Comparative Analysis of Cyclic and Standard Aspiration in Acute Ischemic Stroke

Thrombo‐aspiration for acute ischemic stroke is typically performed by generating a constant vacuum with a syringe or an electronic pump. The advent of cyclic aspiration technology, which combines high frequency pulsed vacuum forces, is thought to significantly improve the efficiency of the thrombo‐aspiration technique. Recent studies have reported the benefits of retrieving clots with cyclic aspiration techniques both pre‐clinically and in humans. This systematic literature review aims to compare the procedural outcomes of standard aspiration techniques to cyclical aspiration in both pre‐clinical and clinical settings respectively. A systematic literature review of cyclic vs standard aspiration techniques published by August 2025 was conducted using PubMed and Cochrane databases on the Nested Knowledge platform, where pre‐clinical studies needed to include both arms (static and cyclic), while clinical studies need only include a cyclic arm. Data was extracted on procedural efficacy and safety outcomes and compared across the cohorts. The primary outcome was a comparison of first pass recanalization (FPR) rates defined as mTICI 2c‐3 in one pass clinically or complete clot removal in one pass on the bench. Cyclic vs standard results were compared using a Welch's t‐test, where possible. Then the results of pre‐clinical rates of cyclic aspiration were compared to clinical outcomes as a measure of reliability for pre‐clinical testing to predict clinical outcomes. Out of 963 articles screened, 9 pre‐clinical and 3 clinical articles were identified and included in the analysis. All pre‐clinical studies were in vitro bench‐top studies (n=542 experimental passes) using a variety of tough clot models, and all clinical studies were in humans with large vessel occlusions (n=96), 2 of them using a cyclic pump and 1 with a manual syringe mechanism. In the pre‐clinical studies, FPR trended higher with cyclic compared to standard aspiration techniques (84.7±8.6% vs 45±20.1%, p=0.33). Similarly, in the clinical studies, FPR trended higher with cyclic compared to historical standard aspiration techniques (63.7±6.5% vs 33.3±5.3%, p=0.69). Clinical FPR was approximately 35% lower than bench FPR for both standard (33% vs 45%) and cyclic (64% vs 85%) aspiration groups. Further, FPR outcomes were nearly twice as high due to cyclic vs standard aspiration in pre‐clinical studies (89% increase) and clinical studies (94% increase), suggesting a high ability for pre‐clinical studies to predict improvements clinically. The pre‐clinical total emboli count was lower with cyclic vs standard aspiration (9.9 [‐4.6, 24] vs 20.5 [1.17, 39.9]). Similarly, the clinical rate of embolization to new territories (ENT) was lower with cyclic compared to standard aspiration (1.8% vs 2.5%). The median number of attempts to achieve recanalization were comparable pre‐clinically (1.2 vs 1.6) and clinically (2.0 vs 1.5) for cyclic vs standard aspiration techniques. Cyclic aspiration is associated with more favourable procedural efficacy and safety outcomes across both pre‐clinical and clinical cohorts. Although the pre‐clinical evidence reported non‐significant higher rates of FPE and emboli compared to clinical data, the additional benefit of cyclic aspiration reasonably predicted the clinical outcomes. Therefore, these data are indicative of a reliable pre‐clinical predictive model for cyclic aspiration procedural outcomes in the clinic.