To investigate the causes and strategy of difficult intraarterial mechanical thrombectomy (≥3 times) in patients with acute ischemic stroke (AIS).

The clinical data of 8 cases of AIS with thrombectomy ≥3 times admitted in Department of Neurology, the 306^th Hospital of People's Liberation Army from June to October in 2015 was analyzed retrospectively. There were 7 male and 1 female patients, aged from 38 to 86 years with an average age of (70±15) years, in which 5 cases were cardiogenic cerebral embolism and 3 cases were large artery atherosclerotic infarction. The National Institute of Health stroke scale (NIHSS) score (M (Q_R)) was 16 (12) before procedure and modified thrombolysis in cerebral infarction (mTICI)score were 0 in all the patients. Solitaire AB was used in thrombectomy in the occlusion of the arteries.

The causes of difficult intraarterial thrombectomy included multiple thrombus, tortuosity in vascular paths, guiding catheter being placed below the internal carotid artery siphon leading to weak strength of suction and support of stent, embolus dropping in the thrombectomy and inadequate anesthesia. After successful thrombectomy 3 cases had mTICI score of 2a, 4 cases of 2b, 1 case of 3. The NIHSS score was 5 (24) at 7^th day after treatment. At the 90-day follow-up 5 patients had good prognosis (modified Rankin score 0 to 2) and 3 had disability (modified Rankin score 3 to 4).

Cases of AIS with difficult intraarterial thrombectomy can be treated by improving thrombectomy materials and technique, reasonable anesthesia and perioperative medication in decision-making strategy.

Stroke; Endovascular procedures; Thrombectomy