Life expectancy and late stroke following carotid endarterectomy

Vascular Surgery in Senescence Carotid Endarterectomy in Patients over 70 Years

In order to evaluate the immediate and long-term results of carotid endar terectomy in patients over seventy years of age, 54 patients undergoing a total of 59 surgical procedures were followed for a mean time of forty-three months. There was no operative mortality. Perioperative central neurological complica tions developed in 18 patients (33%), 9 (17%) of whom suffered permanent neurological deficits. During the follow-up period we found an annual stroke rate of 5% according to life table arialysis. The five-year survival rate was 67%. At termination of follow-up or before death, 85% of the patients lived indepen dently in their own homes. Compared with younger age groups, carotid endar terectomy in senescence yielded poorer results in terms of immediate and late neurological status. The old patients had, however, the same life expectancy as a contemporary age- and sex-matched population and had to a remarkable degree been able to maintain an independent life.

Is Preoperative Cardiac Testing Indicated Prior to Elective Carotid Endarterectomy?

The high incidence of coronary artery disease in patients with peripheral and cerebrovascular occlusive disease has been well established. While preoperative cardiac evaluation has been shown to be beneficial in patients undergoing elective aortic reconstruction, the role of preoperative cardiac testing in patients undergoing elective carotid endarterectomy has not been defined. In this study, the charts of 289 consecutive patients undergoing elective carotid endarterectomy between January 1, 1995, and December 31, 1995, were evaluated to determine the need for cardiac “clearance” prior to surgery. Ages ranged from 48 to 98, with a mean of 70.4 years. The male-to-female ratio was 165:124. Risk factors for coronary artery disease were also assessed: 203 patients (70%) were hypertensive, and 162 patients (56%) gave a history of smoking. An abnormalappearing preoperative EKG was identified in 139 patients (48%). Sixty-seven patients (23%) presented with a history of angina pectoris, and 80 patients (28%) had sustained a myocardial infarction in the past. No patient presented with unstable angina or angina at rest. No patient underwent coronary artery bypass grafting or coronary artery angioplasty immediately prior to carotid endarterectomy. Of the 289 endarterectomies 154 (53%) were performed under regional anesthesia. All patients were monitored with intraoperative arterial pressure catheters. There were no postoperative deaths. No patient sustained a documented postoperative myocardial infarction. One patient experienced chest pain for 24 hours postoperatively. This patient had a history of angina pectoris and a previous myocardial infarction. One patient had an episode of shortness of breath postoperatively. There were two postoperative strokes. These data suggest that patients with known or suspected coronary artery disease can safely undergo elective carotid endarterectomy without extensive cardiac testing prior to surgery.

Treatment of Recurrent Carotid Disease

The purpose of this study was to determine whether repeat carotid endarterectomy (CEA) poses a greater risk than first-time CEA. The authors analyzed data from 893 consecutive CEA cases (1981-1993). Thirty-three patients (3.7%) had repeat CEA, and 860 (96.3%) had first-time CEA. There were statistically significantly higher incidences of hypertension (60.6% vs 44.6%), smoking (84.8% vs 55%), hypertriglyceridemia (33.3% vs 16.2%), and coronary artery disease (66.6% vs 36%) in the repeat CEA group than in the first-time CEA group.

Symptomatic disease was present in 25 (75.8%) patients in the repeat group and in 576 (67%) patients in the first-time group (P>0.05). The cause of recurrence was atherosclerosis in 25 patients (76%), myointimal hyperplasia in seven patients (21.2%), and intraluminal thrombus without an underlying lesion in one patient (3%). Redo CEA with vein patch angioplasty was performed in 27 patients (82%), vein patch angioplasty alone in five patients (15%), and interposition vein graft in one patient (3%).

The hospital operative mortality was 0% (n=0) in the repeat CEA group and 0.6% (n=5) in the first-time CEA group (P>0.05). The incidence of postoperative stroke was 0% (n=0) in the repeat group and 1.2% (n= 10) in the first-time group (P>0.05). There was one case (3%) of transient ischemic attack (TIA) in the repeat group, and two cases (0.2%) of TIA in the first-time group. There was no difference in the incidence of cranial nerve dysfunction between the repeat group (n=2, 6%) and the first-time group (n=41, 4.8%; P>0.05). Late follow-up data were obtained for 30 patients (mean: 61.4 months, range: 5-158 months) in the repeat CEA group and 501 patients (mean: 55.8 months, range: 17-168 months) in the first-time CEA group. The incidence of late failure (ipsilateral stroke or TIA) was 3.3% (n= 1) in the repeat group and 3.2% (n= 16) in the firsttime CEA group; P>0.05. The overall late mortality was 20% (n=6) in the repeat CEA group and 14.6% (n=73) in the primary CEA group; P>0.05.

Repeat CEA can be performed safely in individuals with severe recurrent carotid stenosis, and perioperative and long-term mortality and neurologic morbidity rates are similar to those for patients undergoing first-time carotid endarterectomy.

Decision analysis and carotid endarterectomy

A data base and a framework for clinical decision analysis are provided to enable the clinician to determine the value of carotid endarterectomy in patients with transient ischemic attacks. This approach permits optimal utilization of available data, maximizes the value of informed consent by clearly delineating areas of physician and patient expertise, and permits a quantitative assessment of the impact of uncertainty regarding underlying variables on decision outcome. The results of the analysis indicate that (a) the late nonstroke death rate has little effect on the value of endarterectomy, (b) the patient's relative valuation of stroke and immediate versus delayed death are among the most crucial variables underlying the value of endarterectomy, and (c) endarterectomy may be indicated in certain patients with transient ischemic attacks, but when its utility is measured in terms of value rendered to the patient, its relative cost may be greater than that of certain life-saving operations such as heart or liver transplant.

Systematic review of the risks of carotid endarterectomy in relation to the clinical indication for and timing of surgery

BACKGROUND AND PURPOSE

Reliable data on the risk of carotid endarterectomy (CEA) in relation to clinical indication and timing of surgery are necessary to target CEA more effectively, to inform patients, to adjust risks for case mix, and to understand the mechanisms of operative stroke.

METHODS

We performed a systematic review of all studies published from 1980 to 2000 inclusive that reported the risk of stroke and death resulting from CEA. Pooled estimates of risk by type of presenting ischemic event and time since the last event were obtained by Mantel-Haenszel meta-analysis.

RESULTS

Of 383 published studies, only 103 stratified risk by indication. Although the operative risk for symptomatic stenosis overall was higher than for asymptomatic stenosis (odds ratio [OR], 1.62; 95% confidence interval [CI], 1.45 to 1.81; P<0.00001; 59 studies), risk in patients with ocular events only tended to be lower than for asymptomatic stenosis (OR, 0.75, 95% CI, 0.50 to 1.14; 15 studies). Operative risk was the same for stroke and cerebral transient ischemic attack (OR, 1.16; 95% CI, 0.99 to 1.35; P=0.08; 23 studies) but higher for cerebral transient ischemic attack than for ocular events only (OR, 2.31; 95% CI, 1.72 to 3.12; P<0.00001; 19 studies) and for CEA for restenosis than primary surgery (OR, 1.95; 95% CI, 1.21 to 3.16; P=0.018; 6 studies). Urgent CEA for evolving symptoms had a much higher risk (19.2%, 95% CI, 10.7 to 27.8) than CEA for stable symptoms (OR, 3.9; 95% CI, 2.7 to 5.7; P<0.001; 13 studies), but there was no difference between early (<3 to 6 weeks) and late (>3 to 6 weeks) CEA for stroke in stable patients (OR, 1.13; 95% CI, 0.79 to 1.62; P=0.62; 11 studies). All observations were highly consistent across studies.

CONCLUSIONS

Risk of stroke and death resulting from CEA is highly dependent on the clinical indication. Audits of risk should be stratified accordingly, and patients should be informed of the risk that relates to their presenting event.

Carotid angioplasty and stenting in high-risk patients

BACKGROUND

To examine our initial experience in carotid stenting (CS) for the prevention of stroke in patients with high-grade carotid stenoses.

METHODS

The authors performed 26 CS procedures in 25 carotid vessels in 22 patients over a 15-month period. All carotid stenoses treated, except one, were 70% or greater. Of all CS procedures, 84% were performed for obstructing atherosclerotic plaques. CS was performed in one patient each for carotid dissection and pseudoaneurysms caused by a gunshot wound, post-radiation stenosis, post-carotid endarterectomy (CEA) restenosis, and a flow-obstructing post-CEA intimal flap. Of all patients, 68.2% were symptomatic, with a history of stroke or transient ischemic attacks ipsilateral to the treated carotid artery. In addition, 36.4% of our patients were either hospitalized or required skilled nursing care before CS because of severe neurologic deficits. Using the Sundt CEA-risk classification system, 59.1% of our patients were classified as Grade III and 40.9% were Grade IV pre-CS. All but one patient had either a compelling medical or anatomic reason for endovascular treatment of their carotid disease. We used both Wallstents and Palmaz stents, and all procedures were performed via the transfemoral route. Three procedures were performed in conjunction with detachable platinum coil embolization for multiple carotid pseudoaneurysms, a residual carotid "stump" after previous ICA thrombosis, and an ipsilateral MCA saccular aneurysm.

RESULTS

We had a 96.2% procedural technical success rate. There was one death in our series 3 weeks post-CS attributable to myocardial infarction. Despite a high 30-day combined death, stroke, and ipsilateral blindness rate of 27.3% (6/22 patients), only two ipsilateral strokes directly related to CS occurred (7.7% per procedures performed) from which one patient recovered fully within 5 days. The average follow-up post-CS was 5.9 months (range, 3 weeks-15 months). Of successfully treated vessels, 58.3% have undergone 6-month follow-up vascular imaging, which has revealed a 14.3% rate of occlusion or restenosis greater than 50%. At or beyond 1 month post-CS, 19 of 21 surviving patients (90.5%) were ambulatory, fluent of speech, and independent, and none has thus far suffered a delayed stroke or TIA.

CONCLUSION

CS seems to be a reasonable alternative to medical management for the treatment of carotid disease in patients deemed to be poor candidates for standard carotid surgery. Longer term follow-up is necessary to assess the durability of carotid revascularization using CS.

Early outcome assessment for 2228 consecutive carotid endarterectomy procedures: the Cleveland Clinic experience from 1989 to 1995

PURPOSE

Several randomized trials now have established guidelines regarding patient selection for carotid endarterectomy (CEA) that have been widely accepted but have little relevance unless they are considered in the context of perioperative risk. The purpose of this study was to demonstrate the feasibility of early outcome assessment using a computerized database.

METHODS

Since 1989 demographic information and in-hospital results for all surgical procedures performed by the members of our department have been entered into a prospective registry. For the purpose of this report, we have analyzed the stroke and mortality rates for 2228 consecutive CEAs (2046 patients), including 1924 that were performed as isolated operations and 304 that were combined with simultaneous coronary artery bypass grafting (CABG). This series incidentally contains a total of 153 reoperations for recurrent carotid stenosis.

RESULTS

The respective stroke and mortality rates were 0.5% and 1.8% for all isolated CEAs, 4.3% and 5.3% for all CEA-CABG procedures, and 4.6% and 2.0% for carotid reoperations. According to a multivariable statistical model, the composite stroke and mortality rate for isolated CEA was significantly influenced by female gender (p = 0.050), by the urgency of intervention (p = 0.026), and by carotid reoperations (p = 0.024). Gender (p = 0.030) and urgency (p = 0.040) also were associated with differences in the stroke rate alone; furthermore, the incidence of perioperative stroke was higher in conjunction with synthetic patching (odds ratio, 2.6; 95% confidence interval, 1.2 to 5.3) and was marginally higher with primary arteriotomy closure (odds ratio, 2.7; 95% confidence interval, 0.8 to 9.5) compared with vein patch angioplasty (1.3%). The method used to repair the arteriotomy was the only independent factor that qualified for the multivariable composite stroke and mortality models that were applied to the combined CEA-CABG procedures, but too few patients in this cohort had synthetic patches or primary closure to validate the perceived superiority of vein patching.

CONCLUSIONS

Prospective outcome assessment is essential to reconcile the indications for CEA with its actual results, and it may lead incidentally to important observations concerning patient care.

Cardiac events after combined surgery for coronary and carotid artery disease

OBJECTIVE

To evaluate serious cardiac events after combined (either single or two stage) coronary artery surgery (CAS) and carotid endarterectomy (CEA) for concomitant coronary and carotid artery disease.

METHODS

We have analyzed our 15 year experience (January 1981-September 1996) with 201 consecutive patients operated on using both approaches. Group A consisted of 48 patients with the single-stage procedure, while in group B (153 patients), two stage procedure was carried out, either as carotid endarterectomy (CEA), followed by coronary artery bypass surgery (CAS) (group B1- 103 patients), or as CAS followed by CEA (group B2- 50 patients). Five patients from B1 group died after the CEA procedure, but were included, despite the fact they never reached the second stage. Left main coronary artery disease was found in 41 patients (20.4%), poor left ventricular function in 49 (24.4%) previous MI in 133 (66.2%), while 136 (67.7%) were in NYHA functional class III or IV. Bilateral carotid involvement was present in 61 patients (30.3%). Unstable angina was more prevalent in groups A and B2 (P < 0.0001). NYHA class III/IV in group A (versus B1, P = 0.001 and versus B2, P = 0.02), low ejection fraction in groups A and B2 (P < 0.0001), bilateral carotid stenosis in group B1 (versus A, P = 0.003 and versus B2, P < 0.0001), and ulcerated plaque in group B1 (P < 0.0001). These differences dictated the surgical strategy, which resulted in different protocols for clinical and operative management.

RESULTS

Early mortality for the entire group was 5.5% (11/201) 6.2% in group A, 7.8% in group B1 and 0% in group B2, respectively; (P > 0.05). Serious morbidity occurred in 7.5% of patients (8.3% in group A, 7.8% in group B1 and 6% in group B2, respectively; P > 0.05). Univariate analysis revealed only bilateral carotid stenosis to influence early outcome (P = 0.04).

CONCLUSION

Patients with concomitant coronary and carotid artery disease have relatively good immediate operative results, providing all existing lesions are corrected. Despite it did not reach the statistical significance, cardiac events were less frequent in groups A and B2 indicating possible protective effect of prior CAS in patients with concomitant disease.

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.

Treatment of recurrent cerebrovascular disease. Review of a 10-year experience

OBJECTIVE

The authors determined whether carotid endarterectomy in patients with recurrent cerebrovascular disease poses a greater perioperative risk than for those individuals undergoing first-time carotid endarterectomy.

SUMMARY BACKGROUND DATA

A percentage of patients undergoing carotid endarterectomy for atherosclerosis experience recurrent cerebrovascular disease. Reoperation may be difficult because of postoperative scarring of the soft tissues of the neck and the carotid artery itself. Such patients were believed to be at greater risk for perioperative morbidity than those undergoing first-time carotid endarterectomy.

METHODS

To address this concern, the authors retrospectively reviewed their experience with 69 patients who underwent repeat carotid endarterectomies over a recent 10-year period of time. This subgroup represented 6.4% of 1072 total carotid endarterectomies performed during the same time period. The average extent of stenosis on the operated side was 81% and the time elapsed after previous endarterectomy averaged 83 months. Twelve patients (17.4%) had contralateral internal carotid occlusion, and 30 patients (43.5%) had undergone previous endarterectomies on the contralateral side.

RESULTS

Complications within 30 days of operation included two deaths (2.9%) and one stroke (1.4%), for a combined stroke and death rate of 4.3%. Six patients developed cervical hematomas requiring drainage; one of these had rupture of a saphenous vein patch. No patient had a significant cranial nerve injury in the reoperative group, whereas 2.0% of patients undergoing first-time carotid endarterectomy had cranial nerve injuries. Overall, these results compared favorably with a combined stroke and death rate of 4.0% among 1003 patients who underwent first-time carotid endarterectomy during the same period.

CONCLUSIONS

This review suggests that repeat carotid endarterectomy can be performed safely in individuals with severe recurrent carotid stenosis, with morbidity and mortality rates similar to those for patients undergoing first-time carotid endarterectomies. For this population, reoperative carotid endarterectomy represents a safe and important mechanism for the prevention of stroke.

Guidelines for carotid endarterectomy. A multidisciplinary consensus statement from the Ad Hoc Committee, American Heart Association

BACKGROUND AND PURPOSE

Indications for carotid endarterectomy have engendered considerable debate among experts and have resulted in publication of retrospective reviews, natural history studies, audits of community practice, position papers, expert opinion statements, and finally prospective randomized trials. The American Heart Association assembled a group of experts in a multidisciplinary consensus conference to develop this statement.

METHODS

A conference was held July 16-18, 1993, in Park City, Utah, that included recognized experts in neurology, neurosurgery, vascular surgery, and healthcare planning. A program of critical topics was developed, and each expert presented a talk and provided the chairman with a summary statement. From these summary statements a document was developed and edited onsite to achieve consensus before final revision.

RESULTS

The first section of this document reviews the natural history, methods of patient evaluation, options for medical management, results of surgical management, data from position statements, and results to date of prospective randomized trials for symptomatic and asymptomatic patients with carotid artery disease. The second section divides 96 potential indications for carotid endarterectomy, based on surgical risk, into four categories: (1) Proven: This is the strongest indication for carotid endarterectomy; data are supported by results of prospective contemporary randomized trials. (2) Acceptable but not proven: a good indication for operation; supported by promising but not scientifically certain data. (3) Uncertain: Data are insufficient to define the risk/benefit ratio. (4) Proven inappropriate: Current data are adequate to show that the risk of surgery outweighs any benefit.

CONCLUSIONS

Indications for carotid endarterectomy in symptomatic good-risk patients with a surgeon whose surgical morbidity and mortality rate is less than 6% are as follows. (1) Proven: one or more TIAs in the past 6 months and carotid stenosis > or = 70% or mild stroke within 6 months and a carotid stenosis > or = 70%; (2) acceptable but not proven: TIAs within the past 6 months and a stenosis 50% to 69%, progressive stroke and a stenosis > or = 70%, mild or moderate stroke in the past 6 months and a stenosis 50% to 69%, or carotid endarterectomy ipsilateral to TIAs and a stenosis > or = 70% combined with required coronary artery bypass grafting; (3) uncertain: TIAs with a stenosis < 50%, mild stroke and stenosis < 50%, TIAs with a stenosis < 70% combined with coronary artery bypass grafting, or symptomatic, acute carotid thrombosis; (4) proven inappropriate: moderate stroke with stenosis < 50%, not on aspirin; single TIA, < 50% stenosis, not on aspirin; high-risk patient with multiple TIAs, not on aspirin, stenosis < 50%; high-risk patient, mild or moderate stroke, stenosis < 50%, not on aspirin; global ischemic symptoms with stenosis < 50%; acute dissection, asymptomatic on heparin. Indications for carotid endarterectomy in asymptomatic good-risk patients performed by a surgeon whose surgical morbidity and mortality rate is less than 3% are as follows. (1) Proven: none. As this statement went to press, the National Institute of Neurological Disorders and Stroke issued a clinical advisory stating that the Institute has halted the Asymptomatic Carotid Atherosclerosis Study (ACAS) because of a clear benefit in favor of surgery for patients with carotid stenosis > or = 60% as measured by diameter reduction. When the ACAS report is published, this indication will be recategorized as proven. (2) acceptable but not proven: stenosis > 75% by linear diameter; (3) uncertain: stenosis > 75% in a high-risk patient/surgeon (surgical morbidity and mortality rate > 3%), combined carotid/coronary operations, or ulcerative lesions without hemodynamically significant stenosis; (4) proven inappropriate: operations with a combined stroke morbidity and mortality > 5%.

Guidelines for carotid endarterectomy. A multidisciplinary consensus statement from the ad hoc Committee, American Heart Association

BACKGROUND AND PURPOSE

Indications for carotid endarterectomy have engendered considerable debate among experts and have resulted in publication of retrospective reviews, natural history studies, audits of community practice, position papers, expert opinion statements, and finally prospective randomized trials. The American Heart Association assembled a group of experts in a multidisciplinary consensus conference to develop this statement.

METHODS

A conference was held July 16-18, 1993, in Park City, Utah, that included recognized experts in neurology, neurosurgery, vascular surgery, and healthcare planning. A program of critical topics was developed, and each expert presented a talk and provided the chairman with a summary statement. From these summary statements a document was developed and edited onsite to achieve consensus before final revision.

RESULTS

The first section of this document reviews the natural history, methods of patient evaluation, options for medical management, results of surgical management, data from position statements, and results to date of prospective randomized trials for symptomatic and asymptomatic patients with carotid artery disease. The second section divides 96 potential indications for carotid endarterectomy, based on surgical risk, into four categories: (1) Proven: This is the strongest indication for carotid endarterectomy; data are supported by results of prospective contemporary randomized trials. (2) Acceptable but not proven: a good indication for operation; supported by promising but not scientifically certain data. (3) Uncertain: Data are insufficient to define the risk/benefit ratio. (4) Proven inappropriate: Current data are adequate to show that the risk of surgery outweighs any benefit.

CONCLUSIONS

Indications for carotid endarterectomy in symptomatic good-risk patients with a surgeon whose surgical morbidity and mortality rate is less than 6% are as follows. (1) Proven: one or more TIAs in the past 6 months and carotid stenosis > or = 70% or mild stroke within 6 months and a carotid stenosis > or = 70%; (2) acceptable but not proven: TIAs within the past 6 months and a stenosis 50% to 69%, progressive stroke and a stenosis > or = 70%, mild or moderate stroke in the past 6 months and a stenosis 50% to 69%, or carotid endarterectomy ipsilateral to TIAs and a stenosis > or = 70% combined with required coronary artery bypass grafting; (3) uncertain: TIAs with a stenosis < 50%, mild stroke and stenosis < 50%, TIAs with a stenosis < 70% combined with coronary artery bypass grafting, or symptomatic, acute carotid thrombosis; (4) proven inappropriate: moderate stroke with stenosis < 50%, not on aspirin; single TIA, < 50% stenosis, not on aspirin; high-risk patient with multiple TIAs, not on aspirin, stenosis < 50%; high-risk patient, mild or moderate stroke, stenosis < 50%, not on aspirin; global ischemic symptoms with stenosis < 50%; acute dissection, asymptomatic on heparin. Indications for carotid endarterectomy in asymptomatic good-risk patients performed by a surgeon whose surgical morbidity and mortality rate is less than 3% are as follows. (1) Proven: none. (As this statement went to press, the National Institute of Neurological Disorders and Stroke issued a clinical advisory stating that the Institute has halted the Asymptomatic Carotid Atherosclerosis Study (ACAS) because of a clear benefit in favor of surgery for patients with carotid stenosis > or = 60% as measured by diameter reduction. When the ACAS report is published, this indication will be recategorized as proven. (2) acceptable but not proven: stenosis > 75% by linear diameter; (3) uncertain; stenosis > 75% in a high-risk patient/surgeon (surgical morbidity and mortality rate > 3%), combined carotid/coronary operations, or ulcerative lesions without hemodynamically significant stenosis; (4) proven inappropriate: operations with a combined stroke morbidity and mortality > 5%.

Carotid surgery in the octogenarian

The records of 52 patients aged 80 years or older who underwent 56 carotid artery reconstructions were analyzed retrospectively. Four patients had amaurosis fugax, 27 patients had experienced one or more transient ischemic attacks, eight had a completely or partially reversible stroke, and 10 had vertebrobasilar insufficiency. Three patients were asymptomatic. Arteriograms documented stenosis > 80% on the operated side in 48 cases, whereas the contralateral carotid artery was occluded or had > 80% stenosis in 10 cases each. Two or more cerebral arteries were involved in 37 patients. CT scans were normal in only 21 (40%) patients. General anesthesia was used in 54 of 56 operations. Thirty-six endarterectomies, 18 bypasses, and two resection-anastomoses (for tortuosity) were performed. A shunt was employed in eight (14.3%) cases. One lethal stroke (1.9%) occurred during the first postoperative month. Three patients experienced nonfatal strokes, two of which gave rise to residual deficits. Two patients were lost to follow-up. For the remaining 49 patients the mean follow-up was 24 months. Two-year actuarial survival was 76.3% for the entire series and 67% for those surviving without neurologic events. This study shows that when properly selected the elderly population can safely undergo carotid surgery.

The use of duplex scanning to diagnose perioperative carotid occlusions

Perioperative stroke following carotid endarterectomy is reported to occur in 3-20% of patients and may be associated with spontaneous development of thrombus at the operation site or technical imperfections. In 118 consecutive patients, duplex scanning performed immediately before anaesthesia was used to confirm that all high grade carotid stenoses had not progressed to occlusion since the arteriogram. A new technique at completion, using subcuticular prolene sutures for the skin and a plastic dressing for the wound, permitted immediate postoperative assessment by duplex scanning if necessary. Of the 118 patients, symptoms of neurological instability developed in 4 (3.4%) in the first 6 hours after surgery. At duplex scanning, developing thrombus was demonstrated in three of these patients. Arterial thrombus was removed at reoperation and all three patients recovered with no neurological deficit. The fourth patient had occluded the contralateral carotid artery, developed a major stroke and was not considered for re-exploration. Duplex scanning provides accurate diagnostic information in selecting patients for urgent re-exploration, reducing the 24 h stroke rate to 0.8% in this series.

Internal carotid artery surgery: ten-year results

The twofold purpose of this study was to compare the immediate results of surgery for lesions of the internal carotid artery in two series of patients operated on at 10-year intervals and to assess long-term results in the earliest series. Series I comprised 242 reconstructions in 220 patients (160 men and 60 women, mean age 64.4 years) performed between 1980 and 1982. Seventy patients (35%) were asymptomatic, 113 had monocular or hemispheric symptoms, and 30 had nonhemispheric symptoms. Contrast arteriograms revealed internal carotid artery stenosis of < 30% in 74 cases (30.6%), between 30% and 70% in 49 (20.2%), and > 70% in 119 (49.2%). Reconstruction was achieved by endarterectomy in 164 cases (67.8%), by vein graft in 75 cases (31%), and by other methods in 3 cases (1.2%). Postoperative mortality was 5% (11/110). Nonfatal postoperative stroke occurred in 1.8% (4/220) and transient ischemic attack in 0.5% (1 patient). All reconstructions were patent on postoperative control. The combined mortality/morbidity rate in patients in series II operated on between 1990 and 1991 was significantly lower, that is, 2.4% (4/170) vs. 6.8% (15/220) (p < 0.05). In series I, 11 patients (5%) were lost to follow-up and 124 were still alive at the beginning of the tenth postoperative year. Cumulative survival was 79 +/- 5.6% at 5 years and 60.9 +/- 6.7% at 10 years. The causes of late death were stroke in 7 cases, cardiovascular disease in 30 cases, cancer in 16 cases, and other causes in 20 cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Carotid endarterectomy for prevention of stroke

Carotid endarterectomy, a frequently performed operation, has been used as a strategy for preventing stroke in patients with carotid bifurcation disease. The safety and efficacy of the operation were recently challenged by a number of sources. Three major responses to this challenge were to retrospectively review the natural history of carotid bifurcation disease compared with the immediate and long-term results of carotid endarterectomy, to initiate 6 prospective randomized trials to determine the efficacy of carotid endarterectomy for a variety of indications, and to develop appropriateness initiatives and guidelines for using this surgical procedure by organizations concerned with health care policy. I review the current status of these 3 areas of endeavor. In those areas where studies are complete, carotid endarterectomy has been shown to be highly effective in reducing stroke risk. Risk reduction has ranged from 66% to 80% compared with medical management. Based on these sources and findings, I present a list of indications for the operation for surgeons who are able to do the operation safely and within the guidelines established by the Stroke Council of the American Heart Association.

Stroke rates in patients with lacunar and large vessel cerebral infarctions

A stroke registry was developed to determine the value of various clinical data in distinguishing lacunar from large vessel infarctions. Adequate localization was achieved in 98% of 246 patients with brain infarcts. These and 30 transient ischemic attack patients were followed for a median of 1082 days (range 2-1657). Follow-up data on TIA patients were invalidated by evidence of serious underreporting of TIAs in our general population. Among 212 male patients with cerebral infarcts not due to cardiogenic embolism, syphilis, migraine, vasculitis, or other unusual etiologies, 1-, 12-, and 36-month recurrence rates were 23%, 31% and 39% among patients with large vessel anterior circulation infarcts; 15%, 20% and 28% among patients with large vessel posterior circulation infarcts; and 8%, 16% and 21% among patients with lacunar anterior circulation infarcts, respectively. Six patients with posterior circulation lacunes did not experience recurrence. Comparative case fatality data were also compiled. Large vessel infarcts tended to be followed by further large vessel infarcts, usually in the same vascular distribution, whereas lacunar infarcts were not predictive of the type or location of subsequent events.

Neurologic events following carotid endarterectomy: prediction of outcome

A total of 1572 carotid endarterectomies were performed at one institution between 1975 and 1987. One hundred five patients had early (< 3 weeks) neurologic events following carotid endarterectomy. Sixty-five patients had cerebral vascular accidents (CVAs) (4.1%), 14 patients had reversible ischemic neurologic deficits (0.9%), and 26 patients had transient ischemic attacks (1.7%). Eight patients died from CVAs (0.5%). The mean follow-up was 31 months (range 1 to 137 months) with a 5-year cumulative survival of 77%. The median time of occurrence of neurologic events was 4 hours. Ages, cerebral protection, patches, carotid occlusion time (mean 29 minutes), gender, and status of the contralateral carotid arteries were not predictors of outcome. Death from neurologic events increased significantly in patients who had preoperative CVAs compared with patients with preoperative transient neurologic deficits (p < 0.05). The time of occurrence of CVA after carotid endarterectomy affected outcome, and an early CVA (< 4 hours) was associated with a higher mortality at 30 days and at 4 months as a consequence of the initial CVA (p = 0.11). Patients who had a neurologic event more than 4 hours after surgery had a significantly better resolution of their symptoms (66%) compared with patients who had an early neurologic event (35%, p < 0.05). The long-term follow-up of the surviving patients demonstrated an improvement in neurologic function in 75% of the CVA group (36/48) and 92% (76/83) of all patients who had neurologic events in long-term follow-up.

Improved prognosis for asymptomatic carotid stenosis with prophylactic carotid endarterectomy

BACKGROUND AND PURPOSE

The value of carotid endarterectomy in asymptomatic patients with high-grade stenosis is controversial. The objective of this study is to compare the immediate and long-term outcome of patients after carotid endarterectomy for asymptomatic carotid stenosis (greater than 75%) with the reported natural history of patients followed nonoperatively to determine whether carotid endarterectomy reduces the subsequent neurological event rate.

METHODS

The data from 141 carotid endarterectomies performed in 123 patients between January 1980 and December 1986 were reviewed from the perspective of perioperative results and long-term follow-up to January 1990, providing a follow-up ranging from 3 to 10 years. The mean follow-up was 56.6 months (range 27-117 months).

RESULTS

There were no perioperative deaths. There were two postoperative stokes: one in the cerebellar distribution and one in the middle cerebral distribution. During the course of follow-up, no patient suffered a stroke in the hemisphere ipsilateral to carotid endarterectomy. One patient developed ipsilateral transient ischemic attacks 24 months after surgery associated with carotid restenosis. A total of three patients developed four recurrent carotid stenoses, for an incidence of 2.8%. All four recurrences were corrected surgically.

CONCLUSIONS

These findings are in marked contrast to the reported natural history of patients with greater than 75% stenosis in which the 1-year neurological event rate is 18% and the 1-year stroke rate is 5%. Although final proof of efficacy for prophylactic carotid endarterectomy in asymptomatic patients will await the outcome of randomized trials, until these data are available, prophylactic carotid endarterectomy is justified in centers of excellence that can perform the surgery with low perioperative risk.

Asymptomatic carotid stenosis: a benign lesion?

Recent reports of the risk of asymptomatic carotid stenosis have been compromised by flawed patient selection or the performance of a large number of carotid endarterectomies during follow-up. We report the natural history of a randomly selected group of asymptomatic patients (n = 188; 114 males and 74 females) with documented carotid artery disease who were prospectively followed without intervention for up to 8 years. Risk factors included ischaemic heart disease in 17%, diabetes in 10%, hypertension in 46% and 88% were smokers. The degree of internal carotid stenosis was classified by duplex scanning and a total of 259 vessels had evidence of atherosclerosis. Study end-points included TIA, CVA and death. At mean follow-up of 4 years 3% of the 96 patients with internal carotid artery stenosis of less than 50% had died and 2% suffered a stroke. Six per cent of patients with a stenosis of 50-79% had died and 4% and 2% had suffered a CVA and TIA, respectively. In the 59 patients with greater than 80% stenosis 7% had suffered a TIA and an additional 7% a CVA, while 2% had died. None of the patients suffering a stroke had an antecedent TIA. Though the incidence of ischaemic events is significantly higher in patients with greater than 80% stenosis the incidence of unheralded stroke remains low. We therefore continue to recommend a conservative approach to the management of asymptomatic carotid stenosis.

A methodological appraisal of research on prognosis after transient ischemic attacks

We analyzed existing research on the prognosis of patients who have had a transient ischemic attack to identify studies that adhere to basic methodological principles and to identify underinvestigated questions. Studies were eligible for analysis if they were published in peer-reviewed journals after 1950, written in English, and included at least 50 patients with transient ischemia. Studies that included patients with stroke were included only if they reported outcome rates separately for the subgroup of patients with transient ischemia. All eligible studies were extracted by one investigator who recorded adherence to six key methodological principles. Among 60 eligible studies, 54 were observational cohort studies and six were randomized trials. Adherence to the six methodological principles was as follows: eight studies included an adequate description of diagnostic criteria and of procedures used to assure adherence to the criteria, 54 used appropriate end points, two assembled inception cohorts, 10 included an adequate description of end point surveillance, 22 adequately reported and analyzed censored patients, and 10 included a multivariate analysis for predictive variables. No study adhered to all six principles, but two adhered to the three most important ones (appropriate end points, inception cohort, and adequate reporting and analysis of censored patients). Aspects of prognosis after transient ischemia that have not been completely investigated include the severity of subsequent strokes and methods for estimating the outcome risk for individual patients. We conclude that only a few published investigations on prognosis after transient ischemia are methodologically complete. This finding helps explain why it is difficult to interpret many studies. Further research is needed and should target underinvestigated topics.

Safety and long-term benefit of carotid endarterectomy in the asymptomatic patient

In order to determine the safety and long-term salutary effects of carotid endarterectomy in the asymptomatic patient, we retrospectively reviewed all asymptomatic patients who underwent carotid endarterectomy from 1980 through 1986. There were 60 carotid endarterectomies performed in 54 patients, 53 men and one woman. The mean age was 64 years. Arteriography revealed a high grade stenosis of 70% or greater in 46 carotid arteries (77%), ulceration in five (8%), and both in nine (15%). Risk factors included coronary artery disease in 60% of patients, smoking in 87%, hypertension in 67%, and diabetes in 22%. Perioperative morbidity included three cranial nerve injuries, one myocardial infarction and one contralateral stroke. There were no deaths. Mean follow-up was 47 months with only two patients being lost to follow-up. During follow-up three patients suffered ipsilateral transient ischemic attacks without recurrent carotid stenosis and one patient had a transient ischemic attack secondary to contralateral carotid occlusion. There was one ipsilateral stroke occurring two years after operation secondary to restenosis that required reoperation and four late contralateral strokes. Ten patients died in the follow-up period. Causes of death were stroke (1), cardiac (4), malignancy (2), pulmonary (2), and unknown (1). All surviving patients were evaluated by duplex scan at a mean interval following surgery of 47 months. Restenosis of endarterectomized arteries was seen at the following rates: less than 50% in 41 (87%); 50-75% in four (8.5%); 80% in one (2%); and 90% in one (2%). Life table analysis revealed a 98% ipsilateral stroke-free rate at five and eight years.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiographic long-term outcome of carotid endarterectomy

Late postoperative digital subtraction angiographic (DSA) findings after a mean follow-up of 6 years were examined after 61 internal carotid artery (ICA) endarterectomies performed for symptomatic (mainly TIAs) ICA stenosis on 52 patients. All 34 surviving patients were re-examined. Six of them (17.6%) had become neurologically symptomatic during the follow-up period with an annual stroke rate of 1%. DSA revealed progression of ipsilateral ICA stenosis in seven cases (23%), two of whom had evidence of bilateral angiographic deterioration. Two out of seven patients had symptomatic ipsilateral restenosis (6%). Progression of contralateral ICA stenosis was detected in five cases (16%).

Long-term follow-up of surgically managed carotid bifurcation atherosclerosis. Justification for an aggressive approach

To document the efficacy of our aggressive surgical approach to stroke prevention, we compiled follow-up data on 619 patients undergoing 993 carotid endarterectomies at our institution since 1970. Following carotid endarterectomy, crude annual stroke incidence, including perioperative strokes (2.2%), was 1.9%. In our symptomatic patients crude annual stroke incidence, including perioperative strokes (2.7%), was 2.1%. This is superior to the annual stroke incidence seen in patients on "optimal" medical therapy as defined by the Canadian Cooperative Study (4.6% in men), the AICLA Study (2.9%), the American Multicenter Trial (8%), and the Canadian- American Cooperative Trial (approximately 5%). In our asymptomatic patients, crude annual stroke incidence, including perioperative strokes (1.1%), was 1.4%. This is superior to nonsurgical therapy for asymptomatic patients with hemodynamically significant or more than 75% stenoses as reported by the Mayo Clinic (3.4%) or Chambers and Norris (2.7%). An aggressive surgical approach to carotid bifurcation atherosclerosis is superior to nonsurgical therapy in symptomatic and selected asymptomatic patients if low perioperative mortality/stroke morbidity rates are achieved.

Stroke, myocardial infarction, and survival during long-term follow-up after carotid endarterectomy

Epidemiological data on 211 patients undergoing 256 carotid endarterectomies were reviewed, and current data for the 205 perioperative survivors were analyzed by the actuarial method. The median follow-up period was 7.0 years (range: 1 month to 23.2 years). Seven percent of patients were lost to follow-up. Actuarial survival was 77% (5 years) and 49% (10 years), but lower than for the general population. Late stroke occurred in 27 patients (13%) (fatal in 9), being ipsilateral to an endarterectomy in only 10 (4.9%). The annual ipsilateral stroke rate (0.41%), comparable to that of the general population, suggests protection from subsequent stroke. Myocardial infarction occurred in 69 patients (34%), and accounted for 49% of late deaths.

Transient cerebral ischemia

Stroke is a major cause of disability and death in North America. About 30% to 40% of patients with stroke have had transient ischemic attacks (TIAs). The recognition and treatment of TIAs and possibly of asymptomatic stenoses of the carotid arteries may be beneficial in preventing stroke. We review the epidemiologic features, natural history, pathogenetic features, clinical presentation, methods of investigation and management of patients with TIAs.

Carotid endarterectomy: what is its current status?

The plethora of recent articles regarding carotid endarterectomy has tended to confuse rather than clarify its indications, efficacy, and acceptability. The National Institutes of Health has recently funded two large multicenter controlled clinical trials, one including asymptomatic persons with carotid stenoses, and the other, patients having transient ischemic episodes or minor strokes. Eight academic professors of neurology (four), neurosurgery (two), and vascular surgery (two) with a long and abiding interest in cerebrovascular disease prepared a statement delineating acceptable levels of mortality and morbidity from this procedure. These might serve as guidelines until the large trials have been completed.

Reoperative carotid surgery

Fourteen patients underwent carotid reoperation for symptomatic recurrent carotid stenosis after previous ipsilateral carotid endarterectomy. Eight of these patients presented with focal transient ischemic attacks, two with strokes, and four with vertebrobasilar insufficiency. Recurrent symptoms in eight patients were similar to those prompting the initial carotid endarterectomy. Symptoms recurred early after previous carotid endarterectomy in 2 patients and late in 12 patients. Eleven patients underwent repeat endarterectomy and carotid patch angioplasty, two patients underwent patch angioplasty alone, and one patient underwent carotid artery replacement with a vein graft. Persistent or recurrent focal symptoms referable to the reoperated carotid artery were not present during follow-up (mean 27.4 months, range 4 to 79 months). Vertebrobasilar symptoms were relieved by carotid reoperation in each patient. Although the natural history of asymptomatic postoperative carotid restenosis is unknown, reluctance to reoperate on symptomatic patients is unwarranted, since carotid reoperation can be performed safely with the expectation that recurrent focal and nonfocal vertebrobasilar symptoms will be relieved.

Imaging human atherosclerosis with 99mTc-labeled low density lipoproteins

The feasibility of localizing human atherosclerotic plaques by gamma scintillation camera external imaging with technetium-99m-labeled low density lipoproteins (99mTc-LDL) was tested in 17 patients who had atherosclerosis. Imaging demonstrated focal accumulation of radiolabel consistent with 99mTc-LDL sequestration by plaques in the carotid, iliac, or femoral vessels of four patients 8 to 21 hours after intravenous injection of the radiopharmaceutical. Focal accumulation of 99mTc-LDL also appeared in the location of coronary lesions in four patients, but this accumulation could not be distinguished with certainty from residual blood pool radioactivity. When carotid endarterectomy specimens from six patients who received 99mTc-LDL 1 day before endarterectomy were examined, the specimens had focal accumulations of radiolabel, with two to four times greater radioactivity in some regions of each specimen than in others; this occurred whether or not the lesions were detected on the gamma camera images. Lesion composition may have determined whether accumulation was quantitatively sufficient to produce an external image. Histologically, the imaged carotid specimen had abundant foam cells and macrophages and poorly organized intramural blood consistent with a plaque hemorrhage; in contrast, nonimaged endarterectomy specimens were mature, fibrocalcific plaques. We conclude that: 1) 99mTc-LDL did accumulate in human atherosclerotic plaques; 2) in some patients, the accumulation of 99mTc-LDL was sufficient for detection by gamma camera imaging; 3) the amount of LDL that accumulated appeared to depend on lesion composition; and 4) the design of new radiopharmaceuticals with reduced residual blood pool activity relative to plaque accumulation should lead to improved external imaging of atherosclerosis.

Long-term results after carotid artery surgery

This study presents the results from a follow-up after 414 carotid reconstructions performed on 352 patients during the years 1971-82. At the end of the follow-up period 267 patients were alive (75.8%) and 253 patients remained asymptomatic. The median follow-up time was 35 months (6 months-12 years). Patients with coronary artery disease (CAD) had a significantly lower survival than patients without signs of CAD. Coronary artery disease was significantly more frequent among patients with bilateral carotid lesions compared to patients with unilateral lesions. The actuarial stroke frequency, operative morbidity included, on the operated side was 2.5%/year. However, from 6 months postoperatively up to 8 years the stroke frequency was 1%/year. In the stroke frequencies all neurological deficits of more than 24 h duration are accounted for. Although there was a trend toward higher stroke rates among older patients there were no significant differences between age groups. Assuming a 10% stroke frequency during the first year after a TIA and a 6% annual stroke rate thereafter our results would cross even such a natural course curve at 18 months.

The appropriateness of carotid endarterectomy

Carotid endarterectomy is a commonly performed but controversial procedure. We developed from the literature a list of 864 possible reasons for performing carotid endarterectomy, and asked a panel of nationally known experts to rate the appropriateness of each indication using a modified Delphi technique. On the basis of the panel's ratings, we determined the appropriateness of carotid endarterectomy in a random sample of 1302 Medicare patients in three geographic areas who had had the procedure in 1981. Thirty-five percent of the patients in our sample had carotid endarterectomy for appropriate reasons, 32 percent for equivocal reasons, and 32 percent for inappropriate reasons. Of the patients having inappropriate surgery, 48 percent had less than 50 percent stenosis of the carotid artery that was operated on. Fifty-four percent of all the procedures were performed in patients without transient ischemic attacks in the carotid distribution. Of these procedures, 18 percent were judged appropriate, as compared with 55 percent judged appropriate in patients with transient ischemic attacks in the carotid distribution. After carotid endarterectomy, 9.8 percent of patients had a major complication (stroke with residual deficit at the time of hospital discharge or death within 30 days of surgery). We conclude that carotid endarterectomy was substantially overused in the three geographic areas we studied. Furthermore, in situations in which the complication rate is equal to or above the study's aggregate rate, carotid endarterectomy would not be warranted, even in cases with an appropriate indication, because the risks would almost certainly outweigh the benefits.

Prognosis of high-risk patients with nonoperated symptomatic extracranial carotid tight stenosis

Forty-five patients with symptomatic (20 with transient ischemic attack, 25 with minor stroke) greater than or equal to 75% stenosis of the cervical internal carotid artery had no endarterectomy and received only medical therapy because the surgical risks (severe cardiac disease, chronic obstructive pulmonary disease, hypertension or diabetes with systemic complications, aortic aneurysm) were believed to be unacceptable. During follow-up (mean 48 months), occlusion of the internal carotid artery developed without symptoms in two patients and with symptoms in three patients. The cumulative stroke and/or death rate was 24% at 2 years and 50% at 6 years. The ipsilateral infarct rate was 10% after the first year, but decreased markedly thereafter (2.4% per year), and one third of these infarcts were probably lacunes due to hypertensive small vessel disease. Overall, stroke related to previously symptomatic internal carotid artery stenosis was not the major problem during follow-up but was largely overcome by other strokes and cardiac death.

Carotid endarterectomy in patients with occlusion of the contralateral carotid artery. Perioperative risk and late results

Recent reports on the outcome of carotid endarterectomy in patients with contralateral occlusion have been conflicting. Therefore, we reviewed 51 cases identified, among 675 consecutive carotid endarterectomies. A perioperative mortality of 2% and a permanent morbidity rate of 16% was observed. Compared with a complication rate of about 5% previously reported from this institution, this clearly indicates contralateral carotid occlusion as a major risk factor in carotid surgery. Though not statistically significant, patients with severely reduced cerebral perfusion pressure (CPP) had suffered more severe strokes when compared to patients with only minor reduction in CPP. In addition, the internal carotid artery blood flow following endarterectomy was significantly higher in the low pressure group (P less than 0.02). No patients were lost during follow-up, for a mean of 34 months. The cumulative five-year survival rate was 74%, not significantly different from the expected survival of an age and sex matched population. During the period of follow-up 16 patients experienced new neurologic symptoms, in six (2 strokes and 4 TIA's) referable to the hemisphere ipsilateral to operation and in 10 (2 strokes and 8 TIA's) referable to the contralateral hemisphere. The five-year stroke rate was 16%. This together with the observed survival rate indicated a better-than-expected course in this group of patients with severe cerebrovascular atherosclerosis.

Morbidity and mortality of carotid endarterectomy. A literature review of the results reported in the last 10 years

A review of the mortality and morbidity of carotid endarterectomy reported during the last 10 years was made and compared to the risk of carotid stenosis managed by the best medical treatment. For comparison, the patients were classified in asymptomatic patients (grade I), patients with transient ischaemic attacks (grade II), patients with ischaemic neurological deficits operated on acutely (grade III) and into patients with no or incomplete recovery 4-6 weeks after the stroke (grade IV). Based on the results of this literature review, only patients in grade II seem to benefit from carotid endarterectomy.