Gelatin±thrombin-based Hemostatic Sealant for Intraoperative Bleeding in Vascular Surgery Fred A. Weaver, MD, 1 Douglas B. Hood, MD, 1 Michael Zatina, MD, 2 Louis Messina, MD, 3 and Brian Badduke, MD, 4 San Francisco and Fremont, California, and Baltimore, Maryland Vascular surgical procedures may be prolonged because of intraoperative bleeding that is not easily controlled by cautery or suture ligation. This trial compared the ability of a new hemostat, FloSeal TM Matrix FM), with a known hemostat, Gelfoam â plus thrombin GT), to control intra- operative bleeding. Patients undergoing vascular surgery procedures at four institutions were entered in the trial. After a bleeding site was identi®ed, patients were randomized to one of the study agents: 1) FM, a cross-linked gelatin of bovine origin combined with thrombin, or 2) GT. The assigned agent was applied and the site observed for bleeding at 1, 2, 3, 6, and 10 min. The primary end point was cessation of bleeding within 10 min for the ®rst identi®ed site treated. Secondary end points were cessation of bleeding within 10 min for all sites and time to cessation of bleeding. Patients were assessed for morbidity at 30 days and 6-8 weeks after the operation. Analysis was performed on an intent-to-treat basis for analysis of hemostasis at 10 min and on protocol-valid patients for analysis of time to hemostasis. From our results we concluded that for patients undergoing vascular surgery procedures, the new topical hemostat, FloSeal Matrix, provides more rapid and effective hemostasis than Gelfoam plus thrombin. INTRODUCTION Surgical procedures may be prolonged because of intraoperative bleeding that cannot be controlled by conventional approaches such as manual pres- sure, cauterization, or sutures. This results in in- creased utilization of operating room time, personnel, and, on occasion, blood bank products. Persistent bleeding during or after an operative procedure may be secondary to coagulopathy, in- adequate reversal of heparin, poor tissue charac- teristics, inaccessibility of bleeding sites for ``surgical'' control, or surgical technique. Evolution in many surgical procedures to smaller, more minimally invasive incisions or approaches are a potentially high-risk setting, since the access and capacity to control troublesome persistent bleeding sites are diminished. The availability and develop- ment of reliable products to control bleeding in this setting will potentially enhance the safety of these procedures. Over the years, a number of topical hemostatic agents have been developed to control troublesome intraoperative bleeding. Some agents such as col- lagen-based powders, sponges, or cloths are of a 286 1 Department of Surgery, University of Southern California School of Medicine, Los Angeles, CA 1 . 2 Department of Surgery, St. Agnes HealthCare, Baltimore, MD. 3 Department of Surgery, University of California at San Francisco, San Francisco, CA. 4 Department of Surgery, Washington Hospital, Fremont, CA. Correspondence to: F.A. Weaver, MD, USC School of Medicine, 1510 San Pablo Avenue, Suite 514, Los Angeles, CA 90033-4612, USA, E-mail: fweaver@surgery.hsc.usc.edu. Ann Vasc Surg 2002; 16: 286-293 DOI: 10.1007/s10016-001-0073-0 Ó Annals of Vascular Surgery Inc. Published online: 18 April 2002