The superiority of mechanical thrombectomy (MT) in patients with acute ischemic stroke from large vessel occlusion compared to standard medical therapy alone has been demonstrated by several randomized clinical trials and become the standard of care for these patients. A direct aspiration first pass technique (ADAPT) for the endovascular treatment of stroke using a large-bore catheter has been reported to be an effective method of achieving MT. Recent studies reported that ADAPT is as efficient and safe as stent retrievers, with a similar successful recanalization rate, but may have better functional outcomes, fewer procedure related-adverse events, and a tendency for faster revascularization compared to the stent-retriever thrombectomy.

However, navigation of a large-bore aspiration catheter is not always possible due to unsuccessful passage of the ophthalmic artery origin ("ledge effect") or tortuous vascular anatomy. The coaxial technique comprises guiding the large-bore catheter with a smaller inner catheter and can facilitate distal access. However, there is a gap between the inner catheter and the distal tip of the large-bore outer catheter that creates a risk of damaging the vessel wall and causing dissection or subarachnoid hemorrhage. Even with this coaxial technique, it is not always possible to reach the clot site with the large-bore catheter. To decrease the gap between the two catheters, several authors have used, in place of the inner microcatheter, a compliant balloon catheter positioned and inflated at the distal tip of the large-bore catheter. The aim of the present study was to evaluate the safety and efficacy of ADAPT assisted by a compliant balloon (ADAPT-AB) when ADAPT using the coaxial technique fails to reach the clot site.

Inclusion Criteria:

• Endovascular therapy were large arterial occlusions proven by MR angiography,
• Alberta Stroke Program Early CT Score (ASPECTS) >5 on MRI,
• Baseline National Institutes of Health Stroke Scale (NIHSS) score >5.

If eligible, patients received intravenous thrombolysis (IVT).

Exclusion criteria:

- Vertebro-basilar occlusion

All patients who underwent an endovascular procedure for acute stroke in a single center from November 2018 to February 2020 were included in the study