Carotid endarterectomy (CEA) is an effective surgical intervention for reducing long-term risk for stroke in patients with symptomatic and asymptomatic carotid artery stenosis (CAS) [1,2]. In its latest guidelines, published in 2023, the European Society of Vascular Surgery (ESVS) [3] stated that elderly patients >80 years of age were a “high-risk” patient group (both in symptomatic and asymptomatic significant CAS) that may not gain the benefit of late stroke prevention and recommended best medical treatment (BMT) only. This was clearer in asymptomatic CAS patients with a life expectancy <5 years; however, it is less clear in symptomatic octogenarians (i.e., those in their 80s [ninth decade of life]) with CAS, and the benefit of CEA has long been questioned [4].

However, the ESVS guidelines [3] are based on subgroup analysis of data from the Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) [5] and the Asymptomatic Carotid Artery Surgery Trial (ACST1) [6] studies, which, together with data from other randomized clinical trials (RCTs) that contributed to current guidelines, are approximately two decades old. In contrast, a recent RCT reported that both perioperative and long-term risks for stroke/death have decreased in patients who underwent CEA, in addition to significant improvements in BMT, diagnostic methods, and patient selection [7].

In 2021, the United Kingdom (UK) Office for National Statistics [8] reported a continued increase in model age at death, with an average of 86.7 and 89.3 years for males and females, respectively, which was projected to increase further. This is reflected in the daily practices of vascular surgeons in the UK and worldwide.

A recent Japanese study [9] questioned whether octogenarians continue to be at high risk for adverse outcomes after CEA in the era of super-aged societies and the ongoing demand to perform CEA in this patient cohort and reported good short- and medium-term outcomes. Furthermore, an Italian study [10] concluded that long-term relative survival after CEA in octogenarian patients was better than that in the age- and sex-matched population; therefore, the possibility of living long enough to benefit from CEA may not necessarily be compromised by being very elderly.

Studies investigating CEA in octogenarians are needed to update the current guidelines for this patient cohort, especially in the current aging population, in which the number of octogenarians is expected to triple by 2050 [11].

The aim of the present study was to assess the short (up to 1 year), medium (1-5 years), and long-term (>5 years) outcomes of CEA surgery in very elderly (≥80 years of age) patients in terms of overall postoperative complications, early and late stroke, morbidity, and mortality.

The study is a retrospective study and all patients’ data were collected anonymously as outlined in the Declaration of Helsinki.

Consecutive patients, who underwent CEA at a single center (The Lister Hospital, East and North Hertfordshire NHS Trust, Stevenage, UK) between April 2016 and April 2022, were identified from a prospectively maintained electronic operating room database. The authors’ institution is a tertiary center for stroke referral and covers a population of approximately 800,000. Only patients who were ≥80 years of age on the day of their CEA surgery were included in the study. The exclusion criteria were CEA patients <80 years of age and those who underwent carotid artery stenting.

Data from patient medical notes, electronic hospital databases, and hospital radiology systems were retrospectively reviewed. Clinical characteristics, such as age, sex, ischemic heart disease, peripheral arterial disease, hypertension (HTN), diabetes mellitus (DM), chronic kidney disease (estimated glomerular filtration rate <60 mL/min/1.73 m²), smoking, and alcohol consumption were collected. Demographic characteristics and associated risk factors are summarized in Table 1. Carotid duplex ultrasound, and either brain computed tomography (CT) or magnetic resonance imaging (MRI), were performed in all patients preoperatively. Duplex criteria for carotid stenosis exceeding 70% were as follows: peak systolic velocity ≥230 cm/s; end diastolic velocity, ≥70 cm/s; or an internal carotid artery (ICA) to common carotid artery ratio ≥3.2 [12]. Additional preoperative cross-sectional carotid imaging data were also collected. Indications for CEA and the time from the event to surgery were recorded.

Table 1 . Demographics and comorbidities according to sex.

	Total (n=70)	Sex		χ2	P-value
		Male (n=47)	Female (n=23)
ASA
Grade 2	23 (32.9)	18 (38.3)	5 (21.7)	1.919	0.166
Grade 3	47 (67.1)	29 (61.7)	18 (78.3)
Diabetes mellitus	20 (28.6)	13 (27.7)	7 (30.4)	0.058	0.809
Hypertension	46 (65.7)	29 (61.7)	17 (73.9)	1.022	0.312
Renal disease (eGFR<60)	15 (21.4)	7 (14.9)	8 (34.8)	3.628	0.070a
Ischemic heart disease	24 (34.3)	19 (40.4)	5 (21.7)	2.393	0.122
Cholesterol/hyperlipidaemia	12 (17.1)	9 (19.1)	3 (13.0)	0.405	0.738a
Smoker	42 (60.0)	26 (55.3)	16 (69.6)	1.306	0.253
Alcohol	34 (48.6)	27 (57.4)	7 (30.4)	4.511*	0.034*
Respiratory Hx COPD/asthma	10 (14.3)	8 (17.0)	2 (8.7)	0.874	0.480a
Afib Hx	13 (18.6)	8 (17.0)	5 (21.7)	0.227	0.746a

Values are presented as number (%)..

P-value for comparing between sex..

χ², chi square test; ASA, American Society of Anesthesiologists; eGFR, estimated glomerular filtration rate; Hx, history; COPD, chronic obstructive pulmonary disease..

^aFisher exact. *Statistically significant at P≤0.05..

All patients were discussed at a vascular multidisciplinary team (MDT) meeting, if time permitted. However, surgery progressed if waiting for the MDT would delay CEA within 14 days from the event to surgery after being discussed with stroke and radiology consultants and deemed indicated. When surgery was recommended, informed consent was obtained from the patient and their family (if the patient wished). Patients were reviewed by a consultant anesthetist who requested further tests for preoperative assessment or optimized patients preoperatively before surgery and classified patients according to American Society of Anesthesiologists (ASA) grade. General anesthetic (GA) and local anesthetic (LA) techniques were available and discussed with the patients. If a patient was found to be at very high risk (ASA grade 4), further discussions were held among the patient, stroke consultant, and surgeon(s). If deemed unsuitable for the procedure, this decision was reviewed again at the vascular MDT. Management for these patients was maintained at the BMT level, which included antiplatelet medication (aspirin 300 mg for 14 days’ post-event, then converted to 75 mg clopidogrel indefinitely), smoking cessation, lipid-lowering drugs (40 mg statin with 6 monthly checks and dose adjustment accordingly), and management of other risk factors, such as control of HTN and DM. Patients deemed to be at a very high risk for recurrent symptoms were referred to a tertiary center for consideration of carotid stenting (CS). Patients with indications for CEA were managed preoperatively by the stroke team and underwent BMT. The patients were administered aspirin (300 mg) at presentation, which was converted to clopidogrel (75 mg) postoperatively.

All patients were administered a minimum of 5,000 units intraoperative heparin, and shunt usage was considered in all cases undergoing GA and in some involving LA in which patient cerebral function deteriorated intraoperatively. Surgical details, including type of anesthesia, use of shunt/patch, any unexpected finding(s), nerve injury, major bleeding, or stroke after recovery from anesthesia, were collected from patient operative records. Postoperatively, all patients were monitored in a high-dependency unit (HDU) for at least 24 hours. Metaraminol and labetalol infusions were used to maintain blood pressure (BP) within the requisite postoperative range of 100-160 mmHg systolic BP, in accordance with our hospital’s established protocol for BP control. Any postoperative mortality or morbidity, including stroke, was collected from medical notes, discharge letters, and/or outpatient letters.

A post-discharge duplex ultrasound was arranged within 4 weeks to ensure resolution of stenosis. Patients were reviewed on an outpatient basis by both the surgical and stroke teams 6 weeks post-CEA. A routine follow-up carotid duplex was performed 12 months post-CEA. Patients were discharged from further vascular follow-up if no additional monitoring was necessary. Late-stroke data were collected from the hospital’s imaging system, a local electronic clinical notes and letters system, and general practitioner letters. Late mortality data were collected in April 2023 from the electronic database system of the local national health service trust.

1) Definitions

ASA grade 2: patients with mild systemic disease, with no functional limitations and well-controlled chronic disease (e.g., treated HTN, obesity with body mass index <35 kg/m², social alcohol drinker, and/or cigarette smoker [13]).

ASA grade 3: patients with a severe systemic disease that is not life-threatening with some functional limitations (e.g., poorly controlled HTN or DM, morbid obesity, chronic renal failure, bronchospastic disease with intermittent exacerbation, stable angina, or an implanted pacemaker [13]).

ASA grade 4: severe systemic disease that is a constant threat to life (e.g., unstable angina, poorly controlled chronic obstructive pulmonary disease, symptomatic congestive heart failure, and recent [<3 months ago] myocardial infarction [MI] [13]).

2) Statistical analysis

Data were analyzed using SPSS version 20.0 (IBM Corp.). Qualitative data are expressed as number and percentage. The chi-squared test was used to compare the two groups; alternatively, Fisher exact or Monte Carlo correction tests were applied when the expected cell count was <5. Continuous data were tested for normality using the Shapiro–Wilk test. Data are expressed as range (minimum and maximum), mean±standard deviation, and median. Student t-test was used to compare normally distributed quantitative variables between the two groups. The Mann-Whitney test was used to compare two groups with quantitative variables that were not normally distributed. Kaplan-Meier (K-M) curves were used for survival analysis to compare the two groups using the log-rank test. Differences with P≤0.05 were considered to be statistically significant.

A total of 258 CEAs were recorded during the 6-year study period, of which 70 (27.1%) were performed in patients ≥80 years of age and included in the current study. This included 66 octogenarians (i.e., 80-89 years of age) and 4 nonagenarians (i.e., ≥90 years of age) on their surgery dates. The mean age was 84 years (range, 80-96 years), with the majority being male (67.1%). There was no statistical difference between males and females in terms of demographics and comorbidities (Table 1), except for higher alcohol intake (>14 units per week) in males (P=0.034). Patients were stratified according to ASA grade: grade 2, 23 (32.9%); grade 3, 47 (67.1%).

Preoperative brain imaging was performed in all patients, with 17 (24.3%) undergoing MRI and 64 (91.4%) undergoing CT. Acute ipsilateral infarcts were observed in 55 (78.6%). Carotid imaging methods included carotid duplex ultrasonography for 29 (41.4%), CT angiography for 24 (34.3%), and magnetic resonance angiography for 17 (24.3%). The degrees of ipsilateral and contralateral carotid artery stenosis are detailed in Table 2.

Table 2 . Degree of ipsilateral and contra-lateral carotid stenosis.

Degree of carotid stenosis (%)	Ipsilateral (operative side) carotid stenosis	Contralateral stenosis
100	0 (0.0)	1 (1.4)
70-99	43 (61.4)	10 (14.3)
60-69	17 (24.3)	8 (11.5)
50-59	10 (14.3)	4 (5.7)
<50	0 (0.0)	47 (67.1)
Grand total	70 (100.0)	70 (100.0)

Values are presented as number (%)..

Most of the patients (69/70, 98.6%) were symptomatic, with limb weakness observed in 29 (41.4%). Dysphagia and amaurosis fugax was diagnosed in 12 (17.1%) patients, lower face symptoms in 5 (7.1%), and combined limb, speech, and amaurosis fugax in 11 (15.7%). Only 1 patient (82 years of age) underwent CEA for asymptomatic CAS (70%-99%), who had symptomatic contralateral carotid occlusion, and the MDT decided that intervention was necessary to prevent bilateral occlusion. In 63 patients (91.3% of 69 symptomatic patients), the time from the event to surgery (Table 3) was within the recommended 2-week timeframe, as per the ESVS guidelines [3]. Additionally, 6 CEAs were performed beyond 2 weeks because of delayed referral.

Table 3 . Time from event to carotid endarterectomy.

Event to surgery in day	Patient count (n)	Percentage (69 symptomatic)
1-7 d	47	68.1
8-14 d	16	23.2
15-21 d	4	5.8
1-2 mo	2	2.9
Asymptomatic	1	N/A
Grand total	70	100

N/A, not applicable..

Forty-one (58.6%) patients underwent CEA under LA, of whom 4 (9.7%) required a Javid shunt due to intraoperative cerebral function deterioration. In contrast, shunts were used in 25 of 29 (86.2%) patients who underwent surgery under GA.

When surgery was performed under LA, no shunt was used unless the patient developed reduced cerebral function while clamping the ICA. When GA was induced, shunt placement was standard. However, due to technical reasons (small distal ICA), no shunt was used in 4 (5.7%) patients with GA, none of whom experienced 30-day stroke. A patch was used in 67 (95.7%), but direct closure was performed (3 cases) with poorly tolerated LA to reduce surgery time (with adequate artery size). Neither sex nor ASA grade exhibited any statistical association with the type of anesthesia or the use of shunts or patches (Table 4).

Table 4 . Operative details according to ASA grade.

	Total (n=70)	ASA		P-value
		Grade 2 (n=23)	Grade 3 (n=47)
Local anaesthesia	41 (58.6)	15 (65.2)	26 (55.3)	0.430
General anaesthesia	29 (41.4)	8 (34.8)	21 (44.7)
Shunt	29 (41.4)	7 (30.4)	22 (46.8)	0.191
Patch	67 (95.7)	22 (95.7)	45 (95.7)	>0.999a

Values are presented as number (%)..

ASA, American Society of Anesthesiologists..

^aFisher exact..

Fifty-five (78.6%) patients experienced an uneventful postoperative recovery. There were no immediate (<24 hours) deaths. One (1.4%) patient experienced a stroke (contralateral limb weakness) at <24 hours, which was recorded when the patient recovered from GA. The patient was re-intubated and re-explored; however, no carotid thrombus was found, and brain CT revealed an ipsilateral ischemic stroke. The modified Rankin Scale (MRS) score increased from 1 to 3. Overall, 30-day stroke was recorded in 3 (4.3%) patients, of whom 1 (1.4%) died within 30 days postoperatively (day 10) secondary to aspiration pneumonia (MRS score increased from 2 to 6). Another patient developed facial drooping on day 2, which improved within a few days, with no changes in MRS score 2. All of the recorded 30-day strokes were ipsilateral ischemic in nature. The mean postoperative HDU stay was 1.46±0.91 days. ASA grade did not exhibit any statistically significant association with the above-mentioned events.

Other minor postoperative complications (Table 5) were observed in 13 (18.6%) patients, which were slightly higher in the ASA grade 2 group but without a statistically significant difference.

Table 5 . Postoperative morbidity and mortality, length of hospital stay, and week-4 duplex ultrasonography.

	Total (n=70)	ASA 2 (n=23)	ASA 3 (n=47)	P-value
Immediate (<24 h) stroke	1 (1.4)	0 (0.0)	1 (2.1)	>0.999a
HDU (d)				0.442
Mean±standard deviation	1.46±0.91	1.26±0.45	1.55±1.06
Median (minimum-maximum)	1 (1-6)	1 (1-2)	1 (1-6)
30 days stroke	3 (4.3)	1 (4.3)	2 (4.3)	>0.999a
30 days death	1 (1.4)	0 (0.0)	1 (2.1)	>0.999a
Other complications 30 days	13 (18.6)	7 (30.4)	6 (12.8)	0.279a
Hypertension (>160 mmHg SBP)	2 (2.9)	1 (4.3)	1 (2.1)	>0.999a
Hypotension (<100 mmHg)	1 (1.4)	1 (4.3)	0 (0.0)	0.329a
Confusion	1 (1.4)	1 (4.3)	0 (0.0)	0.329a
Respiratory infection	4 (5.7)	3 (13.0)	1 (2.1)	0.100a
Voice hoarseness, Vagus nerve traction	1 (1.4)	1 (4.3)	0 (0.0)	0.329a
Minor wound complication, numbness/minor bleeding	3 (4.3)	0 (0.0)	3 (6.4)	0.546a
Total stay (d)
Mean±standard deviation	3.94±3.55	4.78±5.18	3.53±2.37	0.870
Median (minimum-maximum)	2 (1-21)	2 (1-21)	2 (1-10)
Week 4 duplex U/S result
No stenosis	61 (87.1)	20 (87.0)	41 (87.2)	0.298b
<30% stenosis	6 (8.6)	1 (4.3)	5 (10.6)
30%-49% stenosis	3 (4.3)	2 (8.7)	1 (2.1)
Late Ipsilateral stroke	3 (4.3)	2 (8.7)	1 (2.1)	>0.999a

Values are presented as number (%)..

ASA, American Society of Anesthesiologists; HDU, high-dependency unit; SBP, systolic blood pressure; duplex U/S, duplex ultrasound..

^aFisher exact. ^bMonte Carlo..

In the routine 4-week postoperative carotid duplex examination, most patients exhibited no residual narrowing and no statistical association with ASA grade (Table 5).

Late ipsilateral stroke was recorded in 3 (4.3%) patients, which included 1 who experienced an ischemic stroke 32 months postoperatively and survived 41 months after surgery. Another patient experienced a hemorrhagic stroke 32 months postoperatively and survived for 1 month, while the third patient experienced a fatal hemorrhagic stroke 43 months postoperatively. Three (4.3%) patients were lost in follow-up after six weeks due to a change in address and move to another health trust; nevertheless, major event data were collected. The overall mean follow-up for data collection was 50.5±17.9 months. At 1, 3, and 5 years, the cumulative freedom-from-stroke rate was 95.7%, 92.9%, and 91.4%, respectively, and the cumulative survival rates were 94.3%, 75.7%, and 61.4%, respectively. ASA categorization did not affect stroke rate (HR, 1.006; 95% confidence interval [CI], 0.184-5.493; Fig. 1). However, the cumulative survival rate was significantly lower in those with ASA grade 3 than in those with ASA grade 2 (HR, 5.29; 95% CI, 1.590-17.603; P<0.01; Fig. 2).

Figure 1. Kaplan-Meier curve for cumulative freedom from stroke according to American Society of Anesthesiologists (ASA) grade. 95% CI, 95% confidence interval; SE, standard error; χ², chi square test.

Figure 2. Kaplan-Meier curve for cumulative survival according to American Society of Anesthesiologists (ASA) grade. 95% CI, 95% confidence interval; SE, standard error; χ², chi square test. *P<0.01.

There were 4 nonagenarians (2 male) in the current cohort, all of whom were symptomatic and ASA grade 3, and underwent CEA under LA. The mean HDU stay was 1.25 days, and the mean LoS was 2.75 days, with no recorded early (<24 hours), 30-day morbidity, 1-year stroke, or mortality. By the end of the study, 3 mortalities were recorded at 16-, 30- and, 53-months post-CEA, respectively, and only 1 (25.0%) patient was alive (57 months post-surgery). The mean survival was 39 months and none of the patients experienced late stroke.

The current study examined CEA practice involving octogenarians and nonagenarians at a tertiary vascular center and outcomes up to 84 months’ post-CEA surgery. According to the World Health Organization [11], there is no “typical older person” as some octogenarians may have mental and physical capacities similar to those of 30-year-olds. Life expectancy is increasing globally, and clinicians more often encounter elderly, high-risk patients. Therefore, CEA is becoming increasingly important to perform on elderly patients [9]. Many landmark CEA trials investigating both symptomatic and asymptomatic carotid diseases have excluded patients older than a specific age [14]. Both the North American Symptomatic Carotid Endarterectomy (NASCET) [15] and ACST1 [16] studies initially excluded patients >79 years of age (although NASCET later changed the exclusion criteria and permitted octogenarians to enter the study within the last 6 years of recruitment [17]).

Outside of such trials, given the increasing demand for CEA in high-risk groups, including octogenarians, and the lack of sufficient evidence-based data, octogenarians have become a significant population in CEA practice [9,10,18-22].

In the current study, we reported 30-day postoperative stroke and combined 30-day stroke and death rates of 4.3%. Our 30-day stroke rate may be marginally higher than that reported in the ESVS guidelines (3%) [3], which included all patients of different ages. However, it may be acceptable considering our mainly symptomatic high-risk elderly subgroup and is consistent with studies by Stoner et al. [18] and Ting et al. [19], who reported combined 30-day stroke and death rates of 5% and 6.8%, respectively, in patients >80 years of age, versus 3.5% and 2.8%, respectively, in those <80 years of age. Other studies, such as that by Schneider et al. [14], reported lower 30-day ipsilateral stroke rates among octogenarians and nonagenarians (1.6% and 1.1%, respectively), but were still higher than those in younger patients (1.1% and 0.8%, respectively) (P<0.01). Furthermore, a recent meta-analysis [20] reported a perioperative stroke rate of 2.04% in symptomatic octogenarians.

Early (30-day) mortality was recorded in 1 (1.4%) patient in the current cohort, which is similar to the findings of Schneider et al. [14], who reported a 30-day mortality rate of 1.6%, while their younger patients (<80 years) had a lower mortality rate (0.6%) (P<0.001).

Few studies have examined long-term outcomes in octogenarians. Interestingly, a Japanese study [9] did not report any late stroke or stroke-related mortality after CEA compared to our 3- and 5-year stroke-free rates of 92.9% and 91.4%, respectively. Our results, however, were similar to those reported by Ting et al. [19], who reported a 4-year freedom-from-stroke rate in octogenarians of 94%.

Ballotta et al. [21] demonstrated a significant benefit in freedom from stroke at 5 years for their octogenarian cohort, which underwent CEA plus BMT versus BMT alone (98% vs. 84%; P=0.04), compared to 91.4% in our study, which would still be superior to their BMT-alone group. Compared to the study by Ballotta et al. [21], which exclusively focused on asymptomatic octogenarians, the majority of our patients underwent CEA for symptomatic disease, with only one asymptomatic patient. Despite the difference in freedom from stroke rates after CEA, the results could be deemed acceptable with respect to the indications for CEA in our cohort.

Regarding the long-term survival after CEA in octagenarians, several studies demonstrated the outcomes after CEA. Ting et al. [19] reported a 4-year survival rate of 78%, whereas Okawa et al. [9] reported 3- and 5-year overall survival rates of 92.9% and 61.9%, respectively, in their octogenarian cohort, compared to our 3- and 5-year cumulative survival rates of 75.7% and 61.4%, respectively. Notably, a previous study conducted by Ballotta et al. [21] demonstrated remarkably similar 5-year survival rates (66% vs. 68%) between the CEA plus BMT group and the BMT alone group. This lack of difference is likely attributed to the inherently shorter survival expected in elderly patients of this age group, compounded by other comorbidities. However, Ballotta et al. [10] reported 7-year freedom from stroke and mortality rates after CEA in octagenarian of 96.6% and 52.4%, respectively, which supports the argument that, with the ongoing increase in age, there is a continuous need to reassess the benefits of CEA in very elderly patients.

CS was an exclusion criterion in the current study, but it may be an option for symptomatic CAS in octagenarians. It was reserved for high-risk patients experiencing recurrent episodes. CS is considered to be less invasive in vulnerable age groups. However, different outcomes have been reported in the literature. The SAPPHIRE study [5] examined high-risk patients, including those >80 years of age, and reported a 5.8% stroke risk in patients with CS vs. 6.1% in patients with CEA. A recent North American study [22] based on a national registry reported a combined 30-day stroke and death rate of 6.4% in the CS group and 4.5% in the CEA group (P=0.326). However, the 30-day mortality was highly significant in the CS group (5.6% vs. 1.7%; P=0.001). An Italian study [23] described their 7-year carotid revascularization experience and reported a combined stroke, death, and procedural MI incidence of 12.5% in CS versus 11.1% in CEA, with a 3-year survival of 62% and 79% in the CS and CEA groups, respectively.

Cardiovascular complications have been the second most feared complications after CEA in this vulnerable age groups. In our study, 2 (2.9%) patients experienced persistent hypertension >160 mmHg despite medical treatment, with no recorded seizures or permanent sequelae. There were no cases of early postoperative angina or MI. Similarly, Hobbs et al. [24] recorded only 1 (2.3%) nonfatal MI in their cohort of 44 symptomatic CEA nonagenarians. In contrast, an older study [19] reported MI in 6.8% of octogenarians versus 3% in the younger group. This may represent an improvement in the perioperative management of such high-risk groups over the past two decades.

In the current study, we examined different parameters that could affect outcomes in elderly patients. ASA grade 3 was associated with a significantly shorter survival rate (Fig. 2), despite no differences in the 30-day stroke rate, early morbidity, mortality, or cumulative freedom-from-stroke at 3- or 5-years. Few studies have addressed the effect of ASA grade on CEA. Vettukattil et al. [25] suggested that patients with ASA grade >2 are as safe as those with ASA grade 2 in undergoing CEA under GA, with equivalent rates of death, stroke, and MI without age differentiation. In contrast, Pandit et al. [26] examined factors affecting frailty, such as modified frailty indices and high ASA grade >3, on CEA outcomes and concluded that they were strong predictors of postoperative complications and mortality.

The present study had some limitations, the first of which was its retrospective, single-center design. Moreover, there were no control groups, such as BMT-alone or CS. Despite careful efforts to review all data sources (including computer systems, actual patient paper records, outpatient letters, and imaging scans), our study was prone to inherent bias in retrospective data collection. This study may be prone to type II errors because there were only Three 30-day stroke patients in our cohort. In addition, long-term follow-up of K-M analysis after 5 years may be prone to an Page 8 of 9 increase in standard error >10% when more data are censored, thus reducing reliability.

CEA combined with BMT was safe and effective in patients ≥80 years of age. Higher-risk patients (i.e., ASA grade 3) were not associated with increased risk for 30-day postoperative stroke, morbidity, or mortality, but did exhibit significantly worse long-term survival, which may affect the benefit of surgical intervention in the long term. Careful patient selection and perioperative management are required for such patients, and their reduced long-term survival should be considered before CEA. More studies are needed to identify other individual factors related to increased 30-day stroke risk and 5-year mortality to help predict which octogenarians may not benefit from CEA surgery in our aging population.

The authors have nothing to disclose.

Concept and design: MM, AE. Analysis and interpretation: MM, AE. Data collection: SF, SS, AE. Writing the article: all authors. Critical revision of the article: all authors. Final approval of the article: all authors. Statistical analysis: AE. Obtained funding: none. Overall responsibility: all authors.