Safety Evaluation of New Hemostatic Agents, Smectite Granules, and Kaolin-Coated Gauze in a Vascular Injury Wound Model in Swine

In 2007, a potent procoagulant mineral called WoundStat WS, consisting of smectite granules, received clearance from the Food and Drug Administration for marketing in the United States for temporary treatment of external hemorrhage. Previously, we found that microscopic WS particles remained in the injured vessels that were treated, despite seemingly adequate wound debridement. Thus, we investigated the thromboembolic risk of using WS when compared with kaolin-coated gauze, Combat Gauze CG or regular gauze, Kerlix KX to treat an external wound with vascular injuries in pigs. Methods The right common carotid artery and external jugular vein of pigs were isolated and sharply transected 50. After 30 seconds of free bleeding, the neck wounds were packed with WS, CG, or KX and com- pressed until hemostasis was achieved n 8 per group. Wounds were debrided after 2 hours, and vascular injuries were primarily repaired with suture. Blood flow was restored after infusin g1Lof crystalloid no heparin or aspirin and the wounds were closed. Two hours later, computed tomographic angiography was performed, and the wounds were reopened to harvest the vessels. The brains and lungs were recovered for gross and microscopic examination after euthanasia. Results No differences were found in baseline measurements. Thrombelastography showed similar hypercoagulability of the final blood samples when compared with baselines in all groups. All vessels treated with KX or CG were patent and had no thrombus or blood clot in their lumen. In contrast, seven of eight carotid arteries and six of eight jugular veins treated with WS developed large occlusive red thrombi and had no flow. Small clots and WS residues were also found in the lungs of two pigs. Histologically, significant endothelial and transmural damage was seen in WS-treated vessels with luminal thrombi and embedded WS residues.