In vitro effectiveness study for hydrodynamic thrombectomy devices of the second generation

To determine the efficacy of clot removal and the amount of applied saline and aspirated fluid and to compare procedure-related particle embolization for the hydrodynamic thrombectomy devices the LF 140 Angiojet (LF 140), the double-lumen Hydrolyser (double HL), and the triple-lumen Hydrolyser (triple HL) in an in vitro flow model.

Thrombectomy of clots (n = 42) from 7-day-old porcine blood (9.8 g) was performed with the LF 140, the double HL, and the triple HL in a flow model (flow 1 L/min) made of silicone tubes (7 mm inner tube diameter). All catheters were used according to the manufacturer's recommendations.

Mean time of thrombectomy ranged from 20 seconds (triple HL) to 58 seconds (LF 140, P < 0.05). Only for the triple HL was remaining thrombus found within the tubes (41 mg). None of the tested devices worked isovolumetrically: the mean ratio of applied saline and aspirated fluid for the devices ranged from 0.79 (triple HL) to 0.89 (double HL, P < 0.05). Mean embolus weight and percentage of embolism from original thrombus were 675 mg/6.7% (LF 140, P < 0.05), 38 mg/0.4% (double HL), and 26 mg/0.3% (triple HL).

Thrombectomy time and embolus weight depend on the device chosen. The ratio of applied to aspirated fluid, indicating the capability to work nearly isovolumetrically, is acceptable for all tested devices. In vitro, the triple HL seems to be the most appropriate device for rapid mechanical, hydrodynamic thrombectomy. Because of the high in vitro particle embolization rate, the LF 140 seems to be strictly limited to small-caliber vessels.