Cerebrovascular Pressure Restoration Rates during Recanalisation with Aspiration and Stent-Retriever Thrombectomy for Acute Ischaemic Stroke: An in Vitro Study.

OBJECTIVE

Mechanical thrombectomy alters cerebrovascular hemodynamics in ways that remain poorly characterized. This in vitro study investigated the pressure restoration rate (PRR), a quantitative measure of how quickly pressure returns to baseline in an occluded vessel, during thrombectomy using aspiration and stent-retriever devices in different cerebrovascular anatomical configurations.

METHODS

A cerebrovascular glass model with pulsatile flow was constructed to simulate good (symmetrically connected) and poor (unilateral) collateral anatomy. Pressure sensors were integrated into the system to record hemodynamic responses during thrombectomy procedures using SOFIA 5F and 6F aspiration catheters (Terumo Neuro, Aliso Viejo, CA, USA) and a Solitaire 6 × 30-mm stent retriever (Medtronic, Irvine, CA, USA). PRR was calculated in the middle cerebral artery at a 5-ms resolution and compared across devices and anatomical variants using Kruskal-Wallis tests.

RESULTS

Aspiration thrombectomy exhibited significantly higher PRRs than the stent-retriever thrombectomy across both good and poor collateral models (p <0.05). Median PRRs were 17.9 μmmHg/5 ms (SOFIA 5F), 13.5-14.3 μmmHg/5 ms (SOFIA 6F), and 0.8-1.3 μmmHg/5 ms (stent retriever). Aspiration was associated with a rapid, near-instantaneous return to baseline pressure, whereas stent-retriever thrombectomy produced a more gradual restoration with a plateau phase followed by a lower magnitude instantaneous return. Momentary reciprocal pressure fluctuations were also observed in neighboring vessels during clot removal.

CONCLUSION

This study demonstrates that thrombectomy induces different hemodynamic flow return patterns in the targeted vessel, with technique-specific PRR values. High PRRs, particularly with aspiration, may subject compromised cerebral vessels to potentially injurious pressure surges during reperfusion. These findings suggest a possible mechanistic link between device-technique modality and complications such as hemorrhagic transformation, warranting further investigation in clinical settings.