LifeScience PLUS sponsored a preclinical study performed in accordance with GLP guidelines. Device application and evaluation of the BloodSTOP® Hemostatic Gauze and BloodSTOP® iX Absorbent Hemostat was performed at LyChron, LLC in Mountain View CA in four healthy swine on 7/29/11. Three animals were assigned to individual test groups receiving anticoagulants (Coumadin, Aspirin and Plavix, or Heparin) and one were assigned as the control group, receiving no anticoagulants. Six linear skin incisions were made on the left and right sides of the abdomen using a scalpel blade. Each incision was approximately 1.5-2 cm in length and extended down to the innermost layer of the dermis. A pad containing BloodSTOP or Blood STOP iX was applied to the wound in accordance with the manufacturer’s instructions for use and was repeated for each of the six wounds. The number of test article layers, pressure hold time, and time to achieve hemostasis were recorded. At completion of the procedure, the animals were recovered from anesthesia. The treatment sites were observed for any signs of bleeding, discomfort, or infection. At the end of the 13-day survival period, all animals were humanely euthanized and each treated surgical site was collected and immersion fixed formalin for histological analysis.
Hemostasis was successfully achieved for both test BloodSTOP and BloodSTOP iX for all animals. An increase in time to achieve hemostasis was seen in the BloodSTOP iX for the test animals (received anticoagulants) compared to the control. The time to achieve hemostasis for the heparinized animal for BloodSTOP Hemostatic Gauze was slightly less compared to the control. The time to achieve hemostasis in the Coumadin and Plavix/Aspirin animals was increased compared to the control for BloodSTOP Hemostatic Gauze. Time to achieve hemostasis was tested for statistical significance of differences. The time to achieve hemostasis was compared between each test and control animal for both test articles (BloodSTOP and BloodSTOP iX). Time to achieve hemostasis with BloodSTOP and BloodSTOP iX was also compared within each animal. No statistical differences were found at a 95% level of significance. Therefore, the time to achieve hemostasis in the anticoagulant group (test animals) is considered comparable to the control animal for both test articles. The increase in time to achieve hemostasis corresponds with the hemostasis delays seen in the Coagulation blood panel.
During the first 3 days following the procedure, mild to moderate inflammation, erythema, and/or swelling was noted in several of the incision sites for all animals as well as scabbing and crusting. In many cases, these clinical findings were noted until Day 7 and began to resolve by Day 12. Most incisions were noted to be almost completely healed by Day 12. Histologically, the Heparin treated animal showed delayed levels of healing of the epidermis. The level of inflammation was comparable to the control. The least affected animal was Animal, which received the Coumadin and was considered equivalent to the control animal. Also in terms of healing the Plavix treated animal had complete healing in all sites exposed to test article BloodSTOP iX on the right side and BloodSTOP Hemostatic Gauze on the left side. The Plavix treated animal is considered to be equivalent to the control animal.
In comparing areas treated with BloodSTOP iX with the areas treated with BloodSTOP Hemostatic Gauze histologically for the four treatments, the healing process with BloodSTOP Hemostatic Gauze is somewhat less and the level of inflammation is higher than for areas treated with BloodSTOP iX. These results suggest that both test articles are effective and that the test article BloodSTOP iX is marginally superior in terms of healing to that of BloodSTOP Hemostatic Gauze. The full data on the levels of healing and the inflammation were tested for significance of differences and were found not to be different at a 95% level of significance. Therefore both of the test articles were found to be effective in promoting coagulation and healing.