Cerebrovascular Procedures Research Articles

Extravascular Optical Coherence Tomography

Extravascular optical coherence tomography (OCT), as a noninvasive imaging methodology with micrometer resolution, was evaluated in a murine model of carotid atherosclerosis by way of assessing the efficacy of pravastatin therapy. An OCT device was engineered for extravascular plaque imaging. Wild-type mice and apolipoprotein E-deficient (ApoE(-/-)) mice were randomized to 3 treatment groups: (1) wild-type on a diet of standard rodent chow (n=13); (2) ApoE(-/-) on a high-fat, atherosclerotic diet (HFD; n=13); and (3) ApoE(-/-) on a HFD given daily pravastatin (n=13). Mice were anesthetized and the left common carotid was surgically exposed. Three-dimensional (3D; 2 spatial dimensions+time) and 4D (3 spatial dimensions+time) OCT images of the vessel lumen patency were evaluated. After perfusion, in situ OCT imaging was performed for statistical comparison with the in vivo results and final histology. Intraoperative OCT imaging positively identified carotid plaque in 100% of ApoE(-/-) mice on HFD. ApoE(-/-) mice on HFD had a significantly decreased lumen patency when compared with that in wild-type mice (P<0.001). Pravastatin therapy was found to increase lumen patency significantly in ApoE(-/-) mice on HFD (P<0.01; compared with ApoE(-/-) on HFD). The findings were confirmed with OCT imaging after perfusion and histology. OCT imaging offers the potential for real-time, detailed vessel lumen evaluation, potentially improving surgical accuracy and outcomes during cerebrovascular neurosurgical procedures. Pravastatin significantly increases vessel lumen patency in the ApoE(-/-) mouse on HFD.

뇌혈관 중재적시술에 있어 측방향 차폐체를 이용한 시술자 피폭 선량 저감화 방법 연구

The bi-plane cerebrovascular angiography radiation is done the radiation exposure at the forward and lateral direction as opposed to the one of the source. So, the exposure dose of radiation workers increases further. Therefore, the medical diagnostic radiation workers as well as patients is interested to ways to reduce the dose. The exposure dose of cerebral angiography and interventional radiology must be considered the primary radiation of X-ray tube directly, scattered primary radiation between lateral tube and lateral detector and relatively small secondary scatter radiation in the walls of room. The aim of study is that the exposure dose of primary and scatter radiation reduce as much as possible to install protection device of lateral protection than common shielding of table and ceiling. As a result, the dose of fluoroscopy was reduced approximately 3.64 times the gonads, thyroid approximately 3.13 times, 4.42 times around eyes. And the dose of DSA was reduced approximately 4.98 times the gonads, thyroid approximately 3.00 times, 1.67 times around eyes. Consequently, medical practitioners can be helpful for radiation dose-exposure for the lateral protection of bi-plane cerebrovascular angiography more than the common shield method in cerebrovascular angiography and interventional radiological procedures. Key Word: bi-plane cerebrovascular, radiation workers, interventional angiology procedures, lateral protection

Correlation of atherosclerotic renal artery stenosis with extracranial carotid and intracranial cerebral artery atherosclerosis in patients with ischemic stroke

Objective. This study was to evaluate the relationship of atherosclerotic renal artery stenosis (ARAS) with extracranial carotid arteries atherosclerosis (ECAS) and intracranial cerebral atherosclerosis (ICAS) in ischemic stroke (IS) patients. Methods. This study was a prospective cohort analysis of consecutive patients with IS who had not a history of renal artery stenosis (RAS). Abdominal aortography was performed to screen for RAS after the cerebrovascular diagnostic procedure. Multivariate logistic regression analysis was performed to investigate the association of the clinical variables with significant ARAS (≥ 50%). Results. ARAS was identified in 61 (23.1%) of all patients and 34 patients (12.9%) had significant ARAS (≥ 50%). ECAS (≥ 70%) and ICAS (≥ 50%) was found in 66 (25%) and 48 (18.2%) respectively. Patients with ECAS (≥ 70%) were more likely to have significant ARAS than patients without ECAS (28.8% vs 6.2%, p < 0.001). In multivariate analysis, only advanced age (≥ 60 years) (OR = 2.84, 95% CI 1.01–7.91) and ECAS (≥ 70%) (OR = 5.27, 95% CI 2.396–11.60) were independent risk factors for significant ARAS. Conclusion. Incidental ARAS is a relatively common finding among patients with IS, and there is a close relationship between ARAS and ECAS. Abdominal aortography should be performed to identify ARAS in elderly patients with IS, especially combined with severe ECAS.

Intra operative indocyanine green video-angiography in cerebrovascular surgery: An overview with review of literature

Microscope integrated Near infra red Indocyanine green video angiography (NIR ICG VA) has been frequently used in cerebrovascular surgery. It is believed to be a simple and reliable method with acquisition of real time high spatial resolution images. The aim of this review article was to evaluate the efficacy of intra operative Indocyanine green video angiography (ICG VA) in Aneurysm, brain arteriovenous malformations (AVM) and extracranial-intracranial (EC-IC) bypass surgeries and also to analyze its limitations. Intra operative imaging is a very useful tool in guiding surgery; thus, avoiding surgical morbidity. Now-a-days, many cerebrovascular units are using ICG VA rather than Doppler and intra operative DSA in most of their aneurysm surgeries, and surgeons are incorporating this technique for AVM and in EC-IC bypass surgeries too. This article is an overview of the beneficial effects of ICG VA in cerebrovascular surgery and will also point out its limitations in various circumstances. Intra operative ICG VA gives high resolution, real time images of arterial, capillary, and venous flow of cerebral vasculature. Although it gives adequate information about the clipped neck, parent/branching artery and perforator involvement, it has some limitations like viewing the neck residuals located behind the aneurysm, thick walled atherosclerotic vessels, and thrombosed aneurysms. In AVM surgery, it is useful in detecting the residual nidus in diffuse type AVM, but cannot be relied in deep seated AVMs and it gives exact information about the anastomosis site in EC-IC bypass, thus, avoiding early bypass graft failure. NIR ICG VA is a simple, reliable, and quick method to pick up subtle findings in cerebrovascular procedures. But in selected cases of aneurysms, endoscopy and intra operative Digital substraction angiography (DSA) may be helpful, whereas in deep seated AVMs, navigation may be required as an adjunct to confirm intra operative findings.

Abstract P238: US Cost Savings Resulting from the Dronedarone-Associated Reduction in Cardiovascular Hospitalizations among Atrial Fibrillation/Flutter Patients in the ATHENA Trial: Full Study Analysis

Introduction: The ATHENA trial randomized atrial fibrillation/flutter (AF/AFL) patients (pts) with ≥1 other cardiovascular (CV) risk factors to dronedarone (n=2301) or placebo (n=2327), plus standard care. Dronedarone reduced the rate of first CV hospitalization over the study period (mean ± SD 21 ± 5 months). This analysis assesses, from a US perspective, potential cost savings from the reduction in overall (first + subsequent) CV hospitalizations in ATHENA. Methods: Using a cost analysis model, we applied hospitalization costs reported from a US cohort of AF/AFL pts to hospitalization events among the ATHENA population. Clinical inputs included all CV- and adverse event (AE)-related hospitalizations over the ATHENA study period. Cost inputs (2008 values) were (i) weighted mean CV hospitalization costs (non-fatal + fatal combined), categorised according to cause of admission, derived from claims data for a cohort of ATHENA-like AF/AFL pts (n=10,200) with Medicare supplemental insurance, and (ii) DRG costs of hospitalizations for AEs recorded in ATHENA. Cost variations were assessed using Monte Carlo sensitivity analysis. Results: In ATHENA, overall CV hospitalization rate fell by 25% with dronedarone (1177/2301 vs 1596/2327, dronedarone vs placebo arms). Based on the observed hospitalization rates and derived hospitalization costs (Table), overall cost savings with dronedarone were estimated at (mean ± SD) $1763 ± 207 per pt over the ATHENA study period. The estimated savings in CV hospitalization costs (mean $1777 per pt) heavily outweighed the added estimated AE hospitalization costs (mean $14 per pt). Sensitivity analysis showed that the cost offset was relatively stable (range $1023−$2596 over 10,000 cycles of random variation). Conclusions: Dronedarone reduced the overall CV hospitalization rate by 25% in the ATHENA population, resulting in estimated mean hospitalization-related cost savings of $1763 per pt over the study period. Cause of hospitalization Number of hospitalizations per 100 patients 1 Default cost per hospitalization Hospitalization cost saving per patient Placebo + standard care Dronedarone + standard care Myocardial infarction or unstable angina 4.86 3.09 $17,360 $307 Cardiac arrhythmia and conduction disorders 2 36.18 22.82 $8,601 $1,150 Cardiovascular surgery (bypass/PCI) 3 4.38 3.91 $21,233 $100 Worsening heart failure, including pulmonary edema or dyspnea of cardiac origin 7.91 7.17 $9,945 $73 Implantation of a pacemaker, ICD or any other cardiac device 3.57 2.83 $18,272 $136 Transient ischemic attack or stroke (except intracranial hemorrhage) 2.75 2.00 $9,006 $68 Other cardiovascular 4 8.90 9.34 $12,807 −$57 Total cardiovascular hospitalizations 68.55 51.15 − $1,777 Adverse events 5 0.26 0.56 $4,681 −$14 All hospitalization events 68.81 51.71 − $1,763 Abbreviations : ICD, implantable cardiac defibrillator; PCI, percutaneous coronary intervention 1. Numbers are rounded up/down from 3 decimal places. 2. Atrial fibrillation and other supraventricular rhythm disorders and ventricular tachycardia (non-sustained and sustained VT), ventricular fibrillation and ventricular extrasystoles and other ventricular arrhythmia. 3. Transcutaneous coronary, cerebrovascular or peripheral procedures and cardiovascular surgery, except cardiac transplantation. 4. Cardiac transplantation, cardiovascular infection, pulmonary embolism or deep vein thrombosis, non-fatal cardiac arrest, major bleeding (requiring ≥2 units of blood or any intracranial hemorrhage), atherosclerosis-related (if not otherwise specified), syncope, blood pressure-related (hypotension, hypertension; except syncope), stable angina pectoris or atypical chest pain. 5. Non-cardiovascular and treatment-related.

Anesthesia for Carotid and Cerebrovascular Procedures in Interventional Neuroradiology

Interventional neuroradiology (INR) continues to evolve as a clinical specialty. About one-third of interventional neuroradiologists now report having admitting privileges. As the complexity of cases coupled with more patient comorbidities increases, the involvement of anesthesiologists in INR realm becomes more important. Research as to how to manage these patients in terms of anesthesia is slowly emerging. Procedures include embolization of arteriovenous malformations (AVMs), aneurysms, and vascular tumors. The procedures can be lengthy and uncomfortable, and patients often require sedation or anesthesia in addition to continuous monitoring of the cardiorespiratory and neurologic systems. Outcome studies indicate that endovascular coiling is superior to neurosurgical clipping if measured as survival and development of seizure states at 1 year even though the risk of rebleeding is higher in the coiling group. The case for carotid artery

The influence of body mass index obesity status on vascular surgery 30-day morbidity and mortality

Mild obesity may have a protective effect against some diseases, termed an "obesity paradox." This study examined the effect of body mass index (Kg/m(2) BMI) on surgical 30-day morbidity and mortality in patients undergoing vascular surgical procedures. As part of the National Surgical Quality Improvement Program (NSQIP), demographic and clinical risk variables, mortality, and 22 defined complications (morbidity) were obtained over three years from vascular services at 14 medical centers. At each medical center, patients from the operative schedule were prospectively and systematically enrolled according to NSQIP protocols. Outcomes and risk variables were compared across NIH-defined obesity classes (underweight [BMI<or=18.5], normal [18.5<BMI<25], overweight [25<BMI<or=30], obese I [30<BMI<or=35], obese II [35<BMI<or=40], and obese III [BMI>40]) using analysis of variance and means comparisons. Logistic regression was used to control for other risk factors. Vascular procedures in 7,543 patients included lower extremity revascularization (24.6%), aneurysm repair (17.4%), cerebrovascular procedures (17.3%), amputations (9.4%), and "other" procedures (31.3%). In the entire cohort, there were 1,659 (22.0%) patients with complications and 295 (3.9%) deaths. Risk factors of hypertension and diabetes increased with BMI (analysis of variance [ANOVA] P < .05) as expected; smoking, disseminated cancer, and stroke decreased (ANOVA P < .01). Twenty other risk factors, as well as mortality and morbidity, had "U" or "J"-shaped distributions with the highest incidence in underweight and/or obese class III extremes but reduced minimums in overweight or obese I classes (ANOVA P < .05). After controlling for age, gender, and operation type, mortality risk remained lowest in obese class I patients (Odds ratio [OR] 0.63, P = .023) while morbidity risk was highest in obese class III patients (OR 1.70, P = .0003), due to wound infection, thromboembolism, and renal complications. Underweight patients have poorer outcomes and class III obesity is associated with increased morbidity. Mildly obese patients have reduced co-morbid illness, surprisingly even less than normal-class patients, with correspondingly reduced mortality. Mild obesity is not a risk factor for 30-day outcomes after vascular surgery and confers an advantage.

Carotid artery stenting: Identification of risk factors for poor outcomes

Age greater than 80 has been identified as a risk factor for complications, including stroke and death, in patients undergoing carotid artery angioplasty and stenting (CAS). This study evaluates other potential predictors of perioperative complications in patients undergoing CAS. All cerebrovascular endovascular procedures performed by the vascular surgery division at our university hospital between July 2003 and December 2005 were retrospectively examined. During the course of 212 admissions, 198 patients underwent 215 procedures. Patient age, comorbidities, and admission status were analyzed as independent (predictor) variables. Complication rate, discharge disposition, and length of hospital stay were considered dependent (outcome) variables. Logistic regression and Fisher exact test or Student t test were performed, as appropriate. Complications included major and minor stroke, myocardial infarction, femoral artery pseudoaneurysm, and death. The rates of perioperative major and minor stroke were 0.5% and 2.8%, respectively. Chronic renal insufficiency was a predictor of perioperative complications, including stroke: patients with serum creatinine greater than 1.3 mg/dL had a 37% complication rate and a 11.1% stroke rate, while those with normal renal function had a 13% complication rate (P = .003) and a 0.6% stroke rate (P =.001). Similar association was seen between creatinine clearance and both stroke and complications. Obesity was a risk factor for complications, but not stroke: obese patients had a complication rate of 28%, while others had a 16% complication rate (P = .024). Emergency admission predicted both extended hospital stay (P < .001) and requirement for further inpatient care in a rehabilitation or nursing facility (P = .007). There was no significant difference in complication rate or stroke rate between octogenarians and others. This experience demonstrates that chronic renal insufficiency, obesity, and emergent clinical setting are risk factors for patients undergoing CAS.

Transcranial Doppler test for evaluation of cerebral artery embolism: Microemboli detection

About one third of ischaemic cerebrovascular diseases have embolic properties. Because of that, transcranial Doppler (TCD) test for detection of microembolic signals (MES), as the only one method for detection of microemboli, is a very important test for the evaluation of cerebral artery embolism. Cerebral emboli are particles of thrombus or atheromatous plaque, platelet aggregates, lipid or air particles in cerebral circulation, which can occlude arterioles and cause ischaemic transient attack (TIA) or stroke. Most frequently, they derive from exulcerated plaques of the carotid bifurcation or the aortic arch, from the atrial thrombus, prosthetic heart valves, as well as during carotid endarterectomy, arterial stent, aortocoronary by-pass. For MES detection, bilateral monitoring of a. cerebri mediae (ACM) is performed with each probe held in place over a temporal bone. MES are represented as brightly coloured embolic tracks as they pass through the insonated arteries. A computer hard disk provides continuous recording that is replayed for counting embolic signals. Colour intensity or acoustic range indicate the size and structure of MES. MES in the range of one ACM indicate the source of embolism on the ipsilateral carotid artery, while the bilateral detection of MES suggests a cardiogenic source. Indications for TCD detection of MES are the evaluation of pathogenesis and risk for embolic stroke or TIA and assessing the source of embolism. We started applying this method at the Institute of Neurology in Belgrade 2 years ago. We have investigated 78 patients till today and detected MES in 23 patients (28.7%). The Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology, 2004, considers that TCD is probably useful for detection of cerebral MES in various cardiovascular and cerebrovascular disorders and procedures.

NS01 IS THERE A RESURGENCE OF CEREBRAL REVASCULARIZATION?

Since the publication in 1985 of the EC‐IC bypass study group, which demonstrated failure of EC‐IC bypass surgery to reduce stroke rate, there has been a dramatic reduction in the number of EC/IC bypass surgeries performed globally.However there have been ongoing concerns amongst neurosurgeons that the EC‐IC bypass operation still has a role, at least in selected groups of patients. These groups include, patients with Moya Moya disease, those requiring arterial sacrifice (particularly when trial occlusion demonstrates symptomatic cerebral ischaemia), and in certain patients with cerebral ischaemia in whom medical management has failed and there is a demonstrable reversible ischaemic deficit.Over the past decade there has been de‐skilling of the neurosurgical community in cerebrovascular procedures. Even those neurosurgeons who have maintained a high cerebrovascular case‐load rarely perform EC‐IC bypass surgeries. The technical demands of the procedure are such that it is difficult to maintain skill proficiency with a low case‐load.Nevertheless a few cerebrovascular surgeons at large institutions have recently noted an increase in referral of patients requiring EC‐IC bypass. Current multicentre studies are underway to re‐evaluate its role. It would seem likely that a modest increase in the demand for this surgery will occur.

The history and present status of deep hypothermia and circulatory arrest in cerebrovascular surgery

After the development of deep hypothermia and circulatory arrest for cardiothoracic procedures in the late 1950s, this technique was adopted by several neurosurgeons as an aid to complex cranial surgery. Woodhall and colleagues described its first use for a neurosurgical procedure in 1960. Although their case did not involve a cerebrovascular procedure, the technique was subsequently used for the surgical treatment of cerebrovascular lesions, especially complex and giant aneurysms as well as large and solid hemangioblastomas. At the beginning, incorporation of this technique into common neurosurgical practice was impeded by several factors. For example, postbypass coagulopathy had been a serious source of morbidity. Furthermore, the need for cooperation among multiple subspecialties and the requirements for expensive equipment had further limited the availability of this technique. Subsequent improvements in the technique and advances in the equipment designed for cardiopulmonary bypass have led to its more widespread use starting in the 1980s. Hypothermic circulatory arrest has been described in several reports as a safe and useful tool in the treatment of large and giant aneurysms. Nevertheless, improvements in endovascular procedures and further refinement in skull base surgical techniques have limited the indications for circulatory arrest and deep hypothermia. The authors describe the history of hypothermia and circulatory arrest, its implementation in cerebrovascular surgery, and the changes in indications for and results of its use over time.

Intraoperative monitoring of cerebral blood oxygenation and hemodynamics during extracranial-intracranial bypass surgery by a newly developed visible light spectroscopy system

Background Cerebrovascular reconstruction procedures run the risk of changing the balance between oxygen supply and consumption during surgery. We assessed the value of visual light spectroscopy for detecting changes in cerebral blood oxygenation (CBO) during superficial temporal artery–middle cerebral artery (STA-MCA) anastomosis. Methods We developed a VLS monitoring system which permits continuous monitoring of CBO changes during surgery. Using the VLS, we evaluated the CBO changes in the MCA territory on the lesion side in 18 patients who underwent STA-MCA anastomosis. Results Temporary occlusion of the MCA (M4 portion) did not change the CBO in 17 patients. However, in the patient with dissecting aneurysm, it caused decreases of oxyhemoglobin and cortical oxygen saturation (CoS o 2) associated with an increase of deoxyhemoglobin, although these CBO changes were normalized by STA blood flow. In 5 patients, STA blood flow increased the oxyhemoglobin and CoS o 2 and decreased the deoxyhemoglobin, indicating that cortical blood flow (CoBF) was increased. The CoS o 2 before anastomosis was significantly low in the patients who showed an increase of CoS o 2 by STA blood flow (63.0% ± 2.5%) as compared with those who did not (72.0 ± 6.1%, P = .024). Conclusion Temporary occlusion of a cortical artery during bypass surgery did not affect the CBO in patients who had chronic cerebral ischemia, but caused acute ischemia in the patient who did not. STA blood flow increased the CoBF during surgery more frequently in patients who showed a low perfusion pressure. The VLS monitoring system is considered useful for evaluating bypass function and facilitates safe and accurate bypass surgery.

J. Lawrence Pool, M.D.: a pioneer in vascular neurosurgery

Neurofibromatosis Type 1 (NF1) is one of the most common inherited diseases in humans. It is caused by a mutation in the NF1 gene on chromosome 17, and is associated with numerous central and peripheral nervous system manifestations. Children with NF1 are at high risk of harboring numerous lesions that may require the attention of a neurosurgeon. Some of these include optic nerve gliomas, hydrocephalus, intraspinal tumors, and peripheral nerve tumors. Although most of the neoplasms that affect the brain, spine, and peripheral nerves of children are low-grade lesions, there is a small but real risk that some of these lesions may become high grade over time, requiring other forms of therapy than surgery alone. Other associated disorders that may result from NF1 in childhood include Chiari malformation Type I, scoliosis, and pulsating exophthalmos from the absence of the sphenoid wing. In this review, the major lesions that are found in children with NF1 are reviewed as well as the types of treatment that are offered by neurosurgeons and other members of the treating team. Today, optimum care of the child with NF1 is provided by a multidisciplinary team comprising neurosurgeons, neurologists, ophthalmologists, radiologists, orthopedic surgeons, and plastic surgeons.

Long-term survival after vascular surgery: Specific influence of cardiac factors and implications for preoperative evaluation

We sought to identify specific determinants of long-term cardiac events and survival in patients undergoing major arterial operations after preoperative cardiac risk stratification by American College of Cardiology/American Heart Association guidelines. A secondary goal was to define the potential long-term protective effect of previous coronary revascularization (coronary artery bypass grafting [CABG] or percutaneous coronary intervention [PCI]) in patients with vascular disease. Four hundred fifty-nine patients underwent risk stratification (high, intermediate, low) before 534 consecutive elective or urgent (<24 hours after presentation) open cerebrovascular, aortic, or lower limb reconstruction procedures between August 1996 and January 2000. Long-term follow-up (mean, 56 +/- 14 months) was possible in 97% of patients. The Kaplan-Meier method was used for survival data. Long-term prognostic variables were identified with the multivariate Cox proportional hazards model and contingency table analysis censoring early (<30 days) perioperative deaths. While 5-year survival was 72% for the overall cohort, cardiac causes accounted for only 24% of all deaths, and new cardiac events (myocardial infarction, congestive heart failure, arrhythmia, unstable angina, new coronary angiography, new CABG or PCI, cardiac death) affected only 4.6% of patients per year during follow-up. High cardiac risk stratification level (hazards ratio [HR], 2.2, 95% confidence interval [CI], 1.4-3.4), adverse perioperative cardiac events (myocardial infarction, congestive heart failure, ventricular arrhythmia; HR, 2.2; 95% CI, 1.2-4.1), and age (HR, 0.33; 95% CI, 0.2-0.6) were independently prognostic for latemortality. Preoperative cardiac risk levels also correlated with new cardiac event rates ( P < .01) and late cardiac mortality ( P = .02). Modestly improved survival in patients who had undergone CABG or PCI less than 5 years before vascular operations compared with those who had undergone revascularization 5 or more years previously and those at high risk without previous coronary intervention (73% vs 58% vs 62% 5-year survival; P = .02) could be demonstrated with univariate testing, but not with multivariate analysis. Type of operation, urgency, noncardiac complications, and presence of diabetes did not affect long-term survival. Despite cardiac events being a less common cause of late mortality after vascular surgery, perioperative cardiac factors (age, preoperative risk level, early cardiac complications) are the primary determinants of patient longevity. Patients undergoing more recent (<5 years) CABG or PCI before vascular surgery do not have an obvious survival advantage compared with patients at high cardiac risk without previous coronary interventions.

Renal cholesterol embolism in patients with carotid stenosis: a severe and underdiagnosed complication following cerebrovascular procedures

Here, we report two cases with rapidly progressive renal failure, caused by cholesterol crystal embolism (CCE), after an angiography for carotid artery stenosis. The diagnosis was determined by histological examination and from clinical symptoms, including livedo reticularis and eosinophilia. Neurologists and neuroradiologists tend to underdiagnose CCE, which results from the same atherosclerotic risk factors as cerebrovascular disease. We need to understand more about CCE and identify its unique clinical symptoms to enable an early diagnosis and treatment.

Renal cholesterol embolism in patients with carotid stenosis: a severe and underdiagnosed complication following cerebrovascular procedures

Here, we report two cases with rapidly progressive renal failure, caused by cholesterol crystal embolism (CCE), after an angiography for carotid artery stenosis. The diagnosis was determined by histological examination and from clinical symptoms, including livedo reticularis and eosinophilia. Neurologists and neuroradiologists tend to underdiagnose CCE, which results from the same atherosclerotic risk factors as cerebrovascular disease. We need to understand more about CCE and identify its unique clinical symptoms to enable an early diagnosis and treatment.

TECHNIQUES AND USE OF INTRAOPERATIVE ANGIOGRAPHY

The goal of cerebrovascular surgical procedures for surgical repair of an aneurysm or excision of a cerebral arteriovenous malformation is to achieve total obliteration of the lesion with preservation of normal vascular anatomy. Although there is no substitute for direct visual inspection at high magnification, other adjuncts such as intraoperative digital subtraction angiography may avoid inadvertent occlusion or efferent vessels or residual malformation.

Racial variation in the use of laparoscopic cholecystectomy in the Department of Veterans Affairs Medical System

Background: While studies have found racial differences in the rates of use of established invasive cardiac and cerebrovascular procedures, no study has evaluated racial variation in the rates of adoption of new surgical procedures. For patients undergoing laparoscopic cholecystectomy, the procedure represents a new and safe option that shortens the duration of postoperative hospitalization by almost one week. In this study, we evaluated whether, in the equal access Veterans Affairs (VA) medical system, the rate of adoption of this procedure and improvements in the duration of postoperative hospitalization differed between African-American and Caucasian patients. Study Design: Data were obtained from two sources—administrative claims files and prospectively compiled clinical data from medical records and patient interviews. In both data sets, frequency of use, length of stay, and outcomes for African-American and Caucasian patients undergoing minimally invasive and open gallbladder surgery were analyzed for the first four years of use of the procedure in the VA system (1992 to 1995). Results: Analyses based on claims files indicated that, after adjustment for potentially confounding variables, African-American patients who underwent cholecystectomy in VA medical centers were 25% less likely to undergo a minimally invasive cholecystectomy during the first 4 years of use of the new procedure (adjusted odds ratio, 0.74; 95% confidence interval, 0.66–0.83). Shortening of the average postoperative length of stay from 9 days or more in the prelaparoscopic era to less than 4.5 days for patients undergoing the laparoscopic procedure occurred in the first year for Caucasian patients, but did not occur until the fourth year for African-American patients (p < 0.001). The overall difference in postoperative length of stay between African-American and Caucasian patients more than doubled from 1.7 days before introduction of laparoscopic cholecystectomy to 3.8 days in the fourth year. In comparison, analyses based on nurse-compiled clinical data indicated that, after adjustment for relevant clinical factors, racial variations in the rate of laparoscopic surgery were even larger (adjusted odds ratio for laparoscopic versus open cholecystectomy for African-American versus Caucasian veterans, 0.68; 95% confidence interval, 0.55–0.84). Conclusions: Compared to Caucasian patients, African-American patients who underwent cholecystectomy in VA medical centers had an approximately 25% to 32% lower likelihood of undergoing minimally invasive cholecystectomy procedures. The differences in rates of adoption of laparoscopic surgery did not appear to be from more comorbid illnesses among African-American patients. African-American and Caucasian veterans may differ in their preference for new surgical procedures like laparoscopic cholecystectomy. Conversely, VA physicians may have been less likely to recommend laparoscopic cholecystectomies to African-American patients.

Bilateral internal carotid artery occlusion: natural history and surgical alternatives

Purpose and background: Bilateral internal carotid artery occlusion is an extremely rare entity, therefore, studies of the natural history of this disease are lacking in the English literature. The purpose of this study is to analyze the natural history and surgical alternatives for patients with bilateral internal carotid artery occlusion. Patient population and methods: Twenty-one patients with bilateral internal carotid artery occlusion were encountered with a mean age of 61 years (range of 48–73 years). Their clinical presentations included eight with hemispheric transient ischemic attacks, three with amaurosis fugax, five with strokes and five with non-hemispheric transient ischemic attack. Diagnosis was confirmed using carotid duplex ultrasound and angiography. The majority of patients had more than one risk factor for atherosclerosis: smoking in 100%, hyperlipidemia in 14/21 (67%), hypertension in 17/21 (81%), coronary artery disease in 15/21 (71%) and diabetes mellitus in 7/21 (33%). In addition to the usual medical treatment, 13 patients underwent surgical intervention: eight had an external carotid endarterectomy, four had a carotid–subclavian bypass (to increase external carotid or vertebral flow for tight stenosis or occlusion of the common carotid or subclavian artery) and one patient had an ascending aorta to innominate artery bypass. At a mean follow-up of 6 years (range 1–11 years), the overall mortality rates were 11/21 (52%), in the surgical group it was 5/13 (38%) and 6/8 (75%) in the medical group. The causes of death included seven myocardial infarctions (four in the surgical group and three in the medical group) and four strokes (one in the surgical group and three in the medical group). In the surgical group, 2/13 (15%) had late neurological deficits (one hemispheric transient ischemic attack and one stroke), in contrast to 6/8 (75%, three strokes and three hemispheric transient ischemic attacks) in the medical group. Conclusions: Bilateral internal carotid artery occlusions have grave prognoses and should be considered a marker for severe systemic disease. Various cerebrovascular reconstructive procedures, if feasible, may be beneficial for some of these patients.

Bilateral Internal Carotid Artery Occlusion: Natural History and Surgical Alternatives

Purpose and background: Bilateral internal carotid artery occlusion is an extremely rare entity, therefore, studies of the natural history of this disease are lacking in the English literature. The purpose of this study is to analyze the natural history and surgical alternatives for patients with bilateral internal carotid artery occlusion. Patient population and methods: Twenty-one patients with bilateral internal carotid artery occlusion were encountered with a mean age of 61 years (range of 48–73 years). Their clinical presentations included eight with hemispheric transient ischemic attacks, three with amaurosis fugax, five with strokes and five with non-hemispheric transient ischemic attack. Diagnosis was confirmed using carotid duplex ultrasound and angiography. The majority of patients had more than one risk factor for atherosclerosis: smoking in 100%. hyperlipidemia in 14/21 (67%), hypertension in 17/21 (81%), coronary artery disease in 15/21 (71%) and diabetes mellitus in 7/21 (33%). In addition to the usual medical treatment, 13 patients underwent surgical intervention: eight had an external carotid endarterectomy, four had a carotid—subclavian bypass (to increase external carotid or vertebral flow for tight stenosis or occlusion of the common carotid or subclavian artery) and one patient had an ascending aorta to innominate artery bypass. At a mean follow-up of 6 years (range 1–11 years), the overall mortality rates were 11/21 (52%). in the surgical group it was 5/13 (38%) and 6/8 (75%) in the medical group. The causes of death included seven myocardial infarctions (four in the surgical group and three in the medical group) and four strokes (one in the surgical group and three in the medical group). In the surgical group, 2/13 (15%) had late neurological deficits (one hemispheric transient ischemic attack and one stroke), in contrast to 6/8 (75%. three strokes and three hemispheric transient ischemic attacks) in the medical group. Conclusions: Bilateral internal carotid artery occlusions have grave prognoses and should be considered a marker for severe systemic disease. Various cerebrovascular reconstructive procedures, if feasible, may be beneficial for some of these patients.