Showing papers by "L. Nelson Hopkins published in 2002"

Prognostic significance of hypernatremia and hyponatremia among patients with aneurysmal subarachnoid hemorrhage.

Abstract: OBJECTIVE Abnormal serum sodium levels (hyponatremia and hypernatremia) are frequently observed during the acute period after aneurysmal subarachnoid hemorrhage (SAH) and may worsen cerebral edema and mass effect. We performed this study to determine the prognostic significance of serum sodium concentration abnormalities. METHODS We analyzed prospectively collected data for the placebo treatment group in a clinical trial conducted at 54 neurosurgical centers in North America. The presence of hypernatremia (serum sodium concentration of >145 mmol/L) and hyponatremia (serum sodium concentration of <135 mmol/L) was determined with serum sodium measurements obtained at admission and 3, 6, and 9 days after SAH. The effects of hypernatremia and hyponatremia on the risk of symptomatic vasospasm and on 3-month outcomes were analyzed after adjustment for the following potential confounding factors: age, sex, preexisting hypertension, admission Glasgow Coma Scale score, initial mean arterial pressure, subarachnoid clot thickness, intraventricular blood or intraparenchymal hematoma, ventricular dilation, and aneurysm size and location. RESULTS Of 298 patients in the analysis, 58 (19%) developed hypernatremia and 88 (30%) developed hyponatremia. Hypernatremia was significantly associated with poor outcomes (odds ratio, 2.7; 95% confidence interval, 1.2-6.1). A positive correlation was observed between the highest sodium values recorded and Glasgow Outcome Scale scores at 3 months (P < 0.0001 by analysis of variance). Hyponatremia was not associated with 3-month outcomes (odds ratio, 1.9; 95% confidence interval, 0.9-4.3). Neither hypernatremia nor hyponatremia was associated with the risk of symptomatic vasospasm. CONCLUSION Hyponatremia seems to be more common than hypernatremia after SAH. However, hypernatremia after SAH is independently associated with poor outcomes, and this association is independent of previously identified outcome predictors, including age and admission Glasgow Coma Scale scores. Further studies are needed to define the underlying mechanism of this association.

Aggressive Mechanical Clot Disruption and Low-dose Intra-arterial Third-generation Thrombolytic Agent for Ischemic Stroke: A Prospective Study

Abstract: Objective We prospectively evaluated the safety and effectiveness of aggressive mechanical disruption of clot in conjunction with intra-arterial administration of a low-dose third-generation thrombolytic agent (reteplase) to treat ischemic stroke in patients who were considered poor candidates for intravenous alteplase therapy or who failed to improve after intravenous thrombolysis. Mechanical clot disruption was used if low-dose pharmacological thrombolysis was ineffective. This strategy was adopted to increase the recanalization rate without increasing the risk of intracerebral hemorrhage. Methods Patients were considered poor candidates for intravenous therapy because of severity of neurological deficits, interval from symptom onset to presentation of at least 3 hours, or recent major surgery. We administered a maximum total dose of 4 U of reteplase intra-arterially in 1-U increments via superselective catheterization. After the initial doses were administered, we performed mechanical angioplasty (for proximal occlusion) or snare manipulation (for distal occlusion) at the occlusion site if recanalization had not occurred. The remaining doses of thrombolytics were subsequently administered if required for further recanalization. Angiographic responses were graded using modified Thrombolysis in Myocardial Infarction (TIMI) criteria. Clinical evaluations were performed before and 24 hours, 7 to 10 days, and 1 to 3 months after treatment. Results Nineteen consecutive patients were treated (mean age, 64.3 +/- 16.2 yr; 10 were men). Initial National Institutes of Health Stroke Scale scores ranged from 11 to 42. Time from onset to treatment ranged from 1 to 9 hours. Occlusion sites were in the following arteries: cervical internal carotid (n = 7), intracranial internal carotid (n = 1), middle cerebral (n = 9), and basilar (n = 2). Of the 19 patients, thrombolysis alone was used in 5 patients, angioplasty was performed in 11 patients, and snare maneuvers were used in 5 patients. Complete restoration of blood flow (modified TIMI Grade 4) was observed in 12 patients, near-complete restoration of flow (modified TIMI Grade 3) in 4 patients, minimal response (modified TIMI Grade 1) in 1 patient, and no response in 2 patients (modified TIMI Grade 0). Neurological improvement at 24 hours (decline of at least 4 points in National Institutes of Health Stroke Scale score) was observed in seven patients. Five other patients experienced further improvement in National Institutes of Health Stroke Scale score at 7 to 10 days. No vessel rupture, dissection, or symptomatic intracranial hemorrhages were observed. At the time of follow-up evaluation, 7 of 19 patients were functionally independent. Conclusion A high rate of recanalization and clinical improvement can be observed in patients with ischemic stroke using low-dose thrombolytic agents with adjunctive mechanical disruption of clot. Moreover, this strategy may reduce the risk of intracerebral hemorrhage observed with thrombolytics.

Recommendations for the endovascular treatment of intracranial aneurysms: a statement for healthcare professionals from the Committee on Cerebrovascular Imaging of the American Heart Association Council on Cardiovascular Radiology.

Abstract: Intracranial aneurysms are common, with a prevalence of 0.5% to 6% in adults, according to angiography and autopsy studies.1 Most intracranial aneurysms are asymptomatic and are never detected. Some are discovered incidentally in neuroimaging studies and some produce symptoms due to compression of neighboring nerves or adjacent brain tissue. Others are detected only after they have ruptured and caused subarachnoid hemorrhage, a devastating type of stroke asso-ciated with 32% to 67% case fatality and 10% to 20% long-term dependence in survivors due to brain damage.2 To prevent subarachnoid hemorrhage, physicians have developed methods to treat aneurysms. For ruptured aneurysms, early treatment within 24 to 72 hours has been recommended because the risk of subsequent rupture is high, with approximately 20% risk of rerupture in the first 2 weeks after subarachnoid hemorrhage.3 Each additional rupture substantially increases the risk of mortality and morbidity. Treatment has also been recommended for most unruptured aneurysms,4 although there is uncertainty about treatment of some small aneurysms <10 mm because their risk of rupture appears low.5,6⇓ The American Heart Association formed this special writing group to summarize the literature and create recommendations on endovascular therapy of ruptured and unruptured intracranial aneurysms. This statement is meant to extend previous statements on treatment of subarachnoid hemorrhage3 and on treatment of unruptured aneurysms.4 During the review, it became evident that any recommendations would be based primarily on expert opinion weighing evidence only from nonrandomized cohort studies and case series. In 1937, Walter Dandy reported the first successful surgical clipping of the neck of an aneurysm. Microsurgical techniques have steadily evolved since then, with development of a variety of surgical approaches and metal aneurysm clips. Repair of aneurysms in nearly all intracranial locations is possible by placing a clip made from a …

Intracerebral Hemorrhages Associated With Neurointerventional Procedures Using a Combination of Antithrombotic Agents Including Abciximab

Abstract: Background— We report the occurrence of fatal intracerebral hemorrhage associated with using a combination of antithrombotic agents, including abciximab, in patients undergoing neurointerventional procedures. Summary of Report— Seven patients (average age 60, range 46 to 73 years) developed fatal intracerebral hemorrhages associated with neurointerventional procedures and the use of intravenous abciximab. The procedures included angioplasty and stent placement in the cervical internal carotid artery (n=4), angioplasty of the intracranial internal carotid artery (n=1), and angioplasty of the middle cerebral artery (n=2). Clinical deterioration was observed within 1 hour of the procedure in 5 patients and 7 and 8 hours after the procedure, respectively, in the remaining 2 patients. All patients had received heparin and clopidogrel; 6 had also received aspirin. Conclusions— Intracerebral hemorrhages can occur after neurointerventional procedures in patients with recent cerebral ischemic events, particularly ...

Staged stent-assisted angioplasty for symptomatic intracranial vertebrobasilar artery stenosis.

Abstract: Object. Medically refractory symptomatic vertebrobasilar atherosclerotic disease has a poor prognosis. Studies have shown that longer (≥ 10 mm), eccentric, high-grade (> 70%) stenoses portend increased procedure-related morbidity. The authors reviewed their experience to determine whether a staged procedure consisting of angioplasty followed by delayed (≥ 1 month later) repeated angioplasty and stent placement reduces the morbidity associated with endovascular treatment of symptomatic basilar and/or intracranial vertebral artery (VA) stenoses. Methods. The authors retrospectively reviewed the medical records in a consecutive series of eight patients who underwent planned stent-assisted angioplasty for medically refractory, symptomatic atherosclerotic disease of the intracranial posterior circulation between February 1999 and January 2002. Staged stent-assisted angioplasty was planned for these patients because the extent and degree of stenosis of the VA and/or basilar artery (BA) lesion portended an exces...

Angioplasty for Intracranial Symptomatic Vertebrobasilar Ischemia

Abstract: OBJECTIVE: Although anterior circulation disease has both medical and surgical treatment options, management of vertebrobasilar disease has predominantly had only medical options. Some patients remain symptomatique despite medical treatment, and angioplasty has been demonstrated to relieve critical stenose. However, the relative safety and effectiveness of medical and surgical treatments is not clearly known. This report reviews the clinical characteristics, indications, and procedural risks of intracranial angioplasty in a series of patients with symptomatic posterior circulation ischemia. METHODS: All patients undergoing angioplasty for critical intracranial vertebral or basilar artery stenosis at the University of California at San Francisco Medical Center between June 1986 and July 1999 were included in a retrospective record review. Clinical features and procedural complications were recorded. RESULTS: Angioplasty was performed on 25 vessel lesions in 25 patients in whom medical therapy had failed. The patients ranged in age from 50 to 87 years. Of the 25 stenoses, 10 were intracranial vertebral, 9 vertebrobasilar juction, and 6 basilar in location. Angioplasty was effective in reducing the degree of slenosis by more than 40% in all 25 vessels. The overall risk of stroke or death was 28% and the risk of disabling stroke or death was 16%. CONCLUSION: Intracranial posterior circulation angioplasty is effective in the reduction of stenosis and can be performed with relative safety. Angioplasty can be considered as a treatment option in patients with recurrent ischemic symptoms despite medical therapy.

Follow-up of stented carotid arteries by Doppler ultrasound.

Abstract: OBJECTIVE Blood flow velocity (BFV) in the carotid artery is altered by stent placement. The significance of these alterations is unknown. In our experience, both standard BFV criteria for stenosis and customized criteria recommended by other authors have led to high rates of false-positive studies.

Stent placement for the treatment of occlusive atherosclerotic carotid artery disease in patients with concomitant coronary artery disease

Abstract: Object. The authors report their experience with carotid artery stent placement (CASP) in patients with concomitant carotid artery (CA) and coronary artery (CorA) diseases. Methods. In a review of 320 consecutive patients who underwent CASP, the authors identified 49 with severe CorA disease in addition to significant CA stenosis, who had undergone CASP before planned CorA bypass grafting (CorABG). The average age of these 49 patients was 68 years. In 39 patients (80%) the New York Heart Association functional classification grade was IV and in 10 the grade was III. In 26 patients 50% or greater stenosis of the left main CorA was found. Seventeen patients (35%) suffered from either significant hemodynamic contralateral CA stenosis (> 60% stenosis; eight patients) or contralateral CA occlusion (nine patients). Sixteen patients (33%) had symptomatic CA disease. No cerebrovascular events occurred during CorABG. Four patients (8%) died of cardiac arrest and one patient (2%) suffered a major stroke within 30 d...

Carotid angioplasty and stent placement: a prospective analysis of perioperative complications and impact of intravenously administered abciximab.

Abstract: Objective To determine the frequency of perioperative complications since the introduction of abciximab, we prospectively evaluated our experience in a consecutive series of patients undergoing carotid angioplasty and stent placement (CAS). CAS has been introduced recently for treatment of carotid artery stenosis. A major limitation to this modality is the risk of perioperative thromboembolic and ischemic events. To reduce the risk of ischemic complications, abciximab, a platelet glycoprotein IIb/IIIa receptor inhibitor, has been introduced as adjunctive treatment for high-risk patients. Methods Each patient was evaluated by a neurologist before, immediately after, and 24 hours after CAS for identification and classification of new neurological deficits. Bleeding events or other complications during hospitalization were recorded. Bleeding complications were classified as major (hemoglobin decrease,g5 g/dl), minor (hemoglobin decrease, 3-5 g/dl), or insignificant. Abciximab was administered intravenously as a single bolus (0.25 mg/kg) and then via infusion (10 microg/min) for 12 hours as an adjunct to CAS in patients considered to be at high risk for thromboembolic events owing to recent ischemic symptoms and/or complex lesion morphology. Results Intravenously administered abciximab was used in 37 patients (mean age, 70 yr; 21 patients were men) as an adjunct to high-risk CAS. Thirty-three other patients underwent CAS performed with standard intraprocedural heparinization (mean age, 69 yr; 17 patients were men). Minor ischemic strokes were observed in 1 of 37 abciximab-treated patients and in 4 of 33 heparin-treated patients. No major ischemic strokes were observed in either group. Transient neurological deficits were observed in nine patients in the abciximab-treated group and in one patient in the heparin-treated group. Transient neurological deficits in abciximab-treated patients were mainly related to hemodynamic factors (associated with balloon inflation in two patients and with hypotension in another two patients) or occurred after completion of infusion (in three patients). Minor bleeding complications were observed in three patients who received abciximab and in four patients who received standard heparinization. Major bleeding complications were observed in four patients from each group. Two patients who received abciximab developed intracerebral hemorrhages; one hemorrhage was fatal. Conclusion The frequency of ischemic stroke in high-risk patients (3%) with the use of intravenously administered abciximab was lower, but not significantly so, than rates observed in lower-risk patients (12%), although the benefit was lost because of the high rate of intracranial hemorrhages (5%). Further efforts are required to determine appropriate selection criteria for use of intravenously administered abciximab and the effect of other strategies that involve distal protection devices.

Isolated and Borderline Isolated Systolic Hypertension Relative to Long-Term Risk and Type of Stroke A 20-Year Follow-Up of the National Health and Nutrition Survey

Abstract: Background and Purpose— Although the short-term risks of stroke and types of stroke associated with isolated systolic hypertension (ISH) and borderline isolated systolic hypertension (BISH) have been described, the long-term effects of these hypertensive conditions, particularly in younger individuals, are unclear. We performed this study to evaluate the long-term risks of stroke, type of stroke, and predictors of stroke associated with ISH and BISH and how this risk compares with that for persons with diastolic hypertension and normotension. Methods— We used the 20-year follow-up data for 12 344 adults aged 25 to 74 years who participated in the First National Health and Nutrition Examination Survey Follow-Up Study to determine the aforementioned risks. Blood pressure (BP) measurements of the participants were obtained during baseline evaluation. ISH was defined as systolic BP ≥160 mm Hg and diastolic BP <90 mm Hg. BISH was defined as systolic BP between 140 and 159 mm Hg and diastolic BP <90 mm Hg. Dias...

Brainstem infarction after delayed thrombosis of a stented vertebral artery fusiform aneurysm: Case report

Abstract: Objective and importance Recent technological advances have provided clinicians with stents that can be navigated throughout the tortuous proximal vessels of the posterior intracranial circulation. There have been few reports of fusiform and wide-necked aneurysms treated with stents. Of the known risks involved in stent placement in the intracranial circulation, delayed stent thrombosis has not been well described. Clinical presentation A 34-year-old man who experienced the sudden onset of a severe headache with increasing lethargy was found on computed tomographic imaging to have a subarachnoid hemorrhage. Angiography revealed a left vertebral artery fusiform aneurysm that incorporated the posteroinferior cerebellar artery origin. Intervention A low-porosity Magic Wallstent (Boston Scientific, Natick, MA) was placed in the left vertebral artery across the aneurysm and the origin of the posteroinferior cerebellar artery. Angiography performed 9 days later revealed significant reduction in filling of the aneurysm. The patient returned 3 months after stent placement with severe neurological deterioration from a brainstem infarction caused by complete thrombotic occlusion of the left vertebral artery at the stented segment of the vessel. Conclusion Stenting of fusiform aneurysms has provided an alternative to surgical clipping or parent vessel reconstruction. With the increasing frequency of intracranial stent placement for various cerebrovascular disease entities, we must become aware of potential complications associated with these procedures. Such awareness may influence decision-making processes regarding treatment and follow-up care.

Regional intraparenchymal pressure differences in experimental intracerebral hemorrhage: effect of hypertonic saline.

Abstract: OBJECTIVE: To study regional intraparenchymal pressures within the cranial cavity during and after formation of intracerebral hemorrhage. We also assessed the effect of hypertonic saline on intraparenchymal pressure in different brain regions and on regional brain distribution of sodium within the brain. DESIGN: Prospective, controlled, laboratory trial. SETTINGS: Animal research laboratory. SUBJECTS: Eight mongrel dogs, weighing 15-25 kg. INTERVENTION: We introduced an intracerebral hematoma in eight mongrel dogs by infusing 6 mL of autologous arterial blood in the deep white matter adjacent to the basal ganglia. Sodium chloride (23.4%, 1.4 mL/kg) then was administered intravenously 6 hrs after introduction of hematoma. MEASUREMENTS AND MAIN RESULTS: Parenchymal pressure monitors were placed in the perihematoma region, both frontal lobes, and the cerebellum to record intraparenchymal pressure during and 6 hrs after intracerebral hematoma formation. Intraparenchymal pressure measurements were recorded for 3 more hours after administration of 23.4% sodium chloride. Regional cerebral perfusion pressure was calculated for each intraparenchymal pressure measurement. Regional sodium distribution was measured in extracts from brain regions by using ion selective electrode technique. A higher elevation in intraparenchymal pressure was recorded in the perihematoma region during the introduction of the hematoma compared with other compartments. After 5 mL of autologous blood was introduced, intraparenchymal pressure (mm Hg +/- SE) was significantly higher in the perihematoma region (42.1 +/- 3.5) than in the ipsilateral (30.0 +/- 4.6, p <.05) and contralateral (27.1 +/- 5.5, p <.01) frontal lobes and cerebellum (29.1 +/- 4.5, p <.05). Four hours after introduction of the hematoma, the cerebral perfusion pressure recorded in the perihematoma region (43.6 +/- 9.7) remained significantly lower than in the ipsilateral (58.6 +/- 9.3, p <.05) but not the contralateral frontal lobes (54.7 +/- 10.1) and cerebellum (51.0 +/- 11.1). Administration of 23.4% sodium chloride immediately reduced intraparenchymal pressure in each compartment. This effect was still observed at 3 hrs in each compartment. Sodium concentration was higher in the perihematoma region than in the frontal lobes, cerebellum, or brain stem. CONCLUSIONS: Prominent differences were observed in intraparenchymal pressure and cerebral perfusion pressure in the perihematoma region and frontal lobes during and after intracerebral hematoma. We speculate that the potential importance of regional intraparenchymal pressure differences in the clinical settings may be under appreciated. In this canine model of intracerebral hematoma, a single dose of hypertonic saline effectively reduces the intraparenchymal pressure in all regions of the brain.

Apolipoproteins A-1 and B and the likelihood of non-fatal stroke and myocardial infarction -- data from The Third National Health and Nutrition Examination Survey

Abstract: BACKGROUND The measurement of plasma apolipoproteins (APO) has been proposed for predicting the risk of cardiovascular diseases. However, the association between APOs and stroke is not well defined. MATERIAL/METHODS We evaluated the association between plasma concentrations of APO A-1 and APO B with a physician diagnosis of stroke (n=153), and electrocardiogram evidence or physician diagnosis of myocardial infarction (n=379), in a nationally representative sample of 3,696 US adults aged >40 years who participated in the Third National Health and Nutrition Examination Survey. Multivariate logistic regression analyses were used to investigate these relationships. RESULTS After adjusting for differences in age, gender, race/ethnicity, education, hypertension, cholesterol, body mass index, and cigarette smoking, the upper quartile of APO A-1 (> or = 161 mg/dl) when compared with the lowest quartile ( or = 1.59 when compared with a ratio < or = 1.04 was associated with a decreased likelihood of myocardial infarction (OR, 0.3; 95% CI, 0.2-0.6); and stroke (OR 0.4, 95% CI, 0.2-1.0). CONCLUSIONS Higher APO A-1 concentrations were associated with a decreased likelihood for myocardial infarction but not for stroke. The APO A-1 to B ratio was inversely associated with both myocardial infarction and stroke and may be an important protective clinical marker for atherosclerosis.

Multicenter study of the feasibility and safety of using the Memotherm carotid arterial stent for extracranial carotid artery stenosis

Abstract: Object. Carotid artery (CA) angioplasty with stent placement has been proposed as an alternative technique for revascularization in cases of CA stenosis. In this report the authors review the results of a multicenter Phase I study in which they evaluated the safety and feasibility of using a new self-expanding nitinol stent, the Bard Memotherm, to treat CA stenosis. Methods. Enrollment was limited to patients in whom there was either 50% or greater symptomatic or 70% or greater asymptomatic stenosis of the internal CA. The primary endpoint was a technically successful implantation procedure (delivery of the stent to the target site and retrieval of the delivery device), resulting in less than 30% residual stenosis demonstrated on immediate postprocedure (control) angiograms, and no incidence of mortality, ipsilateral stroke, Q-wave myocardial infarction, or other major cardiovascular events immediately after or within 30 days following the procedure. Stent placement was attempted for 73 lesions in 71 pati...

Should interventional cardiologists treat ischemic strokes? A global perspective.

Abstract: Stroke is the third leading cause of death and the leading cause of severe neurological disability in our nation. The stroke death rate has the potential to reach epidemic proportions as the elderly segment of the population continues to rise. There is an insufficient number of trained physicians to supply the care for this patient population. The logical source for qualified physicians to care for these patients is the interventional cardiologist. We review the recent intraarterial therapy trials and detail the training necessary to allow interventional cardiologists to treat ischemic strokes.

Endovascular aneurysm treatment: A proven therapy

Abstract: Endovascular treatment of aneurysms is an evolving technique. Endovascular techniques for the treatment of aneurysms have been available for 10 years. During this time, we have seen major advances and improvements in our ability to embolize aneurysms via an endoluminal approach. We have continued to modify our techniques and selection of patients who would most benefit from this approach. This article summarizes the current literature and attempts to develop a management strategy toward improving patient outcome by optimizing the choice between endovascular and surgical treatment modalities.

Endovascular surgery: the future without limits.

Abstract: The new millennium brings with it tremendous advances in technology and information sharing. Various medical, surgical, and engineering specialities are becoming more focused, thus enabling experts in these fields to gain insight and understanding previously unappreciated by those who came before us. Economic and technologic evolution will eliminate some of the drawbacks of endovascular therapy, such as persistent neck remnants. It is likely that drug delivery systems exist that would allow maximal benefit with little or no systemic adverse effects. It is likely that devices are available that could minimize various procedural complications. We as future neurosurgeons must persist in the quest to find collaborations that will promote cross-fertilization and cross-pollination among cardiologists, neurosurgeons, physicists, radiologists, neurologists, engineers, and other scientists so that the technology can be translated to reality. It is clear that, in time, transcatheter techniques will replace many operations for the treatment of cerebrovascular pathologies. Let us not allow ourselves the luxury of time.