Combination of a liquid fibrin sealant with sheet-type hemostatic agents: experimental evaluation in partial nephrectomy animal model.

Liquid fibrin sealants, together with sheet-type hemostatic agents, have been used during partial nephrectomies to secure effective hemostasis at the suture site. Using animal kidneys, we investigated which hemostatic agent might adhere most effectively to the renal tissue and serve best as a bolster. Liquid fibrin sealant alone, or in combination with a sheet-type hemostat, such as collagen, gelatin or oxidized-cellulose hemostat, was applied to the cut surface of the kidney of anesthetized rabbits, and the differences in the degree of adherence to the kidney and resultant hemostatic efficacy were evaluated. Histological analyses were also carried out to compare the degree of adherence of each of the aforementioned hemostats to the kidney tissue. Fibrin sealant plus the collagen or gelatin hemostat was found to have a stronger hemostatic effect than fibrin sealant applied alone or fibrin sealant plus oxidized-cellulose hemostat. The histological investigation showed that the fibrin sealant adhered well to kidney tissue when it was applied with the collagen or gelatin hemostat, showing the advantage of combining these two materials for achieving effective hemostasis. Fibrin sealant used in combination with the collagen or gelatin hemostat was the most suitable for obtaining a reinforced hemostatic effect at the suture site in a partial nephrectomy animal model.

Improvement of the tissue-adhesive and sealing effect of fibrin sealant using polyglycolic acid felt.

Although fibrin sealant (FS) has an advantage of high biocompatibility, its adhesive force and sealing effect have been generally considered to be inadequate. In the present study, a high adhesive force and sealing effect were obtained by first rubbing fibrinogen solution into the target tissue, attaching polyglycolic acid (PGA) felt to the treated area, and finally spraying it with FS. This method was compared with three conventional FS application methods and a method using fibrin glue-coated collagen fleece. The adhesive force resulting from the present method was 12 times higher than that for the sequential application method, 4.5 times higher than the spray method, 2.5 times higher than the rubbing and spray method, and 2.2 times higher than the use of fibrin glue-coated collagen fleece. The high adhesive force of FS with PGA felt seemed to be due the high fibrin content of the fibrin gel (FG). Light and electron microscopic observations suggested that the formation of FG in closer contact with the muscle fibers was a factor contributing to this superior adhesive force. Comparison of the sealing effect of the present method with other methods using various biomaterials in combination with FS showed that the sealing effect of FS with PGA felt was 1.4 times higher that of polyglactin 910, 1.8 times that of polytetrafluoroethylene, and 6.7 times that of oxidized regenerated cellulose.

Hemostatic efficacy of a recombinant thrombin-coated polyglycolic acid sheet coupled with liquid fibrinogen, evaluated in a canine model of pulmonary arterial hemorrhage.

BACKGROUND: In thoracic surgery, although infrequent, we encounter unexpected damage to the pulmonary artery (PA). In the present study, we evaluated the hemostatic efficacy of a newly developed fibrin-based sheet material, thrombin sheet, coupled with liquid fibrinogen (TSF), in an experimental model of PA hemorrhage. METHODS: Female beagles (n = 8) were used for the study. Left thoracotomy was performed under general anesthesia. PA injury (approximately 4 x 2 mm) was created, and repaired by TSF (TSF group) or TachoComb (TC group). The animals were allowed to survive, and the repaired site was evaluated 4 weeks after the experiment. RESULTS: The number of sheet application and compression procedures required for hemostasis was increased in the TC group compared with in the TSF group (TC vs. TSF, 4 +/- 1 vs. 1 +/- 0.5, p = 0.01, unpaired t test). The time required to achieve hemostasis was increased in the TC group compared with in the TSF group (TC vs. TSF, 7 +/- 3 vs. 1 +/- 0.5 minutes, p = 0.01, unpaired t test). The amount of bleeding during the hemostasis procedure was increased in the TC group compared with in the TSF group (TC vs. TSF, 48 +/- 22 vs. 3 +/- 3 g, p = 0.01, unpaired t test). At 4 weeks, rethoracotomy revealed no apparent indication of delayed bleeding, such as intrathoracic hematoma formation or excessive adhesion formation in the vicinity of PA, in either group. Histologically, the vessel lumen was well sustained in both groups, with no apparent stenosis or thrombus formation. CONCLUSION: The hemostatic efficacy of TSF was superior to TC in this particular experiment. Single application of TSF was sufficient to achieve hemostasis in all but one animal. Compression time of approximately 1 minute was also very short albeit that the bleeding was from the PA and not an artery. These results were presumably because the adhesion was stronger, faster, and the sheet was more pliable in TSF compared with TC.