In Vitro Effectiveness of Mechanical Thrombectomy Devices for Large Vessel Diameter and Low-pressure Fluid Dynamic Applications
To determine in vitro the efficacy of clot removal of the AngioJet (AJ; new 6-F generation), Hydrolyser (HL; 6-F), and Oasis (OS; 6-F) hydrodynamic thrombectomy devices and the Amplatz Thrombectomy Device fragmentation catheter (ATD; 8-F and new-generation 7-F) in large-diameter vessels and low-pressure fluid dynamic applications (ie, pulmonary embolism).
Thrombectomy of clots (N = 60; n = 12 for each tested device) created from 5-day-old porcine blood (16 g) was performed with the AJ (with coaxial 0.035-inch guide wire), HL, OS, and ATD in a bench-top model simulating low-pressure fluid dynamics (pulsed flow, 1,250 L/min). Tubes made of silicone (20-mm inner diameter) containing thrombus simulated a large-diameter vessel. The effluent was passed through a three-step filter system (10-1,000 micro m; pressure drop, 15 mm Hg).
Mean thrombectomy time ranged from 83 seconds (7-F ATD) to 185 seconds (OS; P <.0001 compared to all). Remaining thrombus ranged from 5.4 g/32.7% (AJ) to 11.1 g/68.1% (HL; P <.001 compared to all). The AJ's fluid balance was 0.92, whereas the mean ratio of applied saline solution to aspirated fluid for the other devices were significantly different than isovolumetric conditions (HL, 0.64; OS, 0.59; P <.0001 compared to AJ). The AJ (0.36%), HL (0.43%), and OS (0.38%) caused the least overall emboli larger than 10 micro m; the ATD (7-F, 0.82%; 8-F, 0.74%) caused the most (P <.001 for both).
The tested mechanical thrombectomy devices showed performance differences in thrombectomy time, efficacy of thrombus removal, and peripheral embolization rates. Based on low embolization rates for all devices tested, the experimental data indicate that the 7-F ATD and the 0.035-inch guide-wire-compatible AJ showed feasibility advantages for thrombectomy in large vessel diameter and low-pressure fluid dynamic applications.
Available from: Gregory W Munson
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ABSTRACT: Extracellular senile plaques composed predominantly of fibrillar amyloid-beta (Abeta) are a major neuropathological feature of Alzheimer's disease (AD). Genetic evidence and in vivo studies suggest that apolipoprotein E (apoE) may contribute to amyloid clearance and/or deposition. In vitro studies demonstrate that native apoE2 and E3 form an SDS-stable complex with Abeta(1-40), while apoE4 forms little such complex. Our current work extends these observations by presenting evidence that apoE3 also binds to Abeta(1-42) and with less avidity to modified species of the peptide found in senile plaque cores. These modified peptides include a form that originates at residue 3-Glu as pyroglutamyl and another with isomerization at the 1-Asp and 7-Asp positions. In addition, we used binding reactions between apoE3 and various Abeta fragments, as well as binding reactions with apoE3 and Abeta(1-40) plus Abeta fragments as competitors, to identify the domain(s) of Abeta involved in the formation of an SDS-stable complex with apoE3. Residues 13-28 of Abeta appear to be necessary, while complex formation is further enhanced by the presence of residues at the C-terminus of the peptide. These results contribute to our understanding of the biochemical basis for the SDS-stable apoE3/Abeta complex and support the hypothesis that Abeta can be transported in vivo complexed with apoE. This complex may then be cleared from the interstitial space by apoE receptors in the brain or become part of an extracellular amyloid deposit.
Biochemistry 01/2001; 39(51):16119-24. DOI:10.1021/bi0017475 · 3.02 Impact Factor
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ABSTRACT: To determine the in vitro effectiveness of the Amplatz and Rotarex catheters for thrombus fragmentation and combined thrombus fragmentation and aspiration.
Clots (n = 100) from 5-day-old porcine blood (8.5 g) were fragmented with the 8F Rotarex trade mark catheter (RR; 40.000 rpm), which was directed with or without a coaxial guide wire (GW 0.020 inch [8 F RR(GW)], GW 0.014 inch [6 F RR(GW)]), and with the 7 F Amplatz catheter (ATD; 150.000 rpm), in an artery flow model (pulsed flow of 700 ml/min) simulating the superficial femoral artery. To increase the wall adherence of the thrombus, an additional equal number of silicon tubes (with an inner diameter of 7 mm) were fitted inside with a metallic mesh (wall-adherent thrombus [WAT]; 6 F RR(WAT), 8 F RR(WAT), 6 F R(WAT-GW), 8 F RR(WAT-GW), ATD(WAT) ). The effluent was passed through a three-step filter system (10 to 1000 micro m; pressure gradient 35 mmHg).
Highest effectiveness was found for 8 F RR (no remaining thrombus detectable) compared to 6 F RR (0.08 g) and ATD (0.07 g), with a p < 0.001 for both methods. The aspirated volume was significantly lower when 6 F and 8 F RR were used with a coaxial guide wire (p < 0.001). The total emboli rate for 8 F RR was significantly lower compared to ATD (p < 0.001). Even when working without a guide wire, 8 F RR caused the lowest proportion of emboli (depending on the modification 0.12 % to 1.76 %; compared to all p < 0.05). Emboli rates reached 7.99 % for 6 F RR (compared to all p < 0.001) and were maximal 5.61 % for ATD.
The tested mechanical thrombectomy catheters have a high potential for in vitro thrombectomy with moderate performance differences. In contrast to the guidewire-directed Rotarex fragmentation-aspiration device, the ATD trade mark fragmentation catheter and prototype Rotarex 6 F catheter have a considerable peripheral embolization rate of particles larger than 1000 micro m, probably requiring additional measures for in vivo thrombectomy.
RöFo - Fortschritte auf dem Gebiet der R 03/2003; 175(3):406-12. DOI:10.1055/s-2003-37829 · 1.40 Impact Factor
Techniques in Vascular and Interventional Radiology 04/2003; 6(1):2-5. DOI:10.1053/tvir.2003.36442
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