the efficacy and safety of a fibrin-film-covered stent compared with that of a bare metal stent in the porcine coronary injury model.

BACKGROUND

Biodegradable stents are a potential method of achieving total lesion coverage and delivering local, lesion-specific drug therapy.

METHODS

Two coronary arteries in each pig were randomly assigned to deployment of either a fibrin-film or a bare tantalum wire-coil stent. An oversized balloon injury, 1.15 to 1.30 times the reference vessel diameter, was induced in each coronary segment before stenting to simulate angioplasty injury. Thirty pigs were studied: group 1 for 28 days (15 pigs); group 2 for 90 days (5 pigs); group 3 for 6 months (5 pigs); group 4 for 1 year (5 pigs).

RESULTS

Two pigs died of occlusion of the bare stent and one of occlusion of the fibrin stent (p > 0.99). There were no significant differences between the fibrin-stented and bare-stented coronary segments with regard to arterial injury. In group 1 (28 days, 14 pigs), the mean neointimal thicknesses in the fibrin-stented and bare-stented groups were 0.57+/-0.31 and 0.57+/-0.27 mm, respectively (p=0.89). In groups 2 to 4 (90 days, four pigs; 6 months, four pigs; 1 year, five pigs), the mean neointimal thicknesses for fibrin- and bare-stented coronary segments at the times studied were 0.48+/-0.26 versus 0.50+/-0.22 mm at 90 days; 035+/-0.04 versus 0.35+/-0.16 mm at 6 months; and 0.33+/-0.14 versus 0.30+/-0.14 mm at 1 year (p=0.98).

CONCLUSIONS

Fibrin-film stents appear to be an excellent candidate for local drug delivery because they can completely and safely cover the stented coronary segment while degrading slowly over 1 to 3 months. This result is important when compared with the poor results of previous studies of synthetic polymer stents.

Platelet gel: an autologous alternative to fibrin glue with applications in oral and maxillofacial surgery

The preparation and use of platelet gel, an autologous formulation of fibrin glue, are described. The unique features of this biologic sealant are that it is derived from autologous blood collected in the immediate preoperative period by the anesthesiologist, it contains a high concentration of platelets, and it can be used in patients who are not candidates for blood bank donation. Platelet gel has been used successfully in the area of reconstructive oral and maxillofacial surgery in conjunction with ablative surgery of the maxillofacial region, mandibular reconstruction, surgical repair of alveolar clefts and associated oral-antral/ oral-nasal fistulas, and adjunctive procedures related to the placement of osseointegrated implants.

Prospective, randomized evaluation of the efficacy of fibrin sealant as a topical hemostatic agent at the cannulation site in neonates undergoing extracorporeal membrane oxygenation

BACKGROUND

The topical hemostatic effect of fibrin sealant that has been solvent/detergent treated and plasminogen depleted was evaluated in a multicenter prospective, randomized controlled study at the cannulation site wound of infants undergoing extracorporeal membrane oxygenation (ECMO).

METHODS

The test group received standard cauterization and Fibrin sealant, while the control group was given cauterization alone to control hemostasis at this site. Efficacy data were available on 173 randomized study subjects of whom 149 met study entry criteria. All were managed according to standard ECMO practice.

RESULTS

Fibrin sealant reduced the risk of bleeding, was associated with less shed blood, and was associated with shorter duration of hemorrhage. Further, control infants showed an increased bleeding risk with less depressed fibrinogen levels and prothrombin time elevations >18 seconds prior to ECMO.

CONCLUSION

Fibrin sealant is useful as a topical hemostatic agent in patients with coagulopathy not responding to standard surgical techniques.

Dural Closure with Laser Tissue Welding

This study investigates the use of tissue-soldering techniques to substitute or reinforce traditional suture closure of dural incisions. Fresh human cadaveric dura was incised and subsequently closed by use of three techniques: (1) conventional interrupted suture with 4–0 silk ( n = 25), (2) laser solder reinforced suture closure ( n = 25), and (3) laser solder closure alone ( n = 25). Anastomosis tensile strength and hydrostatic leak pressures were measured. Dural repair was also performed in 15 live Lewis rats. Dural closure was accomplished with 9–0 Prolene sutures ( n = 5), laser-reinforced suture closure ( n = 5), and laser solder closure alone ( n = 5). Histologic examination of the closure immediately after soldering and 2 weeks later was performed. Suture closure alone had the lowest leak pressure, 9.4 ± 1.7 mm Hg, and an intermediate break point, 13.3 ± 2.1 Kgf/cm2. Measurements with laser solder alone revealed a mean leak pressure of 26.2 ± 3.7 mm Hg and a break point of 4.6 ± 1.4 Kgf/cm2. Solder-reinforced suture closure leak pressure measured 64.0 ± 6.7 mm Hg and 21.4 ± 2.4 Kgf/cm2. There was a statistically significant increase in leak pressure and tensile strength in the closures performed with laser weld reinforcement of traditional suture technique ( p = 0.0001). Dural closure with laser tissue welding alone provided an immediate leak-free closure, but with poor tensile strength. Histologic examination of welded dura and underlying brain tissue showed no evidence of thermal injury in four of five animals studied. Laser welding may significantly decrease the incidence of cerebrospinal fluid leak after dural closure. In addition, laser tissue welding also makes dural closure possible where space constraints make traditional suture closure difficult.

Biological molecule-impregnated polyester: an in vivo angiogenesis study

Specific extracellular matrix molecules and growth factors (GFs) with angiogenic properties could be combined with biomaterials to enhance angiogenesis and subsequently tissue ingrowth through the wall of the porous structure. In this study, composite fibrin matrices containing hyaluronic acid (HA), fibronectin (FN) and/or fibroblast growth factor-1 (FGF-1), FGF-2 and an endothelial cell growth supplement (ECGS) were adsorbed onto Dacron meshes which were then implanted subcutaneously in mice. The release from the implants and the tissue distribution of implanted GFs were determined in vivo using radiolabelled FGF-2. Angiogenesis was quantified by counting the number of capillaries present in each Dacron histological serial section. Radiolabelled GF was rapidly released from matrices and was absent from them by day 28. A very low percentage of the implanted radiolabelled GFs was found in the kidneys and livers of the animals. The number of microvessels formed within fibrin-impregnated samples was increased in the presence of HA and ECGS at 14 d and of FN and ECGS or FGF-2 at 28 d. FGF-1 had no direct effect on angiogenesis in our model. These results indicate that enhancement of vascularization within prosthesis mesh may be achieved by using fibrin as a support for angiogenic molecules such as HA, FN and FGFs.

Haemostasis in periradicular surgery

The successful performance of endodontic surgical procedures is predicated on many factors. However, the ability of achieve sustained tissue haemostasis in the surgical site is crucial to the performance of these procedures. This achievement improves vision in the surgical site, minimizes surgical time, enhances the surgical procedures (root-end resection, preparation and filling), and reduces surgical blood loss, postsurgical haemorrhage and postsurgical swelling. A multitude of materials have used in dentistry and medicine to achieve both generalized and localized haemostasis, many without full assessment of their biological implications. The purpose of this paper is to provide a thorough and critical review of these materials from the perspective of surgical endodontics, highlighting their development, application and potential role in achieving proper haemostasis.