Staple line reinforcement with fleece-coated fibrin glue (TachoComb) after thoracoscopic bullectomy for the treatment of spontaneous pneumothorax

BACKGROUND

We investigated the cause of pneumothorax recurrence after thoracoscopic surgery and the effectiveness of staple line reinforcement with fleece-coated fibrin glue (TachoComb) in the prevention of postoperative pneumothorax recurrence.

METHODS

From April 3, 1992 to the end of December 2005, thoracoscopic bullectomy was performed on 499 patients of primary spontaneous pneumothorax. The causes of recurrence were investigated on 39 patients on the basis of surgical observations, preoperative chest computed tomography, and so on. The most common cause was new bulla formation (37 cases), 19 of which were apparently related to the staple line (within 1 cm of the staple lines) and 15 of which were not related to the staple line. After 2000, we stopped using forceps to grasp lungs and we have reinforced the staple line by applying fleece-coated fibrin glue.

RESULTS

The staple line reinforced with fleece-coated fibrin glue, or sprayed with fibrin glue solution and the untreated group (bullectomy only with staples) were compared, and the recurrence rates were 1.22%, 7.25%, and 10.00%, respectively (P = 0.0006021).

CONCLUSIONS

The recurrence rate after thoracoscopic bullectomy with fleece-coated fibrin glue was significantly lowered and we consider this procedure to be the treatment of choice for the management of spontaneous pneumothorax.

Effects of fibrin sealer and resorbable gelatin on the repair of osseous defects in rat tibia

Gelfoam - a biologically resorbable gelatin sponge - has the function of restricting hemorrhage, providing platelet rupture, and supporting fibrin threads. Beriplast - a fibrinogen-thrombin compound - is used to adhere tissues, to consolidate sutures and in hemostasis. The objective of this study was to perform a histological analysis of the effects of haemostatic agents on osseous repair. These materials were inserted into surgical sites in young rat right and left tibiae. After the observation periods of 7, 14, 30 and 45 days, according to the bioethic protocol, the animals were killed, the tibiae were removed and fixed in 10% formalin and decalcified in equal parts of formic acid and sodium citrate solutions. After routine processing, the specimens were embedded in paraffin for microtomy. Analysis of the results demonstrated that the haemostatic agents are effective in controlling hemorrhage; they stimulate osteogenesis, featuring a pattern of osseous tissue formation similar to the control pattern, although the amount of osseous trabeculae was superior, especially in the Gelfoam group in the periods of 7 and 14 days; 30 days after surgery, the delay in tissue healing in the control group in relation to the experimental groups started to decrease, and the control and experimental groups exhibited similar tissue repair after 45 days, when all the groups exhibited secondary osseous tissue.

[Effects of exogenous basic fibroblast growth factor on in-sheathed tendon healing and adhesion formation]

OBJECTIVE

To explore the effects of exogenous basic fibroblast growth factor (bFGF) on in-sheathed tendon healing and adhesion formation.

METHODS

Ninety Leghorn chickens were randomly divided into 3 groups (groups A, B and C), 30 animals for each group, and the right third digitorum longus tendon of the chicken was transected to make defect models. In group A, the tendon was sutured in situ after transection. In group B, the tendon was sutured after 0.6 microl fibrin sealant (FS) was applied at repair site. In group C, the tendon was sutured after 0.6 microl FS mixed with 500 ng bFGF was applied at repair site. At 1, 2, 4 and 8 weeks after operation, the tendons of 6 chickens in each group were harvested for morphological and histological evaluation. Six specimens of each group was obtained for biomechanical test at 8 weeks.

RESULTS

The gross observation showed that the differences of grading of tendon adhesion were not significant between groups A, B, and C 8 weeks after operation (P > 0.05). Histological evaluation showed that there were no significant differences in fibroblast counting and the content of collagen fibers between groups A and B (P > 0.05). The angiogenesis, fibroblast proliferation and collagen production in the sheath, epitendon and parenchyma at repair site in group C occurred earlier and were more than those in groups A and B, showing significant differences (P < 0.05). The biomechanical tests showed that the gliding excursion of the tendon in group A, B and C were 3.44 +/- 0.43, 3.51 +/- 0.56 and 2.84 +/- 0.42 mm respectively; the work of flexion were 14.87 +/- 1.72, 14.08 +/- 1.85 and 20.62 +/- 3.52 Nmm respectively; the ultimate tensile strength of the tendon was 10.34 +/- 1.45, 11.26 +/- 1.83 and 15.02 +/- 2.20 N respectively; showing no significant differences between groups A and B (P > 0.05), but showing significant differences between group C and groups A, B (P < 0.05).

CONCLUSION

The exogenous bFGF at tendon repair site can facilitate in-sheathed tendon healing, but also increase the tendon adhesion formation.

The role of biological extracellular matrix scaffolds in vascularized three-dimensional tissue growthin vivo

An in vivo murine vascularized chamber model has been shown to generate spontaneous angiogenesis and new tissue formation. This experiment aimed to assess the effects of common biological scaffolds on tissue growth in this model. Either laminin-1, type I collagen, fibrin glue, hyaluronan, or sea sponge was inserted into silicone chambers containing the epigastric artery and vein, one end was sealed with adipose tissue and the other with bone wax, then incubated subcutaneously. After 2, 4, or 6 weeks, tissue from chambers containing collagen I, fibrin glue, hyaluronan, or no added scaffold (control) had small amounts of vascularized connective tissue. Chambers containing sea sponge had moderate connective tissue growth together with a mild "foreign body" inflammatory response. Chambers containing laminin-1, at a concentration 10-fold lower than its concentration in Matrigel, resulted in a moderate adipogenic response. In summary, (1) biological hydrogels are resorbed and gradually replaced by vascularized connective tissue; (2) sponge-like matrices with large pores support connective tissue growth within the pores and become encapsulated with granulation tissue; (3) laminin-containing scaffolds facilitate adipogenesis. It is concluded that the nature and chemical composition of the scaffold exerts a significant influence on the amount and type of tissue generated in this in vivo chamber model.

Biological Glues and Collagen Fleece for Hemostasis during Laparoscopic Partial Nephrectomy: Technique and Results of Prospective Study

PURPOSE

The aim of this prospective study was to evaluate the advantages or disadvantages of the use of fibrin glue and collagen fleece during laparoscopic partial nephrectomy.

PATIENTS AND METHODS

Two groups of patients were studied. Group A (n = 24) received parenchymal suture, whereas Group B (n = 20) received parenchymal suture with fibrin glue and collagen fleece. The two groups were similar in baseline characteristics. We evaluated patient age, size of the lesion at CT, operative time, ischemia time, and sealant technique in relation to blood loss, hospital stay, and hemorrhagic complications.

RESULTS

No significant difference was observed in perioperative parameters (P > 0.05). The mean size of lesion was 3.3 +/- 1.2 (range 1-8 cm) for group A and 3.0 +/- 1.3 (range 2-5 cm) for Group B. The mean operative time was 116 +/- 26.6 minutes (range 90-220 minutes) for group A and 130 +/- 23.5 minutes (range 90-210 minutes) for group B. The mean warm ischemia time was 28.8 +/- 5.7 minutes (range 18-60) minutes) and 35.6 +/- 6.2 minutes (range 20-52 minutes), respectively. The mean blood loss was 178 +/- 34.5 mL (range 50-400 ml) for group A and 219 +/- 44.6 mL (range 80-750 ml) for group B. The mean hospital stay was 5.9 +/- 1.2 days (range 5-8 days) for group A and 6.3 +/- 2.1 days (range 5-9 days) for group B. Four and two postoperative hemorrhage complications were observed in groups A and B, respectively.

CONCLUSION

The use of fibrin glues and collagen fleece should be considered an adjuvant, as it does not present any substantial advantages, the suture being the key point in hemostasis control. We believe that in order to improve hemostasis, the efficacy of other types of sealants should be studied, as we were not convinced by those we used.

Use of human fibrin glue (Tissucol) versus staples for mesh fixation in laparoscopic transabdominal preperitoneal hernioplasty: a prospective, randomized study

OBJECTIVE

The aim of this study was to compare the morbidity of fixation of prosthetic meshes using Tissucol fibrin glue versus staples in laparoscopic transabdominal preperitoneal (TAPP) repair of inguinal and femoral hernias.

SUMMARY BACKGROUND DATA

In patients undergoing laparoscopic hernia repair, fixation of mesh prostheses with staples may affect inguinocrural nerves causing early postoperative neuralgia and chronic neuralgia.

METHODS

Between June 2003 and February 2005, 197 patients with inguinal or femoral hernia were enrolled in this prospective, randomized study, to assess morbidity following hernia repair with staples (n = 98) or Tissucol (n = 99). The primary outcomes were early postoperative and late neuralgia recorded using a visual analog scale (VAS). The effects of neuralgia on functional status were evaluated using the modified SF-36 questionnaire. Secondary outcomes included complications such as nonspecific pain and recurrence.

RESULTS

Assessments took place at 1, 3, 6, and 12 months, with all patients completing each follow-up visit. Mean VAS scores were significantly lower in the Tissucol group versus the staples group (MANOVA, P < 0.05). Higher scores for the modified SF-36 questionnaire at 1 month were demonstrated in the Tissucol group compared with the staples group (23.2 and 22.6, respectively; P < 0.05). The mean recovery time for normal physical activity was significantly shorter in the Tissucol group compared with the staples group (7.9 vs. 9.1 day, respectively; P < 0.001). One recurrence was seen in the fibrin glue group, which was attributable to a technical error in fixation of the mesh.

CONCLUSIONS

The use of Tissucol provides distinct advantages in laparoscopic treatment of inguinal/femoral hernias compared with conventional TAPP, including a lower incidence of postoperative neuralgia and an earlier resumption of physical and social activities.

Effect of Platelet Rich Plasma and Fibrin Sealant on Facial Nerve Regeneration in a Rat Model

OBJECTIVE

To investigate the effects of platelet rich plasma (PRP) and fibrin sealant (FS) on facial nerve regeneration.

STUDY DESIGN

Prospective, randomized, and controlled animal study.

METHODS

Experiments involved the transection and repair of facial nerve of 49 male adult rats. Seven groups were created dependant on the method of repair: suture; PRP (with/without suture); platelet poor plasma (PPP) (with/without suture); and FS (with/without suture) groups. Each method of repair was applied immediately after the nerve transection. The outcomes measured were: 1) observation of gross recovery of vibrissae movements within 8-week period after nerve transection and repair using a 5-point scale and comparing the left (test) side with the right (control) side; 2) comparisons of facial nerve motor action potentials (MAP) recorded before and 8 weeks after nerve transection and repair, including both the transected and control (untreated) nerves; 3) histologic evaluation of axons counts and the area of the axons.

RESULTS

Vibrissae movement observation: the inclusion of suturing resulted in overall improved outcomes. This was found for comparisons of the suture group with PRP group; PRP with/without suture groups; and PPP with/without suture groups (P < .05). The PRP without suture group had a significantly greater degree of recovery than the PPP without suture group (P < .05), but it did not have better performance than suture group (P > .05). The movement recovery of the suture group was significantly better than the FS group (P = .014). The recovery of function of the PRP groups was better than that of the FS groups, although this did not reach statistical significance (P = .09). Electrophysiologic testing: there was a significantly better performance of the suture group when compared with the PRP and PPP without suture groups in nerve conduction velocity (P < .05). The PRP with suture group had the best results when compared with the suture as well as the PPP with suture groups in duration and latency-2 of MAP (P < .05). For the FS groups, no results were found demonstrating a biological effect. The PRP with suture group demonstrated the best performance in the latency-2 and the area under the curve of MAP when compared with the suture and FS with suture groups (P < .05). Histomorphometric analysis: PRP with suture demonstrated the greatest increase in axon counts when compared with suture, FS with suture, and PPP with suture groups (P < .05). There was no statistically significant difference seen in axon diameter.

CONCLUSION

The best results for the return of function in our rat facial nerve axotomy models occurred when the nerve ends were sutured together. At the same time, the data demonstrated a measurable neurotrophic effect when PRP was present, with the most favorable results seen with PRP added to suture. There was an improved functional outcome with the use of PRP in comparison with FS or no bioactive agents (PPP). FS showed no benefit over conventional suturing in facial nerve regeneration. Our study provides the potential of a new clinical application for PRP in peripheral nerve regeneration.

[Effect of injectable fibrin sealant compounded with bone morphogenetic protein on proliferation and differentiation of marrow stromal cells towards osteoblasts in rabbits]

OBJECTIVE

To investigate the effect of the injectable osteoinductive material with fibrin sealant (FS) as a carrier compounded with bone morphogenetic protein (BMP) on the proliferation and differentiation of marrow stromal cells (MSCs) towards osteoblasts and to provide the experimental foundation for the clinical application.

METHODS

MSCs were extracted and cultured from bone marrow of the 3-day-old rabbit, and the third generation cultured MSCs were studied. The experiment included the experimental group (FS, including 1 microg/ml rhBMP-2), FS control group(FS)and blank control group (no material). The proliferation rate, the adhesive rate, the expression of the collagen I and alkaline phosphatase, cell growth condition in the material and the ultrastructure of MSCs were investigated by electron microscopy, histochemistry and cell culture.

RESULTS

The proliferation rate and the adhesive rate of MSCs in experimental group was significantly higher than those in blank control group, but lower than those in FS control group (P<0.05). The expression level of the collagen I and alkaline phosphatase in the experimental group was significantly higher than those in all control groups (P < 0.05). Scanning electron microscope showed that the surface of material was rough and had many pores and that cell and material mixed. Transmission electron microscope showed that MSCs of the experimental group were mostly of the phenotype of osteoblasts with relatively low proliferation activity and high differentiation degree toward osteoblasts and with plenty of extracellular matrix and collagen fibers. MSCs of FS control group had low differentiation degree toward osteoblasts with few extracellular matrix and collagen fibers and high proliferation activity. MSCs of blank control group had low differentiation degree toward osteoblasts with few extracellular matrix and collagen fibers, and low proliferation activity.

CONCLUSION

The injectable osteoinductive material with fibrin sealant as a carrier compounded with BMP could significantly accelerate the differentiation of MSCs towards osteoblasts. But it could not significantly accelerate the proliferation activity of MSCs.

Stability, sterility, coagulation, and immunologic studies of salmon coagulation proteins with potential use for mammalian wound healing and cell engineering

Fibrin sealants made by polymerization of fibrinogen activated by the protease thrombin have many applications in hemostasis and wound healing. In treatments of acute injury or surgical wounds, concentrated fibrin preparations mimic the initial matrix that normally prevents bleeding and acts as a scaffold for cells that initiate tissue repair. However risks of infectious disease, immunogenic reaction, and the high cost of purified human or other mammalian blood proteins limit widespread use of these materials. Purified coagulation proteins from Atlantic salmon represent a potentially safer, equally effective, and less costly alternative in part because of the low ambient temperature of these farmed animals and the absence of endogenous agents known to be infectious in mammalian hosts. This study reports rheologic measurements of lyophilized salmon fibrinogen and thrombin that demonstrate stability to prolonged storage and gamma irradiation sufficient to reduce viral loads by over five orders of magnitude. Coagulation and immunologic studies in rats and rabbits treated intraperitoneally with salmon fibrin show no deleterious effects on coagulation profiles and no cross reactivity with host fibrinogen or thrombin. The results support the potential of salmon fibrin as an alternative to mammalian proteins in clinical applications.

Maxillary sinus floor augmentation using autogenous bone grafts and platelet-enriched fibrin glue with simultaneous implant placement

OBJECTIVE

The aim of this study was to evaluate the use of autogenous bone in combination with platelet-enriched fibrin glue as a grafting material for maxillary sinus augmentation with simultaneous implant placement in dogs.

STUDY DESIGN

The mucous membranes of 12 sinuses in 6 dogs were elevated bilaterally. In the right sinus, autogenous bone mixed with platelet-enriched fibrin glue was grafted into the space between the membrane and the sinus wall. In the left sinus, autogenous bone alone was grafted as a control. At the same time, 2 dental implants were inserted into the grafting material through the maxillary sinus floor. The animals were killed 6 months after surgery.

RESULTS

The mean bone-implant contact was 40.5% on the fibrin glue side and 32.3% on the control side (P < .05). The mean height of newly formed bone in the augmented area was 12.2 mm on the fibrin glue side and 10.7 mm on the control side (P < .05).

CONCLUSION

The results indicate that the use of autogenous bone mixed with platelet-enriched fibrin glue can achieve results superior to those for grafts of autogenous bone alone. The specific improvements of this technique include enhanced osseointegration of dental implants and increased height of new bone.

Human U937 monocyte behavior and protein expression on various formulations of three-dimensional fibrin clots

Fibrin sealant products such as Tisseel (Baxter Healthcare Corporation) are used in hemostasis and tissue sealing. Tisseel consists of two components, a fibrinogen-containing component and thrombin, which when mixed together form a fibrin clot. There is an interest in delivering monocytes to the wound because they are known to play an important role in the wound-healing process. Therefore, we were interested in finding the best fibrin formulation for delivering monocytes by examining monocyte behavior on 3D-fibrin clots. Using standard adhesion and proliferation assays, we found that monocytes differentially adhere, proliferate, and cluster on and within the 3D-fibrin clots depending on the final fibrinogen and thrombin concentration. Moreover, using a Boyden chamber assay, we found that monocytes migrated through the 3D-fibrin clots in 1-2 days. Furthermore, the protein expression in monocytes seeded on 3D-fibrin clots for various time points varied depending on the fibrinogen and thrombin concentrations in the final 3D-fibrin clots. The above data suggest that various formulations of fibrin sealant Tisseel present a good surface for monocyte adhesion, proliferation and migration in vitro and potentially during the wound-healing process in vivo. Moreover, because the monocytes proliferated well and clustered in the 3D fibrin, Tisseel could be a good delivery vehicle for delivering monocytes into chronic wounds to overcome a healing deficiency.

An in vitro and in vivo analysis of fibrin glue use to control bone morphogenetic protein diffusion and bone morphogenetic protein-stimulated bone growth

BACKGROUND CONTEXT

Recombinant human bone morphogenetic protein-2 (rh-BMP2) has become popular for augmenting spine fusion in the lumbar and cervical spine. Concerns exist, however, over bone morphogenetic protein (BMP)-stimulated soft-tissue swelling and bone growth stimulation in areas where bone is not desired, especially as the material "leaks" into such spaces. The most detrimental effects of such leakage might be airway compromise, while heterotopic bone formation into the spinal canal has been reported in animal and human studies. Fibrin glue has been used as a carrier of many osteoinductive materials; however, its efficacy at modulating the clinical effects of BMP are not known. The amorphous nature of fibrin glue makes it a candidate to control diffusion of BMP and possibly limit bone formation by limiting BMP diffusion to areas where such bone is not desired.

PURPOSE

To evaluate the use of fibrin glue to limit BMP diffusion and BMP-stimulated bone growth.

STUDY DESIGN/SETTING

This is an in vitro basic science study and an in vivo prospective randomized animal study.

STUDY SAMPLE

Eighteen Lewis rats.

OUTCOME MEASURES

In vitro study: Enzyme-linked immunosorbent assay measurement of rh-BMP2 concentration in saline. In vivo study: At day 60, rats were evaluated for neurologic deficits before sacrifice. Spines were harvested, and the following studies were performed: 1) manual testing for fusion and bone growth; 2) X-ray evaluation; 3) Micro-computed tomography (micro-CT) scans.

METHODS

In vitro study: Collagen sponges soaked with BMP at two different concentrations were incubated in saline solution with and without encapsulation by fibrin glue. Saline BMP concentrations were measured at consecutive time points. In vivo study: A rat fusion model using rh-BMP2 for fusion has been developed and tested with resultant100% fusion in over 100 rats. Lewis rats were divided into two groups and treated as follows: I: Exposure of L4-L5 transverse processes, decortication, and placement of BMP sponge in the lateral intertransverse space. II: Exposure and decortication as above and placement of fibrin glue before BMP sponge placement.

RESULTS

In vitro study: Peak rh-BMP2 concentrations in saline were 20% and 45% of the maximum possible for fibrin glue encapsulated sponges and controls, respectively, with a more gradual increase to peak concentration in samples encapsulated in fibrin glue. In vivo study: No rats exhibited any neurologic deficits. X-rays revealed at least partial bone formation in all rats. Manual testing of intertransverse fusion spines revealed 100% fusion in rats treated with BMP only, whereas rats treated with fibrin glue before placement of BMP sponges revealed only one possible fusion. Posterior-lateral bone formation was present on X-ray in both groups, and micro-CT imaging revealed bridging bone from transverse processes to the BMP-stimulated bone in the control groups. In spines treated with fibrin glue before rh-BMP2 placement, bone formation could still be seen within the soft tissues; however, bridging bone connecting to the transverse processes was either significantly decreased or not present.

CONCLUSIONS

Fibrin glue can limit rh-BMP2 diffusion. Also, because it limited bone formation at the transverse processes, it can be inferred that fibrin glue can limit bone formation when used to separate areas of desired bone formation from areas where bone formation is not desired.

Effects of Tissucol and epsilon aminocaproic acid in the healing process following dental extraction in dehydrated rats

A histological study was conducted of the alveolar bone healing process following tooth extraction of dehydrated rats after the implantation of fibrin adhesive (TISSUCOL) associated to previous irrigation of the wound with a 5% epsilon aminocaproic acid solution (EACA). Seventy two rats were used, divided into three groups receiving different treatments after the surgical procedure. In group I, the gingival mucosa was sutured after extraction of the right upper incisor. In groups II and III, chronic dehydration was produced by water deprivation for 9 days (3 days in the preoperative period and 6 days in the postoperative period). In the animals of Group II, after tooth extraction, the gingival mucosa was sutured in the same way as performed in group I. In group III, after extraction, the dental socket was irrigated with 5% EACA, followed by implantation of the fibrin adhesive (TISSUCOL). The mucosa was sutured in the same way as performed in the other groups. At 3, 7, 15 and 21 postoperative days, the animals were sacrificed in number of 6 for each group. Specimens containing the dental socket were removed and fixed in 10% formalin and decalcified in an equal part formic acid and sodium citrate solution. After routine processing, the specimens were embedded in paraffin for microtomy. We obtained 6 microm semi-serial slices that were stained with hematoxylin and eosin for histological evaluation. The results showed that the water deprivation in the pre- and postoperative periods caused a delay in the alveolar bone healing process. The use of the fibrin adhesive (TISSUCOL) produced an improvement in the fibrinolytic picture caused by dehydration.

Differential, time-dependent effects of perivenous application of fibrin glue on medial thickening in porcine saphenous vein grafts☆

OBJECTIVE

Neointimal and medial thickening play a critical role in late vein graft failure following CABG. Previous ex vivo experiment suggested that perivenous application of fibrin glue may reduce the damage in the circular smooth muscle cell layer of the media of the vein graft shortly after exposing to arterial pressure. However, the in vivo as well as the longer term impact of this intervention remain unknown.

METHODS

Bilateral saphenous vein-carotid artery interposition grafting was performed in eight large white pigs (35-45 kg). In each pig, one of the grafts was randomly selected to receive perivenous fibrin glue support while the contralateral graft served as control. At 1 and 4 months following surgery (n=4 pigs in each group), all 16 patent vein grafts were removed and pressure-fixed. Multiple histological sections from each graft were prepared. Proliferating cell nuclear antigen (PCNA) was detected by immunocytochemistry. Vein graft morphology was assessed using computer-aided planimetry.

RESULTS

Although perivenous application of fibrin glue had little effects either on medial thickness 1 month after implantation or on PCNA index, it significantly increased medial thickness (control: 0.37+/-0.02 mm; treated: 0.55+/-0.02 mm, p<0.001) and total wall thickness (control: 0.75+/-0.04 mm; treated: 0.92+/-0.04 mm, p=0.008) at 4 months (mean+/-SEM; n=4 in each group).

CONCLUSIONS

Our data indicated that perivenous application of fibrin glue enhances graft thickening and as such does not constitute a strategy for preventing late vein graft failure after CABG.

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.

Fibrin sealant promotes migration and proliferation of human articular chondrocytes: possible involvement of thrombin and protease-activated receptors

Fibrin sealant (FS), a biological adhesive material, has been recently recommended as an adjunct in autologous chondrocyte implantation (ACI). While FS has been shown to possess osteoinductive potential, little is known about its effects on chondrogenic cells. In this study, we assessed the bioactivity of FS (Tisseel) on the migration and proliferation of human articular chondrocytes in vitro. Using a co-culture assay to mimic matrix-induced ACI (MACI), chondrocytes were found to migrate from collagen membranes towards FS within 12 h of culture, with significant migratory activity evident by 24 h. In addition, 5-bromo-2'-deoxyuridine (BrdU) incorporation experiments revealed that thrombin, the active component of the tissue glue, stimulated chondrocyte proliferation, with maximal efficacy observed at 48 h post-stimulation (1-10 U/ml). In an effort to elucidate the molecular mechanisms underlying these thrombin-induced effects, we examined the expression and activation of protease-activated receptors (PARs), established thrombin receptors. Using a combination of RT-PCR and immunohistochemistry, all four PARs were detected in human chondrocytes, with PAR-1 being the major isoform expressed. Moreover, thrombin and a PAR-1, but not other PAR-isotype-specific peptide agonists, were found to induce rapid intracellular Ca2+ responses in human chondrocytes in calcium mobilization assays. Together, these data demonstrate that FS supports both the migration and proliferation of human chondrocytes. We propose that these effects are mediated, at least in part, via thrombin-induced PAR-1 signalling in human chondrocytes.

Platelet-rich fibrin (PRF): a second-generation platelet concentrate. Part IV: clinical effects on tissue healing

Platelet-rich fibrin (PRF) belongs to a new generation of platelet concentrates, with simplified processing and without biochemical blood handling. In this fourth article, investigation is made into the previously evaluated biology of PRF with the first established clinical results, to determine the potential fields of application for this biomaterial. The reasoning is structured around 4 fundamental events of cicatrization, namely, angiogenesis, immune control, circulating stem cells trapping, and wound-covering epithelialization. All of the known clinical applications of PRF highlight an accelerated tissue cicatrization due to the development of effective neovascularization, accelerated wound closing with fast cicatricial tissue remodelling, and nearly total absence of infectious events. This initial research therefore makes it possible to plan several future PRF applications, including plastic and bone surgery, provided that the real effects are evaluated both impartially and rigorously.

Platelet-rich fibrin (PRF): a second-generation platelet concentrate. Part III: leucocyte activation: a new feature for platelet concentrates?

Platelet-rich fibrin (PRF) belongs to a new generation of platelet concentrates, with simplified processing and without biochemical blood handling. In this third article, we investigate the immune features of this biomaterial. During PRF processing, leucocytes could also secrete cytokines in reaction to the hemostatic and inflammatory phenomena artificially induced in the centrifuged tube. We therefore undertook to quantify 5 significant cell mediators within platelet poor plasma supernatant and PRF clot exudate serum: 3 proinflammatory cytokines (IL-1beta, IL-6, and TNF-alpha), an antiinflammatory cytokine (IL-4), and a key growth promoter of angiogenesis (VEGF). Our data are correlated with that obtained in plasma (nonactivated blood) and in sera (activated blood). These initial analyses revealed that PRF could be an immune regulation node with inflammation retrocontrol abilities. This concept could explain the reduction of postoperative infections when PRF is used as surgical additive.

Platelet-rich fibrin (PRF): a second-generation platelet concentrate. Part V: histologic evaluations of PRF effects on bone allograft maturation in sinus lift

OBJECTIVE

Platelet-rich fibrin (PRF) belongs to a new generation of platelet concentrates, with simplified processing and without biochemical blood handling. The use of platelet gel to improve bone regeneration is a recent technique in implantology. However, the biologic properties and real effects of such products remain controversial. In this article, we therefore attempt to evaluate the potential of PRF in combination with freeze-dried bone allograft (FDBA) (Phoenix; TBF, France) to enhance bone regeneration in sinus floor elevation.

STUDY DESIGN

Nine sinus floor augmentations were performed. In 6 sites, PRF was added to FDBA particles (test group), and in 3 sites FDBA without PRF was used (control group). Four months later for the test group and 8 months later for the control group, bone specimens were harvested from the augmented region during the implant insertion procedure. These specimens were treated for histologic analysis.

RESULTS

Histologic evaluations reveal the presence of residual bone surrounded by newly formed bone and connective tissue. After 4 months of healing time, histologic maturation of the test group appears to be identical to that of the control group after a period of 8 months. Moreover, the quantities of newly formed bone were equivalent between the 2 protocols.

CONCLUSIONS

Sinus floor augmentation with FDBA and PRF leads to a reduction of healing time prior to implant placement. From a histologic point of view, this healing time could be reduced to 4 months, but large-scale studies are still necessary to validate these first results.

Effect of the Combination of Fibrin Glue and Growth Hormone on Incomplete Intestinal Anastomoses in a Rat Model of Intra-Abdominal Sepsis

BACKGROUND

The presence of established intra-abdominal sepsis has been considered a contraindication to primary anastomoses. Our hypothesis was that fibrin glue (FG), growth hormone (rhGH), and combination of them synergistically improve intestinal primary anastomotic healing in a rat model of intestinal fistulae with peritonitis.

MATERIALS AND METHODS

Male Wistar rats, induced intestinal fistulae with peritonitis after 24 h, were performed an enterectomy and intestinal anastomoses. Group A, rats (n = 60) had a complete anastomoses (end-to-end single layer anastomoses using 12 inverted interrupted 6-0 sutures) without peritonitis, group B, rats (n = 60) had a complete anastomoses after 24 h of peritonitis, group C rats had an incomplete anastomoses (four inverted interrupted sutures), groups D, E, F rats (n = 60) received FG, rhGH, or both of them, respectively. rhGH was given daily for 5 days. Anastomoses indicated the anastomotic bursting pressure (ABP), tensile strength, and hydroxyproline content, were determined.

RESULTS

On POD 1, ABP of group C and group D was significantly lower than that of other groups (P < 0.01); On POD 3, ABP could not be determined because of intestinal dehiscence in groups C and E, ABP was significantly higher in groups D and F than that of groups A and B (P < 0.01); the ABP increased after 5 days of operation in groups A, B, and F. At the same time, that of group D decreased (P < 0.01). On POD 5, the tensile strength was significantly higher in groups A, D, and F than that in groups C, and E. On POD 5, hydroxyproline content was higher in groups D and F compared to that in group C (P < 0.05).

CONCLUSIONS

These data suggested that FG improve intestinal primary anastomotic healing within post-operative 5 days in a rat model of intestinal fistulae with peritonitis. RhGH alone fails to improve intestinal anastomotic healing, and the combination of FG and rhGH have no synergistic effect to improves intestinal anastomotic healing.

Perivenous application of fibrin glue prevents the early injury of jugular vein graft to arterial circulation in rabbits

BACKGROUND

Placement of an external support has been reported to prevent intimal hyperplasia of vein grafts. However, it is limited by potential complications. In the present study, we investigated the effect of fibrin glue on preventing vein graft failure as perivenous application.

METHODS

Twenty-four rabbits were divided into non-supported group (n = 12) and fibrin glue group (n = 12). All animals underwent unilateral jugular vein into common carotid artery interposition grafting and then fibrin glue was applied as perivenous support. Samples of tissues were harvested after 4 weeks.

RESULTS

The vein grafts with fibrin glue demonstrated a statistically significant decrease in proliferating cell nuclear antigen in the medial/intimal region [13.38% (11.26% - 15.11%)] compared with non-supported vein grafts [31.22% (27.15% - 35.98%)] (P < 0.001). Light microscopy showed remarkable attenuation of endothelial cell loss and numerous microvessels in neoadventitia in the fibrin glue group compared with the non-supported group. The smooth muscle cells migrated into adventitia significantly in fibrin glue group, whereas the smooth muscle cells migrated into intima in non-supported group. Conclusion Perivenous support of vein graft with fibrin glue in vivo can attenuate the severe injury encountered in the non-supported vein grafts exposed to artery.