Asymptomatic Bruits Research Articles

Common Carotid Dissection following a Bike Injury—Unusual Cause of Carotid Bruit

Carotid dissection is not typically a diagnosis made on ultrasound in an asymptomatic individual. Several factors made this case unique in the literature, including the fact that the dissection was in the distal common carotid artery rather than internal carotid, which allowed the injury to be directly visible by ultrasound. Rather than presenting with acute transient ischemic attack or stroke, headache, or cranial nerve palsy, this patient was referred for an asymptomatic bruit several months after the trauma, which presumably caused the dissection. The lesion identified by ultrasound was unusual, with a high-grade stenosis created by a mobile flap in the artery.

History of Carotid Endarterectomy Then and Now

It seems the first successful carotid endarterectomy (CE) was done by Michael E. DeBakey1 in 1953, although the first published report of CE was by Eastcott et al2 in 1954. During the subsequent 2 decades, the number of these surgeries grew. In 1969, the Joint Study of Extracranial Arterial Occlusion, a methodologically imperfect study, reported that, in 2400 operations performed between 1961 and 1968, there was a surgical mortality of 4.5%, ranging from <2% to 36% among the 24 participating institutions, although there was a steady decline in surgical mortality during the 8 years.3 Fifteen thousand CEs were performed in the United States in 1971, and this grew to 34000 in 1976.4 By 1976, my colleague, David Sherman, and I were becoming troubled with the growth in the number of CEs because we were observing patients experiencing ischemic strokes and deaths in conjunction with these surgeries. We were at Southern Illinois University (SIU) School of Medicine in Springfield, IL, observing the good and the bad results of CE. Our medical colleagues often asked us, “What is the complication rate for carotid endarterectomy in our two hospitals?” We replied, “We don’t know.” The time had come to answer the question. We initiated a retrospective study of 228 consecutive CEs during the arbitrary interval from January 1, 1970, to June 30, 1976, in our two 600-bed community hospitals to determine the perioperative stroke and mortality rate. Our primitive methodology is described in the results publication of the study.5 The combined stroke-mortality rate for our series of patients was 21.1% (48 of 228). Eleven CEs were performed for asymptomatic bruits, and the combined stroke-mortality rate was 18.2% (2 of 11). Fifty-seven CEs were performed for transient ischemic attacks in the symptomatic carotid artery distribution, and the combined stroke …

Diagnosis, management, and future developments of fibromuscular dysplasia

Fibromuscular dysplasia (FMD) is a nonatherosclerotic noninflammatory vascular disease that primarily affects women from age 20 to 60, but may also occur in infants and children, men, and the elderly. It most commonly affects the renal and carotid arteries but has been observed in almost every artery in the body. FMD has been considered rare and thus is often underdiagnosed and poorly understood by many health care providers. There are, however, data to suggest that FMD is much more common than previously thought, perhaps affecting as many as 4% of adult women. When it affects the renal arteries, the most common presentation is hypertension. When it affects the carotid or vertebral arteries, the patient may present with transient ischemic attack or stroke, or dissection. An increasing number of patients are asymptomatic and are only discovered incidentally when imaging is performed for some other reason or by the detection of an asymptomatic bruit. FMD should be considered in the differential diagnosis of a young person with a cervical bruit; a "swishing" sound in the ear(s); transient ischemic attack, stroke, or dissection of an artery; or in individuals aged ≤ 35 years with onset hypertension. Treatment consists of antiplatelet therapy for asymptomatic individuals and percutaneous balloon angioplasty for patients with indications for intervention. Patients with aneurysms should be treated with a covered stent or open surgical repair. Little new information has been published about FMD in the last 40 years. The recently instituted International Registry for Fibromuscular Dysplasia will remedy that situation and provide observational data on a large numbers of patients with FMD.

Contemporary management of fibromuscular dysplasia

Fibromuscular dysplasia is an underdiagnosed and misunderstood disease. The purpose of this review is to inform healthcare providers and the public about a condition that may be more common than previously thought. There has been little new information published about fibromuscular dysplasia in the past 30 years. The International Registry that is now underway will remedy that situation and provide a large number of patients to study with this condition. Fibromuscular dysplasia is a noninflammatory, nonatherosclerotic disease that has been reported in almost every arterial bed and primarily affects women aged 15-50 years. It most commonly presents in the renal and extracranial cerebrovascular arteries, either manifesting as hypertension, transient ischemic attack or stroke, respectively. Some patients may be asymptomatic and fibromuscular dysplasia could only be discovered by imaging for some other reason or by the detection of an asymptomatic bruit. Dissection or aneurysm may also occur in patients with fibromuscular dysplasia. The true prevalence is unknown, partially because of the fact that it is underdiagnosed in many patients. Treatment consists of antiplatelet therapy for asymptomatic individuals and percutaneous balloon angioplasty for patients with indications for intervention. Patients with macroaneurysms should be treated with either a covered stent or surgery.

The influence of ultrasonic Duplex scanning on the management of carotid artery disease.

In order to assess the influence of a non-invasive test such as Duplex scanning on the management of patients with suspected carotid artery disease, we reviewed the data on all new referrals (n = 491) during a year. The patients were grouped according to the reason for the referral: 1, patients with focal neurological symptoms lasting less than 24 h (n = 156); 2, patients with focal neurological symptoms lasting longer than 24 h (n = 107); 3, patients with non-focal neurological symptoms (n = 147); 4, patients with asymptomatic bruits (n = 81). For all four groups there was a statistically significant relationship (chi 2; P less than 0 . 005) between the reporting of the presence of a high grade stenosis (more than 50 per cent diameter reduction) and the likelihood that the patient would undergo arteriography. The finding of a high grade stenosis on the arteriogram resulted in a greater number of patients undergoing carotid artery surgery. The results of this study indicate that the report of the non-invasive test influenced the decision-making process in the management of patients with suspected carotid artery disease.

Endovascular treatment of spinal arteriovenous fistula in a young child with hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia ([HHT] or Osler-Weber-Rendu syndrome) can manifest as sudden onset of epistaxis or neurological deficit in a child with characteristic mucocutaneous telangiectasias or as an asymptomatic bruit with or without overlying cutaneous vascular lesions. The authors present a case study of a pediatric patient with HHT in whom a screening computerized tomography (CT) scan of the chest revealed an asymptomatic arteriovenous malformation (AVM) of the spine. An 18-month-old child with a strong family history of HHT, including fatal central nervous system (CNS) hemorrhage and pulmonary AVMs, presented with a cutaneous telangiectasia of the pinna. The child was subsequently screened for potentially morbid pulmonary and CNS AVMs by using chest CT scanning and brain magnetic resonance (MR) imaging. A spinal MR image revealed a perimedullary macro-AVF (MAVF) resulting in a large venous varix within the parenchyma of the thoracic spinal cord. A transarterial embolization of the fistula was performed using N-butyl cyanoacrylate and ethiodol. Postembolization angiography confirmed obliteration of the fistula, and MR imaging revealed thrombosis and reduction in size of the venous varix. There were no neurological sequelae due to the treatment. In families with HHT and a high risk of sudden severe morbidity or death from undisclosed pulmonary or CNS AVMs, screening chest CT scanning and CNS MR imaging should be considered. Interdisciplinary teams of neurosurgery and interventional radiology specialists should evaluate and treat such patients by using diagnostic and therapeutic angiography and, if necessary, surgery.

Why do some patients with > 80% stenosis of the internal carotid artery not undergo surgery? A retrospective review.

Carotid endarterectomy is known to benefit both symptomatic and asymptomatic patients with high-grade internal carotid artery stenosis. Duplex scanning is the 'gold standard' for non-invasive preoperative investigation of carotid artery stenosis. The aim of the present study was to analyse the indications for duplex scanning and to identify other factors that influenced the management of patients with high-grade stenosis who did not undergo carotid endarterectomy. A total of 271 patients was observed to have > 80% stenosis of the internal carotid artery on duplex scanning during the period of review. Of these patients, 85 did not undergo carotid endarterectomy. The vascular laboratory database and hospital records of these patients were retrospectively reviewed. The indications for requesting a carotid duplex scan in the 85 patients were transient ischaemic attack (22%), stroke (25%), symptomatic bruit (7%), asymptomatic bruit (12%), and stroke and symptomatic bruit combined (7%). Falls and preoperative carotid assessment prior to coronary surgery were the commonest indications in the remaining patients. The main risk factors were cardiac (68%), hypertension (60%), respiratory (21%), diabetes (25%), peripheral vascular disease (19%), neoplasm (16%) and renal disease (16%). Twenty-five per cent of the patients were over 80 years of age. In the present study risk factors associated with increased perioperative morbidity and mortality were the commonest explanation for patients with high-grade stenosis of the internal carotid artery not undergoing surgery. These patients would generally not meet the inclusion criteria for the major carotid endarterectomy trials.

Audit of the effect of introducing local guidelines for referral for carotid duplex scanning.

Guidelines for referral of patients for carotid duplex scanning were introduced stating that scans were only indicated for patients with hemispheric localising symptoms or asymptomatic bruits. A 19% reduction in referral rate was seen for new scans in a one year period. The number of "inappropriate" requests fell from 27.6% in 1994 to 12.8% in 1995. There was no reduction in the numbers of patients identified with effectively occult asymptomatic disease who may have been suitable for surgery in the same period. Guideline introduction had the effect of reducing unnecessary scans without any effect on the overall pick-up, rate for carotid disease.

Carotid endarterectomy for asymptomatic disease

Since carotid stenosis was first recognized as a potential cause of stroke in the 1950s, physicians have been trying to refine a mechanical solution, the carotid endarterectomy (CEA), for a potentially mechanical problem. The purpose of the CEA is to remove an atherothrombotic lesion from the region of the carotid bifurcation before it becomes flow restrictive or becomes a nidus for artery-toartery emboli. The surgery involves exposing the carotid bifurcation in the neck, clamping the common and internal carotid arteries, performing an arterotomy on the carotid artery, and removing the diseased intima. 1 Through the mid-1980s, despite the fact that there had not been any large, prospective randomized trials proving the safety and efficacy of CEA for any indication, the number of procedures performed per year grew. 2 In 1970, approximately 12,000 CEAs were performed annually in the United States. By 1980, that number had grown to over 50,000. By 1985, the number of CEAs in the United States had passed 100,000. For over two decades, the literature was filled with many encouraging anecdotal reports, but there were no rigorous scientific trials on the role of CEA in asymptomatic patients. By way of example, in 1978, Thompson et aP reported a retrospective review of 270 patients who had been evaluated by them for carotid stenosis. 3 One hundred thirty-two had CEA, and 138 did not receive an operation. With follow-up up to 192 months, the investigators reported that 91% of the operated patients remained asymptomatic, and only 56% of the nonoperated patients were asymptomatic. Other anecdotal reports indicated that the natural history of symptomatic stenosis may be benign, and surgery may not be warranted. 4 Although not rigorous scientific studies, such reports suggested that CEA may benefit some patients with asymptomatic carotid stenosis. The risks of CEA were also reported in numerous retrospective series. For example, Thompson et al 5 reported no surgical strokes or deaths in patients with asymptomatic bruit. Fode et al 6 reported a retrospective

U.S. national survey of stroke prevention practices: Asymptomatic bruit: Larry B. Goldstein, Arthur J. Bonito, David B. Matchar, Gregory P. Samsa (Duke University, Durham, NC)

U.S. national survey of stroke prevention practices: Asymptomatic bruit: Larry B. Goldstein, Arthur J. Bonito, David B. Matchar, Gregory P. Samsa (Duke University, Durham, NC)

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

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

Carotid duplex scanning: Patterns of referral and outcome

Review of the results of carotid Duplex scanning. Retrospective review of new referrals for carotid Duplex scanning to a regional vascular laboratory. 1041 referrals made over an 18 month period. Referrals were reviewed for scan quality, diagnostic category and outcome of scanning. The overall detection rate of ipsilateral stenoses > 70% and occlusions was 13.5%; the detection rate of surgically significant carotid lesions (70-99%) was only 8%. Analysis by diagnostic category revealed a significantly greater detection rate for carotid lesions > 70% in patients presenting with amaurosis fugax (24%) in comparison to those with TIAs (9.5%, p = 0.0005) or following a stroke (13%, p = 0.01). Patients referred with asymptomatic bruits or prior to cardiac surgery showed a positive scan rate of 30%. Sixty-seven carotid endarterectomies have resulted from scans performed in this period. The overall rate of detection for surgically relevant lesions is low, but in comparison to a similar audit conducted in 1992, the absolute number of carotid lesions > 70% has risen by 60%. An 8% detection rate for surgically relevant lesions may be valuable in projecting the need for carotid endarterectomy arising from a given number of Duplex scans.

Safety and efficacy of concomitant carotid and coronary artery operations

Controversy exists concerning the best management for patients with concurrent severe carotid and coronary artery disease. The records of 200 consecutive patients having concurrent carotid endarterectomy and coronary artery bypass grafting from 1979 to 1993 were reviewed, and follow-up was obtained (99% complete). Of the group (77% male; mean age, 67 years), 134 (67%) had unstable angina, 130 (65%) had triple-vessel disease, and 86 (43%) had left main coronary stenosis. Preoperative investigation revealed asymptomatic bruits in 116 (58%), transient ischemia in 65 (32%), strokes in 31 (16%), and bilateral carotid disease in 44 patients (22%). Nonelective operations were required in 66 patients (33%). Hospital death occurred in 7 patients (3.5%), myocardial infarction in 5 (2.5%), and permanent stroke in 6 (3%). Ten-year actuarial event-free rates were as follows: death, 58%; myocardial infarction, 81%; stroke, 92%; percutaneous angioplasty, 98%; redo coronary artery grafting, 94%; and all morbidity and mortality, 56%. Significant multivariate predictors of hospital death were postoperative stroke, failure to use an internal mammary artery graft, intraoperative intraaortic balloon, and nonelective operation. Significant predictors of postoperative stroke were peripheral vascular disease and unstable angina. Significant predictors of prolonged hospital stay were postoperative stroke, advanced age, and nonelective operation. Concomitant carotid endarterectomy and coronary bypass grafting can be performed with acceptably low operative risk and good long-term freedom from coronary and neurologic events.

Combined carotid and coronary revascularization: The preferred approach to the severe vasculopath

The timing of carotid endarterectomy (CEA) and coronary revascularization (CABG) for concomitant disease is controversial. Results of combined CEA/CABG in 127 patients (age range, 46 to 82 years; mean age, 65 years; 61% male) from 1978 to 1991 were reviewed. Ninety-five patients (75%) were in New York Heart Association functional class III or IV, 48 (38%) had left main coronary artery disease, and 32 (28%) had depressed ejection fraction (<0.50). Forty (32%) had asymptomatic bruits, 61 (48%) transient ischemic attacks, and 26 (20%) prior strokes. Seventy-five (59%) had bilateral carotid stenosis, including 20 (16%) with contralateral occlusions. Perioperative mortality was 7 of 127 (5.5%), and all deaths were cardiac related. Myocardial infarctions occurred in 6 of 127 patients (4.7%) and were nonfatal in 3 (2.3%). Permanent strokes occurred in 7 of 127 (5.5%) and were ipsilateral in 5 (3.9%). Perioperative stroke did not occur in the asymptomatic group, but the risk was higher in those with prior stroke (19%) or with contralateral carotid occlusion (15%). The stroke risk for our patients with carotid disease having CABG without CEA is not known, but the literature reports rates as high as 14%. For our patients without known concomitant disease, the risk of permanent stroke was 1.0% ( 31 / 3012 ) for isolated CABG and 1.5% ( 7 / 482 ) for isolated CEA. The late results after CEA/CABG revealed a 5-year survival of 70% ± 5%, which correlated with ejection fraction (≥0.50, 81% ± 5%; <0.50, 45% ± 11%; p < 0.003). Freedom from late permanent ipsilateral stroke was 97% ± 2% at 8 years. Freedom from stroke at 5 years was lower among patients with a previous stroke (71% ± 10%) compared with transiently symptomatic (90% ± 4%) and asymptomatic (96% ± 4%) patients ( p < 0.03). Combined CEA/CABG is a useful option in this high-risk group of patients with extensive atherosclerosis; avoids a subsequent hospitalization, anesthetic, and delay period; and provides long-term protection from ipsilateral stroke.

Late complications of revascularization for radiation-induced arterial disease

During a 14-year period 23 patients underwent 25 revascularizations for radiation-induced arterial obstructive disease. An average of 5000 rads was delivered, 3 to 24 (mean 9) years before arterial insufficiency, for malignancies of the following origin: gynecologic (n = 9), lymphoma (n = 7), head and neck (n = 5), testicular (n = 1), and lower extremity sarcoma (n = 1). Arterial occlusive disease occurred in the aortic arch vessels (n = 8), visceral aortic vessels (n = 1), and aortofemoral vessels (n = 16). Presenting symptoms were claudication (n = 8), rest pain or nonhealing ulcers (n = 7), transient ischemic attacks (n = 6), asymptomatic bruit (n = 1), and renal insufficiency (n = 1). Reconstructive operations included anatomic bypass (n = 10), extraanatomic bypass (n = 4), patch angioplasty (n = 5), endarterectomy (n = 3), and resection with interposition graft (n = 1). In this group of patients there were no major perioperative wound complications or other major radiation-associated morbidity. Five patients had late graft infections that manifested from 2 to 5 years after surgery. All occurred in anatomic regions where the bypass graft passed through previously irradiated tissues. Presenting symptoms of infection included a draining groin sinus (n = 3) or soft tissue abscess (n = 2). In all cases the graft had not incorporated into the surrounding tissues when passing through the irradiated area. Treatment included graft excision and extraanatomic bypass through nonirradiated tissue. One patient died of systemic sepsis. Vascular reconstructive surgery can safely be performed for radiation-induced arterial disease. We found a 21% incidence of late graft infection, all of which occurred when a bypass traversed previously irradiated tissue. Use of autologous conduits and extraanatomic bypass to avoid irradiated areas may decrease associated morbidity.

Combined cardiac operation and carotid endarterectomy during aortic cross-clamping

We present a surgical technique that we believe provides superior cerebral protection for simultaneous correction of carotid and cardiac pathology with low operative mortality and stroke rate. Our study population consists of 23 consecutive patients undergoing cardiac operation between August 1969 and April 1991 who also had associated critical (> 85%) carotid artery stenosis. Using 20 °C systemic hypothermia for cerebral protection, we performed simultaneous correction of both lesions during the aortic cross-clamp period, using continuous retrograde blood cardioplegia for myocardial protection. Mean patient age was 69.4 years; 83% were 65 years or older. Eighty-seven percent had angina, 35% had recent myocardial infarctions (within 30 days), and 52% had congestive heart failure. Asymptomatic bruit was found in 39%, and 61% had previous strokes, neurologic symptoms, or both. All had 85% or greater luminal narrowing on cerebral angiography, with 65% having severe or critical contralateral disease as well. Sixty-one percent had associated other vascular pathology, including peripheral vascular occlusive disease, renal artery stenosis, or abdominal aortic aneurysm. There were no postoperative strokes or neurologic events. One early vein graft occlusion resulted in postoperative myocardial infarction and subsequent death (4.3%).

Predictive value of cervical bruit for the detection of obstructive lesions of the internal carotid artery. Data from 2000 patients

Between January 1982 and June 1985, 2000 patients with either symptoms of cerebrovascular insufficiency (1873) or asymptomatic cervical bruits (127) were studied at the Surgical Department of the University of Brescia (Italy). Of these, 441 presented a mono- or bilateral cervical bruit. The value of the bruit as indicator of an obstructive pathology of the extracranial carotid artery was evaluated in comparison with the findings of Doppler spectrum analysis. A stenosis or occlusion of the internal carotid artery was present in 51% of the patients with a bruit (homolateral to the bruit in 91% of the cases) and in 9% of those without a bruit. Stenoses of a medium-high degree were those more often associated with the bruit. Both in patients with bruit and in those without bruit the age and the severity of the presenting symptoms significantly influenced the rate of association with lesions of the internal carotid artery was present in 51% of the patients with a bruit (homolateral to the bruit in 91% of the cases) and in 9% of those without a bruit. Stenoses of a medium-high degree were those more often associated with the bruit. Both in patients with bruit and in those without bruit the age and the severity of the presenting symptoms significantly influenced the rate of association with lesions of the internal carotid artery.

Patients with Asymptomatic Neck Bruits

Patients with Asymptomatic Neck Bruits

Can carotid endarterectomy be justified? Yes.

A severe, nonfatal stroke has a ruinous effect on the quality of life, and the evidence suggests that carotid endarterectomy can prevent stroke in selected patients, as I will try to show. Choosing both the proper patient and a skilled surgeon is the key to achieving this goal. Who is the proper patient? Certainly not the entire pool of patients with asymptomatic bruit. Two studies suggest that the stroke rate is approximately 2% per annum in this group. 1,2 Patients with an asymptomatic bruit face a greater threat of death than they do of stroke, since their annual mortality rate is approximately 4%. Between the low incidence of stroke and a significant mortality rate from causes such as heart disease, it is not likely that the routine performance of carotid endarterectomy in unselected patients with asymptomatic bruit could be shown to be beneficial by any kind of a randomized trial.

Management of asymptomatic carotid bruit

One hundred forty-nine consecutive patients who had peripheral arterial disease (PAD) with clinically audible asymptomatic bruits were studied. Sixty-two of these patients were age- and sex-matched with 62 PAD patients in whom no bruits were detected. The PAD was demonstrated by angiography or by the 1-minute exercise test. Clinical assessment was performed every 6 months and oculoplethysmography and carotid phonoangiography (OPG/CPA) were performed every year. Angiography and reconstructive surgery were performed only if symptoms of transient ischemic attack (TIA) or stroke occurred. Lifetable analysis revealed that over a 5.5-year follow-up, 32% of 211 PAD patients were expected to die. In the control study 45% of bruit patients and 32% of control patients were expected to die (no significant difference). Myocardial infarction accounted for 59% of deaths in the bruit group compared with 28% in the control group (no significant difference). TIA occurred more commonly in the bruit group (26.5%) than in the controls (6%) (p < 0.02). However, stroke without warning occurred in 9% of bruit patients compared with 8% of controls (no significant difference). It is concluded that for asymptomatic carotid bruit it is safe to wait for the onset of symptoms before angiography and corrective reconstructive surgery.