The Experts below are selected from a list of 201 Experts worldwide ranked by ideXlab platform
Shiro Ohue - One of the best experts on this subject based on the ideXlab platform.
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quantitative evaluation of mean transit times obtained with dynamic susceptibility contrast enhanced mr imaging and with 133xe spect in Occlusive Cerebrovascular Disease
American Journal of Roentgenology, 2002Co-Authors: Keiichi Kikuchi, Yoshifumi Sugawara, Kenya Murase, Hitoshi Miki, Yoshifumi Yasuhara, Teruhito Mochizuki, Junpei Ikezoe, Shiro OhueAbstract:OBJECTIVE: We report on quantitative mean transit time images obtained using dynamic susceptibility contrast-enhanced MR imaging after an IV bolus injection of a contrast agent. Our study compared cerebral hemodynamics measured using dynamic susceptibility contrast-enhanced MR imaging with the cerebral perfusion reserve obtained using dynamic (133)Xe single-photon emission computed tomography (SPECT). SUBJECTS AND METHODS: Seventeen patients with chronic cerebral artery occlusion or stenosis diagnosed by digital subtraction angiography were examined. Dynamic susceptibility contrast-enhanced MR imaging data were acquired using a multishot echoplanar sequence. Our procedure for quantification of mean transit time was based on the indicator dilution theory and deconvolution analysis. RESULTS: The increased mean transit time values obtained with dynamic susceptibility contrast-enhanced MR imaging correlated well (r=-0.789, p < 0.0001) with decreased cerebral perfusion reserve determined by performing dynamic (133)Xe SPECT before and after administration of acetazolamide. The mean transit time values in the regions with severely decreased perfusion reserve were significantly higher than those in the regions with normal or moderately decreased perfusion reserve (p < 0.0001 and p = 0.0004, respectively). CONCLUSION: Mean transit time images generated from dynamic susceptibility contrast-enhanced MR imaging data could be used to evaluate the extent of cerebral perfusion reserve impairment in patients with Occlusive Cerebrovascular Disease.
Keiichi Kikuchi - One of the best experts on this subject based on the ideXlab platform.
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quantitative evaluation of mean transit times obtained with dynamic susceptibility contrast enhanced mr imaging and with 133xe spect in Occlusive Cerebrovascular Disease
American Journal of Roentgenology, 2002Co-Authors: Keiichi Kikuchi, Yoshifumi Sugawara, Kenya Murase, Hitoshi Miki, Yoshifumi Yasuhara, Teruhito Mochizuki, Junpei Ikezoe, Shiro OhueAbstract:OBJECTIVE: We report on quantitative mean transit time images obtained using dynamic susceptibility contrast-enhanced MR imaging after an IV bolus injection of a contrast agent. Our study compared cerebral hemodynamics measured using dynamic susceptibility contrast-enhanced MR imaging with the cerebral perfusion reserve obtained using dynamic (133)Xe single-photon emission computed tomography (SPECT). SUBJECTS AND METHODS: Seventeen patients with chronic cerebral artery occlusion or stenosis diagnosed by digital subtraction angiography were examined. Dynamic susceptibility contrast-enhanced MR imaging data were acquired using a multishot echoplanar sequence. Our procedure for quantification of mean transit time was based on the indicator dilution theory and deconvolution analysis. RESULTS: The increased mean transit time values obtained with dynamic susceptibility contrast-enhanced MR imaging correlated well (r=-0.789, p < 0.0001) with decreased cerebral perfusion reserve determined by performing dynamic (133)Xe SPECT before and after administration of acetazolamide. The mean transit time values in the regions with severely decreased perfusion reserve were significantly higher than those in the regions with normal or moderately decreased perfusion reserve (p < 0.0001 and p = 0.0004, respectively). CONCLUSION: Mean transit time images generated from dynamic susceptibility contrast-enhanced MR imaging data could be used to evaluate the extent of cerebral perfusion reserve impairment in patients with Occlusive Cerebrovascular Disease.
Akitake Mukasa - One of the best experts on this subject based on the ideXlab platform.
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cortical venous reddening predicts remote cerebral infarction post superficial temporal artery middle cerebral artery bypass in atherosclerotic Occlusive Cerebrovascular Disease
World Neurosurgery, 2019Co-Authors: Kenyu Hayashi, Ken Uekawa, Takayuki Kawano, Yuki Ohmori, Toshihiro Amadatsu, Yushin Takemoto, Akitake MukasaAbstract:Background The superficial temporal artery (STA)–middle cerebral artery (MCA) anastomosis (STA-MCA bypass) currently is performed to prevent atherosclerotic Occlusive Cerebrovascular Disease. However, the benefits of the bypass surgery remain controversial. To ensure consistent surgical benefits, understanding the mechanisms of perioperative cerebral infarction (CI) is required. Moreover, appropriate patient selection procedures must be determined to decrease the rate of perioperative stroke. We retrospectively investigated patients who underwent bypass surgery at our institution and determined that the patients who presented with cortical venous reddening after anastomosis during the surgery developed perioperative CI. Methods A total of 45 consecutive patients who underwent bypass surgery were retrospectively investigated. Twenty-five of the 45 patients underwent bypass for atherosclerotic occlusion or stenosis of the internal carotid artery or middle cerebral artery. Preoperative iodine-123-N-isopropyl-iodoamphetamine single-photon emission computed tomography was performed with and without acetazolamide administration. Change in color of the cortical veins was observed on recorded surgical videos, and its correlation with perioperative CI was investigated. Results We experienced 2 cases of perioperative extensive CI at a region remote from the site of anastomosis. In both cases, retrospective investigation of surgical videos demonstrated reddening of cortical veins soon after the anastomosis procedure. Of all 45 patients, postoperative CI and venous reddening were observed in only these 2 cases. Conclusions We determined that patients presenting with cortical venous reddening after anastomosis developed perioperative CI. Cortical venous reddening may be an important predictor for the occurrence of CI after STA-MCA bypass surgery for patients with atherosclerotic Occlusive Cerebrovascular Disease.
Jonathan J. Russin - One of the best experts on this subject based on the ideXlab platform.
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rescue cerebral revascularization in patients with progressive steno Occlusive ischemia of the anterior intracranial circulation
World Neurosurgery, 2020Co-Authors: Jeffrey A Steinberg, Kristine Ravina, Robert C Rennert, Ben A Strickland, Jonathan J. RussinAbstract:BACKGROUND: Despite the failure of 2 randomized controlled trials assessing the utility of bypass for steno-Occlusive Cerebrovascular Disease, a specific subset of patients with progressive and/or refractory symptoms may benefit from cerebral revascularization. This study assessed the efficacy and outcomes of bypass surgery for progressive and/or refractory steno-Occlusive Cerebrovascular Disease. METHODS: A retrospective database review was performed to identify patients who underwent bypass for progressive and/or refractory steno-Occlusive Disease of the internal carotid artery or middle cerebral artery over a 4-year period (July 2014-July 2018). Surgical and clinical outcomes were recorded. RESULTS: Seventeen patients (average age 62 +/- 11 years) underwent extracranial-intracranial bypass for refractory and/or progressive steno-Occlusive Disease of the internal carotid artery or middle cerebral artery. Thirteen patients presented with stroke, 3 presented with recurrent transient ischemic attacks, and 1 presented with progressive hemiparesis. All patients had preoperative perfusion imaging deficits. Average temporary clip time was 35 +/- 8 minutes. An interposition graft was used in 7 patients. There was 3 ischemic and 3 hemorrhagic perioperative strokes (35%); all were minor or related to anticoagulation. Over an average of 10 +/- 10 months of follow-up, there were no ischemic strokes in the bypass-dependent territories. Of 17 patients, 16 (78%) achieved a Glasgow Outcome Scale score >/=4, and 13 (85%) achieved a modified Rankin Scale score Occlusive Disease of the anterior intracranial circulation is a potentially effective treatment for patients with progressive and/or refractory ischemic symptoms, although the complication rate is significant. Optimal patient selection criteria and timing of surgery remain open questions.
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rescue cerebral revascularization in patients with progressive steno Occlusive ischemia of the anterior intracranial circulation
World Neurosurgery, 2020Co-Authors: Jeffrey A Steinberg, Kristine Ravina, Robert C Rennert, Ben A Strickland, Jonathan J. RussinAbstract:Background Despite the failure of 2 randomized controlled trials assessing the utility of bypass for steno-Occlusive Cerebrovascular Disease, a specific subset of patients with progressive and/or refractory symptoms may benefit from cerebral revascularization. This study assessed the efficacy and outcomes of bypass surgery for progressive and/or refractory steno-Occlusive Cerebrovascular Disease. Methods A retrospective database review was performed to identify patients who underwent bypass for progressive and/or refractory steno-Occlusive Disease of the internal carotid artery or middle cerebral artery over a 4-year period (July 2014–July 2018). Surgical and clinical outcomes were recorded. Results Seventeen patients (average age 62 ± 11 years) underwent extracranial-intracranial bypass for refractory and/or progressive steno-Occlusive Disease of the internal carotid artery or middle cerebral artery. Thirteen patients presented with stroke, 3 presented with recurrent transient ischemic attacks, and 1 presented with progressive hemiparesis. All patients had preoperative perfusion imaging deficits. Average temporary clip time was 35 ± 8 minutes. An interposition graft was used in 7 patients. There was 3 ischemic and 3 hemorrhagic perioperative strokes (35%); all were minor or related to anticoagulation. Over an average of 10 ± 10 months of follow-up, there were no ischemic strokes in the bypass-dependent territories. Of 17 patients, 16 (78%) achieved a Glasgow Outcome Scale score ≥4, and 13 (85%) achieved a modified Rankin Scale score ≤2. Conclusions Bypass for steno-Occlusive Disease of the anterior intracranial circulation is a potentially effective treatment for patients with progressive and/or refractory ischemic symptoms, although the complication rate is significant. Optimal patient selection criteria and timing of surgery remain open questions.
Eric S Nussbaum - One of the best experts on this subject based on the ideXlab platform.
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extracranial intracranial bypass for symptomatic Occlusive Cerebrovascular Disease not amenable to carotid endarterectomy
Neurosurgical Focus, 2003Co-Authors: Ramachandra P Tummala, Eric S NussbaumAbstract:Object. The role of cerebral revascularization remains unclear in symptomatic Occlusive Cerebrovascular Disease refractory to medical therapy. Despite the disappointing findings of the Cooperative Study on Extracranial–Intracranial Bypass, a subpopulation of patients with ischemic Cerebrovascular Disease and poor hemodynamic reserve may benefit from extracranial–intracranial (EC–IC) bypass. The authors reviewed the records of 65 patients who underwent 71 EC–IC bypass procedures at their institution over the past 6 years. Methods. All patients except one presented with repeated transient ischemic attacks (TIAs) that were referable to the involved vascular region. Eight patients underwent EC–IC bypass urgently for “crescendo” TIAs refractory to antiplatelet and anticoagulation therapy. Indications for surgery included cervical internal carotid artery (ICA) occlusion in 28, supraclinoid ICA stenosis in two, middle cerebral artery stenosis or occlusion in 14, moyamoya Disease in 18, and ICA dissection in three. Cerebral angiography demonstrated poor collateral flow to the involved region in each case. There were no postoperative strokes or deaths in this series. Following EC–IC bypass, the vast majority (95.4%) of patients experienced cessation of their ischemic events and stabilization of preexisting neurological dysfunction. Of the eight patients who underwent EC–IC bypass urgently for crescendo TIAs, two awoke with increased neurological deficits that improved rapidly within 24 hours of surgery. Conclusions. Although the Cooperative Study failed to show benefit from this treatment modality, the authors have continued to perform EC–IC bypass in certain cases. Carefully selected individuals with Occlusive Cerebrovascular Disease and persistent ischemic symptoms refractory to maximal medical therapy appear to benefit from cerebral revascularization.
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Extracranial-intracranial bypass for ischemic Cerebrovascular Disease refractory to maximal medical therapy.
Neurosurgery, 2000Co-Authors: Eric S Nussbaum, Donald L. EricksonAbstract:OBJECTIVE: To examine the potential role of cerebral revascularization in the treatment of patients with symptomatic Occlusive Cerebrovascular Disease refractory to medical therapy. METHODS: Twenty patients with symptomatic Occlusive Cerebrovascular Disease underwent 22 extracranial-intracranial bypass procedures after failing maximal medical therapy. The average follow-up time was 3.5 years, and no patient was lost to follow-up. RESULTS: All patients presented with repeated transient ischemic attacks refractory to medical therapy. Angiographic findings included internal carotid artery occlusion in 8 patients, middle cerebral artery stenosis or occlusion in 4, moyamoya Disease in 4, internal carotid artery dissection in 2, and supraclinoid internal carotid artery stenosis in 2. Outcome was excellent in 17 patients and good in 3. The only surgical complication occurred in one patient, who experienced postoperative seizures and required anticonvulsant therapy. There were no deaths in this series. CONCLUSION: Although the Cooperative Study on Extracranial-Intracranial Bypass failed to show a benefit from the bypass procedure, we have continued to perform the operation in selected cases. Carefully selected individuals with Occlusive Cerebrovascular Disease and persistent ischemic symptoms, despite maximal medical therapy, seem to obtain demonstrable and durable benefit from cerebral revascularization.
