Fibrin sealant in preclinical and clinical studies

Management of haemostasis in surgery: sealant and glue applications

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

Use of BioGlue Surgical Adhesive in Hypospadias Repair

PURPOSE

To prospectively evaluate the efficacy of albumin glutaraldehyde tissue adhesive (BioGlue) in the surgical treatment of patients with hypospadias.

MATERIALS AND METHODS

Two groups of 20 patients each who underwent hypospadias repair were included in the study. In the first group we utilized BioGlue as an additional protective layer to the suture line of the neo-urethra, while patients in the second group were operated on utilizing a routine surgical technique.

RESULTS

There were no statistical differences between patients from the 2 groups in terms of surgical complications. Urethrocutaneous fistula was revealed in 4 (20%) patients after repair with BioGlue and in 3 (15%) patients from the control group (p = 0.686), suture line breakdown in 4 (20%) and in 1 (5%) patients (p = 0.478), meatal stenosis in 1 (5%) and in 1 (5%) patient (p = 1). Furthermore more patients in the BioGlue group (n = 12, 60%) demonstrated poor cosmetic results compared to the control group where most patients - 19 (95%) had acceptable cosmetic outcomes (p = 0.007).

CONCLUSIONS

Our data showed no benefits of BioGlue use in hypospadias repair.

Form Follows Function: Advances in Trilayered Structure Replication for Aortic Heart Valve Tissue Engineering

Tissue engineering the aortic heart valve is a challenging endeavor because of the particular hemodynamic and biologic conditions present in the native aortic heart valve. The backbone of an ideal valve substitute should be a scaffold that is strong enough to withstand billions of repetitive bending, flexing and stretching cycles, while also being slowly degradable to allow for remodeling. In this review we highlight three overlooked aspects that might influence the long term durability of tissue engineered valves: replication of the native valve trilayered histoarchitecture, duplication of the three-dimensional shape of the valve and cell integration efforts focused on getting the right number and type of cells to the right place within the valve structure and driving them towards homeostatic maintenance of the valve matrix. We propose that the trilayered structure in the native aortic valve that includes a middle spongiosa layer cushioning the motions of the two external fibrous layers should be our template for creation of novel scaffolds with improved mechanical durability. Furthermore, since cells adapt to micro-loads within the valve structure, we believe that interstitial cell remodeling of the valvular matrix will depend on the accurate replication of the structures and loads, resulting in successful regeneration of the valve tissue and extended durability.

Adhesive use in oral and maxillofacial surgery

Presently, tissue adhesives and sealants have limited use in oral and maxillofacial surgical procedures. Skin closure occurs regularly with cyanoacrylate adhesives. Sealing of dural tears in conjunction with dural closure has been shown to be very successful. With the development of more head and neck reconstructive procedures and cosmetic procedures, demand will increase for better surgical adhesives. Clinical trials are beginning for newly developed adhesives with the chemical characterizations, the safe reabsorptive profile, and the adhesive strength necessary to benefit oral and maxillofacial surgery patients in the near future. Adhesives for bone fixation, while in early development, also show a promising chemical profile and will be of significant benefit to oral and maxillofacial surgical patients.

Prevention of growth arrest by fibrin interposition into physeal injury

This study investigated the repair effects of fat and fibrin graft interposition through a proximal tibia transphyseal injury model and assessed the effectiveness of treatment to physeal injury with the fibrin. In this study, a unilateral growth plate injury was created in the right proximal tibia of 28 rats without any graft interposition; all left tibias were left untouched. In the other group of 28 rats, a bilateral physeal injury was made with the left tibia filled with autogenously adipose tissue and the right tibia filled with fibrin. To compare the malformed extents induced by different interventions, the length and the metaphyseal-diaphyseal angle of the tibia of three injured groups were examined. Further studies on bone density analysis and histological change were used to compare the bony bridge formation under different interventions. Results showed that the deformity angle and medial length of the tibia were significantly different between the grafted groups and nongrafted group at 4, 16, and 24 weeks postoperative (P<0.01). Results also showed no significant difference between fibrin-graft and fat-graft groups (P>0.05). Furthermore, the bone mineralization density of bony bridge induced by injury was significantly different between the grafted group and nongrafted group at 4, 16, and 24 weeks postoperative (P<0.01). Histological findings showed that bony repair after physeal injury was inhibited by both fibrin and fat interventions. We concluded that fibrin could be a substitute of adipose tissue in preventing the deformities induced by epiphyseal injury. Similar to autogenous fat, fibrin was found to alleviate limb shortness and prevent angular malformation by forming a scar instead of a bony bridge. The use of fibrin can help us to develop effective and compound intervention grafts to prevent skeletal deformity and regenerate normal cartilage tissue in the future.

Effect of fibrin glue on the prevention of persistent cerebral spinal fluid leakage after incidental durotomy during lumbar spinal surgery

Approximately one million spinal surgeries are performed in the United States each year. The risk of an incidental durotomy (ID) and resultant persistent cerebrospinal fluid (CSF) leakage is a significant concern for surgeons, as this complication has been associated with increased length of hospitalization, worse neurological outcome, and the development of CSF fistulae. Augmentation of standard dural suture repair with the application of fibrin glue has been suggested to reduce the frequency of these complications. This study examined unintended durotomies during lumbar spine surgery in a large surgical patient cohort and the impact of fibrin glue usage as part of the ID repair on the incidence of persistent CSF leakage. A retrospective analysis of 4,835 surgical procedures of the lumbar spine from a single institution over a 10-year period was performed to determine the rate of ID. The 90-day clinical course of these patients was evaluated. Clinical examination, B-2 transferrin assay, and radiographic imaging were utilized to determine the number of persistent CSF leaks after repair with or without fibrin glue. Five hundred forty-seven patients (11.3%) experienced a durotomy during surgery. Of this cohort, fibrin glue was used in the dural repair in 278 patients (50.8%). Logistic models evaluating age, sex, redo surgery, and the use of fibrin glue revealed that prior lumbar spinal surgery was the only univariate predictor of persistent CSF leak, conferring a 2.8-fold increase in risk. A persistent CSF leak, defined as continued drainage of CSF from the operative incision within 90 days of the surgery that required an intervention greater than simple bed rest or over-sewing of the wound, was noted in a total of 64 patients (11.7%). This persistent CSF leak rate was significantly higher (P < 0.001) in patients with prior lumbar surgery (21%) versus those undergoing their first spine surgery (9%). There was no statistical difference in persistent CSF leak between those cases in which fibrin glue was used at the time of surgery and those in which fibrin glue was not used. There were no complications associated with the use of fibrin glue. A history of prior surgery significantly increases the incidence of durotomy during elective lumbar spine surgery. In patients who experienced a durotomy during lumbar spine surgery, the use of fibrin glue for dural repair did not significantly decrease the incidence of a persistent CSF leak.

The Potential Utility of Fibrin Sealant Dressing in Repair of Vascular Injury in Swine

BACKGROUND

A previous study in which fibrin sealant dressing (FSD) secured hemostasis in major arterial hemorrhage for 96 hours suggested the applicability of this dressing in damage control operations after severe trauma. The objective of this study was to determine the effective duration of FSD hemostatic function in vivo and to examine its potential utility for definitive repair of a major arterial injury in swine.

METHODS

High pressure bleeding in an infrarenal aortotomy was controlled by placing FSD on the wound with 4-minute compression (n = 15). If hemostasis was achieved, the abdominal cavity was closed. Surviving animals were killed at 2, 4, 6, and 8 weeks and aortotomy sites collected for histology.

RESULTS

FSD stopped arterial hemorrhage after 4-minute compression in 14 of 15 (93%) pigs. Dressings failed in two pigs at 36 and 53 minutes after treatment. Twelve (80%) animals recovered and resumed normal activities. Of the remaining 12, two developed rebleeding at the aortotomy site on days 8 and 11 and were killed; another was killed because of idiopathic low hematocrit on day 10. Nine pigs survived until scheduled to be killed, maintaining hemostasis with stable hematological values. In the surviving animals, serial computed tomography scans showed formation of a pseudoaneurysm at the aortotomy site, which resolved after 2 to 3 weeks. The initial vascular defect and pseudoaneurysm were filled with fibroblast-myoblast collagen rich tissues covered by endothelium.

CONCLUSION

FSD can seal an arterial injury, stop high pressure bleeding, and prevent rebleeding for at least 7 days. The dressing may be most beneficial in damage control operations. If combined with an elective interventional radiologic procedure (e.g. embolization or stenting), it may also offer an alternative to suture repair of vascular injuries in cases where profuse bleeding obstructs visualization.

Effects of Tisseel Fibrin Glue on the Central Nervous System of Nonhuman Primates

For many years, neurosurgeons and otolaryngologic surgeons have used the fibrin glue product Tisseel to repair skull-base spinal fluid leaks and to help secure repairs following anterior cranial-base surgery. Despite the widespread use, the potential focal cerebral toxicity of this fibrin glue has never been investigated. We studied the safety of Tisseel applied directly to neural tissue (brain parenchyma, cervical cord, and C3-C6 spinal roots) of 6 monkeys (Macaca nemestrina) to determine if any underlying biochemical injury would occur. Another 3 animals that served as controls received saline rather than Tisseel. We found that median nerve electroencephalographic tracings and somatosensory evoked potentials in the experimental and control animals were identical. Likewise, cerebrospinal fluid indicators of neuronal or brain injury, inflammatory responses, and infection were negative in both groups. Finally, there were no significant differences between the two groups with respect to edema volumes and apparent diffusion coefficient values. We conclude that Tisseel does not induce an apparent inflammatory response or abnormal neurophysiologic or histologic response within 5 days of its application when it is applied directly to the brain parenchyma or onto the cervical spinal cord.

Laparoscopic heminephrectomy using a new fibrin sealant powder

OBJECTIVES

To determine the ability of a hemostatic fibrin sealant powder (HFSP), delivered laparoscopically, to achieve hemostasis and seal the collecting system during laparoscopic heminephrectomy.

METHODS

An HFSP preparation was applied laparoscopically as a dry powder spray. Twenty-two farm pigs were randomized into two laparoscopic heminephrectomy groups: group 1 underwent conventional intracorporal suturing with vascular control (n = 11) and group 2 received HFSP application alone with regional ischemia (n = 11). Computed tomography was performed at 48 hours and again 6 weeks postoperatively.

RESULTS

The operative findings revealed no differences between the two groups in the weight of the removed segments, mean arterial blood pressure, operating room time, estimated blood loss, or hematocrit and serum creatinine levels. The gross examination 6 weeks postoperatively found no delayed bleeding, urinoma formation, or bowel adhesions. The computed tomography findings at 48 hours postoperatively demonstrated excellent hemostasis in both groups. Urinary extravasation was detected in 8 (80%) of 10 animals in the HFSP group and 1 (9%) of 11 in the conventional group at 48 hours (P < 0.008). At the 6-week computed tomography evaluation, none of the animals showed evidence of urinoma or hematoma formation. Histopathologically, at 6 weeks, the cut surface of the kidneys in both groups had been replaced by dense scar tissue at the cortex with a sharp line of demarcation between the scar and normal kidney.

CONCLUSIONS

HFSP greatly facilitates laparoscopic heminephrectomy by providing rapid and lasting hemostasis without suturing. Early urine extravasation was more common in the HFSP group, but no clinical, gross, or radiographic evidence of urinoma formation was seen in either group 6 weeks after surgery.

Fibrin sealant improves hemostasis in peripheral vascular surgery: a randomized prospective trial

OBJECTIVE

To evaluate the efficacy and safety of an investigational fibrin sealant (FS) in a randomized prospective, partially blinded, controlled, multicenter trial.

SUMMARY BACKGROUND DATA

Upper extremity vascular access surgery using polytetrafluorethylene (PTFE) graft placement for dialysis was chosen as a reproducible, clinically relevant model for evaluating the usefulness of FS. The FS consisted of pooled human fibrinogen (60 mg/mL) and thrombin (500 NIH U/mL). Time to hemostasis was measured, and adverse events were monitored.

METHODS

Consenting adult patients (n = 48) undergoing placement of a standard PTFE graft were randomized in a 2:1:1 ratio to the treatment group using FS (ZLB Bioplasma AG, Bern, Switzerland), oxidized regenerated cellulose (Surgicel, Johnson & Johnson, New Brunswick, NJ), or pressure. Patients received heparin (3,000 IU IVP) before placement of vascular clamps. If the treatment was FS, clamps were left in place for 120 seconds after the application of study material to permit polymerization. If treatment was Surgicel, clamps were left in place until the agent had been applied according to manufacturer's instructions. If the treatment was pressure, clamps were released as soon as the investigator was ready to apply compression. Immediately after release of the last clamp, the arterial and venous suture lines were evaluated for bleeding. The time to hemostasis at both the venous and arterial sites was recorded.

RESULTS

Significant (P < or =.005) reduction in time to hemostasis was achieved in the FS group. Thirteen (54.2%) patients randomized to FS experienced immediate hemostasis at both suture lines following clamp removal compared to no patients using Surgicel or pressure. Only one patient (7.1%) in the Surgicel group and no patients in the pressure group experienced hemostasis at 120 seconds from clamp removal, compared to 13 (54.2%) patients for FS. Adverse events were comparable in all groups. There were no seroconversions.

CONCLUSIONS

FS achieved more rapid hemostasis than traditional techniques in this peripheral vascular procedure. FS use appeared to be safe for this procedure.

Pharmacological strategies to decrease transfusion requirements in patients undergoing surgery

Surgical procedures are inevitably associated with bleeding. The amount of blood loss may vary widely between different surgical procedures and depends on surgical as well as non-surgical factors. Whereas adequate surgical haemostasis may suffice in most patients, pro-haemostatic pharmacological agents may be of additional benefit in patients with (diffuse) surgical bleeding or in patients with a specific underlying haemostatic defect. In general, surgical haemostasis and pharmacological therapies can be complementary in controlling blood loss. The use of pharmacological therapies to reduce blood loss and blood transfusions in surgery has historically been restricted to a few drugs. Antifibrinolytic agents (aprotinin, tranexamic acid and aminocaproic acid) have the best evidence supporting their use, especially in cardiac surgery, liver transplantation and some orthopaedic surgical procedures. Meta-analyses of randomised, controlled trials in cardiac patients have suggested a slight benefit of aprotinin, compared with the other antifibrinolytics. Desmopressin is the treatment of choice in patients with mild haemophilia A and von Willebrand disease. It has also been shown to be effective in patients undergoing cardiac surgery who received aspirin up to the time of operation. However, overall evidence does not support a beneficial effect of desmopressin in patients without pre-existing coagulopathy undergoing elective surgical procedures. Topical agents, such as fibrin sealants have been successfully used in a variety of surgical procedures. However, only very few controlled clinical trials have been performed and scientific evidence supporting their use is still limited. Novel drugs, like recombinant factor VIIa (eptacog alfa), are currently under clinical investigation. Recombinant factor VIIa has been introduced for the treatment of haemophilia patients with inhibitors, either in surgical or non-surgical situations. Preliminary data indicate that it may also be effective in surgical patients without pre-existing coagulation abnormalities. More clinical trials are warranted before definitive conclusions can be drawn about the safety and the exact role of this new drug in surgical patients. Only adequately powered and properly designed randomised, clinical trials will allow us to define the most effective and the safest pharmacological therapies for reducing blood loss and transfusion requirements in surgical patients. Future trials should also consider cost-effectiveness because of considerable differences in the costs of the available pro-haemostatic pharmacological agents.

Does fibrin glue reduce complications after femoral artery surgery? A randomised trial

OBJECTIVES

to determine whether application of fibrin glue before closure of inguinal wounds reduces the incidence of lymphatic complications.

DESIGN

we a prospective randomised trial.

MATERIALS AND METHODS

224 consecutive patients were enrolled. The wounds were randomly assigned to standard closure (group A, n = 134) or closure with application of fibrin glue (group B, n = 132). The incidence of local lymphatic and non-lymphatic complications, the amount of lymphatic fluid collected, and the time to drain removal were compared in the groups.

RESULTS

the incidence of lymphatic complications was 19% in group A and 10% in group B (p = 0.027). The average drain output and the time to drain removal did not differ in the two groups. The total incidence of non-lymphatic local complications was 10% and did not differ in the two groups.

CONCLUSIONS

fibrin glue application is associated with a significant reduction in lymphatic complications.

Innovative minimally invasive pediatric surgery is of therapeutic value for splenic injury

BACKGROUND/PURPOSE

Until now, minimally invasive surgery (MIS) has not had any therapeutic status for operable splenic trauma, because reliable sealing of larger defects is not possible with general techniques.

METHODS

Fleece-bound sealing allows rapid, large-area sealing of erosions and defects, so that with the aid of an MIS applicator system (AMISA), this method of tissue management can be transferred to MIS.

RESULTS

An in vitro evaluation showed that liquid fibrin sealing (FS) exhibits incomplete selective leak closure and low adhesive strength (4.1 hPa) and is not suitable for challenging surfaces. Fleece-bound sealing (ready-to-use v. prepare-to-use) showed reliable sealing and higher adhesive strength for collagen fleeces that are ready coated with fibrinogen-based sealant (TachoComb H; Nycomed, Linz, Austria) compared with various carrier systems that had to be impregnated on the spot (prepare-to-use; 50.2 v 23 hPa; P <.0001). Between October 1993 and October 2001, 19 of 87 children with splenic rupture were treated with the AMISA system (AMISA + TachoComb H) (21.8%), and 3 of these children had multiple trauma. The operation was indicated because of circulatory instability despite adequate volume replacement therapy. Splenic repair always was possible with the AMISA system, a changeover and splenectomy was not necessary, and the postoperative course was complication free. The mean stay in the hospital was 9.2 days.

CONCLUSIONS

The AMISA system efficiently expands the indications for emergency laparoscopy and can be used successfully in emergency laparoscopy for splenic rupture management.

Fibrin Sealant Facilitates Hemostasis in Arteriovenous Polytetrafluoroethylene Grafts for Renal Dialysis Access

A prospective randomized study was performed to evaluate the efficacy of fibrin sealant (FS) in patients undergoing upper-extremity polytetrafluoroethylene (PTFE) graft placement for dialysis. This procedure appears to be a reproducible and clinically relevant model for evaluating FS in vascular surgery. Consenting adult patients (n = 28) undergoing placement of a PTFE graft (6 mm) were randomized to either the treatment group using FS (Hemaseel APR, Haemacure Corp., Sarasota, FL) or control comparator groups (four) of bovine thrombin (T) (Thrombogen, GenTrac Inc., Middleton, WI), pressure (P), bovine thrombin (Thrombogen, GenTrac Inc.) -soaked cellulose sponges (TG) (Gelfoam, Upjohn Co., Kalamazoo, MI), or oxidized regenerated cellulose (S) (Surgicel, Johnson & Johnson, New Brunswick, NJ). All patients received heparin (3000 IU intravenous push) before placement of vascular clamps. The mean time to hemostasis was 29.3 seconds for FS, 147.4 seconds for T, 872.2 seconds for P, 346 seconds for TG, and 1044.5 seconds for S. There were no significant adverse events. FS appeared to be a superior hemostatic agent in these vascular procedures. No complications from FS were noted.

Development of an animal model for assessment of the hemostatic efficacy of fibrin sealant in vascular surgery

PURPOSE

Sustained hemostatic function of fibrin sealant (FS) is crucial when it is used in cardiovascular surgery. The purpose of this study was to develop a model that can determine the long-term hemostatic efficacy of tissue sealants in a vascular surgery.

METHODS

To determine the ability of the model to detect differences in FS performance, various concentrations of FS were prepared and tested. Tensile strength of FS clots was determined in vitro using a tensiometer. Laparotomy was performed on 49 anesthetized rabbits, and a segment of the aorta was occluded, transected, and then sutured in an end-to-end fashion with four or eight interrupted 9-O sutures. The four-suture repair was covered with FS or placebo, and blood flow restored. Spilled blood was absorbed with gauze and weighed to estimate blood loss. Four weeks after surgery the animals were euthanized and the vessels recovered for histology.

RESULTS

Average tensile strength of FS clots at 120, 90, and 60 mg/ml topical fibrinogen complex (TFC) concentration was 0.42 +/- 0.07 N, with no significant difference among them. The lowest TFC concentration, 30 mg/ml, produced weaker clots than either 120 or 90 mg/ml (P < 0.05). All rabbits with four-suture anastomoses that were treated with placebo bled to death after the vessel was unclamped (n = 6). Treatment of suture line with standard FS concentration (120 mg/ml TFC, n = 8) sealed the anastomosis and prevented blood loss. Hemostasis was sustained for 4 weeks, allowing vascular healing. All rabbits with the eight-suture anastomosis survived the operation but lost 42 +/- 9.2 ml blood (n = 5). Hemostatic efficacy of FS was unchanged when TFC was diluted to 90 mg/ml (n = 6) but further dilution to 60 mg/ml with water (n = 8) produced significantly less effective clots, with an average blood loss of 5.5 +/- 7.6 ml (P < 0.05) and two fatal clot failures postoperatively. When FS was diluted to 60 mg/ml TFC with a buffer, it maintained its hemostatic strength (n = 6). Further TFC dilution to 30 mg/ml led to consistent bleeding with an average blood loss of 35.3 +/- 10.3 ml (P < 0.001, n = 6).

CONCLUSIONS

The four-suture anastomosis of rabbit aorta offers a consistent and reliable method for evaluating the short- and long-term hemostatic efficacy of FS products. This model is not only able to determine the functional differences in various concentrations of FS, but it is also sensitive to detect the subtle changes in FS preparation (e.g., medium composition) that is not detected by in vitro testing.

Newer techniques in intracorporeal tissue approximation: suturing, tissue adhesives, and microclips

Great strides have been made in the discovery of alternative tissue approximation techniques for use in laparoscopy. Although none of the techniques have eliminated the need for suturing laparoscopically, their potential in achieving this end is promising. When an ideal approximation technique is discovered that is easy to use, safe, and reliably able to hold tissue together laparoscopically, laparoscopic reconstructive surgery should become less formidable and more appealing to urologists.

Fibrin glue applications in urology

Fibrin glue is used as a hemostatic and adhesive agent. Until recently, safety issues had delayed approval of the commercial preparation in the United States. Fibrin glue has found several urologic applications, especially as an adhesive agent. It has excellent potential in laparoscopic surgery, where conventional tissue approximation techniques are cumbersome and time-consuming. Fibrin glue has also been used as a delivery vehicle for autologous cell transplantation and may play a major role in tissue engineering techniques in the future.