Total Carotid Occlusion Research Articles

Carotid Endarterectomy is often not Possible after an Unheralded Stroke: Unheralded Stroke in Carotid Artery Stenosis

ObjectivesThe ongoing literature recommends carotid endarterectomy (CEA) primarily for patients with neurological symptoms, however CEA can be precluded by the onset of a severe stroke or a total carotid occlusion. The present study aims to evaluate the effect of unheralded strokes in patients with a previously asymptomatic carotid stenosis (ACS) possibly considered for CEA. Materials and MethodsFrom 2009 to 2019, patients with an unheralded stroke from an ACS were considered. By neurological examination, patients were divided in unfit-for-CEA (uCEA) – either for the severity of the stroke (according to modified Rankin-Scale – mRS) or the onset of a total carotid occlusion – and patients submitted to CEA. Predictors for uCEA and stroke severity were evaluated. ResultsOver a total of 532 patients with symptomatic carotid stenosis, 277 (52%) with unheralded stroke were included in the study. One hundred and one (36%) were considered uCEA: 64(23%) due to their neurological conditions (mRS:5) and 37 (13%) because of the onset of carotid occlusion. One hundred seventy-six (64%) patients underwent CEA. The preoperative medical therapy was similar in uCEA vs CEA patients. Age≥80 years and female sex were independently associated with uCEA (OR:5.9, 95%CI:3.1–11.4, P<.01; OR:3.9, 95%CI:2.0–7.6, P<.01. respectively). Patients submitted to CEA had mRS: 0–2 in 102(37%) cases and mRS:3–4 in 74 (27%). The contralateral carotid occlusion (CCO) was independently associated with mRS:3–4 (OR:8.4, 95%CI 1.8–79, P=.01). Postoperative stroke rate after CEA was 2.9% (4/167); patients with preoperative mRS:3–4 had a higher risk for postoperative stroke compared to those with mRS:0–2 (5.9% vs. 0%. P=.02). ConclusionsAn unheralded stroke in patients with ACS leads to a severe neurological damage in more than half of cases, either precluding CEA (36%) or increasing the risk of postoperative complications (27%). Female sex, age≥80 and CCO are independent predictors of these occurrences and should be considered in ACS patients.

Assessment of Intracranial Collateral Circulation Using Novel TCCS Grading System in Patients With Symptomatic Carotid Occlusion.

Objectives: To establish a novel transcranial color-coded sonography (TCCS) grading system for collateral circulation in cases of symptomatic chronic total carotid occlusion (TCO), and to correlate this new grading system with cerebrovascular reserve capacity (CVR) measured by SPECT.Methods: Thirty-four patients with symptomatic chronic TCO recruited from the neurovascular ultrasound laboratory of the department of Neurology at Cairo University Hospital during 3 years' time period and diagnosed by color-coded duplex were subjected to: clinical assessment, grading of cerebral collaterals using a proposed TCCS criteria, Brain SPECT studies at rest and with dipyridamole stress.Results: The new grading system for cerebral collateral circulation showed a significant positive correlation with CVR (P < 0.001 and Spearman correlation coefficient 0.686).Conclusion: The current study showed that this new TCCS grading system for cerebral collaterals is a reliable indicator for cerebral perfusion and reserve capacity in cases of chronic symptomatic TCO.

Retinal arterial occlusion with multiple retinal emboli and carotid artery occlusion disease. Haemodynamic changes and pathways of embolism

ObjectiveTo introduce a special subgroup, retinal artery occlusion (RAO) with multiple emboli, which is highly associated with ipsilateral carotid artery occlusion disease (CAOD).Methods and analysisThis is a cohort study. Cases...

CAR 14. Hybrid Surgery for Symptomatic Chronic Near-Total or Total Occlusion of Internal Carotid Artery

Chronic symptomatic near-total or total occlusion of the carotid artery is relatively difficult to treat compared with routine carotid artery stenosis by either endarterectomy or endovascular procedures. Herein, we present our hybrid surgery strategies for the purpose of improving operational safety and recanalization rate. Six cases with total carotid occlusion and seven cases with near-total carotid occlusions were treated by hybrid surgery, combining endarterectomy of the proximal segment of the internal carotid artery with endovascular angioplasty of the distal segments of the internal carotid artery. Five of the six total occlusions were recanalized successfully, and six of the seven near-total occlusions were recanalized. The symptoms of the recanalized patients were resolved. Follow-up computed tomography angiography found good patency rate of the treated carotid artery. We believe that hybrid surgery for the treatment of total or near-total carotid artery occlusion is feasible, with a satisfactory operational safety and patency rate.

Predictors of poor cerebral collaterals and cerebrovascular reserve in patients with chronic total carotid occlusion

Background: This study aims to investigate the relationship between cerebrovascular reserve (CVR) capacity, as measured by single-photon emission computed tomography (SPECT) and collateral blood flow, according to a transcranial colour-coded duplex(TCCD), in patients with symptomatic total carotid occlusion (TCO). Additionally, the study aims to determine whether vascular risk factors have an effect on collateral blood flow, as well as on the CVR.Methods: Thirty-four patients with chronic TCO, diagnosed by carotid duplex scanning and confirmed by other vascular imaging modalities, who had ischaemic symptoms either as stroke or transient ischaemic attack, were subjected to clinical assessment, SPECT under dipyridamole stress, and grading of cerebral collateral blood flow using TCCD. Demographics and vascular risk factors were correlated with SPECT and TCCD findings.Results: CVR showed a significant positive correlation with the intensity of collaterals with P value <0.001 and a Spearman correlation coefficient of 0.686. Hypertension was the only predictor of poor collaterals (p value =0.049; OR =11.5 with 95% CI 1.01–131.16).Smoking was predictive of poor CVR as measured by qualitative SPECT (p value =0.02; OR =13.2 with 95% CI 1.4–120.6).Conclusion: Cerebral collaterals have an important role in the maintenance of CVR in patients with TCO. Preventive measures should be directed towards hypertension and smoking to preserve cerebral collateral patency and consequently improve CVR in patients with TCO.

Aggressive revascularization of acute internal carotid artery occlusion in patients with NIHSS > 20 and poor collateral circulation: Preliminary report

BackgroundAcute occlusion of internal carotid artery (ICA) is a clinical catastrophic entity with mortality as high as 50%. With innovative devices and technology, we want to clarify the benefit and risk of interventional treatment for those patients. Methods and resultsFrom 2005 to 2009, 62 patients were enrolled and 7 patients were diagnosed as total ICA occlusion with severe neurological deficit and poor collateral circulation received endovascular interventions. Intra-arterial thrombolysis was performed in all the 7 patients. Besides, angioplasty was done in 2 patients, stenting in 3, and thrombosuction in 1. The average NIHSS was 23.3 (standard deviation=3.6) before revascularization, was 14.2(standard deviation=6.8) on day 7. Three patients had symptomatically hemorrhagic transformation and one developed severe brain edema after procedure. Decompressive craniotomy has been conducted in 3, who survived thereafter. One patient died for refusal of decompressive craniotomy. The 30-day modified Rankin scale was 1 in 1, 2 in 1, 3 in 1, and 4 in 3. All of our patients had distal residual lesions at anterior or middle cerebral artery area, and delayed recanalization was noted in 4. ConclusionsEndovascular therapy was promising as a hyperacute management for patients of ICA total occlusion leading to survival rate more than 80% and significant neurological recovery in 50% of our patients. Distal residual lesions were common in patients of total carotid occlusion after aggressive revascularization. Although the mechanism was not clear, delayed re-canalization was common in such patients.

Safety of coronary artery bypass grafting in patients with bilateral total carotid occlusions

The presence of bilateral carotid artery occlusions in patients that require coronary artery bypass surgery is rare. Here, we report the successful coronary revascularization of two patients with cardiopulmonary bypass under moderate hypothermia. Routine preoperative carotid artery duplex sonographies revealed bilateral total internal carotid occlusions. However, no neurological deficits or abnormalities were found on clinical examination or brain computed tomography, respectively. The vertebral blood flows of both patients were also found to be highly increased. Following successful surgery, the postoperative courses were uneventful and patients were discharged from the hospital on the seventh postoperative day.

Indirect Reperfusion in the Setting of Symptomatic Carotid Occlusion by Treatment of Bilateral Vertebral Artery Origin Stenoses

Patients with total carotid occlusions can develop ischemic stroke as a result to hemodynamic impairment. Flow augmentation can be provided through a variety of surgical and endovascular techniques. We describe a patient treated with vertebral artery stent placement to augment indirect flow to the territory of an occluded carotid artery. A 52-year-old man presented with ST elevation myocardial infarction and ischemic stroke manifesting with right-sided hemiparesis and aphasia. A computed tomography (CT) angiogram confirmed the presence of a left internal carotid artery total occlusion with prolongation of the mean transit time and reduced estimated cerebral blood flow on CT perfusion maps. The patient was taken for angiography and found to have bilateral vertebral artery ostial stenosis and a posterior communicating artery supplying the left hemisphere. The patient underwent successful stenting and angioplasty of both lesions with stabilization of neurologic symptoms. A follow-up CT perfusion study showed marked improvement in the estimated cerebral blood flow, and reduction of the mean transit time. Stenting and angioplasty of a stenosis of an artery providing indirect blood flow to the territory of an occluded ipsilateral vessel can stabilize neurologic decline and improve CT perfusion parameters.

Chronic Total Symptomatic Carotid Artery Occlusion Treated Successfully with Stenting and Angioplasty

Treatment of symptomatic chronic totally occluded carotid artery has been limited to medical management. An ongoing clinical trial is examining the role of extracranial to intracranial bypass surgery in select patients with impaired cerebrovascular reserve based on PET imaging parameters. We describe a case utilizing stenting and angioplasty to treat a chronic total carotid occlusion as a potential alternative therapy. A 55-year-old woman presented with a right hemispheric ischemic stroke in the setting due to a right internal carotid artery total occlusion. She was treated medically with antiplatelet therapy and oral vasopressor agents. She returned with new symptoms 1 month later and was successfully treated with stenting and angioplasty. At the 9-month follow-up, she remains neurologically intact. Stenting and angioplasty may be a therapeutic option in select patients with chronic total carotid occlusion. Further study is required to determine the safety profile of this treatment modality.

Magnetic Resonance Imaging of the Harderian Gland in Piglets

The main purpose of the present study was to investigate the suitability of functional and morphological magnetic resonance imaging (MRI) to assess the extent of brain injury in a hypoxia‐ischemia piglet model and further to validate that the ischemic injury was successfully induced. MR imaging was performed at 1.5 T (Siemens Vision, Siemens Medical, Erlangen, Germany) in piglets (n = 10; age 12–36 h) under general anaesthesia. Hypoxia was induced by ventilation of a gas mixture containing 8% O2 in N2 (AGA, Oslo, Norway). Ischemia was induced by bilateral clamping of the common carotid arteries (CCA). HI was maintained for 30 min, followed by re‐oxygenation with ambient air (21% O2) for 2.5 h. Relative cerebral flow (rCF) was estimated using a single shot SE‐EPI sequence (TE = 85 ms, voxel size 1 × 1 × 5 mm3), measuring the first‐pass response following bolus injection of an intravascular iron oxide nanoparticulate contrast agent (NC100150 Injection; Amersham Health, Oslo, Norway) at a dose of 4.5 mg Fe/kg. rBF maps were generated on a pixel‐by‐pixel basis from the peak height of a gamma‐variate function fitted to the first‐pass contrast agent response. The presence of total carotid occlusion was assessed by MR angiography (MRA). MRA images (3D‐GRE, TR/TE 4.4 ms/1.8 ms, voxel size 0.9 × 0.9 × 1.5 mm3) were acquired after contrast administration; utilizing the T1‐effect of NC100150 injection. Mean blood pressure and heart rate were measured continuously during the experiment via a catheter placed in the femoral artery. Blood gasses and rectal temperature were measured at regular intervals. At the end of the experiment, the piglets were given an overdose of 150 mg/kg Pentobarbital i.v., and a dissection was performed in order to identify structures identified on the MRI. MR angio (MRA) and volume rendering identified a prominent, highly vascularized, defined structure close to the eyeball, medioventrally. At dissection, when comparing with the MR images, the deep gland of the third eyelid, the Harderian gland, corresponded to this structure both by topography and size. It was thick, brownish and finely lobulated, and extended from the cartilage of the third eyelid towards the origin of the extrinsic eye muscles at the apex of the orbit. In contrast, the lacrimal gland presented as a small, soft and pale structure that was difficult to distinguish from the surrounding connective tissue. At histological examination, the Harderian gland consisted mostly of compact areas of alveolar glands with abundant eosinophilic granules. Wide thin‐walled vessels were conspicuous in the interlobular connective tissue and the capsule. The present MRI demonstration of the Harderian gland was an accidental finding during an investigation to assess the extent of brain injury in a hypoxia‐ischemia piglet model. In pig, this gland has received little attention in the literature. However, taking its size and blood supply into consideration, it must be of significant importance also in the pig. It is mostly studied in rodents and lower vertebrates and is found to possess various endocrine functions as well as exocrine.

Future of extracranial–intracranial bypass

Total occlusion of internal carotid artery in the cervical region is an end result of progressive occlusive vascular disease. A small proportion of these patients will have symptoms of cerebral ischemia due to cerebral hypoperfusion in a delayed fashion. Identification of those individuals who are at risk of developing symptoms and prophylactically treating with a revascularization procedure will prevent such catastrophic events. With the co-operative study for bypass not supporting the bypass procedure and trial being questioned for its design and conclusions, a new trial of extracranial-intracranial bypass, The Carotid Occlusion Surgery Study, using the currently available technology will be undertaken to verify that the bypass will decrease the future stroke rate by at least 40% in patients with total carotid occlusion. A subset of patients with skull base pathology including tumors and aneurysms who may have to undergo carotid sacrifice as part of the surgical procedure are at risk of peri-operative and delayed stroke. Identification of these patients at risk by pre-operative tests may allow performance of extracranial-intracranial bypass prior to undertaking complex skull base procedures. The new imaging technology will guide management of these patients at risk and help identify patients who may need a bypass procedure. [Neurol Res 2002; 24: S80-S83]

Improved Imaging of Carotid Artery Bifurcation Using Helical Computed Tomographic Angiography

Although duplex scan and magnetic resonance angiography (MRA) provide reliable and noninvasive tests for detecting extracranial carotid artery disease, they sometimes fail to differentiate between high-grade stenosis and total carotid occlusion. Helical computed tomographic angiography (CTA) is a safe, noninvasive technique that allows the rapid acquisition of data that can be reconstructed into two- and three-dimensional images. Axial images can be magnified and provide a cross-sectional view of the carotid vessel and the atherosclerotic plaque. Maximal intensity projection technique allows data to be reconstructed into images that closely resemble conventional arteriograms. Helical CTA has previously been shown to have a diagnostic accuracy approaching 90%. We present two case reports demonstrating the utility of helical CTA in carotid artery imaging when duplex scan and MRA results are ambiguous. These cases illustrate improved carotid imaging with helical CTA. Duplex scan results are unreliable in the presence of thick calcified plaques, and severe stenoses can be misread as occlusion by duplex and MRA due to low blood flow. Thus, helical CT angiography should be considered as a confirmatory test, before arteriography, when duplex scan or MRA results are equivocal.

Stroke risk factors and development of collateral flow in carotid occlusive disease.

Blood flow through collateral vessels compensates for reduced blood flow through stenotic or occluded extracranial carotid arteries. Previous studies have shown that extent of collateral flow influences likelihood of stroke and its outcome. Here we analyzed the relationship between stroke risk factors (hypertension, coronary artery disease, diabetes mellitus, tobacco smoking and hypercholesterolemia) and number of patent intracranial collaterals detected by transcranial Doppler ultrasonography. We studied 182 patients with various degrees of angiography proven unilateral stenosis of the internal carotid artery. Contribution of the anterior and posterior communicating arteries to the perfusion of the cerebral hemisphere on the side of the stenosis or occlusion was evaluated by a series of compression tests performed during continuous insonation of the middle cerebral artery. The number of detected collateral vessels was correlated with analyzed stroke risk factors. Subjects with stenosis more than 75% or occlusion of the internal carotid artery had a higher frequency of two major intracranial collateral vessels (P< or =0.01 and P< or =0.001, respectively). Hypertensive patients with stenosis more than 75% or total carotid occlusion were more likely to have only a single collateral vessel than patients without hypertension (P< or =0.01 and P< or =0.05, respectively). Other risk factors did not influence the patency of preformed collateral vessels. Hypertension hindered the development of preformed intracranial collateral vessels in our patients with carotid occlusive disease.

The reliability of color duplex ultrasound in diagnosing total carotid artery occlusion

Color duplex ultrasound has been advocated as an alternative to arteriography before carotid endarterectomy. However, one limitation of color duplex ultrasound is that it sometimes fails to differentiate high-grade stenosis from total carotid occlusion. This study was done to determine (1) the accuracy of carotid duplex ultrasound in diagnosing total carotid occlusion, and (2) when angiography is necessary. Carotid duplex ultrasound and angiography results were compared for 520 carotid arteries, and 103 of these had a duplex diagnosis of total carotid occlusion or suspected almost total-to-total occlusion. The diagnosis of total carotid occlusion was primarily based on the absence of flow in the internal carotid artery as visualized on B-mode imaging for at least 1 inch beyond the bifurcation (optimal study). If the internal carotid artery was not optimally seen beyond the bifurcation, but secondary criteria were present, such as dampening of the common carotid signal and internalization of the external carotid artery, a diagnosis of suspected subtotal to total occlusion was made (limited study). In the optimal studies, 91 arteries had total carotid occlusions and of these, 87 were confirmed by angiography. The accuracy of carotid duplex ultrasound in diagnosing total carotid occlusion was 97% with a positive predictive value of 96%, negative predictive value of 98%, sensitivity of 91%, and specificity of 99%. Twelve arteries were diagnosed as suspected subtotal to total occlusion (limited studies), and of these, three were occluded on angiography, eight had stenoses ranging from 90% to 99%, and one had 80% stenosis. A carotid duplex ultrasound study is an acceptable method for predicting total carotid occlusion when the study is optimal, and angiography is unnecessary in asymptomatic patients. Angiography is recommended for patients who are surgical candidates with a limited duplex study.

Carotid surgery: the past is prologue. The John Homans lecture.

Carotid surgery: the past is prologue. The John Homans lecture.

Handbook of interventional radiologic procedures

Microsurgical carotid endarterectomy Julian Bailes and Robert Spetzler, Philadelphia, 1996, Lippincott-Raven, 220 pages, $150. This text of 200 pages contains 10 chapters by the senior editors, neurologic surgeons at Allegheny General Hospital (Pittsburgh) and the Barrow Neurologic Institute (Phoenix), as well as 15 other authors who are neurosurgeons, neuroanesthesiologists, neurologists, and neuroradiologists. Introductory chapters include overviews on the epidemiology and natural history of carotid stenosis, preoperative risk assessment, and patient selection for carotid endarterectomy. The next chapter reviews carotid angiography, magnetic resonance, and magnetic resonance arteriography, followed by chapters describing the anesthetic management during carotid endarterectomy and the operative technique itself, which is beautifully illustrated. The final chapters in the text discuss the postoperative medical management of the carotid endarterectomy patient and the unique management of total occlusion. As stated by the authors, the purpose of this text was to “collect the entire spectrum of care associated with microsurgical carotid endarterectomy into one reference volume.” Most of the chapters in the text are competent review and overview sections, but do not add new information to previously published texts on the management of the patient with cerebrovascular disease. Indeed, the significance of the 36-page chapter on “Rationale and Protocol for Microsurgical Carotid Endarterectomy” escapes this reviewer. The operative instructions offered are those that have been well described for decades, except the arteriotomy closure is performed with an operating microscope in lieu of loop magnification. The section, however, on perioperative complications including postoperative thrombosis, intracerebral hemorrhage, and controversies in carotid endarterectomy (ie, carotid patch angioplasty, intraoperative shunting) is quite good. The chapter discussing intraoperative transcranial Doppler (TCD) is well written and well-illustrated. The illustrative case examples of “competent vs incompetent collateral reserves,” microembolization, and carotid thrombosis were helpful in understanding TCD as an adjunct for cerebral surveillance during operation. The most intriguing chapter in the text was on management of total carotid occlusion. The authors reviewed and documented the natural history and operative results of internal carotid artery occlusion and report their results in 42 patients who underwent “emergency carotid endarterectomy for appropriate symptoms.” The authors opened 24 arteries with thromboembolectomy, performed internal carotid “stumpectomy” with external carotid ligation in nine, and stumpectomy with external carotid endarterectomy and EC-IC bypass in four. The long-term follow-up results demonstrate an 88% patency rate by color-flow ultrasonography in patients who initially were thrombectomized. The authors conclude that the natural history of carotid occlusion has been ill defined, and the authors believe they have improved their ability to reopen occluded arteries. An algorithm is presented as a management guideline. In general, this text is beautifully illustrated, well documented, and well written. It does not, however, offer much new about carotid endarterectomy, but would serve as an appropriate reference text. The receipt of the books listed below is acknowledged. This listing is regarded as appropriate return for the courtesy of the sender. The books that are of particular interest will be reviewed and the review published as space permits. Arterial aneurysms: Diagnosis and management Michael Horrocks, Oxford, Mass., 1995, Butterworth-Heinemann, 246 pages, $110. Noninvasive electrocardiology: Clinical aspects of Holter monitoring Arthur Moss and Shlomo Stern, Philadelphia, 1996, W.B. Saunders, 541 pages, $59. Computer analysis of cardiovascular signals M. DiRenzio, G. Marcia, G. Parati, H. Pedotti, A. Zanchetti, Amsterdam, 1995, IOS Press, 315 pages. Surgical treatment of aortic dissection Hams Borst, Markus Heinemann, and Christopher Stone, New York, 1996, Churchill Livingstone, 357 pages, $119.95. Venous disorders: A manual of diagnosis and treatment G. Belcaro, A.N. Nicolaides, and M. Veller, Philadelphia, 1995, W.B. Saunders, 204 pages, $35. Handbook of venous disorders: Guidelines of the American Venous Forum Peter Gloviczki and James S. T. Yao, London, 1996, Chapman & Hall Medical, 686 pages. Renal vascular disease Andrew Novick, John Sobule, and George Hamilton, Philadelphia, 1996, W.B. Saunders, 550 pages, $97. Atlas of cardiovascular pathology Renu Virmani, Allen Burke, and Andrew Farb, Philadelphia, 1996, W.B. Saunders, 234 pages, $169. Handbook of interventional radiologic procedures Krishna Kandarpa and John Aruny, Boston, 1996, Little, Brown and Company, 508 pages, $37.95.

Compromised cerebral blood flow reactivity is a predictor of stroke in patients with symptomatic carotid artery occlusive disease

The purpose of this study was to determine whether the hemodynamic consequences of extracranial carotid disease correlate with the risk of subsequent cerebral infarction. In 95 patients with symptoms who had greater than or equal to 70% stenosis (31 patients) or who had occlusion (64 patients) of the ipsilateral carotid artery, cerebral blood flow was measured by the stable xenon/computed tomography technique both at baseline and after vasodilatory challenge with intravenous acetazolamide. Patients were stratified into group 1, 43 patients with no more than a 5% decrease in flow in any vascular territory, and group 2, 52 patients with greater than a 5% decrease in one or more vascular territories after an acetazolamide challenge. In group 2, 15 (28.9%) of 52 patients had a new stroke, but only one (2.3%) of 43 patients in group 1 did (p = 0.0005). Of patients with total carotid occlusion 10 (26%) of 38 in group 2 and none (0%) of 26 in group 1 had a new stroke (p = 0.003). Of patients with greater than or equal to 70% stenosis, five (36%) of 14 in group 2 and only one (6%) of 17 in group 1 had a stroke (p = 0.067). The loss of cerebral reactivity in patients with symptoms who had greater than or equal to 70% carotid stenosis or occlusion is an important predictor of impending cerebral infarction.

Identifying total carotid occlusion with colour flow duplex scanning

A major limitation of conventional duplex scanning is its inability reliably to differentiate severe stenosis from total occlusion of the internal carotid artery (ICA). Colour flow duplex scanning (CFS) facilitates the identification of internal and external carotid arteries, enables simultaneous evaluation of flow in multiple vessels in longitudinal and transverse views, and allows more accurate assessment of very low Doppler-shift frequencies with new "slow-flow" software technology. From July 1987 to January 1991, 9731 ICAs (4866 patients) were evaluated with CFS. Arteriography was performed in 483 of these patients (959 ICAs), and the results of the two studies were compared. Colour flow scanning was highly accurate in differentiating total occlusion from carotid stenosis. Eighty-two of 87 totally occluded ICAs were detected (sensitivity 94%) and 873 of 878 patient arteries were properly identified (specificity 99%). Positive and negative predictive values were 93 and 99%, respectively. False positive results (n = 6) were due to interpreter error (n = 4) and poor scanning technique (n = 2). All false negative results (n = 5) were the result of interpreter error. During the last 24 months of the study, no false positive or false negative results were detected, giving an accuracy of 100%. We conclude that CFS offers distinct advantages in the diagnosis of carotid occlusion, thereby overcoming the limitations of conventional duplex scanning in distinguishing total occlusion of the ICA from less severe disease, and is the method of choice for evaluating the carotid bifurcation.

Should we perform carotid endarterectomy synchronously with cardiac surgical procedures?

From Jan. 1, 1979 through July 31, 1987, 63 patients had carotid endarterectomy (CEA) concurrently with cardiac surgical procedures including coronary artery bypass grafting (CABG) in 61, CABG plus mitral value replacement in one, and aortic valve replacement in one. Among the 62 patients having CABG, unstable angina had been present in 36 (58%), left main coronary artery disease in 21 (34%), and both unstable angina and left main coronary artery disease in 13 (21%). Indications for carotid surgery included previous stroke, amaurosis fugax, or hemispheric transient ischemic attacks (TIAs) in 33 patients (52%); bilaterally significant carotid disease was noted in 48% of the patients. Major neurologic complications occurred in three patients (4.8%), including perioperative stroke in two (3.2%) (fatal in one) and a TIA in a third patient. Bilateral carotid lesions, a contralateral total carotid occlusion, previous cerebrovascular symptoms, and intraaortic balloon pump support did not increase neurologic risk. Seven patients died postoperatively (11%). The mortality rate was 2.8% in patients younger than 65 years vs 22% in patients 65 years or older, 19% in patients with left main coronary artery disease vs 7.3% in patients without, 13.3% in men vs 5.6% in women, 25% in patients with a history of congestive heart failure vs 7.8% in patients without failure, and 6.2% in patients with unilateral carotid disease, 17% in patients with bilateral carotid disease, and 23% in patients with bilateral disease including a contralateral carotid occlusion. A mortality predictive index (MPI) was developed to summarize individual risk for a fatal outcome. Survivors had a mean MPI of 1.98 vs 3.30 for those who died. The mortality rate was 2.4% in patients with an MPI of 0 to 2 vs 29% for those with an index of 3 to 5. In elderly cardiac surgical patients and those with an MPI of 3 or greater, the risks of operation may outweigh the potential benefits of synchronous CEA.

Diagnosis of Carotid Arterial Occlusive Disease

A retrospective analysis of 1500 patient records was performed to assess the validity and reliability of combined oculoplethysmography and carotid phonoangiography (OPG/CPA) as indicators of carotid arterial occlusive disease. The tests were interpreted by means of a five-level grading system based on percentage of flow reduction. Reliability statistics were calculated by using arteriography as a comparison in 10% (152) of the patients. Of the 1500 tests, 477 (32%) were abnormal, but only 252 (17%) were graded as hemodynamically significant (levels II-V). Arteriography confirmed total carotid occlusion in 16 of 19 (84%) grade V patients; the remaining 3 (16%) had significant stenosis but on a less severe level (III or IV). In the inter mediate grade II-IV results, 39 of 44 (89%) were accurate; 2 (4%) false positive and 3 (7%) overestimated cases were in this group. In the normal- grade I patients, 81 of 89 (91%) interpretations were confirmed. The false negatives (9%) in the latter group were attributable to nonstenosing ulcera tive plaques (6 patients) and moderately significant stenosis (2 patients). Overall reliability was 90%, with 1% false positives, 4% false negatives, and about 5% erroneous assessment of severity within the abnormal grades II-V. Thus OPG/GPA testing is a valuable, reliable, noninvasive screening and diagnostic tool for carotid disease detection, but it is sensitive only to stenotic lesions, not to ulcerative plaques.