Stenting and angioplasty of the symptomatic chronically occluded carotid artery.

Patients with hemodynamic impairment ipsilateral to a carotid occlusion are at a high risk of subsequent stroke, and currently 2 surgical options have been studied: extracranial-to-intracranial bypass and direct thromboendarterectomy. We report the successful revascularization of 2 symptomatic chronically occluded carotid arteries with stenting and angioplasty.

Factors predicting hemorrhagic complications after multimodal reperfusion therapy for acute ischemic stroke.

BACKGROUND AND PURPOSE: We sought to find predictors for hemorrhagic complications in patients with acute ischemic stroke treated with multimodal endovascular therapy. MATERIALS AND METHODS: We retrospectively reviewed patients with acute ischemic stroke treated with multimodal endovascular therapy from May 1999 to March 2006. We reviewed clinical and angiographic data, admission CT Alberta Stroke Programme Early CT Score (ASPECTS), and the therapeutic endovascular interventions used. Posttreatment CT scans were reviewed for the presence of a parenchymal hematoma or hemorrhagic infarction based on defined criteria. Predictors for these types of hemorrhages were determined by logistic regression analysis. RESULTS: We identified 185 patients with a mean age of 65+/-13 years and mean National Institutes of Health Stroke Scale score of 17+/-4. Sixty-nine patients (37%) developed postprocedural hemorrhages: 24 (13%) parenchymal hematomas and 45 (24%) hemorrhagic infarctions. Patients with tandem occlusions (odds ratio [OR] 4.6 [1.4-6.5], P<.016), hyperglycemia (OR 2.8 [1.1-7.7], P<.043), or treated concomitantly with intravenous (IV) tissue plasminogen activator (tPA) and intra-arterial (IA) urokinase (OR 5.1 [1.1-25.0], P<.041) were at a significant risk for a parenchymal hematoma. Hemorrhagic infarction occurred significantly more in patients presenting with an ASPECTS

Pretreatment ipsilateral regional cortical blood flow influences vessel recanalization in intra-arterial thrombolysis for MCA occlusion.

BACKGROUND AND PURPOSE: The aim of acute stroke interventions is to achieve recanalization of the target occluded artery. We sought to determine whether pretreatment cortical cerebral blood flow (CBF) was associated with vessel recanalization in patients undergoing intra-arterial therapy. METHODS: This is a retrospective analysis of patients who underwent a quantitative xenon CT blood flow study and were noted to have a documented M1 middle cerebral artery (MCA) or carotid terminus occlusion less than 6 hours from symptom onset between January 1997 and April 2001. Twenty-three patients who underwent intra-arterial thrombolysis were included in the analysis. Univariate and multivariate analyses were performed to determine whether pretherapy CBF was correlated to the likelihood of recanalization. RESULTS: A total of 23 patients were studied in this analysis with a median age of 69 (range 32-81) and median National Institutes of Health Stroke Score of 19 (range, 8-22). Twelve patients (52%) underwent combined intravenous/intra-arterial therapy, and 11 patients (48%) were treated with intra-arterial thrombolytics alone. Successful vessel recanalization (Thrombolysis in Myocardial Infarction classification 2 or 3 flow) occurred in 13 patients (57%). The only variable associated with recanalization in multivariate modeling was mean ipsilateral MCA CBF (odds ratio, 1.25; 95% confidence interval, 1.01-1.54; P = .035). A receiver operating characteristic curve was generated, and a mean ipsilateral MCA CBF threshold of 18 mL/100 g/min was found to be the threshold for successful recanalization. CONCLUSIONS: Our study suggests that patients with higher mean ipsilateral MCA CBF are more likely to recanalize. The threshold for successful revascularization may be 18 mL/100 g/min. Further study is required to determine whether pretreatment CBF is related to recanalization success.

Self-expanding stents for recanalization of acute cerebrovascular occlusions.

BACKGROUND AND PURPOSE: Stent-assisted revascularization increases prevailing recanalization rates ( congruent with 50%-69%) for vessel occlusions recalcitrant to thrombolytics. Although balloon-mounted coronary stents can displace thrombus (via angioplasty) and retain clot along vessel walls, intracranial self-expanding stents are more flexible and exert less radial outward force during deployment, increasing deliverability and safety. To understand the effectiveness of self-expanding stents for recanalization of acute cerebrovascular occlusions, we retrospectively reviewed our preliminary experience with these stents. MATERIALS AND METHODS: Eighteen patients (19 lesions) presenting with a clinical diagnosis of acute stroke underwent catheter-based angiography documenting focal occlusion of an intracranial artery. A self-expanding stent was delivered to the occlusion and deployed. Stent placement was the initial mechanical maneuver in 6 cases; others involved a combination of pharmacologic and/or mechanical maneuvers prestenting. GP IIb/IIIa inhibitors were administered in 10 cases intraprocedurally or immediately postprocedurally to avoid acute in-stent thrombosis. RESULTS: Stent deployment at the target occlusion (technical success) was achieved in all cases. Thrombolysis in Cerebral Ischemia (TICI)/Thrombolysis in Myocardial Ischemia (TIMI) 2/3 recanalization (angiographic success) was achieved in 15 of 19 lesions (79%). All single-vessel lesions (n=8) were recanalized, but only 7 of 11 combination internal carotid artery and middle cerebral artery lesions were recanalized. No intraprocedural complications occurred. Seven in-hospital deaths occurred: stroke progression, 4; intracranial hemorrhage, 2; respiratory failure, 1. Seven patients had >or=4-point National Institutes of Health Stroke Scale improvement within 24 hours after the procedure, 6 had modified Rankin Score (mRS)

Urgent stenting of the M2 (superior) division of the middle cerebral artery after systemic thrombolysis in acute stroke.

We report a case of a 54-year-old man who presented with a right middle cerebral artery territory infarct and was treated with systemic thrombolytics. He continued to fluctuate neurologically and, with the use of angiography, was found to have an occlusion of the right M2 artery (superior division). This occlusion was successfully revascularized with a coronary stent.

Mineral spirits inhalation associated with hemolysis, pulmonary edema, and ventricular fibrillation.

A previously healthy 42-year-old woman developed severe dyspnea, chest discomfort, and malaise several hours after prolonged exposure to concentrated vapors from mineral spirits. On the way to the hospital, she sustained a cardiopulmonary arrest; on arrival several minutes later, she was found to be in ventricular fibrillation and was resuscitated. Her hospital course included slowly resolving cardiac abnormalities, amnesia, noncardiogenic pulmonary edema, abrupt hemolytic anemia, sustained rhabdomyolysis, and other metabolic abnormalities. It is highly probable that this syndrome represented acute and near-lethal toxicity caused by the inhalational exposure to the petroleum distillate known as mineral spirits. It is important that physicians be aware of this syndrome in order to recognize it on presentation and to warn patients of the risk of such toxic exposure.

Central nervous system germinomas. A review.

The germinoma represents a less malignant form of germ cell tumor. Depending on the individual's age, this neoplasm constitutes approximately 0.1% to 3.4% of all intracranial tumors. The embryologic origin remains a mystery; however, current theories implicate an aberration in primordial germ cell migration. Clinical presentation depends on tumor location and may involve endocrine, hypothalamic, visual, and cognitive dysfunction. In evaluating midline intracerebral masses, it is imperative that one be aware of the various radiologic appearances, endocrinologic changes, and chemical markers that help to distinguish germinomas from other neoplasms that appear in the pineal, suprasellar, and periventricular regions. Only through the careful evaluation of all available studies can the physician institute appropriate therapies such as biopsy, radiation, and chemotherapy. This article focuses on the epidemiology, embryology, clinical presentation, means of diagnosis, treatment, and outcome of this rare neoplasm.

Dyspnea ratings for prescription of cross-modal exercise in patients with COPD.

STUDY OBJECTIVE: To investigate the ability of patients with COPD to reproduce an exercise intensity accurately on the treadmill using dyspnea ratings obtained during incremental exercise on the cycle ergometer (cross-modal exercise prescription). DESIGN: Five visits over an 8-week period. PATIENTS: Thirteen symptomatic patients with stable COPD. Age was 67+/-6 years (mean+/-SD). FEV1 was 1.15+/-0.22 L (45+/-7% predicted). INTERVENTIONS: At each visit, patients performed spirometry and exercise. Visit 1 was a practice incremental exercise test on the cycle ergometer. At visit 2 (1 week later), patients estimated the intensity of dyspnea using the 0 to 10 category-ratio scale during an incremental exercise test on the cycle ergometer (cycle estimation trial). Visit 3, 5 weeks later, was a practice session on the treadmill. At visit 4, 1 week later, patients were instructed to produce specific intensities of dyspnea (ie, dyspnea targets) at 50% and at anaerobic threshold (AT) or 80% of peak oxygen consumption (VO2) as calculated from results at visit 2 (treadmill production trial). Visit 5, 1 week later, was the treadmill estimation trial. MEASUREMENTS AND RESULTS: Lung function was stable at all visits. Dyspnea ratings were 1.9+/-0.9 at 50% of VO2 and 5.6+/-1.5 at AT/80% of peak VO2 (17.5+/-3.3 mL/kg/min). The VO2 at the treadmill production trial (761+/-185 mL/min) was significantly higher than at the cycle estimation trial (612+/-159 mL/min) at the low dyspnea target (p < 0.0002; upward bias, 26+/-16%). In contrast, there was no significant difference in VO2 values (929+/-176 mL/min vs 948+/-259 mL/min) at the high dyspnea target (p > 0.5; 0+/-11% bias). CONCLUSIONS: Patients with COPD can use dyspnea ratings from an incremental cycle ergometry test to regulate exercise on the treadmill without systematic bias at an intensity of 80% of peak VO2, but exceed the desired VO2 when using the dyspnea rating at an intensity of 50% of peak VO2.

Dyspnea ratings for prescribing exercise intensity in patients with COPD.

STUDY OBJECTIVE: We tested the hypothesis that patients with COPD can use dyspnea ratings obtained from a prior graded exercise test as a target to reliably produce specific exercise intensities. DESIGN: Four visits over a 7-week period. SETTING: Pulmonary function and cardiorespiratory exercise laboratory at a university hospital. PATIENTS: Fifteen symptomatic patients with stable COPD. Age was 68 +/- 7 (mean +/- SD) years. FEV1 was 1.12 +/- 0.22 L (45 +/- 8% predicted). INTERVENTIONS: At each visit, patients estimated the heaviness of weights to evaluate their magnitude estimation of a nonrespiratory task; after pulmonary function testing was completed, patients were tested on the cycle ergometer. At estimation trial 1 (day 0), patients estimated the intensity of dyspnea using the 0 to 10 category-ratio scale during an incremental exercise test. Estimation trial 2 (day 5 to 7) was the same as the previous trial. At production trials 1 (day 10 to 14) and 2 (day 40 to 44), patients were instructed to produce specific intensities of dyspnea (ie, dyspnea targets) at 50% and at anaerobic threshold (AT) or 80% of peak oxygen consumption (Vo2) as calculated from results at estimation trial 2. MEASUREMENTS AND RESULTS: Lung function was stable at all visits. Dyspnea ratings were 1.8 +/- 0.9 (range, 1 to 3) at 50% of peak Vo2 and 5.5 +/- 1.5 (range, 4 to 8) at AT/80% of peak Vo2 (17.0 +/- 3.4 mL/kg/min) at estimation trial 2. The individual percent changes in Vo2 at the lower dyspnea target were 12 +/- 19% and 11 +/- 19% for production trials 1 and 2, respectively, compared with estimation trial 2. At the higher dyspnea target, the corresponding individual percent changes in Vo2 were -4 +/- 9% and -7 +/- 11%, respectively. For all 15 patients, there were borderline statistical differences for the Vo2 values at the lower (p = 0.04 and p = 0.07) and at the higher (p = 0.04 for each production trial) dyspnea targets for production trials 1 and 2 compared with estimation trial 2. Two patients showed 50% or greater variability in the calculated exponent for magnitude estimation of weights. In a subgroup analysis of the 13 patients with reproducible magnitude estimation of the heaviness of weights, there were no significant differences in Vo2 for the two production trials compared with estimation trial 2 at both exercise intensities. CONCLUSIONS: Dyspnea ratings obtained from an incremental exercise test can be used as a target for patients with COPD to regulate/monitor the intensity of exercise training. The ability of patients with COPD to achieve a desired Vo2 based on an individual dyspnea target was generally more accurate at the higher exercise level (AT/80% of peak Vo2) compared with the lower intensity (50% of peak Vo2). Acceptable accuracy was maintained over a 5-week time period.

Scanning electron microscopic findings in a basilar tip aneurysm embolized with Guglielmi detachable coils.

With the growing use of endovascular therapy for intracranial aneurysms, it is important that we understand at a cellular level the processes that lead to lesion obliteration. We present autopsy findings, including electron and light microscopic studies, of a basilar artery aneurysm that was successfully embolized with the Guglielmi detachable coil system 4 weeks before the patient died.

Endovascular problem solving with intravascular stents.

BACKGROUND AND PURPOSE: Intravascular stents are being used with increasing frequency in interventional neuroradiology. They provide the potential to expand the therapeutic capabilities of the endovascular therapist and stand to revolutionize endovascular intervention within both the intracranial and extracranial vessels. We present our application of stent technology to further the understanding of endovascular rescue from procedural complications and the solving of complex clinical problems. METHODS: Three patients underwent unplanned placement of intravascular stents. In two patients a stent was used to provide stabilization of an irretrievable intravascular device; in the third patient a stent was used to provide a scaffolding for proximal external carotid sacrifice. RESULTS: Stent deployment was successful in all patients. The intravascular devices stabilized by stent placement included unraveled fragments of a Guglielmi detachable coil (GDC) and a partially deployed coronary stent. Proximal external carotid sacrifice was achieved with the aid of a stent in one patient to control hemorrhage from recurrence of laryngeal cancer. No periprocedural neurologic complications were encountered. Six-month follow-up angiography in one patient showed only minimal myointimal hyperplasia induced by stent-stabilized GDC fragments adjacent to the internal carotid vessel wall. CONCLUSION: Stents can be used to provide stabilization of irretrievable intravascular devices or as a scaffolding for proximal vessel sacrifice. These applications may allow endovascular rescue of procedural complications and solve unique clinical problems.

Remote vascular catastrophes after neurovascular interventional therapy for type 4 Ehlers-Danlos Syndrome.

Type 4 Ehlers-Danlos Syndrome (EDS 4) is the most malignant form of Ehlers-Danlos Syndrome, often accompanied by neurovasacular complications secondary to vessel dissection or aneurysms. The fragile nature of connective tissue in these patients makes exovascular and endovascular treatment hazardous. We have treated four patients with EDS 4 over the last 8 years by using neuroendovascular procedures. Two of these individuals suffered remote vascular injuries around the time of their procedures and ultimately died. The circumstances surrounding their deaths will make up the body of this report.

Vein of Galen aneurysms: a review and current perspective.

Our approach to treating a patient with a vein of Galen aneurysm is, of course, influenced greatly by the age of the patient, the clinical symptoms, and the angiographic architecture of the malformation. Therapeutic options are primarily based on whether a true AVM is present or if the malformation represents an arteriovenous fistula involving the vein of Galen. Arterial endovascular approaches, microneurosurgery, and/or radiosurgery are preferred for management of the former; the transvenous endovascular approach has become the cornerstone of treatment in the latter. The most critical group, however, is the neonates in extreme cardiovascular distress. In this case our therapeutic intervention is initially endovascular from the venous side, either transfemoral or transtorcular. The immediate goal is to increase resistance to right ventricular output. Advantages of this approach over a transarterial approach include a shorter anesthesia time, minimal fluid and/or contrast administration, and creation of a wire "basket" or "bird's nest" on the venous side that helps prevent emboli that may be deposited on the arterial side in subsequent embolizations from passing through the malformation. The transvenous approach can be easily repeated multiple times and may be supplemented by transarterial embolizations. Endovascular coils have been the mainstay for such venous embolizations. The end point of treatment is not complete occlusion of the fistula but improvement in cardiac function. Often, more than one stage is required to reach our goal. The results in recent years have been encouraging and are to a large degree attributable to the advances in endovascular approaches. With future improved tools for diagnosis and treatment, perhaps the prognosis for this difficult malady also will continue to improve.

Use of intravascular stents in the treatment of internal carotid and extracranial vertebral artery pseudoaneurysms.

The management of extracranial carotid or vertebral artery pseudoaneurysms is controversial. Although some of these lesions resolve spontaneously, many clinicians opt to treat them with trapping procedures that result in vessel sacrifice. We describe two cases in which an intravascular stent was used to obliterate an aneurysm of the extracranial vertebral artery and the internal carotid artery, respectively, while maintaining the patency of the parent vessel. The technique, which has been successful in experimental animal models, shows promise for application in humans.

Calcium 45 autoradiography and dual-isotope single-photon emission CT in a canine model of cerebral ischemia and middle cerebral artery occlusion.

PURPOSE: To determine whether transient ischemia can be separated from permanent ischemia via calcium 45 autoradiography and to assess the applicability of dual isotope single-photon emission CT (SPECT) in the evaluation of cerebral blood flow. METHODS: We examined calcium influx in 12 dogs (group A) by using whole-brain calcium 45 autoradiography: Animals received 250 microCi/kg 24 hours after 30-minute (n = 6) or permanent (n = 6) middle cerebral artery (MCA) occlusion. Forty-eight hours after MCA occlusion, 5-mm coronal brain sections were fixed for either autoradiography or pathologic examination. In a separate study, 9 mongrel dogs (group B) were given 250 microCi/kg calcium 45 and a mean dose of 700 microCi/kg technetium Tc 99m hexamethylpropyleneamine oxime intravenously. A silicone plug was then injected into the internal carotid artery and angiography was performed to verify MCA occlusion. A 10th (control) animal did not undergo occlusion. In an 11th animal, placement of the plug could not be achieved and a slurry of microfibrillar collagen was injected into the carotid artery. No angiography was performed in animals 10 and 11. After occlusion, each animal was injected with a mean dose of 126 microCi/kg simultaneous acquisition for technetium 99m and 123I-iodoamphetamine. RESULTS: In group A, all animals who had permanent MCA occlusion showed infarction and increased calcium 45 uptake in infarcted territories. None of the animals who had 30-minute occlusion had either increased calcium 45 uptake or infarction at 48 hours. In group B, 7 or 10 dogs had SPECT findings that were consistent with the calcium autoradiographic marker for ischemia. One animal died during the procedure and 1 dog served as a control. CONCLUSION: Calcium 45 autoradiography allowed distinction between areas of temporary and permanent occlusion. Iodoamphetamine imaging was not consistently sensitive to that level of ischemia. Timing of calcium influx may lead to insight that could impact timing of pharmacologic or endovascular intervention.

Clinical evaluation of exertional dyspnea.

The medical history is the first step in the clinical evaluation of exertional dyspnea. It should include pertinent questions about the characteristics of dyspnea, especially descriptive qualities, onset, frequency, severity, and activities that provoke the symptom. Based on this information, along with the physical examination, the health care provider should be able to categorize the cause of exertional dyspnea as suspected cardiac disease, suspected respiratory disease, or as unexplained. Laboratory testing is ordered using a logical approach to diagnose the most probable cause of dyspnea. Cardiopulmonary exercise testing is indicated to differentiate cardiac and respiratory limitation, to document deconditioning, and to identify psychogenic dyspnea. The measurement of dyspnea and leg discomfort during exercise testing can be performed using the Borg 0 to 10 category-ratio scale or the visual analog scale. These perceptual responses can provide useful information about symptom limitation, which is complementary to physiologic data.

The use of stents in the management of neurovascular disease: a review of historical and present status.

In the mid-1960s, radiologists began experimenting with stents for use in the peripheral vasculature in the hope of treating vascular insufficiency resulting from vessel stenosis in a nonsurgical manner. The 1990s saw stents move into the neurovascular arena for the management of a variety of disease processes, including arterial and venous sinus stenosis, arterial dissection, arterial aneurysms, and arteriovenous fistulae. This article reviews the current status of stenting in regard to the management of neurovascular maladies.

Intraoperative urokinase infusion for embolic stroke during carotid endarterectomy.

Embolic stroke is an infrequent complication of carotid endarterectomy. Somatosensory evoked potential monitoring detected delayed acute neurological deterioration during endarterectomy performed on a 71-year-old woman. Intraoperative arteriography performed via an indwelling shunt revealed thrombus within the middle cerebral artery and distal branches. A microcatheter was placed into the internal carotid artery via the arteriotomy and advanced into the middle cerebral artery. Urokinase was infused into and around the thrombus until almost complete thrombolysis had been achieved. The patient recovered quickly and was discharged without neurological deficit.

Percutaneous transluminal angioplasty and stenting of midbasilar stenoses: three technical case reports and literature review.

OBJECTIVE AND IMPORTANCE: Symptomatic basilar artery stenosis is a highly morbid disease process. Recent technological and pharmaceutical advances make endovascular treatment of this disease process possible. CLINICAL PRESENTATION: We report three cases of patients with a symptomatic basilar artery stenosis despite anticoagulation. INTERVENTION: All patients were successfully treated with a flexible coronary stent and perioperative antiplatelet medications without incident. Poststenting angiography demonstrated a normal-caliber artery with patent perforators. In one case, a poststenting cerebral blood flow study revealed improved perfusion. CONCLUSION: A new generation of stents and balloons makes access to intracranial intradural arterial pathological abnormalities possible. Such devices may well revolutionize the management of ischemic and hemorrhagic intracranial cerebrovascular disease.

Rupture of intracranial aneurysms during endovascular coiling: management and outcomes.

OBJECTIVE: In this study, the incidence, etiologies, and management with respect to clinical outcome of patients with iatrogenic aneurysmal rupture during attempted coil embolization of intracranial aneurysms are reviewed. METHODS: A retrospective analysis was conducted of 274 patients with intracranial aneurysms treated with Guglielmi detachable coils over a 6-year period from 1994 to 2000. Patient medical records were examined for demographic data, aneurysm location, the number of coils deployed preceding and after aneurysmal rupture, the etiology of the rupture, and the clinical status on admission and at the time of discharge. RESULTS: Of 274 patients with intracranial aneurysms treated with coil embolization, six (2%) had an intraprocedural rupture. Of these six, two were women and four were men. The mean age was 67 years (range, 52-85 yr). Mean follow-up time was 8 months (range, 0-25 mo). Aneurysmal rupture resulted from detachment of the last coil in three patients, detachment of the third coil (of four) in one patient, and insertion of the first coil in another patient. In one patient, the aneurysmal rupture was a result of catheter advancement before detachment of the last coil. The Glasgow Outcome Scale score at last follow-up examination was 1 in two patients, 2 in two patients, and 5 in two patients. CONCLUSION: The rate of rupture of aneurysms during coil embolization is approximately 2 to 4%. The clinical outcome may be related to the timing of the rupture and the number of coils placed before rupture. If extravasation of contrast agent is seen, which suggests intraprocedural rupture, further coil deposition should be attempted if safely possible.