Treatment Methods and Early Neurologic Improvement After Endovascular Treatment of Tandem Occlusions in Acute Ischemic Stroke

Background and Purpose: A tandem occlusion of the intracranial circulation and the extracranial carotid artery (ICA) occurs in 10-20% of all strokes based on large vessel occlusion (LVO). The optimal treatment strategy for those patients is unknown. We report our management strategy and the outcome in these patients in a large single-center cohort. Materials and Methods: We retrospectively analyzed all patients treated by Mechanical Thrombectomy (MT) for an intracranial LVO associated to an occlusion of the extracranial ICA between April 2009 and May 2016. The following data were collected: Recanalization rate (mTICI IIb and III), clinical result including early neurological improvement (ENI, NIHSS score improvement of ≥ 8 points after 24 hours or NIHSS score of 0 or 1 after 3 days) and functional outcome during long term follow up. Secondary endpoints were the patency of the internal carotid artery at 24 hours and the rate of symptomatic hemorrhage. Patient demographics and antiaggregation regimen were recorded as co-variables. Results: 163/1645 (9.9%) MT patients had a tandem occlusion. All thrombectomy procedures were performed with stent retrievers. PTA without additional placement of a stent was achieved in 14 patients, additional placement of a stent was achieved in 149 patients. The overall rate of mTICI IIB/III recanalization was 91.4%. An early neurological improvement was found in 79 of 163 patients (48.4%), respectively 51% (76/149) and 21% (3/14) in the Stent vs non Stent group. 120/163 patients (73.6 %) had a late favorable outcome (mRS 0-2). The ICA reocclusion rate at 24 hours was respectively 5.4 % (8/149) and 42% (6/14) in the Stent vs non Stent group. The rate of symptomatic hemorrhage was 4.9%. Younger age (p=0.002) and shorter recanalization times (p=0.017) were associated with good outcome. Conclusion: Stent-PTA of the ICA in addition to MT with a stent retriever was safe and effective in tandem occlusion of the anterior brain circulation. PTA and MT without stenting in tandem lesions showed a higher early re-occlusion rate and lower rate of early neurological improvement. The technical approach should aim the fastest possible recanalization of the intracranial vessels, either with stenting first or last.