Mechanical Thrombectomy for M2 Occlusions: A Single-Centre Experience

The recent success of several mechanical thrombectomy trials has resulted in a significant change in the management of patients presenting with stroke. However, questions still remain as to whether certain groups will benefit from mechanical thrombectomy. In particular, it is still uncertain whether mechanical thrombectomy should be performed in the M2 branches and, more generally, in the distal vasculature.

We retrospectively analysed our prospectively maintained database of all patients undergoing mechanical thrombectomy between January 2008 and August 2016. We collected demographic, radiological, procedural and outcome data.

We identified 106 patients that met our inclusion criteria. The mean age of the patients was 68 ± 13.8 years, and there were 58 (54.7%) male patients. Associated medical conditions were common with hypertension seen in 71% of the patients. The average Alberta Stroke Program Early CT (ASPECT) score on admission was 8.5 ± 1.7. The mean National Institutes of Health Stroke Scale score was 11.8 ± 7.02. The mean duration of the procedure was 103 ± 3.4 min, and the average number of thrombectomy attempts required was 1.8 (range 1-8). Angiographically, Thrombolysis in Cerebral Infarction Scale (TICI) ≥2b was obtained in 90.5% of the patients. Five patients (4.7%) had symptomatic intracranial haemorrhage on follow-up. At 90-day follow-up, 54.6% of the patients had a modified Rankin Scale (mRS) score 0-2, and 71.5% had an mRS score ≤3. There were 15 deaths at 90 days (14.1%).

Mechanical thrombectomy in patients with solitary M2 clots is technically possible and carries a high degree of success with a good safety profile. Patients with confirmed M2 occlusion should be considered for mechanical thrombectomy.