The sequelae of aneurysmal subarachnoid hemorrhage (SAH) include vasospasm and hydrocephalus. To ... more The sequelae of aneurysmal subarachnoid hemorrhage (SAH) include vasospasm and hydrocephalus. To assess whether intraventricular tissue plasminogen activator (tPA) results in less vasospasm, fewer angioplasties, or fewer cerebrospinal fluid shunting procedures. 41 patients (tPA group, Hunt and Hess 3, 4, 5) from 2007 to 2008 received intraventricular tPA and lumbar drainage for a minimum of 5 days (range 5-7 days) and were compared to a matched group of 35 patients from 2006 to 2007 (Control, HH 3, 4, 5). Statistical comparison was done by t test analysis or Fisher exact tests and data are expressed as average+/-standard error of the mean. There were no significant differences in demographic data, although the tPA group had a trend toward more surgical patients. The tPA group of patients had a significantly higher modified Fisher grade than controls (P<.001) and had a significantly better Hunt and Hess grade than controls (P<.03). The angioplasty rate was significantly lower among the tPA patients (15.0%+/-5.6) than controls (40.0%+/-8.5, P=.019). The number of days spent in severe vasospasm normalized over the 14-day monitoring period by transcranial Doppler was significantly lower in the tPA group (0.09+/-0.02) than controls (0.17+/-0.03). The shunt rate was significantly lower among tPA patients (17.5%+/-6.0) than controls (42.8%+/-8.6). There were 2 clinically silent tract hemorrhages in the tPA group (4.8%). Intraventricular tPA is a safe and effective treatment for reducing both angioplasty and shunting rates in patients with SAH H&H Grades 3 to 5. A randomized trial is indicated.
As device sizes shrink and the complexity of single-chip functionality increases, designers find ... more As device sizes shrink and the complexity of single-chip functionality increases, designers find that they must express their ideas at higher levels of abstraction. This not only forces a greater reliance on tools to enable and implement their designs, but it also forces a move to new ...
As chip capacity increases and system-on-a-chip becomes a reality, hardware and system design are... more As chip capacity increases and system-on-a-chip becomes a reality, hardware and system design are being driven in new directions. The quality of results and the time to market for the overall system--both hardware and software--are now becoming the driving metrics of success ...
Vertebrobasilar insufficiency (VBI) resulting from embolism, atherosclerosis or arterial dissecti... more Vertebrobasilar insufficiency (VBI) resulting from embolism, atherosclerosis or arterial dissection has long been a challenge for successful management and outcomes. The three main treatment options include medical therapy, angioplasty and stenting and surgical revascularization. Unlike cardiac or peripheral vascular revascularization, large randomized trials with cerebro-revascularization have not revealed favorable outcomes. In patients who have failed maximal medical therapy, and having persistent debilitating symptomology, cerebral revascularization may still be a viable option. We present three patients who presented with symptoms of VBI. The diagnosis was verified by computerized tomographic arteriography (CTA) and digital subtraction angiography (DSA) and subsequently underwent revascularization with a radial artery graft (RAG). With then present a review of the literature of treatment for vertebrobasilar insufficiency.
Fig. 2. Task structuring provides the link between requirements and system design C. Timing Drive... more Fig. 2. Task structuring provides the link between requirements and system design C. Timing Driven Structuring of the Network Graph Task structuring [24] captures the parallelism inherent in the design of the system. The design of the network task graph allows the designer to ...
2. Calabrese L, et al. Reversible cerebral vasoconstriction syn-dromes. Ann Intern Med 2007;146:3... more 2. Calabrese L, et al. Reversible cerebral vasoconstriction syn-dromes. Ann Intern Med 2007;146:34–44. 3. Muehlschlegel S, et al. Dantrolene mediates vasorelaxation in cerebral vasoconstriction: a case series. Neurocrit Care 2009;10:116–21. 4.Muehlschlagel S, Sims ...
What Is the Correct Approach to Aneurysm Management in 2011? ... No abstract is available. To rea... more What Is the Correct Approach to Aneurysm Management in 2011? ... No abstract is available. To read the body of this article, please view the Full Text online. ... Commentary on: Principles in Case-Based Aneurysm Treatment: Approaching Complex Lesions ...
Various techniques of cerebral bypasses are used to treat aneurysms and tumors. To study long-ter... more Various techniques of cerebral bypasses are used to treat aneurysms and tumors. To study long-term clinical and radiological outcome of various bypass types and to analyze techniques used in the management of long-term graft problems. A consecutive series of patients who underwent revascularization during a 5-year period were analyzed for indications, graft patency, and neurological outcomes. Potential risk factors for bypass problems and the management of bypass stenosis were studied. A total of 80 patients (69 with aneurysms and 11 with tumors) underwent 88 bypasses (59 extracranial-to-intracranial [EC-IC] bypasses [10 low flow, 49 high flow], 9 intracranial-to-intracranial [IC-IC] bypasses [3 long, 6 short], and 20 local bypasses), with mean radiological follow-up of 32 months (range, 1-53 months). At late follow-up, 5 of 9 (56%) IC-IC (5 short, 0 long grafts), 8 of 9 (90%) EC-IC low-flow, 44 of 48 (92%) EC-IC high-flow, and all local bypasses were patent. Four patients with EC-IC high-flow bypass occlusions were asymptomatic, but transient ischemic attacks were noted in 3 of 6 patients with graft stenosis. None of the risk factors evaluated were significantly predictive of EC-IC graft occlusions or stenosis. EC-IC HF graft stenoses were permanently corrected by microsurgery (n = 4) or endovascular surgery (n = 1). The EC-IC and local bypasses have higher long-term patency rates (91% and 100%) compared with IC-IC bypasses (66%, 0% long graft). Some EC-IC bypasses may occlude asymptomatically (9%) or develop graft stenosis (13%) over the long term. Microsurgical and endovascular surgical techniques have been developed to treat graft stenosis.
Giant basilar tip aneurysms are a challenge to treat because of the complex anatomy and critical ... more Giant basilar tip aneurysms are a challenge to treat because of the complex anatomy and critical vessels that arise in this region. For large aneurysms, with multiple recurrences after coiling, when microsurgical clipping is not possible, a bypass to the posterior cerebral artery (PCA) can be helpful in providing definitive treatment. Two patients with giant basilar tip aneurysms were treated with bypass to the PCA. One patient had a microsurgical clipping and the other had a proximal occlusion of the basilar artery along with the bypass. Long-term angiographic and clinical follow-up was obtained. One patient had marked improvement in symptoms and a stable aneurysm remnant and the other patient had complete occlusion. Surgical treatment with a bypass to the PCA, with clipping of the aneurysm or proximal ligation of the basilar artery can be an effective treatment option for giant basilar tip aneurysms.
The sequelae of aneurysmal subarachnoid hemorrhage (SAH) include vasospasm and hydrocephalus. To ... more The sequelae of aneurysmal subarachnoid hemorrhage (SAH) include vasospasm and hydrocephalus. To assess whether intraventricular tissue plasminogen activator (tPA) results in less vasospasm, fewer angioplasties, or fewer cerebrospinal fluid shunting procedures. 41 patients (tPA group, Hunt and Hess 3, 4, 5) from 2007 to 2008 received intraventricular tPA and lumbar drainage for a minimum of 5 days (range 5-7 days) and were compared to a matched group of 35 patients from 2006 to 2007 (Control, HH 3, 4, 5). Statistical comparison was done by t test analysis or Fisher exact tests and data are expressed as average+/-standard error of the mean. There were no significant differences in demographic data, although the tPA group had a trend toward more surgical patients. The tPA group of patients had a significantly higher modified Fisher grade than controls (P<.001) and had a significantly better Hunt and Hess grade than controls (P<.03). The angioplasty rate was significantly lower among the tPA patients (15.0%+/-5.6) than controls (40.0%+/-8.5, P=.019). The number of days spent in severe vasospasm normalized over the 14-day monitoring period by transcranial Doppler was significantly lower in the tPA group (0.09+/-0.02) than controls (0.17+/-0.03). The shunt rate was significantly lower among tPA patients (17.5%+/-6.0) than controls (42.8%+/-8.6). There were 2 clinically silent tract hemorrhages in the tPA group (4.8%). Intraventricular tPA is a safe and effective treatment for reducing both angioplasty and shunting rates in patients with SAH H&H Grades 3 to 5. A randomized trial is indicated.
As device sizes shrink and the complexity of single-chip functionality increases, designers find ... more As device sizes shrink and the complexity of single-chip functionality increases, designers find that they must express their ideas at higher levels of abstraction. This not only forces a greater reliance on tools to enable and implement their designs, but it also forces a move to new ...
As chip capacity increases and system-on-a-chip becomes a reality, hardware and system design are... more As chip capacity increases and system-on-a-chip becomes a reality, hardware and system design are being driven in new directions. The quality of results and the time to market for the overall system--both hardware and software--are now becoming the driving metrics of success ...
Vertebrobasilar insufficiency (VBI) resulting from embolism, atherosclerosis or arterial dissecti... more Vertebrobasilar insufficiency (VBI) resulting from embolism, atherosclerosis or arterial dissection has long been a challenge for successful management and outcomes. The three main treatment options include medical therapy, angioplasty and stenting and surgical revascularization. Unlike cardiac or peripheral vascular revascularization, large randomized trials with cerebro-revascularization have not revealed favorable outcomes. In patients who have failed maximal medical therapy, and having persistent debilitating symptomology, cerebral revascularization may still be a viable option. We present three patients who presented with symptoms of VBI. The diagnosis was verified by computerized tomographic arteriography (CTA) and digital subtraction angiography (DSA) and subsequently underwent revascularization with a radial artery graft (RAG). With then present a review of the literature of treatment for vertebrobasilar insufficiency.
Fig. 2. Task structuring provides the link between requirements and system design C. Timing Drive... more Fig. 2. Task structuring provides the link between requirements and system design C. Timing Driven Structuring of the Network Graph Task structuring [24] captures the parallelism inherent in the design of the system. The design of the network task graph allows the designer to ...
2. Calabrese L, et al. Reversible cerebral vasoconstriction syn-dromes. Ann Intern Med 2007;146:3... more 2. Calabrese L, et al. Reversible cerebral vasoconstriction syn-dromes. Ann Intern Med 2007;146:34–44. 3. Muehlschlegel S, et al. Dantrolene mediates vasorelaxation in cerebral vasoconstriction: a case series. Neurocrit Care 2009;10:116–21. 4.Muehlschlagel S, Sims ...
What Is the Correct Approach to Aneurysm Management in 2011? ... No abstract is available. To rea... more What Is the Correct Approach to Aneurysm Management in 2011? ... No abstract is available. To read the body of this article, please view the Full Text online. ... Commentary on: Principles in Case-Based Aneurysm Treatment: Approaching Complex Lesions ...
Various techniques of cerebral bypasses are used to treat aneurysms and tumors. To study long-ter... more Various techniques of cerebral bypasses are used to treat aneurysms and tumors. To study long-term clinical and radiological outcome of various bypass types and to analyze techniques used in the management of long-term graft problems. A consecutive series of patients who underwent revascularization during a 5-year period were analyzed for indications, graft patency, and neurological outcomes. Potential risk factors for bypass problems and the management of bypass stenosis were studied. A total of 80 patients (69 with aneurysms and 11 with tumors) underwent 88 bypasses (59 extracranial-to-intracranial [EC-IC] bypasses [10 low flow, 49 high flow], 9 intracranial-to-intracranial [IC-IC] bypasses [3 long, 6 short], and 20 local bypasses), with mean radiological follow-up of 32 months (range, 1-53 months). At late follow-up, 5 of 9 (56%) IC-IC (5 short, 0 long grafts), 8 of 9 (90%) EC-IC low-flow, 44 of 48 (92%) EC-IC high-flow, and all local bypasses were patent. Four patients with EC-IC high-flow bypass occlusions were asymptomatic, but transient ischemic attacks were noted in 3 of 6 patients with graft stenosis. None of the risk factors evaluated were significantly predictive of EC-IC graft occlusions or stenosis. EC-IC HF graft stenoses were permanently corrected by microsurgery (n = 4) or endovascular surgery (n = 1). The EC-IC and local bypasses have higher long-term patency rates (91% and 100%) compared with IC-IC bypasses (66%, 0% long graft). Some EC-IC bypasses may occlude asymptomatically (9%) or develop graft stenosis (13%) over the long term. Microsurgical and endovascular surgical techniques have been developed to treat graft stenosis.
Giant basilar tip aneurysms are a challenge to treat because of the complex anatomy and critical ... more Giant basilar tip aneurysms are a challenge to treat because of the complex anatomy and critical vessels that arise in this region. For large aneurysms, with multiple recurrences after coiling, when microsurgical clipping is not possible, a bypass to the posterior cerebral artery (PCA) can be helpful in providing definitive treatment. Two patients with giant basilar tip aneurysms were treated with bypass to the PCA. One patient had a microsurgical clipping and the other had a proximal occlusion of the basilar artery along with the bypass. Long-term angiographic and clinical follow-up was obtained. One patient had marked improvement in symptoms and a stable aneurysm remnant and the other patient had complete occlusion. Surgical treatment with a bypass to the PCA, with clipping of the aneurysm or proximal ligation of the basilar artery can be an effective treatment option for giant basilar tip aneurysms.
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