NOVEL COLLAGEN VASCULAR PLUG FOR FEMORAL ARTERIOTOMY SEALING - ACUTE AND CHRONIC IN-VIVO STUDIES

Background: The current use of collagen vascular hemostasis devices to percutaneously seal femoral arteriotomy sires is limited by a signifi cant incidence of vascular complications. The purpose of the present s tudy was to assess the efficacy of new collagen plug specifically desi gned to avoid these complications by accurately gauging the depth of t he femoral artery and by minimizing the risk of intra-arterial collage n deployment. Methods: The hemostasis device used in this study consis ts of a multicomponent collagen plug with an external rigid collagen t ube lined by art inner layer of absorptive sponge collagen. Placement of this plug is facilitated with a specialized two-lumen dilator, whic h localizes the arterial surface using a ''bleedback'' mechanism from one of the lumens, and prevents the placement of collagen through the arteriotomy sire. The acute efficacy of this device was assessed in 26 adult dogs in which 36 collagen plugs were used to seal 8Fr femoral a rteriotomies. An additional 16 arteriotomies treated with standard man ual compression served as study controls. Following plug placement or manual compression, all puncture sites were observed for bleeding and hematoma formation over a 45-minute period. Patency of each instrument ed artery was assessed with serial femoral angiography and localizatio n of each plug was confirmed with surgical cutdown or the puncture sit e. The chronic efficacy of this device was assessed in three pigs in w hich three collagen plugs were used to seal 8Fr femoral arteriotomies. The three animals were subsequently sacrificed at 7, 14, and 30 days, respectively. For histologic analysis. Results: In acute animals, all 36 plugs were successfully placed without evidence of vascular vascul ar compromise or intra-arterial collagen deployment. In nonanticoagula ted animals, hemostasis was achieved within 5 minutes in 10 of 10 plug s placed with a skin-to-artery distance > 1.8 cm, in 4 of 7 plugs with a skin-to-artery distance of 1.2-1.7 cm, and in 0 of 9 plugs with a s kin-to-artery distance < 1.2 cm. in anticoagulated animals, hemostasis within 5 minutes was demonstrated with 8 of 10 plugs with a skin-to-a rtery distance > 1.8 cm; small hematomas occurred in the remaining two animals in the setting of a PTT > 100 seconds. Time to hemostasis was significantly less for collagen plugs than manual compression in both nonanticoagulated animals (plug 17 +/- 16 minutes; manual compression 28 +/- 5 minutes, P < 0.03) and anticoagulated animals (plug 6 +/- 2 minutes; manual compression 42 +/- 4 minutes; P < 0.01). Chronic studi es demonstrated femoral artery patency in all three pigs. Histologic a nalysis demonstrated progressive collagen resorption with no differenc e between collagen plug placement or manual compression at 30 days. Co nclusions: The local hemostasis device utilized in this study resulted in accurate placement of a collagen plug immediately adjacent to the arteriotomy site with no evidence of acute or chronic vascular comprom ise or intra-arterial collagen deposition. Hemostasis with shorter com pression times than with standard manual techniques was achieved at pu ncture sites in which the skin-to-artery distance was > 1.8 cm and the anticoagulation profile was not excessive. At 1 month postplacement, there is no histologic difference between plug use and standard manual compression.