Cyclic Aspiration in Mechanical Thrombectomy: Influencing Factors and Experimental Validation

ABSTRACT

BACKGROUND AND PURPOSE:

Mechanical thrombectomy is a fundamental intervention for acute ischemic stroke treatment. While conventional techniques are effective, cyclic aspiration (CyA) shows potential for better recanalization rates. We aim to investigate factors affecting CyA and compare them with static aspiration (StA).

MATERIALS AND METHODS:

StA setup consisted of an aspiration pump connected to pressure transducer. CyA was tested with five subsequent iterations: single solenoid valve with air+saline (1) or saline alone (2) as aspiration medium; two solenoid valves with air+saline (3) as aspiration medium; complete air removal and saline feeding (4); pressurized saline feeding (5). To assess the efficacy of clot ingestion, the pressure transducer was replaced with a distal aspiration catheter. Moderately stiff clot analogs (15 mm) were used to investigate the ingestion quantified as clot relative weight loss. Additionally, the aspiration flow rate was assessed for each setup.

RESULTS:

With CyA setup 1, the amplitude of the achieved negative pressure waves declined with increasing frequencies but progressively increased with each subsequent iteration, achieving a maximum amplitude of 81 kPa for setup 5 at 1Hz. Relative clot weight loss was significantly higher with setup 5 at 5Hz than with StA (100% vs. 37,8%; p=0.05). Aspiration flow rate was lower with CyA than with StA (setup 5 at 5Hz: 199,8ml/min vs. StA: 311ml/min; p<0.01).

CONCLUSIONS:

Cyclic aspiration with the appropriate setup may represent an encouraging innovation in mechanical thrombectomy, offering a promising pathway for improving efficacy in clot ingestion and recanalization. The observed benefits warrant confirmation in a clinical setting. ABBREVIATIONS: CyA -cyclic aspiration, StA – static aspiration, FPR -first pass reperfusion, MT -mechanical thrombectomy, DAC -distal aspiration catheter, LVO -large vessel occlusion.