John B. Terry

Elective Stenting of Symptomatic Basilar Artery Stenosis

BACKGROUND AND PURPOSE Percutaneous angioplasty of the intracranial arteries still carries the risk of dissection, with acute closure and embolization. Stenting has been shown to improve the safety and durability of angioplasty in every circulatory bed in which it has been applied. However, stenting of the intracranial arteries has been limited by the availability of stents that can be reliably deployed intracranially. METHODS Twelve patients underwent elective stenting of the basilar artery after episodes of vertebrobasilar ischemia. In all patients, either medical therapy had failed or the patient had a contraindication for long-term anticoagulation. Information from independent neurological examinations, quantitative angiography, and clinical follow-up was collected. Differences between pretreatment and posttreatment degree of stenoses were subjected to 1-way ANOVA for repeated measures. RESULTS There were 10 men and 2 women, all white, aged 40 to 82 years (mean age, 62.6 years). Stent placement was successful in all patients, leading to statistically significant changes in the degree of stenosis, from 71. 4% (range, 53% to 90%) to 10.3% (range, 0% to 36%) (P<0.0001). There were no deaths, stent thromboses, perforations, ruptures, or myocardial infarctions. Clinical follow-up was available for 0.5 to 16 months (mean, 5.9 months). One patient had nonspecific symptoms, and another had a transient ischemic attack. All other patients remained asymptomatic. CONCLUSIONS Elective stenting of the basilar artery is feasible, with minimal risk to the patient. Its impact on long-term stroke prevention and its durability are unknown and will require further study.

Influence of Age upon Complications of Carotid Artery Stenting

Purpose: To examine the impact of age upon the development of neurological and major systemic complications during or after carotid artery stenting. Methods: We reviewed the complications that occurred in patients undergoing elective carotid stent implantation between September 1994 and August 1996. The study population was then divided into 3 groups according to age: ≥ 80 (group A), 75 to 79 (group B), and ≤ 74 (group C) years. The rates of death, major and minor stroke, and myocardial infarction were compared among the groups, as well as with the rates reported by the major carotid endarterectomy (CEA) trials. Results: During the study period, 182 patients (216 vessels) were treated with carotid stenting. There were 19 (10.4%) complications: 1 (0.5%) death, 2 (1.1%) major strokes, 15 (8.2%) minor strokes, and 1 (0.5%) myocardial infarction. Neurological complications were clearly related to increased age with rates of 25.0% in group A versus 8.6% in group C (p = 0.042). The overall per patient rate of death or major stroke was 1.6% (1.4% per vessel). Conclusions: Increasing age has a negative impact on the rate of complications in carotid stent patients. However, the majority of those complications are minor. The relative roles of medical therapy, stenting, and CEA in patients > 80 years of age must await the results of randomized trials.

Carotid artery stenting in patients with high neurologic risks

Forty-four patient with high neurologic risks (Mayo class IV) successfully underwent carotid artery stenting with combined major stroke and death rates of 4.5%. Late follow-up at a mean of 23 +/- 1.8 months showed 1 non-neurologic death, but no neurologic events or repeat stenting procedures.

Emergency endovascular treatment of cerebral sinus thrombosis with a rheolytic catheter device.

Severe thrombosis of the superior sagittal, transverse, and straight sinuses developed in a 53‐year‐old woman. This resulted in extensive multifocal hemorrhagic venous infarction and severe intracranial hypertension refractory to intensive management. Endovascular therapy using a rheolytic catheter device in combination with a small amount of fibrinolytic agent led to rapid normalization of the intracranial pressure, allowing optimization of the cerebral perfusion pressures and was followed by steady, albeit protracted, clinical improvement. The patient not only survived but also left the hospital with minimal neurologic deficit. The rheolytic catheter endovascular treatment is, in the opinion of the authors, the treatment of choice for patients with life‐threatening cerebral sinus thrombosis.

Neurological Monitoring during Carotid Artery Stenting: The Duck Squeezing Test

Purpose: To examine the usefulness of a novel method for neurological monitoring during carotid artery stenting (CAS). Methods: The records of patients who underwent elective CAS between June 1996 and October 1998 were reviewed to identify those who had neurological changes during the procedure. We examined whether the neurological change had been detected by a change in the ability of the patient to respond to predetermined commands involving a small rubber duck placed in the contralateral hand. Results: Two hundred seventy patients (320 vessels) underwent monitoring using the Duck Squeezing Test; 10 suffered neurological events during the procedure. Four of these were transient and temporally related to balloon inflation. Another 6 were tentatively ascribed to distal embolism. All instances were accompanied by a change in the patients ability to perform the Duck Squeezing Test, which allowed the identification of the abnormal clinical situation. In addition, there were 4 false-positive tests secondary to the patient accidentally dropping the rubber duck. Conclusions: The Duck Squeezing Test is a sensitive and specific method for monitoring patients during elective CAS. Its practical applicability is based on sound neurophysiological concepts, which underscore the clinical importance of the test.

ENDOVASCULAR THERAPY OF TRAUMATIC CAROTID-CAVERNOUS FISTULAS

Traumatic carotid-cavernous fistulas (CCF) are capable of causing a large variety of signs and symptoms, including visual loss, glaucoma, chemosis, exophthalmos, and orbital cranial nerve palsies. The high pressure in the veins that normally drain the globe can cause them to engorge and produce local compression of adjacent structures. At present, endovascular closure of the fistula is the treatment of choice, particularly in patients with progressive neurologic deterioration. Endovascular repair of CCF most commonly involves the use of detachable balloons, although coils are also used. Effective closure of the fistula leads to rapid resolution of the symptoms.

Evolution of neuronetworks.

Since the 1970s, the care of critically ill neurologic and neurosurgical patients has emerged as a developing subspecialty. Management of these patients involves an enormous amount of data generation and analysis. Review of the history of neuroepidemiology and neurocritical care demonstrates the inevitability of their present unwieldy burden of information. Compelling advantages of computerization in direct patient care include aid in data acquisition, analysis and remote access. Infrastructure and resources used to collect data on individual patients may be augmented to archive data in clinical databases. Several investigators have initiated information management projects including automation of bedside clinical documentation, development of systems for remote access to information and patient registries to study the natural history and outcome of specific neurological conditions. These are steps toward the development of integrated systems to aid in patient monitoring, data management, continuous quality improvement and the generation of hypotheses for further clinical investigation. Improvements in information management technology will allow increased efficiency in an era where information generation continues to increase exponentially.

Hyperechoic middle cerebral artery: acute occlusion detected by transcranial duplex ultrasonography.

The authors describe the appearance of acute thromboembolic occlusion of the middle cerebral artery (MCA) using transcranial duplex ultrasonography. Acute occlusion of the MCA commonly leads to severe cerebral infarction. In patients with acute MCA occlusion, secondary edema and elevated intracranial pressure are major causes of increased morbidity and mortality. Thus, the prompt detection of occlusion influences early therapy, including thrombolysis and increased control of intracranial pressure. The hyperdense appearance of the acutely occluded MCA as seen using computed tomography (CT) has been extensively reported in the literature. However, its appearance using transcranial duplex ultrasonography has not been reported. The authors report four patients who had clinical features of ischemia throughout the MCA territory. All patients were studied with CT and transcranial duplex ultrasonography within 6 hours of the onset of symptoms. Head CT of all fou r patients showed a hyperdense MCA sign with infarction of t he MCA territory. Transcranial duplex studies using either pulsed Doppler or color Doppler sonography displayed a hyperechoic MCA with no evidence of flow. Subsequent duplex ultrasonography and magnetic resonance angiography showed all four patients had ipsilateral occlusion of the internal carot id artery. Transcranial duplex ultrasonography assists in the early diagnosis of acute MCA occlusion. The affected vessel is displayed as a hyperechoic structure associated with no flow using Doppler examination.