Mechanical Thrombectomy in Acute Stroke Due to Carotid Occlusion: A Series of 153 Consecutive Patients

Strokes due to carotid artery occlusion (CAO) are associated with bad clinical prognosis and poor response to intravenous thrombolysis. Several studies in the past have shown the benefits of mechanical thrombectomy (MT) and compared bridging therapy (BT) and primary MT (PMT) in large vessel occlusions, but only a few studies have focused on the specific population of CAO and their response to endovascular treatment.

Retrospective review of patients treated at our center between January 2010 and June 2017 that (1) presented with acute ischemic stroke caused by CAO in the first 4.5 h since symptom onset, and (2) were treated with MT (BT or PMT). Baseline characteristics of the population, comparison between BT and PMT, intrahospital mortality, symptomatic intracranial hemorrhage, and functional outcome were investigated.

A total of 153 patients were included. Baseline characteristics: 51.6% were male, and the median age was 71 years. The most frequent risk factor was hypertension (71.9%). The main stroke etiology was atherothrombotic (40.5%). The mean admission National Institute of Health Severity Score (NIHSS) was 19, mean discharge NIHSS was 7. Isolated occlusion of the Extracranial or Intracranial Internal Carotid Artery was the most frequent occlusion location (52.3%). TICI 2b-3 was achieved in 87.6%, intrahospital mortality was 26.8%, symptomatic hemorrhage was 8.5%, and 3 months-modified Rankin Score (mRS) 0-2 was 26.8%. Definitive carotid stenting was needed in 33.3% of the cases. BT versus PMT: Patients treated with PMT presented a higher incidence of atrial fibrillation, anticoagulation, and cardioembolic stroke compared to those treated with BT. No differences in TICI 2b-3, 3 months-mRS or symptomatic hemorrhage were found between both groups. Intrahospital mortality: Poor perfusion-CT mismatch (p = 0.005), isolated Internal carotid artery location (p = 0.024), and symptomatic hemorrhage (p < 0.001) were independent predictors. Symptomatic intracranial hemorrhage: Patients with post-treatment symptomatic hemorrhage had higher intrahospital mortality (p < 0.001) and worse 3 months-mRS (p = 0.033). Functional outcome: Admission NIHSS (p = 0.012) independently predicted 3 months-mRS.

In our population, patients with CAO clinically present with severe strokes. Isolated occlusions of the extra- or intracranial segments of the carotid are more frequent than tandem occlusions. Successful recanalization after thrombectomy is achieved in most of the patients, but association with favorable functional outcome is poor. Clinical evolution is similar in patients treated with PMT and BT. Intracranial symptomatic hemorrhage after treatment is associated with higher intrahospital mortality and worse 3 months-mRS. Poor perfusion-CT mismatch, symptomatic hemorrhage, and isolated CAO are independent predictors of intrahospital mortality. Admission NIHSS is an independent predictor of 3 months-mRS.