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.