Risk of subsequent stroke, with or without extracranial-intracranial bypass surgery: a nationwide, retrospective, population-based study

Abstract

OBJECTIVE Although no benefits of extracranial-intracranial (EC-IC) bypass surgery in preventing secondary stroke have been identified previously, the outcomes of initial symptomatic ischemic stroke and stenosis and/or occlusion among the Asian population in patients with or without bypass intervention have yet to be discussed. The authors aimed to evaluate the subsequent risk of secondary vascular disease and cardiac events in patients with and without a history of this intervention. METHODS This retrospective nationwide population-based Taiwanese registry study included 205,991 patients with initial symptomatic ischemic stroke and stenosis and/or occlusion, with imaging data obtained between 2001 and 2010. Patients who underwent EC-IC bypass (bypass group) were compared with those who had not undergone EC-IC bypass, carotid artery stenting, or carotid artery endarterectomy (nonbypass group). Patients with any previous diagnosis of ischemic or hemorrhagic stroke, moyamoya disease, cancer, or trauma were all excluded. RESULTS The risk of subsequent ischemic stroke events decreased by 41% in the bypass group (adjusted hazard ratio [HR] 0.59, 95% CI 0.46-0.76, p < 0.001) compared with the nonbypass group. The risk of subsequent hemorrhagic stroke events increased in the bypass group (adjusted HR 2.47, 95% CI 1.67-3.64, p < 0.001) compared with the nonbypass group. CONCLUSIONS Bypass surgery does play an important role in revascularization of the ischemic brain, while also increasing the risk of hemorrhage in the early postoperative period. This study highlights the fact that the high risk of bypass surgery obscures the true benefit of revascularization of the ischemic brain and also emphasizes the importance of developing improved surgical technique to treat these high-risk patients.

Quantitative Angiographic Hemodynamic Evaluation After Revascularization Surgery for Moyamoya Disease

“…Our previous studies compared the long-term postoperative neurofunctional outcomes of different revascularization strategies and suggested that direct bypass was more effective in preventing recurrent ischemic strokes than indirect bypass for ischemic MMD, although neurological function outcomes were similar [40][41][42]. However, the treatment options for hemorrhagic MMD remain controversial [17,43,44]. The mechanisms underlying hemorrhagic MMD have not been deeply understood and involve interactions between hemodynamic stress and thin arterial walls.…”

Stroke and osteoporosis: a Taiwan cohort study

“…Procedures of craniotomy or craniectomy were evaluated as severity of stroke. Stroke subtypes were classified into haemorrhagic stroke (ICD-9-CM codes 430–432; 430 subarachnoid haemorrhage, 431–432 intracerebral and other intracranial haemorrhage),16 17 ischaemic stroke (ICD-9-CM codes 433–436 excluding 433.x0) 18–20. Individuals with osteoporosis identified with a history of osteoporosis (ICD-9-CM code 733.0 or 733.1) or osteoporotic fractures, including vertebral fractures (ICD-9-CM code 805.2–805.9), humeral fracture (ICD-9-CM code 812), wrist fractures (ICD-9-CM code 813) and hip fractures (ICD-9-CM code 820)21 diagnosed before the index date, those with missing information and those aged younger than 50 years were excluded.…”

Extracranial-intracranial bypass surgery for occlusive atherosclerotic disease of the anterior cerebral circulation: protocol for a systematic review and meta-analysis

“…Therefore, EC-IC bypass surgery may be effective in stroke prevention [22,[27][28][29][30], but was hypothesized to benefit only hemodynamically compromised patients [17,21]. In addition, a high risk of hemorrhage stroke was observed in the early postoperative period, which may obscure the true benefit of revascularization of the ischemic brain [31].…”