Risk factors in a community experience with carotid endarterectomy

Carotid Endarterectomy and Carotid Artery Stenting for Patients With Crescendo Transient Ischemic Attacks: A Systematic Review

Importance

Thromboembolic stroke attributable to an ipsilateral carotid artery plaque is a leading cause of disability in the United States and a major source of morbidity. Randomized clinical trials have demonstrated the efficacy of carotid endarterectomy and carotid stenting at minimizing stroke risk in patients with minor stroke and transient ischemic attack. However, there is no consensus on guidelines for medical management and the timing of revascularization in patients with multiple recurrent episodes of transient ischemic attack over hours or days, an acute neurological event known as crescendo transient ischemic attack.

Objective

To review the management of and timing of intervention in patients presenting with crescendo transient ischemic attack.

Evidence Review

This systematic review included all English-language articles published from January 1, 1985, to January 1, 2019, available from PubMed (MEDLINE) and Google Scholar. Articles were excluded if they did not include analysis of patients with symptoms, did not report the timing of intervention after crescendo transient ischemic attack, or mixed analysis of patients with stroke in evolution with patients with crescendo transient ischemic attack. The quality of the evidence was assessed with the modified rating from the Oxford Centre for Evidence-based Medicine.

Observations

Patients with crescendo transient ischemic attack were found to have a higher risk of stroke or death after carotid endarterectomy compared with patients with a single transient ischemic attack or stable stroke. With medical therapy alone, a considerable number of patients with crescendo transient ischemic attack experience a completed stroke within several months and have a poor prognosis without intervention. Urgent carotid endarterectomy, typically performed within 48 hours of initial presentation, is beneficial in carefully selected patients. There have been several reports of operative treatment within the first 24 hours of presentation; however, review of these reports does not show any additional benefit from emergency treatment. Carotid artery stenting is reserved only for selected patients with prohibitive surgical risk for endarterectomy. The literature does not clearly support any additional benefit of intravenous heparin therapy over mono or dual antiplatelet therapy prior to carotid endarterectomy.

Conclusions and Relevance

Crescendo transient ischemic attack is best managed with optimal medical management as well as urgent carotid endarterectomy within 2 days of presentation. Surgical endarterectomy appears to be preferred because of the increased embolic potential of bifurcation plaque, whereas stenting is an option for patients with contraindications for surgery. With ongoing advances in cerebrovascular imaging and medical treatment of stroke, there is a need for better evidence to determine the optimal timing and preoperative medical management of patients with crescendo transient ischemic attack.

[Treatment tactics for patients with combined atherosclerotic lesions of brachiocephalic and coronary arteries]

OBJECTIVE

To evaluate the tactics of surgical treatment of patients with coronary heart disease and atherosclerotic lesions of cerebral vessels in dependence of risk stratification of heart and brain complications.

MATERIAL AND METHODS

One hundred and fifty-six patients were examined. Cerebral and coronary blood flow and functional state of the brain and heart were studied. According to treatment characteristics, 3 groups were singled out: patients of the 1(st) group underwent simultaneous surgery of coronary and brachiocephalic arteries, patients of the 2(nd) group were first operated for brachiocephalic arteries, in the 3(rd) group, bypass graft was performed in the first stage.

RESULTS AND CONCLUSION

A role of coronary and brachiocephalic arteries, functional state of the myocardium and brain in the postoperative risk was established. The authors suggest the algorithm for choosing the order of priority of surgical interventions on coronary and brachiocephalic arteries.

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 Operative Risks of Carotid Endarterectomy for Recently Symptomatic Stenosis in Relation to the Timing of Surgery

Background and Purpose— Reliable data on the risk of carotid endarterectomy (CEA) in relation to timing of surgery are necessary to plan CEA most effectively, 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 2008 inclusive that reported the risk of stroke and death due to CEA in relation to the time between presenting symptom and surgery. Pooled estimates of risk by the time since the last event were obtained by Mantel–Haenszel meta-analysis.

Results— Of 494 published operative series, only 47 stratified risk by timing of surgery. The pooled absolute risks of stroke and death after urgent CEA were high in patients with stroke-in-evolution (20.2%, 95% CI 12.0 to 28.4) and in patients with crescendo TIA (11.4%, 6.1 to 16.7), with no trends toward reduced risks in more recent studies. However, there was no significant difference between early and later CEA in neurologically stable patients with recent TIA or nondisabling stroke (<1 week versus ≥1 week, OR=1.2, 0.9 to 1.7, P =0.17; <2 weeks versus ≥2 weeks, OR=1.2, 0.9 to 1.6, P =0.13).

Conclusions— Emergency endarterectomy for stroke-in-evolution has a high operative risk, but the risk may be somewhat lower in patients with crescendo TIA. Surgery in the first week in neurologically stable patients with TIA or minor stroke is not associated with a substantially higher operative risk than delayed surgery. More data are required on the risk and benefit of more urgent surgery for TIA and minor stroke and for early versus delayed surgery in patients with major nondisabling stroke.

Urgent Carotid Endarterectomy for Patients with Unstable Symptoms: Systematic Review and Meta-Analysis of Outcomes

Current evidence suggests that carotid endarterectomy (CEA) performed within 2 weeks of symptoms produces better long-term results than if it is delayed. Urgent endarterectomy following unstable presentations such as crescendo transient ischemic attack (cTIA) or progressive stroke has been associated with variable results. The evidence for this treatment strategy required reviewing. A systematic review of articles related to urgent CEA between 1980 and 2008 was performed. For cTIA, there was an odds ratio of 5.6 (95% confidence interval 3.3–9.7, p ≤ .0001) for combined stroke or death compared with surgery for “standard” indications. For unstable stroke, the odds ratio was 5.5 (95% confidence interval 3.1–9.3, p ≤ .0001). Patients with unstable neurologic presentations are at higher risk of complications if operated on urgently. Clearer definitions would help more precise patient selection to avoid inadvertently operating on patients with an unacceptably high risk of poor outcome.

The value of urgent carotid surgery for crescendo transient ischemic attacks

OBJECTIVE

This study audited operative risk in patients undergoing urgent carotid surgery for crescendo transient ischemic attacks (TIAs).

METHODS

Interrogation of the vascular unit database (January 1992 to July 2004) identified 42 patients operated on urgently for crescendo TIAs, which were defined as>or=3 TIAs within the preceding 7 days. Stroke, death, and any major cardiac events were analyzed.

RESULTS

Thirty-nine patients underwent conventional endarterectomy, and three underwent interposition vein bypass. Crescendo TIA patients had sustained a median of five TIAs (range, 3 to 20) in the 7 days before surgery. Three patients died or had a stroke after surgery, for a combined stroke/death rate of 7%. This compares with 2.4% in 1000 patients undergoing elective carotid endarterectomy in this unit during the same time period. The combined stroke/death/major cardiac event rate was 14% (n=6).

CONCLUSIONS

The combined risk of neurologic and cardiac complications after urgent carotid surgery for crescendo TIA is higher than that expected after elective cases but is still acceptable considering the natural history of patients with unstable neurologic symptoms.

Carotid endarterectomy utilization and mortality in 10 states

BACKGROUND

Studies that examined the rates of and mortality after carotid endarterectomy (CEA) mainly were confined to a limited geographical location or population. The primary purposes of this study are to examine the variation of risk-adjusted in-hospital mortality rates after CEA in 10 states, and utilization rates per capita of CEA.

METHODS

An analysis was made of hospital discharge data from 10 states extracted from the Agency for Health Research and Quality national database, Healthcare Cost and Utilization Project (HCUP).

RESULTS

The rates of CEA per capita were found to differ among the 10 states examined. No significant association was detected between geographic location and the adjusted risk of in-hospital mortality. Sex, age, type of admission, and several comorbidities were found to be significant risk factors.

CONCLUSIONS

Rates of CEA per capita differ among states. However, geographical location does not affect the likelihood of risk-adjusted mortality after the procedure.

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.

The volume-outcome relationship: from Luft to Leapfrog

Numerous reports have documented a volume-outcome relationship for complex medical and surgical care, although many such studies are compromised by the use of discharge abstract data, inadequate risk adjustment, and problematic statistical methodology. Because of the volume-outcome association, and because valid outcome measurements are unavailable for many procedures, volume-based referral strategies have been advocated as an alternative approach to health-care quality improvement. This is most appropriate for procedures with the greatest outcome variability between low-volume and high-volume providers, such as esophagectomy and pancreatectomy, and for particularly high-risk subgroups of patients. Whenever possible, risk-adjusted outcome data should supplement or supplant volume standards, and continuous quality improvement programs should seek to emulate the processes of high-volume, high-quality providers. The Leapfrog Group has established a minimum volume requirement of 500 procedures for coronary artery bypass grafting. In view of the questionable basis for this recommendation, we suggest that it be reevaluated.

Integrated care pathway for carotid endarterectomy patients

Modern day health care should incorporate strategies for controlling both the cost and quality of clinical interventions, to ensure that care is evidence based, outcomes are monitored and any areas of poor practice are improved. An integrated care pathway for an area of vascular surgery was devised with these issues in mind. The chosen pathway was for patients undergoing surgery to remove atheromatous plaques from the carotid artery. The evidence base for the interventions detailed in the pathway are given and potential advantages and disadvantages of utilizing care pathways offered. Utilizing this form of structured care, health professionals may be able to ensure cost containment combined with high quality patient care.

The influence of gender on complications of carotid endarterectomy

PURPOSE

Carotid endarterectomy (CEA) effectively reduces stroke risk in properly selected patients. Subgroup analysis of the Asymptomatic Carotid Artery Study trial noted increased complications in women. Additional studies implicate female gender as a risk factor for perioperative stroke, leading some clinicians to modify the indications for CEA in women. The purpose of this study was to determine the influence of gender on the risk of perioperative complications in patients undergoing CEA.

METHODS

The records of all patients who underwent CEA at a university medical center from January 1995 to December 1999 were reviewed. Patient demographics, procedure related risk factors, operative details, and specific complications were entered into a database for statistical analysis.

RESULTS

A total of 324 consecutive patients underwent CEA during the study period. There were 199 men (61%) and 125 women (39%). Among the men and women, there were no differences in age, smoking, hypertension, hypercholesterolemia, diabetes, family history, renal insufficiency, or symptomatic versus asymptomatic indications for CEA. More women than men received a carotid patch (90.4% versus 77.9%, P = 0.003). One woman died (0.8%) and no men died for a total combined 30-day mortality of 0.31% (P = not significant). Men and women did not differ in rates of stroke (1.5% versus 2.4%) or perioperative myocardial infarction (1.0% versus 0.8%). In addition, there was no difference when stroke and death rates were combined (2% versus 3.2%). The length of stay (2.2 versus 2.6 days) was also not different.

CONCLUSIONS

There are no significant differences in rate of stroke, myocardial infarction, or 30-day mortality, between men and women following CEA. Women should not be excluded from the benefits of CEA based on perceived increased complication rates.

Clinical outcomes for patients at high risk who underwent carotid endarterectomy with regional anesthesia

OBJECTIVE

To compare the clinical outcomes for patients with carotid artery stenosis with advanced age, diabetes mellitus, atherosclerotic coronary vascular disease, and contralateral internal carotid artery occlusion who underwent carotid endarterectomy (CEA), using regional anesthesia, with the outcomes for patients without these risk factors.

METHODS

A prospective series of 600 CEAs performed using regional anesthesia was analyzed. All patients were surgically treated under the direction of one neurosurgeon, in an academic medical center. Clinical outcome measures were any stroke, death, or cardiac morbidity within 30 days after surgery. All patients were monitored until a clinical end point was reached and/or 6 weeks had elapsed after surgery. The incidence of adverse clinical outcomes among the suspected high-risk patients was compared with the incidence for the entire series using contingency-table analysis (chi2 and Fisher's exact tests).

RESULTS

Fifteen strokes (2.5%), three cardiac complications (0.5%), and two deaths (0.3%) occurred within 30 days after CEA. None of the suspected risk factors was associated with a significantly (P < 0.05) increased risk of perioperative morbidity or death.

CONCLUSION

CEA using regional anesthesia can be performed for patients with advanced age, diabetes mellitus, atherosclerotic coronary vascular disease, and contralateral internal carotid artery occlusion, with acceptably low perioperative morbidity rates.

The Pitfalls of Establishing a Statewide Vascular Registry: The South Carolina Experience

Concerned about the inadequacy of a centralized database and the importance of low morbidity and mortality on carotid endarterectomy efficacy, the South Carolina Vascular Surgical Society prospectively instituted a computer registry for carotid procedures performed by its members, to establish a statewide standard of practice. From January 1994 through December 1997, 23 of the 30 physician members voluntarily registered data on 1652 carotid operations at 14 hospitals into a central database. Blinded results were reviewed biannually. Complete data (1995–1997) were available for 1199 cases. The patients tended to be >64 years old (72%), male (62%), and white (93%). Carotid endarterectomy was the most frequently performed operation (90%). Perioperative complications (≤30 days) occurred in 173 patients (14.4%), including stroke (n = 19; 1.6%), death (n = 8; 0.7%), and stroke/death (n = 25; 2.0%). Although 23 surgeons (77% of the society) contributed some data, only 10 surgeons (33%) contributed complete data on >10 patients/year. Despite biannual efforts to boost participation, case entry remained stable (1994, 358; 1995, 347; 1996, 425; and 1997, 427), representing about one-third of the estimated carotid procedures performed in the state during that period. The cost of the registry was approximately $11,500. Audit of 8 surgeons revealed a >95 per cent match against the statewide discharge database and low error rate versus independent medical record review. This experience confirms that excellent outcomes after carotid endarterectomy are not limited to a few select centers and can be accomplished by adequately trained surgeons in a variety of institutional settings. Incomplete physician participation, however, inevitably raises questions about the utility of such efforts. Until volunteer registries induce full participation by heightening perceived physician benefit, their role will remain limited for future outcomes research.

Carotid endarterectomy after NASCET and ACAS: a statewide study. North American Symptomatic Carotid Endarterectomy Trial. Asymptomatic Carotid Artery Stenosis Study

PURPOSE

Since the North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the Asymptomatic Carotid Artery Stenosis Study (ACAS) established the efficacy of carotid endarterectomy at large academic centers, there have been two community-based studies of outcomes after this operation. The purpose of this study was to perform a statewide survey to evaluate postoperative morbidity and mortality after carotid endarterectomy among patients throughout Maine.

METHODS

A statewide registry was established to collect prospective data on carotid operations from January 1 to December 31, 1995. All surgeons and hospitals in the state were solicited to participate. All carotid endarterectomies were intended to be included; the only exclusion criterion was out-of-state residence. Comorbidities, preoperative studies, surgical indications, operative technique, and postoperative outcomes were analyzed. State administrative data were used to assess registry coverage.

RESULTS

Ten of 17 hospitals participated, and 58% of all carotid endarterectomies performed in the state were included. Three hundred sixty-four operations were entered into the registry. Forty-four percent of the operations were performed for transient ischemic attack, 37% for asymptomatic stenosis, and 19% for stroke. The postoperative stroke rate was 2.5% with a total neurologic complication rate of 4.7% (transient ischemic attack and stroke). There was one postoperative death (mortality rate 0.3%). Patients with symptoms had a higher incidence of postoperative stroke (4.0% vs 0% asymptomatic; p < 0.05) and transient ischemic attacks (3.8% vs 0.8% asymptomatic). Hospital stroke rates varied from 0% to 7%. Stroke rate did not differ significantly between low-volume hospitals (2 to 28 patients/year, 3.3%) and high-volume hospitals (29 to 101 patients/year, 2.3%) or between low-volume surgeons (fewer than 11 operations/year, 1.7%) and high-volume surgeons (more than 12 operations/year, 2.4%). Among 26 reporting surgeons, stroke rate varied from 0% to 10%; the absolute number of strokes per surgeon varied between zero and two.

CONCLUSION

The statewide registry showed a postoperative stroke plus death rate of 2.8%, comparable with the NASCET and ACAS findings. Although this study had inherent limitations, the results from one state, including a variety of community practices, achieved results comparable with those of landmark trials.

Influence of surgical experience on the results of carotid surgery. The Finnvasc Study Group

OBJECTIVE

To assess the 30-day mortality and morbidity rates related to carotid endarterectomy on a nation-wide basis.

DESIGN

Retrospective cross-sectional study based on vascular registry Finnvasc.

MATERIALS AND METHODS

A total of 17,465 recorded vascular and endovascular procedures included exactly 1600 carotid endarterectomies performed by 104 surgeons in 23 hospitals. Fourteen per cent of the patients were operated on for asymptomatic carotid stenosis.

RESULTS

The combined mortality and permanent stroke rate was 3.3%, without any difference between operations done on symptomatic or asymptomatic patients. There was a clear inverse association between surgeon's carotid case load and poor outcomes in carotid surgery (p < 0.005), the critical patient mass per surgeon and year being 10 operations. There was no association between outcome after carotid surgery and hospital volume of carotid operations.

CONCLUSIONS

Surgeon's experience in carotid surgery clearly improves the results of carotid surgery.

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.

A systematic review of the risks of stroke and death due to endarterectomy for symptomatic carotid stenosis

BACKGROUND AND PURPOSE

Carotid endarterectomy reduces the risk of carotid territory ischemic stroke ipsilateral to a recently symptomatic severe carotid stenosis. However, the benefit is limited by the risks of stroke and death associated with the operation. Although reported surgical risks vary enormously, there has been no systematic review of the published literature.

METHODS

We performed a systematic review of mortality and the risk of stroke and/or death due to endarterectomy for symptomatic carotid stenosis in studies published since 1980.

RESULTS

Fifty-one studies fulfilled our criteria. Overall mortality was 1.62% (95% confidence interval [CI], 1.3 to 1.9), and the risk of stroke and/or death was 5.64% (95% CI, 4.4 to 6.9). However, there was significant heterogeneity of risk of stroke and/or death (P < .001). The risk varied systematically with the methods and the authorship of the study. The risk of stroke and/or death was highest in studies in which patients were assessed by a neurologist after surgery (7.7%; 95% CI, 5.0 to 10.2) and lowest in studies with a single author affiliated with a department of surgery (2.3%; 95% CI, 1.8 to 2.7). After correcting for study methodology, there was no temporal trend in the risk of stroke and/or death between 1980 and 1995.

CONCLUSIONS

The reported risks of endarterectomy for symptomatic carotid stenosis show significantly greater variability than would be expected by chance. However, much of this variability can be accounted for by differences in methodology and authorship. The 5.6% overall risk of stroke and/or death is consistent with present guidelines.

A systematic comparison of the risks of stroke and death due to carotid endarterectomy for symptomatic and asymptomatic stenosis

BACKGROUND AND PURPOSE

There is some evidence that carotid endarterectomy reduces the risk of ipsilateral carotid territory ischemic stroke in patients with severe asymptomatic carotid stenosis. However, the benefit of endarterectomy is dependent on a low risk of stroke and/or death due to surgery. Whether the low operative risks reported in recent clinical trials and cited in recent guidelines are widely generalizable to clinical practice is unclear. Is endarterectomy for asymptomatic carotid stenosis really safer than surgery for recently symptomatic stenosis?

METHODS

We performed a systematic review comparing the risks of stroke and death due to carotid endarterectomy, performed by the same surgeons or in the same institutions, for symptomatic and asymptomatic stenosis in studies published since 1980.

RESULTS

Twenty-five studies fulfilled our criteria. Mortality within 30 days of endarterectomy was 1.31% for asymptomatic stenosis and 1.81% for symptomatic stenosis (odds ratio [OR], 0.69; 95% confidence interval [CI], 0.49 to 0.99). The risks of fatal stroke were 0.47% and 0.91%, respectively (OR, 0.57; 95% CI, 0.34 to 0.98). The overall risk of stroke and/or death was 3.35% for asymptomatic and 5.18% for symptomatic stenosis (OR, 0.61; 95% CI, 0.51 to 0.74).

CONCLUSIONS

Mortality and the risk of stroke and/or death due to carotid endarterectomy are significantly lower for asymptomatic than symptomatic stenosis. These findings are consistent across virtually all studies and are likely to be widely generalizable.

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 endarterectomy--is intensive care unit care necessary?

PURPOSE

The purpose of this study was to determine whether postoperative intensive care unit care is necessary for all patients undergoing carotid endarterectomy and whether a subgroup of patients at low-risk not requiring treatment in the intensive care unit could be identified.

METHODS

Case control analysis of random numbers sample over the last decade of 50% of patients undergoing isolated carotid endarterectomy at a tertiary care hospital. One hundred twenty-nine patients undergoing carotid endarterectomy were identified. Preoperative risk factors, intraoperative course, intensive case unit interventions including vasoactive agents, myocardial ischemia/infarction, arrhythmias, bronchospasm, reintubation, neurologic events, and need for reoperation, were recorded. Timing of interventions, length of stay in intensive care unit, and postoperative course were all recorded. Financial impact was assessed.

RESULTS

Among 129 patients only 31 patients did not require intensive care unit interventions. A multivariate linear regression analysis demonstrated a model in which a preoperative history of hypertension, myocardial infarction, arrhythmia, and chronic renal failure were 83% predictive of the need for an intensive care unit bed. Specifically, patients could be stratified into a low-risk group before the operation by less than four risk factors. Additionally, all patients requiring interventions or with adverse outcomes were identified by the eight postoperative hour.

CONCLUSIONS

In preoperative scheduling of intensive care unit beds, patients with less than four risk factors can be stratified to monitoring beds and those with greater than or equal to four can be stratified to intervention beds. After 8 hours, if no interventions are necessary or adverse outcomes occur, then floor recovery is safe. Patients who satisfy this algorithm would save 50% of current intensive care unit charges.

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.

Carotid endarterectomy: trials and tribulations

Since its introduction 40 years ago, the value of carotid endarterectomy has been controversial. In the early 1980s, several clinical trials were initiated to determine the efficacy of this operation in patients with carotid stenoses who were either symptomatic or asymptomatic for retinal or hemispheric ischemia. In 1991, interim results were published for the North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the European Carotid Surgery Trial (ECST), both reporting efficacy for surgery in patients with symptomatic carotid artery stenosis of greater than 70%. Subgroup analyses revealed variable risk groups. The Veterans Administration (VA) Symptomatic Trial (Cooperative Studies Program 309 of the Department of Veterans Affairs) terminated early because of these results and its findings were consistent with the results of the larger trials. NASCET and ECST continue for symptomatic patients with carotid stenoses between 30% and 69%. The results of three trials in asymptomatic patients, the Mayo asymptomatic trial, the Carotid Artery Stenosis with Asymptomatic Narrowing: Operation Versus Aspirin trial, and the VA Asymptomatic Trial (Cooperative Studies Protocol 167 of the Department of Veterans Affairs), have been reported. None showed a statistically significant benefit for surgery in the prevention of stroke or death. However, none was sufficiently large to exclude such a benefit. The large Asymptomatic Carotid Atherosclerosis Study is in progress. Differences in the results and design of these trials are discussed as are restrictions in the applicability of their results.

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.

The role of a defined protocol for cardiac risk assessment in decreasing perioperative myocardial infarction in vascular surgery

Major elective peripheral vascular surgery has historically carried a significant risk of perioperative myocardial infarction; this risk has been quantified further by its association with proved reduction in cardiac reserve/presence of coronary artery disease by stress testing or invasive monitoring. Recognition of this risk logically should lead to protocols that delineate coronary artery disease/cardiac reserve before surgery and correct for observed abnormalities during surgery. This study sought to show that a coherent algorithm of preoperative cardiac assessment combined with aggressive perioperative management could indeed reduce perioperative myocardial infarction rates. Six hundred thirty consecutive elective vascular operations were performed by the author during 6 years. All patients were entered into a prospective protocol for preoperative cardiac risk assessment, which then determined the choice of operation, type of anesthesia, and level of hemodynamic monitoring. Sixty-eight percent of the patients demonstrated clinical coronary artery disease, 15% had previously undergone coronary catheterization or surgery, and 9% had ejection fractions less than 35%. All patients underwent baseline detailed cardiac histories, radionuclide cardioangiography, and electrocardiograms. Patients with significant historic coronary artery disease or ejection fraction less than 50% underwent stress thallium testing; patients with positive fixed or redistribution defects then underwent catheterization, constituting 7% of the series. Risk stratification by age and cardiac assessment then dictated the perioperative care. The overall perioperative myocardial infarction rate was 0.7% (5/628), ranging from 0% for 156 aortic operations and 114 carotid endarterectomies to 0.6% for 159 femoropopliteal and 3.3% for 90 femorotibial revascularizations.(ABSTRACT TRUNCATED AT 250 WORDS)

Conserving resources after carotid endarterectomy: selective use of the intensive care unit

A retrospective review was undertaken of a random sample (N = 73) comprising 50% of carotid endarterectomies performed during 1986 to evaluate the necessity of routine postoperative intensive care unit (ICU) admission after carotid endarterectomy. Severity of illness was determined with use of the Acute Physiology Score of the APACHE II system. The Therapeutic Index Scoring System was used to quantify postoperative services used. Postoperative morbidity was analyzed. Financial impact was extrapolated with use of 1990 billing data. Length of ICU stay was 24.5 hours. Only 13 of 73 patients (18%) required ICU services. In 10 (77%) of these patients therapy was initiated in the recovery room and discontinued in six patients within 3 hours of ICU admission. Only two patients required ICU services for 16 hours after surgery. The mean Acute Physiology Score was low (4.96) and could not identify patients who required unique ICU services. Neurologic deficits were seen in five patients (6.9%). In three cases deficits were recognized in the recovery room; deficits developed in two patients after discharge from the ICU. Observation in the recovery room with transfer of stable patients would have eliminated ICU admission in 60 patients (82%). In 1990 the incremental ICU charge was $720/patient day. This represents 12.5% of the hospital charges for carotid endarterectomy. The ICU is an expensive and highly used hospital resource. Only a few patients need unique ICU services after carotid endarterectomy, and this is usually apparent within 2 hours of surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Perioperative stroke. Part I: General surgery, carotid artery disease, and carotid endarterectomy

Although stroke, defined as a focal neurological deficit lasting more than 24 hr, is uncommon in the perioperative period, its associated mortality and long-term disability are high. No large-scale data are available to identify the importance of recognized risk factors for stroke in the perioperative period. A review of the literature shows that the incidence and mechanism of its occurrence are influenced by the presence of cardiovascular disease and the type of surgery. The most common cause of perioperative stroke is embolism. In non-cardiac surgery, the incidence of perioperative stroke is higher among the elderly. Properly administered, controlled hypotension is associated with minimal risk of stroke. Cerebral vasospasm may be the cause of focal cerebral ischaemia in eclamptic patients, and the aggressive treatment of hypertension may exacerbate the neurological damage. The risk of stroke associated with carotid endarterectomy is closely related to the preoperative neurological presentation, and the experience of the surgical/anaesthetic team. Symptomatic cerebrovascular disease, acute stroke, asymptomatic carotid lesions, preoperative assessment of risk, local and general anaesthesia, cerebral protection and monitoring during carotid endarterectomy are discussed with reference to reducing the risk of perioperative stroke. Adequate monitoring and protection have minimized the risk of ischaemia from carotid clamping, and the major mechanism of stroke is embolization.