Does a Low-wall Coverage Stent Have a Flow Diverting Effect in Small Aneurysms? / 신경중재치료의학

BACKBROUND AND PURPOSE: The flow diverting effect of a low-wall coverage stent remains controversial. We evaluted patients who underwent stenting for small aneurysms with a low but potential risk of growth and reviewed related literature. MATERIALS AND METHODS: We evaluated 9 small aneurysms among 19 unruptured intracranial aneurysms from eight patients who underwent stenting. The patients had unexplainable severe headache (n = 8), aneurysm originating from the anterior choroidal artery (n = 3), potential growth or rupture risks including hypertension (n = 5), and multiple aneurysms (n = 6). Stents with a relatively low-wall coverage ratio (8-10%) were used. Clinical and angiographic outcomes were assessed. RESULTS: One (n = 8) or two stents (n = 1) were used without any procedural difficulties or complications. Although no immediate changes of aneurysm morphology were observed, aneurysms decreased in size (n = 8) when examined by DSA (n = 8) or MRA (n = 1) during a median 28.9-month follow-up. There were no adverse events, including thromboembolism, aneurysm rupture, or stent movement during a median 31.9-month clinical follow-up (range: 17-69 months). CONCLUSION: Although a variable degree of aneurysm size decrease may not prevent further growth or rupture of small aneurysms, stenting with a low-wall coverage ratio may have some advantageous hemodynamic effect. Flow modification of stent architecture vs. aneurysm characteristics, including size and location, on long-term outcome, requires further clarification.

Anesthetic Consideration for Neurointerventional Procedures / 신경중재치료의학

Interventional neuroradiology (INR) has been a rapidly expanding and advancing clinical area during the past few decades. As the complexity and diversity of INR procedures increases, the demand for anesthesia also increases. Anesthesia for interventional neuroradiology is a challenge for the anesthesiologist due to the unfamiliar working environment which the anesthesiologist must consider, as well as the unique neuro-interventional components. This review provides an overview of the anesthetic options and specific consideration of the anesthesia requirements for each procedure. We also introduce the anesthetic management for interventional neuroradiology performed in our medical institution.

A Study Design to Evaluate Association between Smoking and Intracranial Atherosclerotic Stenosis / 신경중재치료의학

PURPOSE: Smoking is a well known risk factor for stroke. The cerebral arteries may be uniquely susceptible to the atherosclerotic effects of smoking, such that it has a different risk profile for stroke compared with other atherosclerosis risk factors. It remains uncertain whether smoking is associated specifically with intracranial (IC) or extracranial (EC) atherosclerotic cerebrovascular disease. The aim of this study design will be to evaluate the association between smoking and severe IC stenosis, adjusting for other atherosclerosis risk factors, particularly age distribution. STUDY DESIGN: This is a retrospective cohort study design. Participants are patients (n=1714) with severe atherosclerotic stenosis undergoing cerebral catheter angiography because of stroke or transient ischaemic attack. All atherosclerotic steno-occlusive lesions are described in terms of location (anterior versus posterior circulation, IC versus EC, or intradural versus extradural). The atherosclerotic or stroke risk factors for analysis include age, gender, smoking history, number of lesions (single versus multiple), cardiac disease, diabetes mellitus, hypertension, family history, dyslipidemia, history of previous stroke, alcohol intake, metabolic syndrome and body mass index. Statistical analysis includes univariate analysis followed by multivariate logistic regression. The relationship between IC atherosclerotic stenosis and smoking will be assessed. Differences in risk factor distribution is analysed according to age at intervals of 10 years. Significant risk factors associated with IC atherosclerotic stenosis will also be assessed by multivariate logistic regression analysis. SUMMARY: This is an analytical study design that intends to measure the association between IC or EC atherosclerotic stenosis and smoking and other risk factors. We anticipate that it will have the power to detect any relationship between smoking and IC atherosclerotic lesions especially in younger patients.

Intravenous r-tPA Therapy in Acute Ischemic Stroke: The Implication of Immediate Neurological Improvement for the Long-term Outcome

BACKGROUND: Intravenous recombinant tissue plasminogen activator (r-tPA) infusion is the only established treatment for acute ischemic stroke so far. We explored whether the demonstrated efficacy of r-tPA could be applied to communi-ty-based hospitals in Korea and whether the immediate improvements after r-tPA infusion had any predicting value for long-term outcomes. METHODS:Twenty-six patients (mean age, 69; 46% female) with acute ischemic stroke were treated with r-tPA, abiding by the National Institute of Neurological Disorders and Stroke (NINDS) protocol. The Neurological status was measured with the National Institutes of Health Stroke Scale (NIHSS) at baseline, at 1 hour after r-tPA , at 24 hours, and at 7 days and the functional outcome was evaluated with the modified Rankin scale (mRS) and Barthel Index at 90 days after stroke. RESULTS: Of 26 patients, 16 (62%) made full recovery or became independent, 4 (15%) had severe physical disability, and 6 (23%) patients died. Three patients (11.5%) had intracranial hemorrhage (asymptomatic, 2; symptomatic, 1). There were no significant differences in age, sex, risk factors, baseline NIHSS scores, hemorrhagic complication, initial brain CT abnormalities, and onset to needle time between good (full recovery or mRS 0-2) and poor groups (mRS 3-5 or death) at day 90, except for the improvement of NIHSS examined at 1 hour after r-tPA (repeated measured ANOVA test, p<0.01). CONCLUSIONS The NINDS r-tPA protocol is feasible in the community-based hospitals in Korea with the safety and efficacy comparable to the results of NINDS r-tPA trials. In addition, we suggest that the immediate neurological improvement after r-tPA be a predictor for favorable long-term outcomes. (J Korean Neurol Assoc 19(4):364~369, 2001)

24-hour Blood Pressure Monitoring in Chronic Cerebrovascular Disease: Decreased Nocturnal Blood Pressure Dip

BACKGROUND: Periventricular white matter changes(PVWC) in chronic cerebrovascular disease are regarded to be caused by chronic low perfusion and as forms of small arterial disease of cerebral circulation. In some reports, these are suggested to be concerned with the fluctuation of blood pressure. The purpose of this study was to elucidate the diurnal pattern of BP in chronic cerebrovascular disease and the relationship between severity of PVWC and decrement of nocturnal dip through the ambulatory 24 hour blood pressure monitoring (ABPM). Subjects and METHODS: ABPM were carried out every 30 minutes in 36 patients with chronic cerebrovascular disease, prospectively. Twenty-five had PVWCS and/or multiple lacunar infarction (MLI) with various grades, 11 had large artery territorial infarction (LATI) without PVWC. The patterns of ABPM in each group were analyzed by disease entity and severity of PVWC. RESULTS: There was no differences in the two groups; PVWC/MLl and LATI, in properties(age, sex, etc.) and possible stroke risk factors (hypertension, diabetes mellitus, hypercholesterolemia, smoking, etc.) (P<.05). The pattern of ABPM of PVWC/MLl group showed the decrement of nocturnal dip of BP unlike LATI group (P<.05). The decrement of nocturnal dip of BP correlated with severity of PVWC (P<.05). CONCLUSION: We conclude that the diurnal pattern of BP in small artery disease is different from that of large arterial disease group and related to the severity of PVWC.