Comparison of in vitro effectiveness of mechanical thrombectomy devices

To determine the in vitro efficacy of clot removal of the following hydrodynamic thrombectomy devices: the AngioJet (AJ), Hydrolyser (HL), Oasis (OS), and Amplatz Thrombectomy Device (ATD). All devices have 6-F catheters.

Thrombectomy of 5-day-old porcine clots (n = 68; 8.5 g) was performed with the AJ without a guide wire [AJ(gw0)], with a coaxial 0.016-inch guide wire [AJ(gw.016)], and with a 0.035-inch guide wire [AJ(gw.035)]), and with the HL, OS, and ATD in an artery flow model (pulsed flow: 700 L/min) simulating the superficial femoral artery (7-mm inner tube diameter). The effluent was passed through a three-step filter system (10-1,000 microm; pressure drop: 35 mm Hg).

Mean thrombectomy time ranged from 49 seconds (AJ(gw0)) to 88 seconds (OS; P < .001). The fluid balance with use of the AJ(gw.035) was 0.89, whereas the mean ratio of applied saline solution to aspirated fluid for the other devices was not isovolumetric (AJ(gw0), 0.8; AJ(gw.016), 0.78; HL, 0.73; OS, 0.62; P < .05). Remaining thrombus ranged in size from 8.2 mg (AJ(gw0)) to 27.3 mg (AJ(gw.035); P = .079). Hydrodynamic devices (0.6% [OS] to 0.98% [AJ(gw.016)]) caused low amounts of added emboli greater 10 microm, 100 microm, and 1,000 microm. The ATD (5.19%) caused the most extensive embolization (P < .001).

The tested mechanical thrombectomy devices have the power for sufficient thrombectomy in vitro; however, they showed moderate differences in performance. In contrast to hydrodynamic devices, the ATD fragmentation device showed a higher peripheral embolization rate of particles larger than 1,000 microm; adjunctive in vivo treatment would probably be required.