Introduction: Superficial temporal artery to middle cerebral artery (STA-MCA) bypass is a technically reliable technique, however studies for stroke prevention have failed to demonstrate benefit. The situation of subacute stroke when a patient survives a large vessel occlusion but is reliant on leptomeningeal collaterals with a fluctuating exam may represent a population who could benefit from bypass.
Methods: We retrospectively reviewed cases of STA-MCA bypass performed after acute ischemic stroke to determine who may be considered for this procedure. We considered only cases performed after our center began offering routine thrombectomy coverage in 2015.
Results: 5 patients were identified with acute stroke and LVO. Only one of these patients met thrombectomy criteria and she was taken for successful thrombectomy. The patient had underlying M1 stenosis thought to be atherosclerotic which later re-occluded. Other cases excluded for thrombectomy were as follows: one ICA occlusion with only minor initial deficits (NIHSS 2), one bifrontal watershed stroke with moya-moya like proximal occlusion, one bilateral MCA occlusion with drug overdose, and one patient with known M1 stenosis presented outside the time window. All patients had small to moderate infarction on MRI and some degree of fluctuating neurologic exam and so were taken for STA-MCA bypass. All bypasses were open on immediate post op imaging or Doppler and all patient’s exams stabilized without new deficit.
Conclusions: Select patients with fluctuating exam and LVO (ICA/M1) may be considered for acute STA-MCA bypass if not a candidate for thrombectomy. In cases of occluded known intracranial atherosclerotic stenosis, bypass may represent a lower risk alternative to angioplasty and stenting. With recent dramatic advances in mechanical thrombectomy, more patients with ischemic stroke are being considered for intervention and so this group of subacute stroke patients will likely continue to grow.
Patient Care: This technique may offer an additional option for patients to prevent progression of acute stroke.
Learning Objectives: 1) Identify patients with large vela occlusion who may be considered for EC-IC bypass
2) Describe the theoretical advantages of EC-IC bypass in M1 occlusion from atherosclerotic stenosis.