Symptomatic Internal Carotid Artery Occlusion: A Long-Term Follow-Up Study

Abstract

AAAs. There were 28 deaths (6.1%) following elective repair of 459 incidentally detected AAAs (OR, 0.37; 0.24 to 0.68).Comment: The risk of death in a male patient Ͼ65 years operated for an incidentally detected aneurysm is approximately three times more than one operated on for a screened detected AAA. The data do not permit a "drill down" for why patients operated on for screened AAAs have lower operative mortality than those operated on for incidentally detected AAAs. Reasons could include lower ages and decreased comorbidities of screened patients. Also, screened patients may have smaller aneurysms and/or less complex anatomy permitting a higher proportion of endovascular repairs. Overall, however, the author's data provid another bit of evidence to encourage screening in patients at risk at for AAA. Proposed Chronic Cerebrospinal Venous Insufficiency Criteria Do Not Predict Multiple Sclerosis Risk or SeverityCentonze D, Floris R, Stefanini M, et al. Ann Neurol 2011;70:51-8. Conclusion: Chronic cerebrospinal venous insufficiency (CCSVI) has no role in either multiple sclerosis (MS) risk or MS severity. Summary: Anatomic abnormalities of major neck and chest veins are proposed to impair central nervous system venous drainage. Zamboni has proposed that CCSVI has a strong association with multiple sclerosis (J Neurol Neurosurg Psychiatry 2009;80:382-99). His results indicate MS is caused by CCSVI and that CCSVI plays a substantial role in MS progression. Endovascular interventions directed to correct abnormalities of venous drainage reportedly characteristic of CCSVI could potentially improve the clinical course of MS (Zamboni P, et al. J Vasc Surg 2009;50:1348-58). However, some question the very existence of CCSVI (Doepp F et al. Ann Neurol 2010;68:173-83).It has been suggested that studies failing to demonstrate a significant association between CCSVI and MS use alternative approaches to define CCSVI than those utilized by Zamboni et al. The authors, therefore, utilized an experimental protocol they feel is identical to that developed by Zamboni and coworkers. This protocol was applied to an independent population of MS patients and healthy controls by operators specifically trained by Dr Zamboni in CCSVI identification.The Zamboni method for CCSVI identification was studied in 84 MS patients and 56 healthy subjects. There were no significant differences (P ϭ .12) in CCSVI frequency between MS and control subjects. No differences were found between CCSVI-positive and CCSVI-negative patients with respect to MS duration, time between MS onset and first relapse, relapsing progressive MS, and risk of secondary progression. There were no statistical differences found between CCSVI-positive and CCSVI-negative MS subjects by analyzing measures of disability such as the mean expanded disability status scale (P ϭ .07) mean progressive index (P Ͼ .1) and mean MS severity score (P Ͼ .1). The percentage of subjects who reached expanded disability status scale 4.0 and 6.0 was not different among CCSVI-negative and CCSVI-p...

Impaired Cerebrovascular Reactivity Predicts Recurrent Symptoms in Patients with Carotid Artery Occlusion: A Hypercapnia BOLD fMRI Study

“…This finding adds to those in previous studies that investigated associations between impaired CVR and increased stroke risk. 4,11,[19][20][21][22][23][24][25][26][27][28][29][30] Nine of 12 studies found a positive association of reduced or exhausted CVR and recurrent risk of future ischemic events or stroke by using a range of vasodilatory stimuli and CVR metrics. The negative findings may be explained by insufficient vasodilatory stimuli because 2 of the studies with negative findings 3,4 used carbogen (typically 5% CO 2 ), whereas Markus and Cullinane 11 showed that exhausted CVR as assessed by hypercapnia transcranial Doppler with 6% or 8% CO 2 independently predicted future stroke and that the prediction was stronger for 8% CO 2 challenges.…”

“…1 The rate of subsequent recurrent stroke in carotid artery occlusion (CAO) has been estimated between 2.4% and 7% per year. [2][3][4] This risk persists in the face of platelet inhibitory drugs and anticoagulation. 5 A key factor in predicting recurrent ischemic episodes in CAO is the presence of hemodynamic impairment, whereby patients with an exhausted cerebrovascular reserve (CVR) and therefore impaired autoregulatory capacity are at higher risk of recurrent episodes of ischemia.…”