title: Risk factors for neurological worsening and symptomatic watershed infarction in internal carotid artery aneurysm treated by extracranial-intracranial bypass using radial artery graft.
abstract: OBJECT The revascularization technique, including bypass created using the external carotid artery (ECA), radial artery (RA), and M2 portion of middle cerebral artery (MCA), has remained indispensable for treatment of complex aneurysms. To date, it remains unknown whether diameters of the RA, superficial temporal artery (STA), and C2 portion of the internal carotid artery (ICA) and intraoperative MCA blood pressure have influences on the outcome and the symptomatic watershed infarction (WI). The aim of the present study was to evaluate the factors for the symptomatic WI and neurological worsening in patients treated by ECA-RA-M2 bypass for complex ICA aneurysm with therapeutic ICA occlusion. METHODS The authors measured the sizes of vessels (RA, C2, M2, and STA) and intraoperative MCA blood pressure (initial, after ICA occlusion, and after releasing the RA graft bypass) in 37 patients. Symptomatic WI was defined as presence of the following: postoperative new neurological deficits, WI on postoperative diffusion-weighted imaging, and ipsilateral cerebral blood flow reduction on SPECT. Neurological worsening was defined as the increase in 1 or more modified Rankin Scale scores. First, the authors performed receiver operating characteristic curve analysis for continuous variables and the binary end point of the symptomatic WI. The clinical, radiological, and physiological characteristics of patients with and without the symptomatic WI were compared using the log-rank test. Then, the authors compared the variables between patients with and without neurological worsening at discharge and at the 12-month follow-up examination or last hospital visit. RESULTS Symptomatic WI was observed in 2 (5.4%) patients. The mean MCA pressure after releasing the RA graft (< 55 mm Hg; p = 0.017), mean (MCA pressure after releasing the RA graft)/(initial MCA pressure) (< 0.70 mm Hg; p = 0.032), and mean cross-sectional area ratio ([RA/C2 diameter](2) < 0.40 mm [p < 0.0001] and [STA/C2 diameter](2) < 0.044 mm [p < 0.0001]) were related to the symptomatic WI. All preoperatively independent patients remained independent (modified Rankin Scale score < 3). After adjusting for age and sex, left operative side (p = 0.0090 and 0.038) and perforating artery ischemia (p = 0.0050 and 0.022) were related to neurological worsening at discharge (11 [29%] patients) and at the 12-month follow-up or last hospital visit (8 [22%] patients). CONCLUSIONS Results of the present study showed that the vessel diameter and intraoperative MCA pressure had impacts on the symptomatic WI and that operative side and perforating artery ischemia were related to neurological worsening in patients with complex ICA aneurysms treated by ECA-RA-M2 bypass.
authors.affiliation: Department of Neurosurgery, Stroke Center, Teishinkai Hospital, Sapporo; and.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Matsukawa
authors.affiliation: Department of Neurosurgery, Stroke Center, Teishinkai Hospital, Sapporo; and.
authors.forename: Rokuya
authors.initials: R
authors.lastname: Tanikawa
authors.affiliation: Department of Neurosurgery, Stroke Center, Teishinkai Hospital, Sapporo; and.
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Kamiyama
authors.affiliation: Department of Neurosurgery, Stroke Center, Teishinkai Hospital, Sapporo; and.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Tsuboi
authors.affiliation: Department of Neurosurgery, Stroke Center, Teishinkai Hospital, Sapporo; and.
authors.forename: Kosumo
authors.initials: K
authors.lastname: Noda
authors.affiliation: Department of Neurosurgery, Stroke Center, Teishinkai Hospital, Sapporo; and.
authors.forename: Nakao
authors.initials: N
authors.lastname: Ota
authors.affiliation: Department of Neurosurgery, Stroke Center, Teishinkai Hospital, Sapporo; and.
authors.forename: Shiro
authors.initials: S
authors.lastname: Miyata
authors.affiliation: Department of Neurosurgery, Stroke Center, Teishinkai Hospital, Sapporo; and.
authors.forename: Jumpei
authors.initials: J
authors.lastname: Oda
authors.affiliation: Department of Neurosurgery, Stroke Center, Teishinkai Hospital, Sapporo; and.
authors.forename: Rihee
authors.initials: R
authors.lastname: Takeda
authors.affiliation: Department of Neurosurgery, Stroke Center, Teishinkai Hospital, Sapporo; and.
authors.forename: Sadahisa
authors.initials: S
authors.lastname: Tokuda
authors.affiliation: Department of Neurosurgery, Asahikawa Medical University, Asahikawa, Japan.
authors.forename: Kyousuke
authors.initials: K
authors.lastname: Kamada
mesh_terms: D000783:Aneurysm / Q000601:surgery*; D002545:Brain Ischemia / Q000209:etiology*; D002340:Carotid Artery Diseases / Q000601:surgery*; D002343:Carotid Artery, Internal; D002548:Cerebral Revascularization / Q000379:methods*; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D011183:Postoperative Complications / Q000209:etiology*; D017534:Radial Artery / Q000637:transplantation*; D012189:Retrospective Studies; D012307:Risk Factors
keywords: EC-IC = extracranial-intracranial; EC-IC bypass; ECA = external carotid artery; ICA = internal carotid artery; IQR = interquartile range; MCA = middle cerebral artery; PCoA = posterior communicating artery; RA = radial artery; STA = superficial temporal artery; WI = watershed infarction; mRS = modified Rankin Scale; neurological worsening; symptomatic watershed infarction; vascular disorders