RESULTS: Angiography immediately after TAE with GSP or NBCA showed complete occlusion in both coagulopathic conditions. In the ACT 200s state, follow-up angiography at5-30 minutesafterTAE with eitherGSP orNBCA showed no evidence of recurrent hemorrhage. In the ACT 400s state, follow-up angiography showed recurrent hem- orrhage in 4 (80%) of the 5 hemorrhages embolized with GSP and in 1 (20%) of the 5 hemorrhages embolized with NBCA. Microscopically, red thrombiwere observed densely surrounding GSP in mild coagulopathy but were scarcely in severe coagulopathy. CONCLUSION: In a condition with severe coagulopathy, TAE with NBCA was more effective in durability to cease active arterial bleeding than with GSP. 5:00 PM Abstract No. 47 Ultrasound Therapy in a Rabbit Stroke Model: Further Developments in Hemorrhage and Therapeutic Efficacy. W. Culp 1 , R. Flores 1 , J. Lowery 2 , A. Brown 1 , L. Hennings 3 , M. Borrelli 1 ; 1 University of Arkansas for Medical Sciences - Radiology, Little Rock, AR; 2 UAMS - Laboratory Animal Medicine, Little Rock, AR; 3 UAMS - Pathology, Little Rock, AR. PURPOSE: Intravenous (IV) tissue plasminogen activator (tPA) therapy and intraarterial interventions for acute isch- emic stroke are greatly under utilized formany reasons. Early reports of ultrasound (US) augmented thrombolytic therapies in humans are promising, butinclude one with increased bleeding. An optimal technique has not emerged. We compare several US and microbubble (MB) augmented techniques in an angiographic rabbit modelof ischemic stroke. MATERIALS & METHODS: New Zealand White rabbits of 4-5 kg,N172, were randomized to 7 groups: 1) control (n50), 2) tPA (n28), 3) tPAUS (n22), 4) MBUS (n27), 5) hdMBUS (n14), 6) tPAMBUS (n14), and 7)US alone (n17). Group 1 received no therapy. Groups 2 and 3 got IV tPA at 0.9 mg/kg over 60 min. Group 4 got IV MB (perflutren lipid microspheres) at 0.16 mg/kg. Group 5 gotIV MB atthe human dose of 0.014mg/kg. Group 6 combined tPA and MB as in groups 3 and 4. Appropriate groups received transcutaneous pulsed 1 MHz US at0.8 W/cm2 for 60 min. All were embolized with a single 3 to 6 hr autologous blood clot (0.6 x 1.0 mm) using a 3 F catheter in the internal carotid artery. Repeat angiog- raphy and therapy followed. At 24 hrs total brain stroke volume % was measured using triphenyltetrazolium chlo- ride stained brain sections. Microscopic hemorrhage scores (0no hemorrhage to 4severe) were also obtained. The Wilcoxon rank sum and Kruskal-Wallis test were applied. RESULTS: All treatments except US had stroke volumes lower than controls at 0.45% with tPA0.14%, tPAUS0.15%, MBUS0.20%, hdMBUS0.07%, tPAMBUS0.10%. No difference was found between therapies except US alone at 1.0% was higher than the rest, p 0.05. Hemorrhage scores available on 152 rabbits show the MBUS group (mean hemorrhage score0.78) had decreased scores compared with all othergroupswhich ranged from 1.1 to 1.5, p0.015. Bleeding incidence in penumbra was increased in tPAUS, 73% (p0.004) and decreased in MBUS, 19% (p0.003) compared with con- trols at 34%. CONCLUSION: Several ultrasound techniques and standard tPA therapy are similar in efficacy. However, only MBUS produced improved hemorrhage scores in penumbra whil tPAUS worsened these. Further development of MBUS is needed. 5:12 PM Abstract No. 48 Clot Trapping Performance of Different Types of Me tallic Stents: In-Vitro Study in a Flowing Model. J.E.Lopera, H. Nguyen,R. Suri,M. Cura,F. El-Merhi, G. Kroma; UT Health Science Center, San Antonio, TX. PURPOSE: To study the ability of different types of balloo and self expandable, covered and non-covered stents, to t thrombus without causing embolization in an in-vitro flow ing model. MATERIALS & METHODS: A flowing model of bifurcated 5 mm vessel was created with plastic tubing. One leg was free flowing while the other had an occlusive 1 cm length thrombus created with four to five 8 X 4 mm pieces of bovine blood weighting 0.5 g. The system was connected an extracorporeal circulation pump running tap water hea to 37 degrees at 3 Lits/min. Differentypes of stents (11 types of non-covered self expandable, 3 types of balloon expandable, 2 types of self expandable covered, and 1 typ of balloon expandable covered) were deployed inside the thrombosed tubing. After stent deployment any embolized fragments were trapped by a strainer attach to the end of system. All self-expandable stents were post dilated with a 6 mm X 4.0 cm balloon and any additional embolization was recorded. RESULTS: Significant clot embolization was noted with al types of balloon expandable non-covered stents. With non covered self expandable stents the degree of embolization was related to the length of the stent and the initial positi of the distal tip of the stent atinitialdeployment. In most cases the uncovered mesh trapped the clots that occupied 3 cm segment of vessel. When the center of the stents wa deployed over the thrombus, the clots were pushed proxi- mally and migrated over the proximal end of the stent eith occluding the flow and/or causing embolization. Significan embolization was noted with both balloon and self expand able covered stents. The clotwas squeezed between the fabric of the stents and the wall of the tubing occupying aproximately a 6 cm segment. CONCLUSION: In this in-vitro flowing model testing the clot trapping performance of different types of stents, sig- nificant embolization was observed with non-covered bal- loon expandable, and both balloon and self expandable covered stents. With non-covered self expandable stents either no embolization or different degrees of embolizatio were observed according to the lenght of the stent and ini stent position during deployment. 5:24 PM Abstract No. 49 In-Vitro Model of Translumbar Embolization of En- doleaks with n-BCA: Risk of “Gluing” of Different Ac cess Devices. J. Lopera, R. Harper,M.Cura,G. Kroma,F. El-Merhi, R. Suri; UT Health Science Center, San Antonio, TX. PURPOSE: To test the utility of a flowing model to simu- late a translumbar (TL) access to treat endoleaks after ao aneuryms endovascular repair. To access the risk of “glu- ing” different accessdevicesused forTL injectionsof n-BCA at different concentrations. S20