Carotid endarterectomy: Practice guidelines. Report of the Ad Hoc Committee to the Joint Council of the Society for Vascular Surgery and the North American Chapter of the International Society for Cardiovascular Surgery

Rapid High-Volume Population Screening for Three Major Risk Factors of Future Stroke: Phase I Results

Three proximate risk factors for stroke are carotid stenosis, atrial fibrillation, and hypertension. Phase I of this prospective study was designed to establish the prevalence of these conditions among a population of health maintenance organization beneficiaries by using a rapid screening protocol in order to risk-stratify patients for appropriate management and subsequent cohort analysis. Patients at a tertiary care medical center were screened for stroke risk by using directed history, a 3-minute carotid “quick-scan” protocol, an EKG lead II rhythm strip, and bilateral arm blood pressures. Patients with any abnormal result underwent specific diagnostic consultation with vascular surgery, cardiology, or primary care. These evaluations included formal carotid duplex ultrasound, 12-lead EKG ± Holter monitor, and 5-day blood pressure check. Patients were then stratified into risk cohorts for appropriate management and future analysis of stroke incidence and outcomes. In 8 hours on a single day in October 2002, 294 patients (mean age 69) were screened. Combining history with results of screening and diagnostic tests, the overall prevalence of carotid stenosis was 6% (n= 17/294), atrial fibrillation 7% (n= 21/294), and severe hypertension 5% (n= 16/294). Fifty-nine patients (20%) screened positive for carotid stenosis by “quick-scan,” and 29% (n= 17/59) of these had confirmed stenosis (>50%) in 1 or both arteries by formal duplex. The prevalence of confirmed carotid stenosis was 37% among those screening positive for 1 artery (odds ratio [OR] 14.6; p <0.001) and 75% among those screening positive for both (OR 74.7; p <0.001). Significant independent predictors of carotid stenosis by multivariate analysis included coronary artery disease or myocardial infarction, smoking, stroke or transient ischemic attack, male gender, and white race (all p <0.05). The prevalence of confirmed stenosis was 10% with any 3 predictors alone (OR 2.5; p <0.05), 31% with any 4 (OR 21.2; p <0.001), and 50% with all 5 (OR 46.5; p <0.001). Thirty-three patients (11%) were found to have a previously unidentified and untreated arrhythmia, and 12% (n= 4/33) of these had confirmed new atrial fibrillation; 158 patients (54%) had moderate hypertension and 16 (5%) had severe hypertension (>180/100). Overall, 82% (n= 242/294) of patients screened required additional diagnostic tests. Based on these results, 11% (n= 31/294) of patients were stratified as high risk, 64% (n= 188/294) as moderate risk, and 25% (n= 75/294) as low risk for future stroke. Rapid and efficient screening of a large population for stroke risk factors is feasible. The prevalence of undiagnosed, unsurveilled, and untreated carotid stenosis, atrial fibrillation, and severe hypertension is significant, as 75% of patients screened had 1 or more confirmed major risk factors for stroke. Phase II of this study will investigate the degree of stroke risk reduction possible with a multidisciplinary approach to early identification and aggressive treatment of these risks.

Clinical Benefit of Carotid Endarterectomy Based on Duplex Ultrasonography

Carotid endarterectomy has been shown to significantly reduce the risk of stroke caused by carotid artery stenosis in selected patients. Limiting the morbidity and costs of this process without increasing the risks should further improve the benefits of this procedure. Results were prospectively collected from 123 consecutive carotid endarterectomies performed at a community teaching hospital. All patients underwent duplex ultrasonography for preoperative evaluation. Catheter angiography was used on a selective basis. Preferential use of regional anesthetic and selective use of the intensive care unit were applied. The mortality, morbidity, complications, and costs were then compared for the group receiving only preoperative duplex ultrasonography with those undergoing catheter angiography preoperatively. Age, comorbid risk factors, indications for carotid endarterectomy, and incidence of stroke were similar in both patient groups. The rates of mortality, morbidity, and stroke for carotid endarterectomy were low (mortality 0%, morbidity 6.5%, stroke 0.8%). For preoperative evaluation all patients underwent duplex ultrasonography (100%) and 28 (23%) underwent preoperative catheter angiography in addition to duplex ultrasonography. The complication rate associated with catheter angiography was 6/28 (21%). Complications included groin hematoma (7%), pseudoaneurysm (3.6%), bradycardia (7%), and unstable angina (3.6%). Costs for duplex ultrasonography averaged $165 and additional costs incurred by the use of catheter angiography averaged $4,200. Intraoperative assessment of the carotid endarterectomy site did not change based on the use of preoperative catheter angiography. Morbidity, mortality, and stroke rates were the same for the 2 groups. The preoperative use of duplex ultrasonography for the sole evaluation in carotid endarterectomy is well established. The use of preoperative catheter angiography is still preferred by a subset of surgeons. The use of catheter angiography is associated with significant morbidity and additional costs when compared to performing carotid endarterectomy based solely on preoperative duplex ultrasonography. The added costs and morbidity of angiography increase the societal cost of this procedure without significant clinical improvement in patient outcome.

Asymptomatic Carotid Stenosis and Risk of Stroke: A Natural History Study

In patients with asymptomatic carotid stenosis >70% diameter, the annual incidence of ipsilateral stroke is 3-4%. Multicentre randomised studies such as the asymptomatic carotid atherosclerosis study (ACAS) in the U.S.A. and the ACST in Europe aim to answer the question whether carotid endarterectomy can reduce the incidence of stroke in such patients. If the surgical risk is too close to benefit or if a high proportion of patients not at risk of stroke are entered into the ACAS or ACST studies, the latter may fail to demonstrate the benefit of carotid endarterectomy (CE). The need to identify a high risk stroke group (ipsilateral stroke >7% per annum) with randomisation of this group to a subsequent study will then become apparent. If the ACAS and ACST studies indicate that the risk of stroke is reduced by 50% (i.e., from 4 to 2%), it has been calculated that the cost of preventing one stroke will be 1.2 million US dollars because of the large number of operations required. It will still be necessary to identify a high-risk group or, better, a low-risk group in order to spare many patients unnecessary operation. A multicentre, natural history study has been set up under the auspices of the International Union of Angiology and monitored from St Mary's Hospital Medical School in London with over 50 centres taking part. Patients with asymptomatic carotid stenosis 50-70% and 70-90% are entered in a ratio of 1 to 2, a number of noninvasive tests are performed, and the patients are followed for 5 years. The tests performed are (a) Grading the degree of internal carotid stenosis using duplex scanning; (b) grading the opposite side; (c) plaque characterisation; (d) presence of ultrasonic ulceration; (e) plaque thickness (mm); (f) cerebral reactivity to CO2using velocity of internal carotid artery and (optional) middle cerebral artery ; (g) CT brain scan for the presence of silent infarction ; (h) intima-media thickness of the common carotid; and (i) identification of conventional risk factors: hypertension, hypercholeterolaemia, smoking, family history, diabetes. The key end points are stroke (including fatal stroke) and ipsilateral stroke. Patients who die from cardiovascular death other than stroke or noncardiovascular death and patients who develop hemispheric transient ischaemic attacks followed by CE are considered to have reached an exit end point. Because this is a natural history study, the clinician in charge of all patients is free to treat them in any way considered appropriate. Patients in the Medical Limb of the ACST study may be entered into the Natural History (ACSRS) study.

Stenting in the Carotid Artery: Initial Experience in 110 Patients

Purpose:

To evaluate the feasibility, safety, and efficacy of intravascular stents in the treatment of extracranial carotid artery occlusive disease.

Methods:

According to protocol, stent therapy was offered to symptomatic patients with ≥ 70% arteriographically defined carotid stenoses or ulcerative lesions and, after September 1994, to asymptomatic patients with ≥ 75% stenoses. From April 1993 to September 1995, 110 nonconsecutive patients (79 males; mean age 72 years, range 45 to 85) consented to participate in the study. The majority (79 [72%]) were asymptomatic. Lesions meeting the treatment criteria were in the proximal common (n = 3); mid common (n = 12); distal common (n = 8); internal (ICA) (n = 92); and external (n = 2) carotid arteries. Seven patients had bilateral ICA stenoses, and 17 patients were treated for postsurgical recurrent disease. The mean lesion length and diameter stenosis for all lesions were 12.4 ± 9.2 mm and 86.5% ± 10.6%, respectively. The procedures were performed either via direct percutaneous access to the cervical common carotid artery or through a retrograde femoral artery approach. Standard balloon dilation preceded deployment of balloon-expandable stents in most cases. No postprocedural anticoagulation was used (aspirin only).

Results:

In 110 patients (117 arteries) intended for treatment, 109 (99.0%) (116 arteries [99.1%]) were successfully treated with 129 stents (128 Palmaz, 1 Wallstent). One percutaneous procedure failed (0.9%) for technical reasons (stent could not be deployed) and was converted to carotid endarterectomy. Minor complications included 4 cases of spasm (successfully treated with papaverine); 1 flow-limiting dissection (stented); and 6 access-site problems. There were 7 strokes (2 major, 5 reversible) (6.4%) and 5 minor transient events (4.5%) that resolved within 24 hours. Three patients were converted to endarterectomy (2.7%) prior to discharge; 1 stroke patient expired (0.9%), and another patient died of an unrelated cardiac event in hospital. In the 30-day postprocedural period, 2 ICA stents occluded (patients asymptomatic). Clinical success at 30 days (no technical failure, death, endarterectomy, stroke, or occlusion) was 89.1% (98/110). Over a mean 7.6-month follow-up (range 2 to 31), no new neurological symptoms developed. Another stent occlusion at 2 months and one case of flow-limiting intimal hyperplasia at 7 months were detected on routine duplex scanning in asymptomatic patients. Life-table analysis shows an 89% cumulative primary patency rate.

Conclusions:

Based on this early experience, carotid stenting appears feasible from a technical standpoint, with good midterm patency. However, the incidence of neurological sequelae is a serious problem. Technical enhancements and a more aggressive antiplatelet regimen may have a positive impact on these events.

Carotid endarterectomy and carotid artery stenting: changing paradigm during 10 years in a high-volume centre

BACKGROUND

We analysed the results of internal carotid artery (ICA) stenosis treatment at our institution over the last 10 years according to treatment modalities (carotid endarterectomy [CEA] vs carotid artery stenting [CAS]). Furthermore, we compared our results of treatment prior to the EVA-3S study being implemented into our practice (2003-2007) and after that (2008-2012).

METHOD

During the years 2003-2012, a total of 1,471 procedures were performed for ICA stenosis. CEA was done in 815 cases and CAS in 656 cases. The primary outcome was disabling stroke (mRS > 2) or myocardial infarction (MI) within 30 days after treatment. Secondary outcomes were frequency of transient ischaemic attacks (TIAs), minor strokes (stroke without impaired activities of daily living [ADL]) and any other significant complication. Comparisons of the results before and after 2008 were performed.

RESULTS

Major mortality and morbidity were divided according to treatment groups; reached 1.0 % in the CEA group and 3.0 % in the CAS group, p = 0.004. Minor stroke was recorded at 1.8 % and 2.7 % in the CEA and CAS, p = 0.245. TIAs in 1.0 % (CEA) and 4.7 % (CAS), p < 0.001. Any complication in 11.9 % (CEA) and 13.3 % (CAS), p = 0.401. In the overall results (i.e. CEA and CAS together), we found in 2008-2012 a decrease of incidence of TIAs (from 30/840 to 9/631, p = 0.011) and any complications (from 120/840 to 64/631, p = 0.017).

CONCLUSIONS

CEA performed in a high-volume centre is a safe procedure in properly indicated patients. In all subgroup analyses, CEA fared better than or at least of equal benefit as CAS. Since 2008, the frequency of TIAs and other complications decreased significantly. This study supports an idea of CEA being the first choice of treatment and CAS being reserved for strictly selected cases, such as re-stenosis after a previous carotid procedure, carotid dissection, ICA stenosis after radiotherapy, previous major neck surgery, contralateral cranial nerve palsy or tandem stenosis.

Multicenter Experience on Eversion Versus Conventional Carotid Endarterectomy in Symptomatic Carotid Artery Stenosis

Background and Purpose—

Carotid endarterectomy (CEA) is beneficial in patients with symptomatic carotid artery stenosis. However, randomized trials have not provided evidence concerning the optimal CEA technique, conventional or eversion.

Methods—

The outcome of 563 patients within the surgical randomization arm of the Stent-Protected Angioplasty versus Carotid Endarterectomy in Symptomatic Patients (SPACE-1) trial was analyzed by surgical technique subgroups: eversion endarterectomy versus conventional endarterectomy with patch angioplasty. The primary end point was ipsilateral stroke or death within 30 days after surgery. Secondary outcome events included perioperative adverse events and the 2-year risk of restenosis, stroke, and death.

Results—

Both groups were similar in terms of demographic and other baseline clinical variables. Shunt frequency was higher in the conventional CEA group (65% versus 17%; P <0.0001). The risk of ipsilateral stroke or death within 30 days after surgery was significantly greater with eversion CEA (9% versus 3%; P =0.005). There were no statistically significant differences in the rate of perioperative secondary outcome events with the exception of a significantly higher risk of intraoperative ipsilateral stroke rate in the eversion CEA group (4% versus 0.3%; P =0.0035). The 2-year risk of ipsilateral stroke occurring after 30 days was significantly higher in the conventional CEA group (2.9% versus 0%; P =0.017).

Conclusions—

In patients with symptomatic carotid artery stenosis, conventional CEA appears to be associated with better periprocedural neurological outcome than eversion CEA. Eversion CEA, however, may be more effective for long-term prevention of ipsilateral stroke. These findings should be interpreted with caution noting the limitations of the post hoc, nonrandomized nature of the analysis.

Retrospective analysis of bovine pericardium (Vascu-Guard) for patch closure in carotid endarterectomies

BACKGROUND

It has been shown that patch closure after carotid endarterectomy (CEA) decreases the rate of recurrent stenosis. This study was designed to evaluate the utility of bovine pericardium patch as an option for patch closure after CEA.

METHODS

This retrospective study examined 845 CEAs with bovine patch closure that were performed by the surgeons of Indiana-Ohio Heart, Fort Wayne, IN, between May 2003 and March 2009. The average age of the patients was 72.7 ± 10.6 years and postoperative follow-up was performed using duplex ultrasound at (ideally) 1 month, 6 months, 12 months, and annually thereafter. The average duration of follow-up for this study was 19.2 ± 16.8 months (ranging from 1 day to 72 months). All patients were evaluated for demographics and postoperative medications. Restenosis was categorized in three ways: nonsignificant (0-59% narrowing of the artery), significant (60-79%), or critical (80-99%). A total of 796 arteries were studied at least once during the postoperative period.

RESULTS

None of the postoperative duplex studies revealed occlusion of the endarterectomized artery. At the mean follow-up duration, 323 endarterectomized arteries were studied. In all, 24 arteries (7.43%) had significant stenosis and only two (0.62%) had critical stenosis. These numbers compare favorably with the recurrent restenosis rates of other materials. Additionally, the effect of statins on restenosis rates was studied. We were unable to demonstrate a beneficial effect of postoperative statin therapy on restenosis rates.

CONCLUSION

The use of bovine pericardium for patch closure in CEA yields excellent freedom from residual or recurrent postoperative stenosis and the use of statins postoperatively failed to reduce the likelihood of residual or recurrent stenosis.

Risk factors for restenosis after carotid artery angioplasty and stenting

OBJECTIVES

With carotid artery stenting (CAS) becoming an ever-increasing procedure, we sought to determine risk factors for in-stent restenosis after CAS.

METHODS

Consecutive patients undergoing CAS between January 2002 and October 2004 at a tertiary care hospital were retrospectively reviewed. Patient, filter, and stent selection were left to the discretion of the attending surgeon. High-risk patients were defined by significant comorbidities or a hostile neck (prior surgery or radiation, or both), and risk factor analysis was performed. In-stent restenosis was defined as >60%, and selective angiography was performed on patients with an in-stent restenosis >80% by duplex ultrasound imaging.

RESULTS

Reviewed were 101 patients (55 men, 46 women) who underwent 109 CAS procedures. Comorbidities were typical for patients with atherosclerosis. In addition, 38% (n = 41) of procedures were performed in patients who had prior neck surgery, of which 29% (n = 32) had previous ipsilateral carotid endarterectomy. Seventeen patients (16%) had a history of neck cancer, and all had prior neck radiation. Median follow-up was 5 months (range, 0 to 30 months). Neurologic complications included three transient ischemic attacks (2.8%) and one nondisabling stroke (0.9%). There were two myocardial infarctions (1.9%) and no periprocedural deaths (30 days), for a combined stroke, myocardial infarction, and death rate of 2.9%. Asymptomatic in-stent restenosis developed in 12 carotids (11%), five of which required endovascular intervention, with a mean of 6 months to restenosis. Univariate Cox proportional hazard regression models were used to determine risk factors for the development of restenosis. Prior stroke, transient ischemic attack, amaurosis fugax, and prior neck cancer were all significant risk factors. When these significant risk factors from univariate analysis were put into multivariate analysis, however, the only marginally significant risk factor was prior neck cancer (P = .06). Kaplan-Meier analysis revealed a cumulative freedom from in-stent restenosis at 24 months of 88% +/- 6% in patients without neck cancer compared with 27% +/- 17% (P = .02) in patients with neck cancer.

CONCLUSIONS

CAS has been shown to be safe and effective in high-risk patients, with minimal adverse events.

Extensive Mobile Thrombus of the Internal Carotid Artery: A Case Report, Treatment Options, and a Review of the Literature

The presence of a carotid stenosis, a floating thrombus, and a patient with clinical and CT evidence of a stroke represents a significant therapeutic dilemma to the clinician. The evidence of a stroke precludes any active treatment of the carotid stenosis safely, while the floating thrombus demands immediate attention. We recently were involved with just such a patient and chose a conservative approach of anticoagulation followed by operative intervention several weeks later.

Symptomatic patients have similar outcomes compared with asymptomatic patients after carotid artery stenting with emboli protection

In a single-center cohort of 174 consecutive patients, we sought to evaluate whether the use of emboli protection devices (EPDs) results in equivalent rates of adverse events in symptomatic and asymptomatic patients after carotid artery stenting (CAS) with EPDs. Death or stroke occurred in 3.3% in the symptomatic group and in 3.5% of the asymptomatic group at 30 days (p = NS). At 6 months, there was also no significant difference in the rate of stroke or death between the groups. Unlike surgical revascularization, symptomatic patients did not have a greater risk for stroke and death compared with asymptomatic patients after CAS with EPDs.

Semiautomatic segmentation and stenosis quantification of 3D contrast-enhanced MR angiograms of the internal carotid artery

A technique is presented for the segmentation and quantification of stenosed internal carotid arteries (ICAs) in 3D contrast-enhanced MR angiography (CE-MRA). Segmentation with sub-pixel accuracy of the ICA is achieved via level-set techniques in which the central axis serves as the initialization. The central axis is determined between two user-defined points, and minimal user interaction is required. For quantification, the cross-sectional area is measured in the stenosis and at a reference segment in planes perpendicular to the central axis. The technique was applied to 20 ICAs. The variation in measurements obtained by this method in comparison with manual observations was 8.7%, which is smaller than the interobserver variability among three experts (11.0%).

Extracranial carotid artery stenosis

BACKGROUND

Carotid endarterectomy is the most common surgical procedure used to treat stenosis of the extracranial precerebral carotid artery. Data from several randomized controlled trials are available to help guide its use in specific patient subgroups. Carotid angioplasty with stenting is also being performed, and clinical trials comparing this procedure with carotid endarterectomy are in progress.

SUMMARY OF REPORT

For patients with symptomatic high-grade (ie, 70% to 99%) stenosis, carotid endarterectomy is associated with an overall benefit (risk ratio estimate for the combined end point of nonfatal stroke, nonfatal myocardial infarction, or death, 0.67; 95% CI, 0.54 to 0.83). The benefit is more modest for patients with less severe stenosis (ie, 50% to 69%) and may vary with specific patient characteristics. Selected patients with asymptomatic carotid stenosis may also benefit from the operation, but it needs to be performed with very low complication rates, which can be difficult to achieve in clinical practice. Several studies of angioplasty, angioplasty with stenting, and more recently angioplasty with stenting and a so-called distal protection device have also been performed. The technology involved continues to evolve rapidly, presenting a challenge for the design and conduct of clinical trials.

CONCLUSIONS

Surgical intervention for extracranial carotid stenosis remains a major potential therapeutic modality for the prevention of stroke in selected patients. Endovascular approaches continue to be evaluated in ongoing trials.

Carotid endarterectomy and race: do clinical indications and patient preferences account for differences?

BACKGROUND AND PURPOSE

Carotid endarterectomy (CE) has been proved to reduce the risk of stroke for certain patients, but black patients are less likely than whites to receive CE. The purpose of this work was to determine the importance of clinical indications and patient preferences in predicting the use of carotid angiography and CE in a racially stratified sample of patients.

METHODS

Between 1997 and 1999, 708 patients with at least 1 carotid artery containing a >/=50% stenosis were enrolled (617 whites, 91 blacks) from 5 Veteran Affairs Medical Centers. Patient interviews were conducted at the time of the index carotid ultrasound, and each patient was followed up for 6 months to determine clinical events and receipt of carotid angiography or CE.

RESULTS

Black and white patients were similar in terms of age, sex, education level, and social support. More black than white patients received ultrasound for a completed stroke (36% versus 13%), and fewer black patients were classified as asymptomatic (56% versus 70%) or as having had a TIA (8% versus 17%; P<0.001). Health-related quality of life scores, trust in physician, and medical comorbidity scores were similar for black and white patients. Black patients expressed higher aversion to CE than white patients (31% versus 15% in the highest aversion quartile for blacks and whites, respectively; P=0.01). During follow-up, 20% of white patients and 14% of black patients received CE (P=0.19). In adjusted analyses, only patient clinical status as it relates to the indication for CE and site were associated with receipt of CE.

CONCLUSIONS

Contrary to prior research, patient's race was not associated with receipt of invasive carotid imaging or CE for older male veterans. These findings persist after controlling for patient preferences, comorbid illness, and quality of life. For patients enrolled in an equal-access health care system, clinical status was the primary determinant of the receipt of CE.

Carotid surgery in octogenarians: why not?

The latest studies have clearly demonstrated the efficacy of carotid endarterectomy. However, most of these studies excluded patients over the age of 80. Some authors question the efficacy of and indication for endarterectomy in octogenarians. We therefore compared our results for endarterectomies on patients aged under and over 80. The author reviewed 475 carotid endarterectomies that he himself performed between July 1, 1990 and February 28, 2001; 72 of these procedures were carried out on 65 patients (15%) aged 80 and over. Both perioperative neurological events and mortality were studied. The outcome of carotid endarterectomy in both patient population groups was comparable; more than 70% of octogenarians were still alive 4 years later the same indications for carotid endarterectomy should therefore be applied to octogenarians.

Routine early postoperative duplex scanning is unnecessary following uncomplicated carotid endarterectomy

Although early postoperative duplex scanning has become routine after carotid endarterectomy (CEA), it is unclear whether the results of these scans alter clinical management. The purpose of this study was to critically examine the usefulness of early postoperative duplex scans in evaluating the ipsilateral carotid artery (for technical perfection) as well as the contralateral carotid artery (for potential velocity changes after improvements in ipsilateral flow). Consecutive patients undergoing CEA between January 1995 and June 1999 in a tertiary hospital setting were studied. Patients underwent early postoperative duplex scanning according to the discretion of the operating surgeon and the availability of the patient. In 212 patients 236 CEAs were performed with selective use of patch closure (49%), intraluminal shunting (19%), and intraoperative completion imaging studies (14%). Neurologic complications included 3 transient ischemic attacks (TIAs) (1.3%), 3 nondisabling strokes (1.3%), and 3 disabling strokes (1.3%). There was 1 30-day death from myocardial infarction. Patients were followed up for a median of 18 months (range 0-72 months). Sixty-five percent of patients undergoing uncomplicated CEA (147/227) underwent early duplex surveillance within 6 months of operation. Unsuspected sonographic abnormalities were discovered in 8 patients (5%), including 7 cases of mild internal carotid artery (ICA) stenosis (>50% by velocity criteria) and 1 case of common carotid artery (CCA) stenosis (intimal flap). None of the patients with ICA stenosis developed symptoms or required operation at any time. The CCA intimal flap was electively repaired without complication. Postoperative changes in velocity in the contralateral ICA were found in 8/48 (17%) cases. There were 3 cases of increased velocity, upgrading 1 from 0-49% to 50-79% stenosis and upgrading 2 from 50-79% to 80-99% stenosis. The latter patients both underwent uneventful contralateral CEA. There were 6 cases of decreased velocity, resulting in downgrading of stenoses from 50-79% to 0-49% (n=5) or from 80-99% to 50-79% (n=1). Only the latter patient underwent contralateral CEA; the remainder have been followed up without intervention. Early scanning appeared to offer no clinical benefit; survival and neurologic outcome were the same in the 135 patients scanned within the first 6 months as in the 68 patients whose first postoperative scan occurred later (4-year neurologic event rate 0% in both groups; patient survival with early duplex 98 +/- 1.5%, without early duplex 96 +/- 2.6%; = NS). Early ipsilateral duplex abnormalities following CEA are infrequent in asymptomatic patients and, even if found, rarely alter management. Patients with bilateral stenosis being considered for contralateral CEA should undergo repeat duplex scanning after the first operation, because of the significant rate (19%) of contralateral velocity changes induced by ipsilateral CEA.

Eversion technique increases the risk for post-carotid endarterectomy hypertension

OBJECTIVE

The incidence of postoperative hypertension (HTN) after eversion carotid endarterectomy (e-CEA) was compared with that after standard carotid endarterectomy (s-CEA).

METHODS

In a retrospective analysis from January 1998 to January 2000, 217 patients underwent 219 CEAs for symptomatic (68) or asymptomatic (151) high-grade (>80%) carotid artery stenosis by either standard (137) or eversion (82) techniques. The eversion technique involves an oblique transection of the internal carotid artery at the carotid bulb and a subsequent endarterectomy by everting the internal carotid artery over the atheromatous plaque. All procedures were done under general anesthesia, and somatosensory-evoked potentials were used for cerebral monitoring. Patients with s-CEA were compared with those with e-CEA for postoperative hemodynamic instability, carotid sinus nerve block, requirement for intravenous vasodilators or vasopressors, stroke, and death.

RESULTS

Patients who underwent e-CEA had a significantly (P <.005) increased postoperative blood pressure and required more frequent intravenous antihypertensive medication (24%), compared with patients having an s-CEA (6%). Furthermore, postoperative vasopressors were required after 10% of s-CEAs, but after none of the e-CEAs. No statistically significant difference was noted in the morbidity or mortality of patients after s-CEA and e-CEA.

CONCLUSION

e-CEA is a substantial risk factor for HTN in the immediate postoperative period, when compared with the s-CEA. This difference would be even more remarkable in the absence of antihypertensive medications in the e-CEA group and vasopressors in the s-CEA group. Therefore, particular attention should be focused on diagnosing and controlling postoperative HTN in patients after e-CEA.

Colour flow Doppler ultrasound of the carotid bifurcation: can it replace routine angiography before carotid endarterectomy?

The objective of this study was to assess the diagnostic accuracy of colour flow Doppler ultrasound (CFD) and its potential to replace digital subtraction angiography (DSA) before carotid endarterectomy (CEA). All patients undergoing CFD of the carotid bifurcation in our department over a period of 1-1/2 years for whom both CFD and DSA results were available were included in the study. We evaluated the feasibility of CFD, its diagnostic accuracy and its potential to diagnose clinically significant stenosis (50%, 70% and 90% NASCET type diameter stenosis) compared with DSA. 225 carotid bifurcations in 116 patients met the criteria for evaluation (biplane arterial DSA without superimposition). Data analysis yielded the following diagnostic performance of CFD: sensitivity for a 50% stenosis 91.4% (95% confidence interval (CI) 83.3--96.2%), specificity 93.2% (95% CI 87.1--96.8%) and accuracy 92.4% (95% CI 88.4--95.4%); sensitivity for a 70% stenosis 89.2% (95% CI 81.9--94.1%), specificity 96.2% (95% CI 90.5--98.6%) and accuracy 92.4% (95% CI 88.4--95.4%). In 9 of 116 cases, carotid angiography was used to evaluate inconclusive CFD results. DSA disclosed relevant information not suspected by CFD in only 1 of the 116 cases. Thus, 91% (106/116) of the angiographies could have been dispensed with without loss of information. One major stroke occurred during diagnostic DSA. We conclude that DSA of the carotid arteries is unnecessary when CFD is unequivocal. The diagnostic gain of DSA must be counterweighted against its potential risks.

Results of carotid endarterectomy performed with preoperative duplex ultrasound assessment alone

Contrast injection cerebral angiography has been considered for several decades the "gold-standard" technique for diagnosis and operative planning of carotid disease. More recently, however, an increasing number of institutions are using duplex ultrasound as the single independent preoperative test. The objective of this investigation was to evaluate the impact of the utilization of duplex ultrasonography as the only preoperative test on the outcome of the procedure. Between 1993 and 1996, the authors performed 1,149 carotid procedures. Duplex ultrasound as the only preoperative test was employed with increasing frequency in a total of 728 cases. In 1995 and 1996, a cerebral arteriogram was performed only if duplex ultrasound was technically inadequate or questionable or showed an atypical pattern of disease. During the 4 years analyzed in this study, the number of the procedures increased from 165 in 1993 to 412 in 1996. The thirty-day mortality rate was 0.43%, and neurologic morbidity was 1.65%. According to the year in which the procedure was performed, the mortality/morbidity rates were 1.2/2.4 in 1993, 0.52/2.08 in 1994, 0.26/1.57 in 1995, and 0.24/1.21 in 1996. Indication to perform an arteriogram became very selective in 1995. Regardless of these changes in the diagnostic work-up, some degree of reduction in both 30-day mortality and neurologic morbidity was recorded. Considering a cost of 724 European Currency Units (ECU) per arteriogram, 527,072 ECU were saved in this period. In the last 4 years, duplex ultrasound has replaced arteriography as the first-choice technique for preoperative assessment of carotid disease at the authors' institution. There was definitely no detrimental effect on the clinical results that, on the contrary, improved during the same period. This policy has allowed a significant reduction in the cost of the procedure and has most likely prevented several arteriography-related complications. The authors recommend this policy to all institutions in which accurate duplex ultrasound is available.

Carotid thromboendarterectomy for recent total occlusion of the internal carotid artery

BACKGROUND

The efficacy of emergency carotid thromboendarterectomy (CTEA) for acute internal carotid artery (ICA) thrombosis has been questioned. We evaluated the use of CTEA in patients with recent ICA occlusion.

METHODS

From August 1989 to December 1999 patients who underwent urgent CTEA for recent ICA thrombosis were retrospectively evaluated. Patient data analyzed included age, sex, comorbid risk factors, diagnostic evaluation, operative procedure, and long-term follow-up with clinical assessment and carotid duplex scan. Neurologic status was evaluated with the Modified Rankin Scale (MRS) before the operation, immediately after the operation, and at 3- to 6-months' follow-up.

RESULTS

Twenty-nine patients underwent emergency ipsilateral CTEA for acute ICA thrombosis over the last 10 years. The average age of the patients was 69.9 +/- 1.7 years, and 66% were men. Patient risk factors included diabetes (7 [24%]), hypertension (21 [72%]), coronary artery disease (8 [29%]), and history of tobacco abuse (20 [69%]). Presenting symptoms included cerebrovascular accident (7 [24%]), transient ischemic attack (nonamaurosis) (10 [34%]), crescendo transient ischemic attack (7 [24%]), stroke in evolution (2 [7%]), and amaurosis fugax (3 [10%]). Diagnostic evaluation included computed tomographic scan (29 [100%]), magnetic resonance imaging/magnetic resonance angiography (4 [14%]), duplex scan evaluation of the carotid arteries (23 [79%]), and cerebral angiography (18 [64%]). Antegrade flow in the ICA was successfully established in 24 (83%) of 29 patients and confirmed with intraoperative angiography or duplex sonography. Postoperative morbidity included 2 hematomas (7%), 4 transient cranial nerve deficits (14%), and 1 conversion to hemorrhagic stroke (3.6%), which resulted in the only death (3.6%). MRS scores averaged 3.4 +/- 0.2 preoperatively. Follow-up averaging 74.1 +/- 21 months (range, 3-140 months) was obtained in 27 (93%) patients. Improvement or deterioration was defined as a change in MRS +/- 1. Immediately postoperatively, 14 (48%) patients were improved, 2 (7%) deteriorated, and 13 (45%) had no change. At 3 to 6 months, 20 (74%) of 27 patients were improved, seven (26%) had no change, and none deteriorated. Of patients with successful CTEA, 23 (96%) of 24 had a patent ICA on follow-up duplex scan evaluation, and there was no evidence of recurrent ipsilateral neurologic events at an average of 49 months.

CONCLUSION

These data support an aggressive early surgical intervention for acute ICA thrombosis in carefully selected patients. In the previous decade we reported a 46% success rate for establishing antegrade flow in the ICA long term. Data from this decade show a 79% (P =.0114) success rate for establishing antegrade flow long term in all patients undergoing emergency CTEA. New and improved imaging modalities have allowed better patient selection, resulting in improved outcomes.

Unrecognized carotid artery stenosis discovered by calcifications on a panoramic radiograph

BACKGROUND

Approximately 730,000 strokes occur each year in the United States, costing an estimated $40 billion annually. One-half of all strokes are the result of atherosclerotic plaques found in the carotid artery. Such plaques frequently are heavily calcified and can be identified on a panoramic radiograph by the incidental finding of calcifications overlying the carotid bifurcation.

CASE DESCRIPTION

The authors found that a 67-year-old asymptomatic woman had calcium deposits overlying both carotid bifurcation regions on a panoramic radiograph. Subsequent duplex ultrasonic examination indicated bilateral, high-grade carotid arterial stenoses. The patient underwent uneventful bilateral carotid endarterectomy.

CLINICAL IMPLICATIONS

The patient had critical carotid arterial stenoses associated with significant risk of stroke that had not been identified otherwise. The findings on the panoramic radiograph led to appropriate and potentially life-saving treatment. While the positive predictive value of this finding has yet to be defined, the authors believe that calcifications overlying the carotid system region seen on panoramic radiography in an asymptomatic patient should be followed by formal evaluation of the carotid bifurcation.

[Surgery of the internal carotid: locoregional or general anesthesia?]

AIM OF THE STUDY

The aim of this retrospective study was to assess the advantages of regional anesthesia over general anesthesia in carotid artery surgery.

PATIENTS AND METHOD

From January 1989 to December 1998, 670 patients with severe internal carotid artery stenosis were operated in the same center and were classified into two groups according to the type of anesthesia: group I, general anesthesia (n = 312) and group II, regional anesthesia (n = 358). Characteristics of the two groups were almost similar except for a higher rate of unstable heart disease in group I and bypass grafts in group II.

RESULTS

A shunt was used in 16.3% of cases in group I and in 8.4% in group II. Complications resulting from the use of a shunt and intraoperative complications observed with regional anesthesia were reported. There was a conversion from regional to general anesthesia in 6 patients. Median duration of clamping was longer in group II (30 min vs 25 min). Cardiac complication rates were similar in the two groups, particularly cardiac mortality (0.6%). There were more pulmonary and miscellaneous complications in group I. Neurological complications were more frequent in group I, particularly fatal strokes (1% versus 0%). Neurological mortality and morbidity cumulative rates were 3.1% and 1.5%, respectively, not significantly different.

CONCLUSION

These results, in agreement with those of the literature, confirm that carotid artery endarterectomy is associated with a low rate of neurological mortality and morbidity. Although regional anesthesia was associated with a lower rate of complications, we are not allowed to conclude to its superiority, as the present study was retrospective and the difference was not statistically significant.

Patient satisfaction after carotid endarterectomy using a selective policy of local anesthesia

BACKGROUND

Patient satisfaction after carotid endarterectomy has not been specifically studied or reported. Results of carotid endarterectomy using either local or general anesthesia have been widely reported, and outcomes are not significantly different for either technique. Patient satisfaction data were obtained in order to determine whether patients preferred one method of anesthesia over another. Data regarding outcome may be added to the surgical literature as benchmark data when comparing operative carotid endarterectomy to newer techniques.

METHODS

During a 30-month period, 186 consecutive carotid endarterectomies were performed on 169 patients by a single surgeon with assistance from senior surgical residents. All patients were offered local anesthesia using a cervical block technique with intraoperative supplementation. Patients for whom local anesthesia was inappropriate or who declined were operated on using general endotracheal anesthesia. Results of operation were tabulated including indication for operation, method of anesthesia, intraoperative and postoperative complications, and mortality, and completion of a patient satisfaction survey form either on postoperative visit or by telephone questionnaire.

RESULTS

Of 169 patients who underwent carotid endarterectomy, 151 (89%) completed the satisfaction survey form. One hundred fourteen (62%) had local anesthesia and 71 patients (38%) had general anesthesia. There was 1 stroke (0.5%) and 1 death (0.5%) in the series. Perioperative complications including temporary cranial nerve injury, neck hematoma, myocardial infarction, and restenosis were noted and not significantly different in either the general anesthesia or local anesthesia group. Patient satisfaction data including intraoperative discomfort, postoperative pain, attentiveness of the operating room staff, and length of stay were all tabulated. There was no statistically significant difference in satisfaction between the general anesthesia group and the local anesthesia group (chi-square and Fisher's exact test). Additionally, satisfaction with the procedure was extremely high.

CONCLUSIONS

Patient outcome and perception of pain and recovery were not statistically significantly different in patients undergoing carotid endarterectomy using local anesthesia compared with general anesthesia. Overall patient satisfaction was extremely high. Patients should be offered carotid endarterectomy using an anesthesia technique with which the surgeon and patients are both comfortable, having confidence that the outcome is not related to anesthesia technique and that patients will be highly satisfied.

Carotid endarterectomy without angiography: can clinical evaluation and duplex ultrasonographic scanning alone replace traditional arteriography for carotid surgery workup? A prospective study

BACKGROUND

The aim of this study was to determine whether clinical evaluation and duplex ultrasonography (DUS) alone can replace contrast cerebral arteriography (CA) for the detection of patients suitable for surgery at our institution.

METHODS

During an 18-month period, 100 patients underwent DUS and CA during evaluation for carotid endarterectomy (CEA). All patients were studied prospectively; in each case an initial decision for or against CEA on the basis of DUS evaluation of the internal carotid arteries (ICAs) was subsequently compared with the surgeon's final management plan after CA. Of the 200 ICAs evaluated, 113 were considered for CEA but 14 were excluded from the study because the patient could not be evaluated before and after CA. This left 99 ICAs (86 patients) available for comparative analysis.

RESULTS

The outcome of the 2 diagnostic modalities was perfectly consistent in 95.3% of the ICAs (kappa = 0.969). The clinical management decision was altered by the CA findings in only 2 cases (2%). Of the 99 ICAs considered suitable, 97 underwent CEA. No arteriographic complications occurred among the 100 patients undergoing CA. The perioperative stroke risk and mortality rates were 0%.

CONCLUSIONS

Ninety-eight percent of the ICAs considered for surgery would have received appropriate clinical treatment on the strength of the patients' neurologic history and the outcome of DUS alone. Our results indicate that DUS is sufficient to establish the need for surgery in symptomatic and asymptomatic patients being considered for CEA and can replace CA in most clinical circumstances.

Race, presenting signs and symptoms, use of carotid artery imaging, and appropriateness of carotid endarterectomy

BACKGROUND AND PURPOSE

We sought to determine whether there are racial differences in use of carotid artery imaging after controlling for clinical factors and to ascertain racial differences in presenting signs and symptoms and overall appropriateness for carotid endarterectomy (CE).

METHODS

We performed a retrospective cohort study of 803 patients older than 45 years, hospitalized between 1991 and 1994 at any of 4 Veterans Affairs Medical Centers, with a discharge diagnosis of transient ischemic attack or ischemic stroke. Clinical data were abstracted from the medical record, including presenting symptoms, diagnostic test results, and use of surgical procedures. Appropriateness for CE was determined according to RAND criteria.

RESULTS

Black patients were more likely than white patients to present with stroke (78% versus 55%) but less likely to present with transient ischemic attack (22% versus 45%; P=0.001). There was no racial difference in medical comorbidity or preoperative risk. Black patients were less likely to have an imaging study of their carotid arteries (67% versus 79%; P=0.001). Race remained an independent predictor of imaging after adjustment for clinical factors (odds ratio=1.50; 95% CI, 1.06 to 2.13). Because of higher prevalence of significant carotid artery stenosis, whites were significantly more likely than blacks to be assessed as appropriate candidates for surgery with the use of RAND criteria (18% versus 4%; P=0.001).

CONCLUSIONS

Use of carotid artery imaging, a critical step in determining eligibility for CE, is influenced by the patient's race after controlling for clinical presentation. Adjustment for appropriateness of CE reduces but does not eliminate the importance of race.

Outcome of moderate carotid artery stenosis in patients who are asymptomatic

PURPOSE

The incidence rate of disease progression and stroke after the diagnosis of a moderate (50% to 79%) carotid stenosis was determined by means of color-flow duplex scanning.

METHODS

During a 4-year period, 344 male veterans with moderate internal carotid artery stenoses, on one or both sides, were examined at regular intervals for a mean period of 25 months. Carotid color-flow scans were obtained semiannually. Clinical follow-up was performed to determine the incidence rate of amaurosis fugax, transient ischemic attacks, nonhemispheric symptoms, and strokes.

RESULTS

New neurologic symptoms developed in 75 patients (21.8%). Fifty-one (14.8%) had ipsilateral symptoms during follow-up: 18 amaurosis fugax (5.2%), 14 transient ischemic attacks (4%), 5 nonhemispheric symptoms (1.4%), and 14 strokes (4%). Twenty-four patients (6.9%) had contralateral symptoms: 20 strokes (5.8%) and 4 transient ischemic attacks (1.2%). Life-table analysis showed that the annual rate of ipsilateral neurologic events was 8.1%, and the annual rate of stroke was 2.1%. Seventy-five patients (22%) died in the follow-up period. Disease progression to 80% to 99% stenosis or occlusion occurred in 71 of 458 vessels (15.5%). The internal carotid arteries that showed evidence of disease progression had a significantly higher initial peak systolic velocity (251 vs 190 cm/s; P <.0001) and end diastolic velocity (74 vs 52 cm/s; P < 0.0001). Black patients and patients with ischemic heart disease were at a higher risk for disease progression. We could not identify any atherosclerotic risk factors that reliably predicted patients in whom future ipsilateral neurologic symptoms were more likely to develop. However, there was an increased risk of stroke associated with progression of disease.

CONCLUSION

Patients who are asymptomatic and who have moderate carotid stenoses are at significant risk for neurologic symptoms and death, but have a relatively low incidence rate of ipsilateral events. The initial flow characteristics in the stenotic vessel are predictive of future disease progression, but they are not helpful in identifying patients in whom symptoms will develop.

Surgery for asymptomatic carotid stenosis: a study of three patient subgroups

The purpose of this retrospective study was to determine whether patients who undergo prophylactic surgery for asymptomatic carotid stenosis represent a single homogeneous population. Of the 805 carotid reconstructions performed between January 1984 and December 1992, a total of 357 were for asymptomatic atherosclerotic stenosis in 312 patients (227 men, 85 women) with a mean age of 69.6 years. Patients were divided into three groups. Group I included 141 patients (161 procedures) who presented no neurologic manifestations. Group II included 49 patients (55 procedures) who underwent carotid reconstruction before or at the same time as another cardiovascular procedure. Group III included 122 patients (141 procedures) who presented nonhemispheric manifestations. Patients in group III had a significantly higher number of obstructive lesions in brain arteries (p < 0.01). Seven patients died within the first 30 postoperative days, including three who underwent combined single-stage procedures. Nine patients presented nonfatal stroke, including three who progressively recovered. The cumulative death-stroke rate (CDSR) was 5.12% overall, 3.54% in group I, 12.24% in group II, and 4.09% in group III. The difference between groups I and II was statistically significant (p < 0.05). Taking into account only deaths related to carotid surgery and stroke with permanent disability, the CDSR was 2. 83% in group I and 3.25% in group III. Follow-up ranged from 24 to 132 months (mean: 66.2) with a total of 11 patients being lost from follow-up. Actuarial 5-year survival was 81.99 +/- 7.13% in group I, 70.65 +/- 13.72% in group II, and 68.51 +/- 8.93% in group III. Differences between group I and both groups II (p < 0.01) and III (p < 0.05) were statistically significant. Overall 5-year patency was 95.59 +/- 2.28%. Stroke occurred during follow-up in 13 patients. The probability of stroke-free survival was 95.29 +/- 3.76% in group I, 91.03 +/- 8.52% in group II, and 89.09 +/- 6.39% in group III. The difference between groups I and III was statistically significant (p < 0.05). Patients with asymptomatic carotid lesions can be divided into different prognostic groups. Life expectancy is shorter for patients with multiple artery disease. Long-term stroke risk is higher in patients with nonhemispheric neurological manifestations.

Are we detecting and operating on high risk patients in the asymptomatic carotid surgery trial? The Asymptomatic Carotid Surgery Trial Collaborators

OBJECTIVE

This study aims to determine whether asymptomatic carotid surgery trial (ACST) centres have entered and can identify high risk patients using duplex.

DESIGN

Retrospective study.

MATERIALS AND METHODS

Eighty-six vascular laboratories collaborating in ACST were studied, Equipment, operator experience, methodology and interpretation criteria were assessed. The ACST randomisation data were examined to determine whether patients believed to be at higher risk of stroke because of tight stenosis, contralateral occlusion or echolucent plaque were randomised.

RESULTS

Laboratories (92%) had colour duplex and 62% of all operators had > 3 years experience in carotid evaluation. The Doppler angle used to obtain peak velocity was 30-60 degrees in 65%, 60 degrees in 28% and 60-80 degrees in 6% of laboratories. Sixty-two per cent reported diameter reduction, 27% area reduction, and 11% used both methods. One-third of 1657 randomised patients were reported to have ipsilateral echolucent plaque. Median ipsilateral stenosis was 80%, 8% had contralateral occlusion and 8.5% had bilateral > 80% stenosis.

CONCLUSIONS

Centres in ACST use experienced operators, high quality equipment and conscientious data recording. Variations in methods of determining carotid stenosis exist, but can be smoothed by simple data collection. Patients at higher perceived risk of stroke are being entered and with continued recruitment it should be possible to determine whether surgery improves disabling stroke-free survival.

Effect of the Asymptomatic Carotid Atherosclerosis Study on carotid endarterectomy in Florida

BACKGROUND AND PURPOSE

The value of carotid endarterectomy (CEA) has been defined by several recent multicenter trials. The clinical effect of these trials remains undetermined since the Asymptomatic Carotid Atherosclerosis Study (ACAS) Clinical Advisory (dated September 28, 1994).

METHODS

Patients undergoing CEA (ICD-9-CM 38.12) in nonfederal Florida hospitals were identified from the discharge database. Data were analyzed by federal fiscal year (FY, October 1 through September 30), comparing the years following the Advisory (FY95-FY96) to the preceding 3 years (FY92-FY94).

RESULTS

There was a 68.3% increase in the number of CEAs during FY95-FY96 (mean FY92-FY94, 7,343; mean FY95-FY96, 12,356). This exceeded increases in total hospital discharges (4.5%), surgical discharges (2.2%), and the state's population (4.7%). The increase in CEAs spanned all patient demographic groups (gender, race, and age), although the magnitude was not consistent (range, 57.8% increase for 55 to 64 age group; 92.9% increase for > 84 age group). Concomitantly, there was a significant decrease in mortality (1.2% versus 0.8%), cardiac complication rate (ICD-9-CM 997.1, 4.1% versus 3.0%) and percentage of patients discharged > 7 days postoperatively (8.9% versus 4.9%). Mean length of stay declined 28% (5.8 versus 4.1 days), and mean adjusted charges declined 7% ($19,456 versus $18,055). Although the average case was less costly, the increased volume resulted in an estimated $56 million increase in annual hospital payments.

CONCLUSIONS

The dramatic increase in the number of CEAs performed in the state of Florida after release of the ACAS Clinical Advisory suggests a causal relationship and mandates further cost-effectiveness analyses.

Entering the ninth decade is not a contraindication for carotid endarterectomy

The role of carotid endarterectomy (CEA) in stroke prevention is now better defined. However, its role in patients older than 79 years of age is controversial. This group of patients has been excluded in most clinical trials. In this study the authors reviewed their experience with CEA patients >79 years old. The records of all patients older than 79 years of age who underwent a CEA in a recent time period from January 1988 to December 1996 were retrospectively reviewed. Forty-one patients (31 men, 10 women) were identified by computer search. The indication for operation included transient ischemic attack in 12 (29.3%), amaurosis fugax in nine (22%), stroke in two (4.9%), and nonhemispheric symptoms in three (7.3%). Fifteen patients (36.6%) were asymptomatic. Medical risk factors included coronary artery disease in 26 (63.4%), hypertension in 22 (53.7%), and smoking in 12 (29.3%). The procedure was performed under EEG monitoring in all patients. General anesthesia was administered in 37 (90%) and regional anesthesia in four (10%). Shunts were used in four (10%) patients. The internal carotid artery was patched in 16 patients (39%). One patient (2.4%) developed a perioperative stroke and only one patient developed perioperative myocardial infarction (MI). None of the patients died within 30 days of surgery. In addition to the one MI case, five patients developed minor complications. The average length of time for stay after CEA was 3.4 days. Patients were followed up for an average of 20.7 months. Six patients died during follow-up. Four of those died from an MI and two from a stroke. The authors conclude that with proper selection of patients, CEA is safe in the octogenarian. Age alone should not be a contraindication for CEA.

Cost-effectiveness of screening for asymptomatic carotid stenosis

PURPOSE

The benefit of carotid endarterectomy for patients who are asymptomatic with > 60% carotid stenosis has been established by the Asymptomatic Carotid Atherosclerosis Study (ACAS). Which screening strategy is most appropriate is still unclear. This study assessed the cost-effectiveness of ultrasound screening for asymptomatic carotid stenosis.

METHODS

Cost-effectiveness analysis was performed with a Markov model and with data from ACAS and other studies.

RESULTS

For 60-year-old patients with a 5% prevalence of 60% to 99% asymptomatic stenosis, duplex ultrasound screening increased average quality-adjusted life years (QALY; 11.485 vs 11.473) and lifetime cost of care ($5500 vs $5012) under base-case assumptions. The incremental cost per QALY gained (cost-effectiveness ratio) was $39,495. Screening was cost-effective with the following conditions: disease prevalence was 4.5% or more, the specificity of the screening test (ultrasound) was 91% or more, the stroke rate of patients who were medically treated was 3.3% or more, the relative risk reduction of surgery was 37% or more, the stroke rate associated with surgery was 160% or less than that of the North American Symptomatic Carotid Endarterectomy Trial or ACAS perioperative complication rates, and the cost of ultrasound screening was $300 or less. A one-time screening, compared with a screening every 5 years, had more QALY (11.485 vs 11.482) and lower cost ($5500 vs $5790). Screening without arteriography, compared with screening with arteriographic verification, provided few additional QALYs (11.486 vs 11.485) at additional cost ($6896 vs $5500). The cost-effectiveness ratio was sensitive to assumptions about the stroke rate of patients who were asymptomatic and other variables.

CONCLUSIONS

Screening for asymptomatic carotid stenosis can be cost-effective when both screening and carotid endarterectomy are performed in centers of excellence.

Preoperative testing before carotid endarterectomy: a survey of vascular surgeons' attitudes

Traditional surgical practice and published consensus statements from major vascular surgery specialty societies have considered contrast arteriography to be a routine part of the diagnostic evaluation prior to carotid endarterectomy (CEA). However, some surgeons now omit routine preoperative arteriography if a technically adequate carotid duplex scan is performed and indications for CEA are clear. To better establish current practice patterns and to characterize vascular surgeons' opinions about the role of preoperative arteriography, the Peripheral Vascular Surgery Society membership was surveyed by mail. Eighty-six percent of the members responded (430 of 502). Ninety-three percent of all patients considered for CEA are evaluated with duplex scanning; 82% with arteriography. While the majority of surgeons typically obtain both a duplex scan and an arteriogram, 70% have performed CEA without a preoperative arteriogram. Brain imaging studies (CT or MRI) are obtained in 26% and MR angiograms in 10% of cases. Seventy-five percent of the surgeons agreed with the statement that CEA without preoperative arteriography is an acceptable practice if appropriate indications for surgery are present. Furthermore, one third believed that CEA without a preoperative arteriogram is generally acceptable (acceptable more than half the time). Respondents were stratified by surgical experience time in practice and practice type. No significant differences in responses were found, suggesting the acceptance of CEA without preoperative arteriography is broad-based. This survey demonstrates changing attitudes among practicing vascular surgeons regarding the necessity for routine arteriography prior to CEA. Carotid endarterectomy on the basis of duplex scanning and clinical assessment should be considered an accepted alternative.

Hemodynamic ischemic stroke during carotid endarterectomy: an appraisal of risk and cerebral protection

PURPOSE

The purpose of this study was to validate the commonly accepted indicators of risk of ischemic stroke that indicate the necessity for cerebral protection during carotid endarterectomy (CEA), and to examine the efficacy of high-dose thiopentone sodium (thiopental) as a cerebral protection method in patients who are at high risk of intraoperative ischemic stroke.

METHOD

In a prospective study of 37 CEAs performed for symptomatic stenosis > 70%, functional and clinical indicators of risk of ischemic stroke during carotid cross-clamping were identified. Functional indicators of risk were the development of ischemic electro-encephalogram (EEG) changes and stump pressure < 25 mm Hg. Clinical indicators of risk were previous ischemic hemispheric stroke and severe bilateral disease. These indicators were correlated in all patients, some of whom had two or three coexisting indicators of risk. The EEG and stump pressure were monitored continuously during carotid occlusion in all operations. Carotid occlusion times were recorded. Intraluminal shunting was eliminated in favor of high-dose thiopental cerebral protection in all patients. Neurologic outcome was deemed to measure the efficacy of thiopental protection in patients who are identified to be at risk and, hence, in need of cerebral protection. The validity of the indicators used to identify risk of ischemic stroke during CEA was assessed.

RESULTS

The absolute stroke risk was found to be 29.7% for the whole group (37 patients) and 57.9% in 19 patients who had commonly accepted indications for protective shunting. The correlation of ischemic EEG changes with stump pressure < 25 mm Hg was only 27.3%, whereas the expected correlation based on well-documented reports in the literature was 100%. The lack of correlation may have been related to the prevention of ischemic EEG changes by thiopental. There were no neurologic deficits in the series.

CONCLUSIONS

The absence of neurologic deficit in the study indicated that thiopental protection was effective in preventing ischemic stroke in high-risk patients and safely replaced intraluminal shunting.

Carotid endarterectomy in young adults: is it a worthwhile procedure?

PURPOSE

The aim of the study was to investigate surgical indication and long-term outcome of carotid endarterectomy (CE) in young adults.

METHODS

Between 1973 and 1990, 1693 patients underwent CE. Forty-nine patients (group T) 35 to 45 years of age who had carotid artery stenosis greater than 70%, formed the basis for the analysis. They were compared with two additional groups of patients older than 45 years of age selected from the entire series. Group 2 was randomly chosen to determine differences in risk factors, associated diseases, operative indications, preoperative findings, and outcome. Group 3 was matched with patients in group 1 for sex, risk factors, associated diseases, preoperative findings, and operative indications to assess the importance of age in determining the short- and long-term outcome of CE.

RESULTS

Postoperative mortality, cerebrovascular accidents, and cardiac complications in patients of group 1 (2%, 2%, and 2%, respectively) were similar to those of the other groups (p = NS). During the follow-up (76.7 +/- 3.6 months; range, 1 to 120 months) the incidence of strokes and transient ischemic attacks in group 1 was lower than in group 2 (p < 0.05) but similar to group 3 (p = NS). Ten-year disease-free intervals were 75.7%, 58.7%, and 77.6%, respectively, for groups 1, 2, and 3. Mortality rate unrelated to cerebrovascular disease was similar between group 1 and group 3 (p = NS) but was higher in group 1 than in group 2 (p < 0.02). Ten-year survival rates were 46.1%, 71.7%, and 55.5%, respectively, for groups 1, 2, and 3.

CONCLUSIONS

CE in patients younger than 45 years of age is a safe procedure with low operative risks and good disease-free intervals. However, life expectancy is poor because of the high incidence of deaths resulting from complications of atherosclerosis.

Asymptomatic carotid endarterectomy. Patient and surgeon selection

BACKGROUND AND PURPOSE

The applicability of prospective carotid endarterectomy protocols to the general population has been questioned. Outcomes for asymptomatic patients undergoing carotid endarterectomy were compared with the results of the Asymptomatic Carotid Atherosclerosis Study (ACAS) patients treated concurrently at our institution.

METHODS

Asymptomatic patients undergoing carotid endarterectomies (n = 277) from 1987 to 1993 (ACAS enrollment period) were reviewed. Primary end points were mortality, myocardial infarction, and stroke. Five subgroups were studied: (1) ACAS surgical patients; (2) ACAS-eligible patients not enrolled and ACAS surgeons; (3) ACAS-eligible patients not enrolled and non-ACAS surgeons; (4) ACAS-ineligible patients and ACAS surgeons; and (5) ACAS-ineligible patients and non-ACAS surgeons.

RESULTS

ACAS-eligible patients were younger (P = .014), had more severe carotid stenosis (P = .001), and had lower incidences of pulmonary (P = .015) and renal (P = .008) diseases compared with ineligible patients. Patient selection (ACAS eligibility) significantly improved outcomes for mortality (P = .014) and myocardial infarction (P = .006). Length of stay favored ACAS-eligible patients (P = .004). ACAS surgeons operated on more severely stenotic carotid lesions (P = .005) and on patients with a lower incidence of coronary artery disease (P = .007). There was no difference in outcomes between ACAS and non-ACAS surgeons.

CONCLUSIONS

Patient selection was a significant factor in determining outcome. With strict adherence to ACAS enrollment guidelines, the conclusions of ACAS appear applicable to patients seen at our institution with asymptomatic carotid stenosis.

Criteria for selective utilization of the intensive care unit following carotid endarterectomy

The common practice of admitting all patients to an intensive care unit (ICU) following carotid endarterectomy (CEA) is based upon concern for adverse events that may be properly cared for only in the ICU. We developed restrictive criteria for postoperative nursing unit admission based on analysis of adverse outcomes and risk factors. 365 CEAs over 15 years were reviewed. In the first 24 hours after CEA, 38 patients experienced 46 events that may have been best managed in an ICU. Preoperative factors associated with significant risk for complications were indications of cardiac disease within 6 months (n = 62, p < 0.05), emergent CEA (n = 2, p = 0.01), and need for postoperative anticoagulation (n = 2, p = 0.01). Only 56 (15%) of patients had indications for ICU admission, 57 (16%) would have been admitted to an EKG-monitored nursing unit, and 252 (69%) would have been admitted to a standard nursing unit. Immediate admission to the ICU after CEA is indicated for patients undergoing emergent CEA, those requiring anticoagulation postoperatively, those with intraoperative stroke or major cardiac complication, and possibly those with chronic renal failure. All other patients should be admitted to the RR. Patients experiencing stroke, major cardiac events, significant wound hemorrhage, or reintubation in the RR, and those requiring vasoactive medication more than 3 hours after surgery should be transferred to the ICU. Patients with indications of cardiac disease within 6 months prior to CEA but no indications for ICU admission may be discharged from the RR to an EKG monitored unit. All others may be discharged to a standard nursing unit.

Saphenous vein bypass: an alternative to internal carotid reconstruction

OBJECTIVE

Venous grafting is rarely employed for carotid reconstruction; the aim of this retrospective study was to assess its value as an alternative to endarterectomy.

MATERIAL

Between January 1980 and June 1990, we performed 212 carotid artery venous bypasses (CVB) on 208 patients. Twenty-nine patients were asymptomatic, 60 had non-hemispheric symptoms and 119 focal symptoms. The indication for surgery was stenosis in 185 cases, kinking in 18 and aneurysms in nine. The main criteria to use CVB were length of the lesion in 86 cases, extent of atherosclerosis in 75, dysplasia in 12, intraoperative failure of endarterectomy in 21, aneurysms in seven and long-term restenosis or occlusion in 12.

RESULTS

There were 11 deaths, three strokes and nine transient ischaemic attacks. Angiographic control showed one occlusion giving an immediate patency rate of 99.5%. Mean follow-up was 104.3 +/- 46.1 months with 15 patients lost to follow-up. Eighty patients died; life expectancy was 52.4 +/- 7.5 at 10 years. Including occlusions and restenosis as failures, the secondary patency rate was 96.4 +/- 3.7 at 10 years. The annual stroke rate was 1.3% and the neurologic event-free-population 87 +/- 2.4% at 10 years.

CONCLUSION

CVB is a valuable alternative to endarterectomy for reconstruction of the carotid artery. The indications are extensive atherosclerosis involving the common carotid artery, intraoperative anatomic failure of endarterectomy, and long-term restenosis.