Natural history of symptomatic and asymptomatic carotid artery occlusion contralateral to carotid endarterectomy: a prospective study

The natural history of carotid occlusion (CO) has generally been analyzed in the presence of a contralateral patent but diseased internal carotid artery (ICA). Few previous studies have focused on the fate of CO contralateral to the side of a prior carotid endarterectomy (CEA). The aim of this study was to analyze the mortality rate and the incidence of cerebrovascular events in the hemisphere ipsilateral to CO (HICO) in patients who had undergone contralateral CEA. The 30-day and long-term outcomes of 153 consecutive patients who had CEA for severe symptomatic and asymptomatic ICA lesions contralateral to a symptomatic or asymptomatic CO over a 15-year period were considered. The endpoints of the study were mortality and neurological events in the HICO. Overall, the 30-day mortality and stroke rates were 0.6% (1/153) and 1.9% (3/153), respectively; the only death was stroke-related and the stroke was ipsilateral to the operated side. The other 2 strokes were ipsilateral to a symptomatic CO. The follow-up was completed for all patients (mean, 7.7 years; range, 1-172 months). Overall, there were 4 late strokes (2.6%), one of them lacunar in a patient with a symptomatic CO, whereas the other 3 were atheroembolic and ipsilateral to the operated ICA. The risk of late stroke in the HICO at 5 and 12 years was 2%. Overall, there were 19 late deaths, none of them stroke-related. CO, with or without symptoms, contralateral to CEA could be considered a locally benign condition in the long term.     

Natural history of carotid artery disease on the side contralateral to endarterectomy

The natural history of the nonoperated carotid artery opposite an endarterectomy was examined in 134 patients by means of ultrasonic duplex scanning over a period extending to 48 months. None of the nine deaths that occurred during follow-up was stroke related. A total of 22 arteries showed progression of disease over this period. By life-table analysis the mean annual rate of progression for all categories of disease was 12.6% and 7.4% for progression to a diameter reduction greater than 50%. Disease progression was more rapid in patients under 65 years of age. Symptoms occurred in 13 patients for an overall incidence of 10% and a mean annual rate estimated at 5%. All symptoms indicated transient ischemic attacks; there were no strokes. There was a strong relationship between the development of symptoms and stenoses greater than 80% either at the initial examination or secondary to progression. No correlation was found between the presence of bruits or their change over time and the progression or appearance of symptoms. Conservative management of nonoperated vessels opposite an endarterectomy appears appropriate until symptoms develop or a lesion greater than 80% is detected.     

Carotid endarterectomy in patients with contralateral carotid artery occlusion

The aim of this study was to evaluate the 30-day outcome of carotid endarterectomy in patients with contralateral carotid artery occlusion and compare it to that in patients with patent contralateral carotid artery. We compared 2,959 carotid endarterectomies performed in patients with patent contralateral internal carotid artery to 373 carotid endarterectomies performed in patients with occlusion of the contralateral carotid artery in the same institute between 1988 and 2004. Patient demographics, surgical and anesthesiological strategy, perioperative neurological and cardiac events, and deaths were compared. The patients were grouped and analyzed according to the presence or absence of symptoms and to their gender. No significant difference was shown in perioperative cardiological and neurological events and deaths in patients with contralateral carotid occlusion versus patients without contralateral carotid occlusion. Females had significant more neurological events than males, in both the asymptomatic (P < 0.001) and symptomatic (P = 0.02) groups. Concomitant occlusion of the contralateral carotid artery was not associated with increased risk of perioperative cardiological or neurological adverse events. However, female gender was associated with higher risk for adverse neurological events.     

Natural history of carotid artery stenosis contralateral to endarterectomy: results from two randomized prospective trials

PURPOSE: A few nonrandomized studies have reported the natural history of carotid artery stenosis (CAS) contralateral to carotid endarterectomy (CEA). This study analyzed this condition with data from two randomized prospective trials. METHODS: The contralateral carotid arteries in 534 patients from two randomized trials that compared CEA with primary closure versus patching were followed up clinically and with duplex ultrasound scanning at 1 month and then every 6 months. CAS was classified as less than 50%, 50% to 79%, 80% to 99%, and occlusion. Late contralateral CEA was performed to treat significant CAS. Progression was defined as progress to a higher category of stenosis. Kaplan-Meier life table analysis was used to estimate freedom from progression of CAS. The correlation of risk factors and CAS progression was also analyzed. RESULTS: Of 534 patients, 61 had initial contralateral CEA and 53 had contralateral occlusion. Overall, CAS progressed in 109 of 420 patients (26%) at mean follow-up of 41 months. Progression of CAS was noted in 5 of 162 patients (3%) with baseline normal carotid arteries. CAS progressed in 56 of 157 patients (36%) with less than 50% stenosis versus 45 of 95 patients (47%) with 50% to 79% stenosis (P =.003). Median time to progression was 24 months for less than 50% CAS, and 12 months for 50% to 79% CAS (P =.035). At 1, 2, 3, 4, and 5 years, freedom from disease progression in patients with baseline CAS <50% was 95%, 78%, 69%, 61%, 48%, respectively, and in patients with 50% to 79% CAS was 75%, 61%, 51%, 43%, and 33%, respectively (P =.003). Freedom from progression in patients with baseline normal carotid arteries at 1 through 5 years was 99%, 98%, 96%, 96%, and 94%, respectively. Late neurologic events referable to the CCA were infrequent (28 of 420 [6.7%] in the entire series; 28 of 258 [10.9%] patients with contralateral CAS), and included 10 strokes (2.4%) and 18 transient ischemic attacks (4.3%). However, late contralateral CEA was performed in 62 patients (62 of 420 [15%] in the entire series; 62 of 258 [24%] patients with contralateral CAS). Survival rates were 96%, 92%, 90%, 87%, and 82%, respectively, at 1 through 5 years. CONCLUSIONS: Progression of CCA stenosis was noted in a significant number of patients with baseline contralateral CAS. Serial clinical studies and duplex ultrasound scanning every 6 to 12 months in patients with 50% to 79% CAS, and every 12 to 24 months in patients with 50% or less CAS is adequate.     

Long-term results after carotid endarterectomy for carotid artery stenosis with contralateral occlusion

Patients with one internal carotid artery occlusion and a contralateral stenosis run a significantly higher risk of stroke. We performed endarterectomy of the stenotic carotid in 44 such patients and followed them for mean 54 months (range 1–172 months). Early mortality was 2%. Life-table analysis shows that the incidence of a new stroke was 0.6% per year, the survival rate was 78% after three years, and 70% after five years. We conclude that carotid endarterectomy can be safely performed in patients with contralateral internal carotid artery occlusion and can significantly improve the long-term prognosis of these patients.     

Does contralateral internal carotid artery occlusion increase the risk of carotid endarterectomy?

The results of every carotid endarterectomy performed contralateral to an internal carotid artery occlusion (n = 36) (group I) were compared with those performed contralateral to a patent internal carotid artery (n = 169) (group II) over the last 10 years. The patients in each group were evenly matched with respect to male gender (66% vs 69%); mean age (66.7 vs 65.9 years); and incidence of hypertension (55.6% vs 53.2%), diabetes (16.7% vs 20.1%), and hyperlipidemia (8.3% vs 11.8%). Patients in group I had a higher incidence of previous myocardial infarction (25% vs 11.8%, p less than 0.05) and exertional angina (55.6% vs 29.6%, p less than 0.01). Indications for carotid endarterectomy were equivalent, including stroke (19.4% vs 21.9%), transient ischemic attacks (36.1% vs 35.5%), amaurosis fugax (16.7% vs 11.8%), nonhemispheric symptoms (5.6% vs 8.3%), and asymptomatic stenoses (22.2% vs 22.5%), respectively. Perioperative strokes occurred in one (2.8%) patient in group I and seven (4.1%) patients in group II (NS). Among the patients in group II the incidence of perioperative stroke did not correlate directly with the degree of contralateral ICA stenosis: greater than 90% (4%); 70% to 90% (6.7%); 50% to 70% (8.7%); and less than 50% (2.8%). The operative mortality rate was 0% among patients in group I and 1.2% among patients in group II (NS). Cardiac complications occurred in two (5.6%) patients in group I and nine (5.3%) patients in group II (NS).(ABSTRACT TRUNCATED AT 250 WORDS)     

Carotid endarterectomy in awake patients with contralateral carotid artery occlusion.

OBJECTIVES: Patients with severe stenosis of an internal carotid artery with contralateral occlusion (ICO) are at an increased risk for stroke, and therefore surgical treatment is usually recommended. Carotid endarterectomy (CEA) under regional anesthesia enables constant monitoring of neurologic status and selective shunting in cases of clinically evident cerebral ischemia. In this study, we assess the selective use of shunts based solely on changes in neurological status in awake patients with ICO undergoing CEA as well as their complication rates. METHODS: During 1996-1998, we studied intraoperative findings and results of CEA under regional anesthesia with clinical monitoring of neurological status in two groups: (1) patients with stenosis (> 70% by NASCET) and contralateral occlusion (n = 50) and (2) patients with stenosis and no contralateral occlusion (n = 94). RESULTS: Shunt insertion was required in 42% of group 1, and 6% in group 2. All of the patients in group 1 requiring shunts had stump pressures < 50 torr. The average stump pressure of group 1(40 torr) was significantly lower than that of group 2 (75 torr), and was also lower than that of patients with severe contralateral stenosis (35 patients, 76 torr). Perioperative stroke rates were identical in both groups (2.1%). CONCLUSION: Since ICO patients are at a high risk for brain ischemia during ICA clamping, they require shunt insertion frequently. Patients with no contralateral occlusion require shunting at a much lower rate - even in the presence of severe contralateral stenosis. Regional anesthesia allows for early detection of brain ischemia and therefore, the perioperative results in both groups are similar.     

Carotid endarterectomy contralateral to carotid artery occlusion: analysis from a randomized study

BACKGROUND AND AIMS: Many studies have reported the benefits of carotid endarterectomy (CEA) contralateral to an occluded internal carotid artery (ICA), with varying results. This study analyzed perioperative and late outcomes in a recent trial in which patients were randomized to carotid eversion endarterectomy (CEE) or traditional CEA with patching (CEAP). PATIENTS AND METHODS: In 336 primary CEAs (310 patients) 68 were contralateral to an occluded ICA (group I). The remaining 268 CEAs served as control group (group II). All patients underwent clinical follow-up and duplex ultrasonography at 1, 6, and 12 months and every year thereafter. Endpoints of the study were early and late neurological events, and deaths. RESULTS: Group I had a significantly higher incidence of perioperative electroencephalic changes and need for shunting. The perioperative stroke rate in group I was almost three times as high as in group II, but the difference was not significant. Similarly, the perioperative minor neurological event and death rates, as with the cumulative stroke-free and survival rates at 1, 3, and 5 years, were comparable in the two groups. CONCLUSIONS: CEA contralateral to an occluded ICA can be implemented with perioperative stroke and mortality rates and late stroke-free and survival rates comparable to CEA with no contralateral ICA occlusion.     

Fate of the carotid artery contralateral to endarterectomy

The management of internal carotid artery disease contralateral to endarterectomy is highly controversial. At our institution we have adopted an approach by which patients are followed with serial duplex scanning after unilateral carotid endarterectomy. Surgery on the contralateral carotid artery is recommended for patients who exhibit ischemic neurologic symptoms or develop an 80% to 99% carotid stenosis. This strategy is based on previous reports that have documented an increased incidence of strokes in these two groups of patients. As a result, 40 patients among a study population of 200 underwent carotid endarterectomy on the originally unoperated side. The current study reviews the natural history of the patients who were followed without or before operation of the contralateral carotid artery in an attempt to identify other cohorts at increased risk for stroke. Patients were followed for up to 126 months after unilateral carotid endarterectomy (mean, 54 months). Six patients were lost to follow-up (3.0%). By life-table analysis the estimated mean annual rate of progression to greater than or equal to 50% diameter reduction was 3.9% and 1.2% for progression to greater than or equal to 80% stenosis. Only two patients went on to occlusion during follow-up. Neurologic events referable to the contralateral carotid distribution were infrequent. The estimated mean annual rate was 2.9% for transient ischemic attacks and less than 0.8% for strokes. Case history review of the six patients who had strokes during follow-up suggested that only one patient may have benefited from carotid endarterectomy. Conservative management with serial duplex scanning of the unoperated, contralateral carotid artery appears appropriate.(ABSTRACT TRUNCATED AT 250 WORDS)     

Carotid endarterectomy in patients with contralateral carotid occlusion

Total occlusion of the contralateral internal carotid artery has often been considered to be a predictor of adverse neurologic outcomes following carotid endarterectomy of an ipsilateral carotid stenosis. Results from both the North American Symptomatic Carotid Endarterectomy Trial and the Asymptomatic Carotid Atherosclerosis Study have suggested this to be true. However, each of these trials had relatively few patients with contralateral occlusion in the surgical arms of the studies. In contrast to these studies, there are multiple surgical series in the literature demonstrating excellent results of carotid endarterectomy in patients with contralateral total occlusion. Recently, advocates of carotid angioplasty and stenting have suggested that this technique may be preferable in patients with a contralateral occlusion because of the perceived poor outcomes with surgery. As carotid angioplasty and stenting becomes more popular, it is becoming even more crucial to better define those patients who are truly at increased risk following carotid endarterectomy; ultimately, this will help clinicians decide which patients may derive the most benefits from endovascular therapies. With these issues in mind, the purpose of this review is to examine results of carotid endarterectomy in patients with total occlusion of the contralateral carotid artery.     

Carotid endarterectomy in patients with contralateral internal carotid artery occlusion without intraoperative shunting

BACKGROUND: Controversy about the optimal method of performing a carotid endarterectomy (CEA) exists despite its widespread application and support from various randomized clinical trials. Many surgeons selectively or routinely use electroencephalography (EEG) monitoring as well as shunting when performing this operation. ETHODS: We conducted this retrospective study to assess the maximum carotid clamp time without shunting or EEG monitoring during a CEA without the development of neurological deficits in an already compromised cerebral circulation. RESULTS: Fifteen consecutive patients who underwent CEAs between 1988 and 1999 met our criteria of angiographically documented ipsilateral internal carotid artery (ICA) stenosis with contralateral ICA occlusion. The patient presentations included asymptomatic (14%), transient ischemic attack (TIA) (50%), and stroke (36%). All patients were operated under general anesthesia without shunting and only 4 patients underwent EEG monitoring. On angiography, all 15 patients had ipsilateral ICA stenosis (70-99%) and contralateral occlusion. In 54% of patients, the vertebral arteries (VAs) were both patent, while in 46% of patients only 1 VA was patent. Eighty-five percent of patients had at least 1 patent anterior communicating (Pcomm) artery, while 15% had nonvisualized Pcomm arteries bilaterally. Of the 15 patients, 14 had a patent anterior communicating artery. The mean clamp time of the CCA was 18.5 minutes (range 14-30 minutes). None of the 15 patients had new neurological changes immediately postoperatively or during the 6 weeks of follow-up. CONCLUSION: We propose that shunting may not be necessary during CEA for high-grade stenosis with contralateral ICA occlusion, presumably because of adequate distal small vessel collaterals.     

Risk of stroke for carotid endarterectomy patients with contralateral carotid occlusion

The role of a contralateral carotid occlusion in the appearance of neurological complications after carotid endarterectomy (CEA) operations is a matter of some debate. In the North American Symptomatic Carotid Endarterectomy Trial, the risk of perioperative stroke was found to be higher in patients with a contralateral carotid occlusion. In a literature survey in 2004, however, a significantly increased risk of perioperative stroke was found in only one out of 17 studies on contralateral carotid occlusion patients. We therefore examined the frequency of stroke in patients with contralateral carotid occlusion at our own institution and performed a meta-analysis based on 19 representative studies, including the data from our own institution. Out of 1,960 CEAs at the authors' institute, a significantly higher frequency of 5.6% compared to 2.1% (p = 0.012) for perioperative stroke risk was seen in patients with contralateral carotid occlusion compared to those without. The meta-analysis, based on 19 studies, also showed in 13,438 CEA operations a significantly higher perioperative stroke rate of 3.7% compared to 2.4% (p = 0.002) in the presence of a contralateral carotid occlusion. Nevertheless, due to the extremely poor outcomes of medically treated symptomatic patients, a surgical or endovascular procedure should be sought for these patients. Since the superiority of angioplasty/stent procedures has not yet been verified compared to surgical procedures in these patients, special indication for an endovascular procedure should also be taken into consideration.     

Does contralateral carotid occlusion influence neurologic fate of carotid endarterectomy?

Divergent opinions regarding operative risks and late prognosis of patients undergoing endarterectomy for carotid stenosis with contralateral carotid occlusion have prompted a review of the experience at Emory University Hospital from Jan. 1, 1978, through Dec. 31, 1982. Fifty-four patients (37 men, 17 women; mean age 63 years) who underwent carotid endarterectomy (CEA) with contralateral carotid occlusion (group I) were compared with 410 demographically similar patients without contralateral carotid occlusion (group II) who underwent 503 CEAs during the same interval. CEA indications in group I were the following and were proportionately similar to those of group II: hemispheric transient ischemic attacks, 22 patients; asymptomatic stenosis, 12 patients; nonhemispheric symptoms, 11 patients; previous cerebral infarction, eight patients; and vascular tinnitus, one patient. General anesthesia, routine intraluminal shunting, systemic heparinization, and arteriotomy closure without patch were routinely employed in both groups. Three patients in group I suffered permanent neurologic deficits after operation (5.6%) and two had transient postoperative deficits with complete recovery. Ten patients (2.0%) in group II suffered permanent neurologic deficits and 10 patients experienced transient neurologic events after operation. Neither the transient nor the permanent neurologic deficit rates were statistically different (p greater than 0.05; Fisher exact test) in the two groups. Operative mortality rates for group I and group II were 0% and 0.8%, respectively, and were not significantly different (p greater than 0.10; Fisher exact test). Late postoperative ischemic brain infarctions occurred in two patients in group I (3.8%) and in 13 patients (3.6%) in group II (p greater than 0.10; Fisher exact test). Kaplan-Meier survival analyses were virtually identical in both groups, with the majority of deaths caused by cardiac occlusion may undergo CEA with morbidity and mortality rates similar to those without contralateral occlusions. Contralateral carotid occlusion does not necessarily portend an unfavorable early or late prognosis after CEA.     

Internal carotid artery occlusion: operative risks and long-term stroke rates after contralateral carotid endarterectomy.

BACKGROUND. To determine the short- and long-term benefits of carotid endarterectomy (CEA) contralateral to an occluded internal carotid (ICA), we reviewed our experience since 1976. METHODS. In 66 (13.8%) of 478 patients undergoing 544 CEAs, the contralateral ICA was occluded. Mean follow-up was 50.1 months (range, 1 to 165 months). Complete follow-up was available in 83.0% of patients. RESULTS. Operative death occurred in one (1.5%) of 66 patients with contralateral occlusion and six (1.3%) of 478 patients without contralateral occlusion (p = 0.99). Operative strokes occurred in two (3.0%) of 66 patients with contralateral occlusion and 14 (2.9%) of 478 without contralateral occlusion (p = 0.99). Life-table stroke-free rates at 1, 3, 5, and 8 years were 96.8%, 93.0%, and 93.0% in patients with contralateral occlusion and 95.9%, 94.2%, 91.1%, and 88.0% in patients without contralateral occlusion (p = 0.36). Five- and 8-year stroke-free rates were 100% and 100% in the asymptomatic subgroup with occlusion, 95.9% and 92.2% in the asymptomatic subgroup without occlusion (p = 0.45), 91.2% and 91.2% in the symptomatic subgroup with occlusion, and 89.7% and 86.8% in the symptomatic subgroup without occlusion (p = 0.47). Life-table survival rates at 5 and 8 years were 72.5% and 56.0% in patients with contralateral occlusion and 81.8% and 69.0% in patients without contralateral occlusion (p = 0.15). CONCLUSIONS. CEA performed in patients with and without symptoms with a contralateral ICA occlusion produces short- and long-term mortality and stroke morbidity rates comparable to those of similar patients without contralateral ICA occlusion. The indications for CEA in patients with contralateral ICA occlusion should not differ from those applied to patients without contralateral occlusion.     

Carotid artery endarterectomy in patients with contralateral carotid artery occlusion: Perioperative hazards and late results

The aim of this study was to analyze and compare the perioperative hazards and late results of internal carotid endarterectomy (CEA) in patients with and without contralateral internal carotid artery occlusion. From March 1980 to April 1990, 375 consecutive patients underwent 439 CEAs at the First Department of Vascular Surgery of Padova Medical School. Patients were divided into two groups; group 1 (61 patients) had contralateral internal carotid artery occlusion and group 2 (314 patients) did not (378 CEAs, 64 bilateral). Indications for CEA were similar in both groups. The only significant difference in patient characteristics was a higher rate of previous stroke in group 1 (11% vs. 3%,p < 0.001). General anesthesia, continuous EEG monitoring, selective intraluminal shunt, and arteriotomy closure with a polytetrafluoroethylene patch (PTFE) were used routinely in both groups. An intraluminal shunt was inserted more frequently in group 1 than in group 2 (69% vs. 17%,p <0.001). Major perioperativestroke occurred in one patient in each group (1.7% vs. 0.31%, respectively; NS). Early fatal stroke rates were 0% and 0.95% in groups 1 and 2, respectively (NS). All patients had neurologic examinations and duplex scans every 6 months (range 6 to 118 months; mean 42 months). Kaplan-Meier survival curves were virtually identical in the two groups; the majority of deaths were caused by myocardial infarction and cancer. There were no stroke-related deaths in group 1 as compared with 8.2% in group 2 (NS). New neurologic symptoms appeared in 4.7% of patients in group 1 and 6% in group 2 (NS) whereas the late stroke rates were 0% and 3.1%, respectively (NS). Restenosis was observed in two and three patients in groups 1 and 2, respectively (NS). In conclusion, CEA for ulcerated or stenotic lesions of the internal carotid artery in patients with contralateral carotid occlusion is associated with very low early and long-term neurologic morbidity and mortality, similar to findings in patients who undergo CEA with a patent contralateral carotid artery.     

Delayed postoperative nonembolic neurologic deficit after left internal carotid endarterectomy in presence of known contralateral carotid artery occlusion

Neurologic sequelae are known complications of carotid endarterectomy. The current overall perioperative stroke rate is 2-5% (1,2). The incidence of perioperative morbidity and mortality is increased in certain patient subgroups, including neurologically unstable patients and patients who have known contralateral common or internal carotid artery occlusion (3-9). We present the case of a patient who had known total right carotid artery occlusion and a known previous right cerebrovascular accident who sustained a contralateral deficit after a left internal carotid thromboendarterectomy with vein patch angioplasty.     

Carotid endarterectomy with contralateral carotid artery occlusion: is this a higher risk subgroup?

OBJECTIVE: to evaluate early and mid-term term results of carotid endarterectomy (CEA) in patient with and without contralateral carotid occlusion. METHODS: between 1996 and 1999, 1324 CEAs were performed. In 82 patients contralateral carotid artery occlusion was present (group I); 1242 patients had patent contralateral carotid (group II). All patients were operated under general anaesthesia, and selective shunting was based on somatosensory evoked potentials (SEPs). Ultrasonographic follow-up was performed at 1, 6 and 12 months and then once a year. Early results and follow-up data were analysed retrospectively. RESULTS: in group I there was a significantly higher incidence of SEPs reduction and shunt insertion; however, there were no differences in terms of perioperative complications. The cumulative stroke and death rate at 30 days in group 1 and group 2 were 2.4% vs 1.4% (p=n.s.), respectively. At a mean follow-up of 15 months there were no differences between the two groups in terms of cumulative symptom-free survival. CONCLUSIONS:the presence of contralateral carotid occlusion caused an increased use of shunt, but not in early complications rates.     

颈内动脉完全闭塞的手术治疗

目的 探讨颈动脉血运重建治疗完全性颈内动脉闭塞的临床疗效.方法 2001年6月～2010年4月,收治颈动脉狭窄患者397例,术前行磁共振血管造影(MRA)检查,确诊并行颈动脉内膜切除术(CEA)治疗颈内动脉闭塞患者28例,术中切除标本送病理检查,术后复查颈部MRA,并对术后情况进行随访.结果 术后即时通畅率为92.8％,术后平均随访时间10个月,22例颈内动脉通畅,通畅率为78.5％,无脑缺血事件发生;6例颈内动脉闭塞患者中,2例在术后4个月发生短暂性脑缺血及腔隙性梗死;3例术后仍偶有头晕,其中2例单侧肢体麻木;1例记忆力减退.结论 对于有症状的颈内动脉闭塞患者,CEA加取栓术是安全有效的方法.     

Influence of the contralateral carotid artery on neurologic complications following carotid endarterectomy

To examine the effect of contralateral carotid artery stenosis on postoperative events, a retrospective review was made of 451 patients undergoing 510 carotid endarterectomies during a 6-year period. Three degrees of contralateral carotid stenosis were identified radiologically: 0% to 49%, 50% to 99%, and totally occluded. Each group was further separated into two categories according to preoperative symptoms. "Low risk" included asymptomatic lesions, transient ischemic attacks, and nonhemispheric symptoms; "high risk" described poststroke patients and urgent operations. The results show the incidence of stroke or death was not increased in patients with severely stenosed or occluded contralateral vessels in either low- or high-risk patients (p = 0.741 and p = 0.561, respectively). Patients in the high-risk category, however, had a significantly higher risk of postoperative complications than patients in the low-risk category (p less than 0.001). The study reaffirms that preoperative indications have a major influence on surgical outcome and suggests that the status of the contralateral artery has little bearing on postoperative events.