Annals of Vascular Surgery
Volume 24, Issue 6 , Pages 775-785, August 2010

Is Female Gender Really a Risk Factor for Carotid Endarterectomy?

Cardiovascular Surgery Department, Turkiye Yuksek Ihtisas Hospital, Ankara, Turkey

published online 13 May 2010.

Article Outline

Background

The aim of this study was to assess the effect of gender on mortality and morbidity in carotid endarterectomy (CEA) patients.

Methods

Forty-one female and 150 male patients who underwent isolated CEA operations, between 1994 and 2007, were included in this study. To find the role of gender in isolated CEA operations, patients with a previous history of cardiac operations, coronary interventions, and a staged cardiac and/or vascular operation were excluded from the study.

Results

In the postoperative period, one female patient (2.4%) and 8 male patients (4.9%) had neurological complications (p > 0.05). Hospital mortality rates of female and male groups were 0.0% and 2.4%, respectively (p > 0.05). Perioperative events which cause significant increase in hospital mortality were myocardial ischemia, low cardiac output, and need of intra-aortic balloon pump (p = 0.0001). Late mortality rates of female and male groups were 7.5% and 9.9%, respectively. The actuarial survival rate was 82.2 ± 11.6% in women and 71.5 ± 7.5% in men for a mean period of 36.4 ± 29.1 months (p > 0.05). All the observed mortalities in the long term were cardiac-related or with other causes, no neurological deaths observed in both groups (p > 0.05). According to logistic regression analysis smoking and peripheral arterial disease were found as statistically significant risk factors for late mortality.

Conclusion

Female gender is not a risk factor for stroke or death after CEA. Women should not be excluded from the benefits of CEA and gender should not be a consideration in the decision to perform it.

 

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Introduction 

Carotid endarterectomy (CEA) is the gold standard treatment for patients with severe carotid artery stenosis.1 Clinical trials like Asymptomatic Carotid Atherosclerosis Study (ACAS) and the North American Symptomatic Carotid Endarterectomy Trial (NASCET) have identified the role of CEA in reducing the risk of stroke and neurological events in patients with carotid artery stenosis.1, 2, 3, 4, 5, 6, 7, 8 Subgroup analyses of these studies have questioned the ability of CEA to reduce the risk of stroke in females.1, 9 According to results of the NASCET and the ACAS studies, CEA may not be as efficacious in women as it is in men.1 Other series have also identified female gender as an independent risk factor, depending on increased rate of perioperative complications like stroke or death, and have concluded that the benefits of CEA may be gender-dependent.3, 10, 11

In contrast, many reports have shown that there is no evidence of gender-based differences between women and men for stroke and death rates after CEA and concluded that CEA can be performed safely in women with success rates similar to that observed in men.11, 12, 13, 14, 15, 16, 17

The aim of this study was to evaluate and compare the results of CEA in women and men in terms of safety, complication rates, and mortality.

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Materials and Methods 

Between 1994 and 2007, a total of 525 CEAs were performed in 493 patients in our clinic. Of these, 191 patients (41 female and 150 male) who underwent isolated CEA operations were included in this study. Patients with a previous history of cardiac operations, coronary interventions, and a staged cardiac and/or vascular operation were excluded from the study so as to find the role of gender in isolated CEA operations. Patients with coronary artery disease (CAD) assigned for medical treatment were not excluded.

We analyzed the effects of gender, preoperative risk factors, symptoms and signs, complication rates, postoperative events on operative results, and short- and long-term outcomes in terms of mortality and morbidity.

Statistical analysis 

Statistical analyses were performed with “Chi-Square test and Student's t test,” where appropriate. Kaplan–Meier test (log rank test) was used for actuarial survival analyses of the groups. All the values were expressed as mean ± SD. Statistical significance was accepted at p < 0.05. To analyze the effect of all risk factors for mortality, “Logistic Regression Analysis” was performed.

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Results 

Between 1994 and 2007, 205 isolated CEA operations were performed in 191 patients. The ratio of men to women was 3.8:1. Mean age of female and male patients were 64.4 ± 9.0 and 64.9 ± 8.3 years, respectively (p > 0.05).

The preoperative risk factors, smoking and existence of peripheral arterial disease (PAD), were significantly higher in men, whereas hyperlipidemia was higher in women. Vast majority of patients (n = 132, 64.4%) were symptomatic, as compared to 73 (35.6%) who were asymptomatic. Twenty-six (61.9%) female and 106 (65.0%) male patients were symptomatic, and there was no significant difference between female and male groups. The number of patients with CAD was 12 (29.4%) in the female group and 62 (38.0%) in the male group, and all these patients were under medical treatment. Coronary artery disease was detected in 25.8% (34 patients) of symptomatic and 54.8% (40 patients) of asymptomatic patients (p = 0.001). Demographic data, symptoms, and preoperative risk factors are listed in Table I.

Table I. Demographics and preoperative symptoms/risk factors of 205 operations
Women % (n = 42)Men % (n = 163)p valueTotal % (n = 205)
Age (year ± SEM)64.4 ± 9.064.9 ± 8.30.73364.8 ± 8.5
Smoking11.9 (5)34.4 (56)0.00529.8 (61)
Diabetes21.4 (9)22.1 (36)0.92722.0 (45)
Hypertension52.4 (22)41.1 (67)0.18943.4 (89)
Hyperlipidemia40.5 (17)21.5 (35)0.01225.4 (52)
COPD04.9 (8)0.1433.9 (8)
CRF03.7 (6)0.2072.9 (6)
PAD14.3 (6)30.7 (50)0.03427.3 (56)
Family history14.3 (6)8.0 (13)0.2099.3 (19)
CAD 0.100
No26.8 (11)30.7 (50)29.8 (61)
Unknown45.2 (19)31.3 (51)34.1 (70)
1 vessel disease06.1 (10)4.9 (10)
2 vessel disease19.9 (8)12.3 (20)13.7 (28)
3 vessel disease9.5 (4)19.6 (32)17.6 (36)
LMCA disease000
LV dysfunction05.5 (9)0.2754.4 (9)
Clinic 0.706
Symptomatic61.9 (26)65.0 (106)64.4 (132)
Asymptomatic38.1 (16)35.0 (57)35.6 (73)
Symptoms 0.738
TIA26.2 (11)32.5 (53)31.2 (64)
A. Fugax2.4 (1)4.9 (8)4.4 (9)
RIND2.4 (1)4.9 (8)4.4 (9)
Stroke (without neurological sequelae)16.7 (7)14.1 (23)14.6 (30)
Stroke (with neurological sequelae)14.3 (6)8.6 (14)9.8 (20)
Carotid bruits35.7 (15)30.1 (49)0.48131.2 (64)

COPD, chronic obstructive pulmonary disease; CRF, chronic renal failure; PAD, peripheric artery disease; CAD, coronary artery disease; LMCA, left main coronary artery; LV, left ventricular; TIA, transient ischemic attack; RIND, reversible ischemic neurological deficit.

Doppler-Duplex, with or without digital subtraction angiography, computed tomography, or magnetic resonance imaging angiography, was used for diagnosis.

Of the 191 patients, 177 (92.7%) had unilateral and 14 (7.3%) had bilateral CEAs. Five of 14 bilateral CEAs were performed in the same hospitalization period as two different operations. No simultaneous bilateral CEA was performed in any patient. Mean time between two operations was 212.0 ± 0.0 days in female group, and 113.1 ± 198.3 days in male group (p > 0.05). The most frequently used technique was patch closure for both groups. There was no statistically significant difference in operative technique or use of shunt and electroencephalography monitoring between two groups. All procedures were performed by cardiovascular or vascular surgeons, under general or regional anesthesia. Operative techniques, side of operations, and degrees of internal carotid artery stenosis are listed in Table II.

Table II. Operative techniques and preoperative data of 205 operations
Women
% 20.5
(n = 42)		Men
% 79.5
(n = 163)		p valueTotal
% 100.0
(n = 205)
CEA
Unilateral97.6 (41)92.0 (150)0.20093.2 (191)
Bilateral2.4 (1)8.0 (13)6.8 (14)
Bilateral operation—in same hospitalization03.0 (5)0.4392.4 (5)
Side of CEA
Right CA28.6 (12)49.1 (80)0.01744.9 (92)
Left CA71.4 (30)50.9 (83)55.1 (113)
Stenosis in CA
60-79%2.4 (1)8.0 (13)0.2006.8 (14)
80-99%97.6 (41)92.0 (150)93.2 (191)
Anesthesia
General97.6 (41)94.5 (154)0.39995.1 (195)
Regional2.4 (1)5.5 (9)4.9 (10)
Technique
Primary closure11.9 (5)11.0 (18)0.42711.2 (23)
Eversion CEA2.4 (1)1.2 (2)1.5 (3)
Saphenous vein patch23.8 (10)14.7 (24)16.6 (34)
Dacron patch59.5 (25)72.4 (118)69.8 (143)
Dacron tube graft2.4 (1)0.6 (1)1.0 (2)
Tacking11.9 (5)8.6 (14)0.5099.3 (19)
Shunt69.0 (29)69.9 (114)0.91169.8 (143)
EEG monitorization31.0 (13)25.2 (41)0.44726.3 (54)
Time between two CEAs212.0 ± 0.0113.1 ± 198.30.640120.2 ± 192.4
Time to discharge (days)6.6 ± 8.26.7 ± 7.60.9316.9 ± 7.7

CEA, carotid endarterectomy; CA, carotid artery; EEG, electroencephalography.

In the postoperative period, one female patient (2.4%) had a major contralateral stroke, six male patients (3.7%) had minor strokes, and 2 male patients (1.2%) had major ipsilateral stroke. There was no statistically significant difference in postoperative neurological outcome between the groups (Table III). The only statistically significant difference between female and male groups in postoperative complication rates was postoperative hematoma needing re-exploration. Although 20 (12.3%) men were locally re-explored for early postoperative hematoma, but none of the women were (p = 0.017).

Table III. Postoperative outcomes and complications in 205 operations
Women
% (n = 42)		Men
% (n = 163)		p valueTotal
% (n = 205)
Neurological outcome
TIA000.1130
Minor stroke03.7 (6)2.9 (6)
Major stroke (ipsilateral)01.2 (2)1.0 (2)
Major stroke (contralateral)2.4 (1)00.5 (1)
Postoperative hematoma012.3 (20)0.0179.8 (20)
Cranial nerve injury00.6 (1)0.6110.5 (1)
Cerebral hypoperfusion00–0
Myocardial ischemia04.3 (7)0.1723.4 (7)
Low cardiac output02.5 (4)0.3052.0 (4)
IABP01.2 (2)0.4711.0 (2)

TIA, transient ischemic attack; IABP, intra-aortic balloon pump.

Hospital mortality rates of 205 operations in female and male groups were 0.0% and 2.4% (n = 4), respectively (Table IV). There was no statistically significant difference related to gender on hospital mortality.

Table IV. Overall mortality rates
Women
% (n)		Men
% (n)		p valueTotal
% (n)
In hospital mortalitya
Neurological00 0
Cardiac01.8 (3)–1.4 (3)
Other00.6 (1) 0.5 (1)
Total02.4 (4)0.3051.9 (4)
Late mortalityb
Neurological00 0
Cardiac2.5 (1)7.2 (11)0.1806.2 (12)
Other5.0 (2)2.6 (4) 3.1 (6)
Total7.5 (3)9.9 (15)0.6399.4 (18)

aIn 205 operations (42 women - 163 men).

bIn 191 operations (40 women - 151 men).

The only preoperative risk factor affecting the overall hospital mortality rate in 205 operations was the presence of CAD (p = 0.045). There was no other demonstrable relation between the mortality and the preoperative risk factors including chronic renal failure, hypertension, diabetes mellitus, or smoking (Table V).

Table V. Preoperative risk factors affecting early mortality rates in 205 operations
Women % (n)p valueMen % (n)p valueTotal % (n)p value
DischargedDeceasedDischargedDeceasedDischargedDeceased
Number of operations100.0 (42)0 97.5 (159)2.5 (4) 98.0 (201)2.0 (4)
Age (year ± SEM)64.4 ± 9.0––64.9 ± 8.363.5 ± 9.10.73564.8 ± 8.563.5 ± 9.10.758
Clinic
Symptomatic61.9 (26)0–64.8 (103)75.0 (3)0.67264.2 (129)75.0 (3)0.654
Asymptomatic38.1 (16)035.2 (56)25.0 (1)35.8 (72)25.0 (1)
Symptoms
Asymptomatic38.1 (16)0–35.2 (56)25.0 (1)0.58935.8 (72)25.0 (1)0.551
TIA26.2 (11)031.4 (50)75.0 (3)30.3 (61)75.0 (3)
A. Fugax2.4 (1)05.0 (8)04.5 (9)0
RIND2.4 (1)05.0 (8)04.5 (9)0
Stroke (without neurological sequelae)16.7 (7)014.5 (23)014.9 (30)0
Stroke (with neurological sequelae)14.3 (6)08.8 (14)010.0 (20)0
Carotid bruits35.7 (15)0–30.8 (49)00.18431.8 (64)00.174
Smoking11.9 (5)0–35.2 (56)00.14330.3 (61)00.189
Hypertension52.4 (22)0–42.1 (67)00.09144.3 (89)00.077
Diabetes21.4 (9)0–22.0 (35)25.0 (1)0.88721.9 (44)25.0 (1)0.882
COPD00–5.0 (8)00.6454.0 (8)00.684
CRF00–3.8 (6)00.6923.0 (6)00.726
PAD14.3 (6)0–30.2 (48)50.0 (2)0.39626.9 (54)50.0 (2)0.304
Hyperlipidemia40.5 (17)0–22.0 (35)00.29025.9 (52)00.239
CAD
No26.2 (11)0–31.4 (50)00.07630.3 (61)00.045
Unknown45.2 (19)031.4 (50)25.0 (1)34.3 (69)25.0 (1)
1 vessel disease006.3 (10)05.0 (10)0
2 vessel disease19.0 (8)012.6 (20)013.9 (28)0
3 vessel disease9.5 (4)018.2 (29)75.0 (3)16.4 (33)75.0 (3)
LMCA000000
LV dysfunction00–5.7 (9)00.6184.4 (9)00.629

TIA, transient ischemic attack; RIND, reversible ischemic neurological deficit; COPD, chronic obstructive pulmonary disease; CRF, chronic renal failure; PAD, peripheric artery disease; CAD, coronary artery disease; LMCA, left main coronary artery; LV, left ventricular.

Perioperative events which cause statistically significant increase in overall hospital mortality in 205 operations were myocardial ischemia, low cardiac output, need of intra-aortic balloon pump (IABP) (p = 0.0001), and technique of arteriotomy closure (p = 0.002) (Table VI). The results were only applicable for male patient group, as no hospital mortality was observed in the female group.

Table VI. Perioperative events affecting hospital mortality rates in 205 operations
Women % (n)p valueMen % (n)p valueTotal % (n)p value
DischargedDeceasedDischargedDeceasedDischargedDeceased
Number of operations100.0 (42)0 97.5 (159)2.5 (4) 98.0 (201)2.0 (4)
Bilateral operation2.4 (1)0–7.5 (12)25.0 (1)0.2036.5 (13)25.0 (1)0.146
Side of CEA
Right CA28.6 (12)0–48.4 (77)75.0 (3)0.29444.3 (89)75.0 (3)0.221
Left CA71.4 (30)051.6 (82)25.0 (1)55.7 (112)25.0 (1)
Stenosis in CA
60-79%2.4 (1)0–8.2 (13)00.5517.0 (14)00.584
80-99%97.6 (41)091.8 (146)100.0 (4)93.0 (187)100.0 (4)
Anesthesia
General97.6 (41)0–94.3 (150)100.0 (4)0.62495.0 (191)100.0 (4)0.647
Regional2.4 (1)05.7 (9)05.0 (10)0
Technique
Primary closure11.9 (5)0–10.7 (17)25.0 (1)0.000110.9 (22)25.0 (1)0.002
Eversion CEA2.4 (1)00.6 (1)25.0 (1)1.0 (2)25.0 (1)
Saphenous vein patch23.8 (10)015.1 (24)016.9 (34)0
Dacron patch59.5 (25)073.0 (116)50.0 (2)70.1 (141)50.0 (2)
Dacron tube graft2.4 (1)00.6 (1)01.0 (2)0
Tacking11.9 (5)0–8.8 (14)00.5359.5 (19)00.519
Shunt69.0 (29)0–70.4 (112)50.0 (2)0.37970.1 (141)50.0 (2)0.385
EEG monitorization31.0 (13)0–25.8 (41)00.24026.9 (54)00.227
Neurological outcome
Normal97.6 (41)0–95.0 (151)100.0 (4)0.90095.5 (192)100.0 (4)0.980
TIA000000
Minor stroke003.8 (6)03.0 (6)0
Major stroke (ipsilateral)001.3 (2)01.0 (2)0
Major stroke (contralateral)2.4 (1)0000.5 (1)0
Postoperative hematoma00–12.6 (20)00.44910.0 (20)00.507
Cranial nerve injury00–0.6 (1)00.8740.5 (1)00.888
Cerebral hypoperfusion00–00–00–
Myocardial ischemia00–2.5 (4)75.0 (3)0.00012.0 (4)75.0 (3)0.0001
Low cardiac output00–0.6 (1)75.0 (3)0.00010.5 (1)75.0 (3)0.0001
IABP00–0.6 (1)25.0 (1)0.00010.5 (1)25.0 (1)0.0001
Time to discharge (days)6.6 ± 8.2––6.7 ± 7.67.2 ± 10.50.8876.6 ± 7.77.2 ± 10.50.884
Time between two CEAs212.0 ± 0.0––122.0 ± 204.46.0 ± 0.00.596129.0 ± 197.36.0 ± 0.00.559

CEA, carotid endarterectomy; CA, carotid artery; EEG, electroencephalography; TIA, transient ischemic attack; IABP, intra-aortic balloon pump.

Long-term follow-up data were achieved in 93.1% (191 of 205) of operations, for a mean period of 36.4 ± 29.1 months postoperatively for 40 women and 151 men. Late overall mortality rates of 191 operations in female and male groups were 7.5% (3/40 patients) and 9.9% (15/151 patients), respectively. The actuarial survival rate was 82.2 ± 11.6% in women and 71.5 ± 7.5% in men (p > 0.05) (Fig. 1). All the observed mortalities in the long-term were cardiac-related or with other causes; no neurological deaths were observed in both groups. There was no statistically significant difference in late mortality rates related to gender between the two groups (Table IV).

The only specific risk factor for female group that causes a statistically significant increase in late mortality was the presence of PAD. For male group hypertension, PAD and left ventricular dysfunction were significant risk factors for late mortality (Table VII). Perioperative events that were statistically significant in overall late mortality in 191 operations were low cardiac output and need of IABP during the early postoperative period (Table VIII).

Table VII. Preoperative risk factors affecting late mortality rates in 191 operations
Women % (n)p valueMen % (n)p valueTotal % (n)p value
AliveDeceasedAliveDeceasedAliveDeceased
Number of patients92.5 (37)7.5 (3) 90.1 (136)9.9 (15) 90.6 (173)9.4 (18)
Age (year ± SEM)64.3 ± 9.568.0 ± 1.00.51965.1 ± 8.565.1 ± 7.30.98964.9 ± 8.765.6 ± 6.70.755
Clinic
Symptomatic59.5 (22)66.7 (2)0.80665.4 (89)60.0 (9)0.67564.2 (111)61.1 (11)0.798
Asymptomatic40.5 (15)33.3 (1)34.6 (47)40.0 (6)35.8 (62)38.9 (7)
Symptoms
Asymptomatic40.5 (15)33.3 (1)0.31734.6 (47)40.0 (6)0.27035.8 (62)38.9 (7)0.635
TIA27.0 (10)030.1 (41)53.3 (8)29.5 (51)44.4 (8)
A. Fugax2.7 (1)05.1 (7)04.6 (8)0
RIND2.7 (1)05.1 (7)04.6 (8)0
Stroke (without neurological sequelae)13.5 (5)66.7 (2)16.2 (22)015.6 (27)11.1 (2)
Stroke (with neurological sequelae)13.5 (5)08.8 (12)6.7 (1)9.8 (17)5.6 (1)
Carotid bruits37.8 (14)33.3 (1)0.87733.1 (45)26.7 (4)0.61434.1 (59)27.8 (5)0.588
Smoking13.5 (5)00.49640.4 (55)6.7 (1)0.01034.7 (60)5.6 (1)0.012
Hypertension54.1 (20)66.7 (2)0.67347.1 (64)20.0 (3)0.04548.6 (84)27.8 (5)0.093
Diabetes24.3 (9)00.33222.8 (31)20.0 (3)0.80623.1 (40)16.7 (3)0.533
COPD00–5.9 (8)00.3344.6 (8)00.351
CRF00–2.9 (4)6.7 (1)0.4442.3 (4)5.6 (1)0.412
PAD10.8 (4)66.7 (2)0.00924.3 (33)73.3 (11)0.000121.4 (37)72.2 (13)0.0001
Hyperlipidemia43.2 (16)33.3 (1)0.73825.0 (34)6.7 (1)0.11028.9 (50)11.1 (2)0.107
CAD
No27.0 (10)33.3 (1)0.73628.7 (39)33.3 (5)0.15428.3 (49)33.3 (6)0.185
Unknown43.2 (16)66.7 (2)33.8 (46)20.0 (3)35.8 (62)27.8 (5)
1 vessel disease007.4 (10)05.8 (10)0
2 vessel disease26.1 (8)014.0 (19)6.7 (1)15.6 (27)5.6 (1)
3 vessel disease8.1 (3)016.2 (22)40.0 (6)14.5 (25)33.3 (6)
LMCA000000
LV dysfunction000.4073.7 (5)26.7 (4)0.0012.9 (5)22.2 (4)0.0001

TIA, transient ischemic attack; RIND, reversible ischemic neurological deficit; COPD, chronic obstructive pulmonary disease; CRF, chronic renal failure; PAD, peripheric artery disease; CAD, coronary artery disease; LMCA, left main coronary artery; LV, left ventricular.

Table VIII. Perioperative events affecting late mortality rates in 191 operations
Women % (n)p valueMen % (n)p valueTotal % (n)p value
AliveDeceasedAliveDeceasedAliveDeceased
Number of patients92.5 (37)7.5 (3) 90.1 (136)9.9 (15) 90.6 (173)9.4 (18)
Bilateral operation2.7 (1)00.7737.4 (10)13.3 (2)0.4166.4 (11)11.1 (2)0.446
Side of CEA
Right CA29.7 (11)33.3 (1)0.89647.1 (64)60.0 (9)0.34143.4 (75)55.6 (10)0.321
Left CA70.3 (26)66.7 (2)52.9 (72)40.0 (6)56.6 (98)44.4 (8)
Stenosis in CA
60–79%033.3 (1)0.00018.1 (11)13.3 (2)0.4926.4 (11)16.7 (3)0.110
80–99%100.0 (37)66.7 (2)91.9 (125)86.7 (13)93.6 (162)83.3 (15)
Anesthesia
General97.3 (36)100.0 (3)0.77394.9 (129)86.7 (13)0.20495.4 (165)88.9 (16)0.240
Regional2.7 (1)05.1 (7)13.3 (2)4.6 (8)11.1 (2)
Technique
Primary closure10.8 (4)00.9639.6 (13)13.3 (2)0.8409.8 (17)11.1 (2)0.893
Eversion CEA2.7 (1)00.7 (1)01.2 (2)0
Saphenous Vein Patch24.3 (9)33.3 (1)16.9 (23)6.7 (1)18.5 (32)11.1 (2)
Dacron Patch59.5 (22)66.7 (2)72.1 (98)80.0 (12)69.4 (120)77.8 (14)
Dacron Tube Graft2.7 (1)00.7 (1)01.2 (2)0
Tacking13.5 (5)00.4968.8 (12)6.7 (1)0.7779.8 (17)5.6 (1)0.555
Shunt67.6 (25)100.0 (3)0.23872.8 (99)60.0 (9)0.25271.7 (124)66.7 (12)0.655
EEG monitorization32.4 (12)33.3 (1)0.97425.7 (35)33.3 (5)0.52727.2 (47)33.3 (6)0.578
Neurological outcome
Normal100.0 (37)100.0 (3)–94.9 (129)93.3 (14)0.11996.0 (166)94.4 (17)0.106
TIA000000
Minor stroke004.4 (6)03.5 (6)0
Major stroke (ipsilateral)000.7 (1)6.7 (1)0.6 (1)5.6 (1)
Major stroke (contralateral)000000
Postoperative hematoma00–14.0 (19)6.7 (1)0.42811.1 (19)5.6 (1)0.474
Cranial nerve injury00–00–00–
Cerebral hypoperfusion00–00–00–
Myocardial ischemia00–2.2 (3)6.7 (1)0.3071.7 (3)5.6 (1)0.281
Low cardiac output00–06.7 (1)0.00305.6 (1)0.002
IABP00–06.7 (1)0.00305.6 (1)0.002
Time to discharge (days)6.0 ± 8.39.6 ± 9.00.4736.5 ± 7.85.9 ± 4.50.7766.4 ± 7.96.5 ± 5.30.942
Time between two CEAs (days)212.0 ± 0.0––142.9 ± 219.518.0 ± 14.10.457149.1 ± 209.218.0 ± 14.10.411

CEA, carotid endarterectomy; CA, carotid artery; EEG, electroencephalography; TIA, transient ischemic attack; IABP, intra-aortic balloon pump.

We did not observe any demonstrable significant relationship between neurological symptoms and hospital or late mortality rates, in both groups. Also, there were no significant differences between the existence or severity of contralateral stenosis and hospital or late mortality rates, in both groups.

According to logistic regression analysis, smoking and PAD were found as statistically significant risk factors for late mortality (Table IX).

Table IX. Overall risk factor analysis for late mortality
VariablesBS.E.Sig.Exp(B)
Gender0.7390.8570.3892.093
Age0.0080.0400.8391.008
Smoking−3.3681.3280.0110.034
Diabetes−1.0440.8890.2400.352
Hypertension0.6690.8430.4271.953
Hyperlipidemia−0.1201.0160.9060.887
COPD−15.47013,652.4730.9990.000
CRF1.2931.3490.3383.644
PAD2.7890.6800.000116.266
Clinic−1.3360.7170.0620.263
CAD−0.1300.6220.8350.878
Neurological deficit0.3361.2130.7821.399
Low cardiac output41.58834,955.7640.9991E + 018
IABP−1.52737,470.2351.0000.217
Myocardial ischemia−17.32522,999.8720.9990.000

COPD, chronic obstructive pulmonary disease; CRF, chronic renal failure; PAD, peripheric artery disease; CAD, coronary artery disease; IABP, intra-aortic balloon pump.

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Discussion 

Gender differences are recognized as an important prognostic factor in patients with atherosclerotic disease, and carotid artery stenosis is known to be one of them.18 Although ACAS and NASCET studies have shown the role of CEA in reducing the risk of stroke for patients with carotid artery stenosis, subgroup analyses of these studies have questioned the ability of CEA to reduce the risk of stroke in females.1, 2, 3, 4, 5, 6, 7, 8, 9 As a result of these studies, there was a need for new studies to evaluate the role of gender on postoperative outcome in patients with carotid artery stenosis.

Sarac et al.,1 in their series of 3,422 CEAs, concluded that the combined transient ischemic attack or stroke and stroke or mortality rates are higher in women as compared with men in the postoperative period, but these risks remain acceptable when CEA is performed for appropriate indications. They showed that the interaction between symptoms and gender suggested that in patients who are asymptomatic, women are more likely than are men to have early complications. However, they did not find any gender difference in patients who were symptomatic and concluded that, despite a low postoperative complication rate, CEA is appropriate in women who are asymptomatic.1

When evaluating two groups in terms of outcome after CEA, gender differences like higher carotid blood flow velocities in women, more stable, less inflammatory plaques especially in asymptomatic women, rates of hypertension, CAD, PAD, smoking, or comorbid diseases must be considered.19, 20 These findings contradicted the results of Sarac et al.1 and could explain why asymptomatic women benefit less from CEA as compared with men.20 In our study, statistically significant differences for preoperative risk factors were smoking and PAD which were higher in males, and hyperlipidemia which was higher in females. In symptomatic or asymptomatic patients, we did not observe any statistically significant difference between two groups for early and late outcomes.

Lane et al.,9 in their series of 361 CEAs, showed that perioperative stroke rate was similar for women and men, but in women with previous neurological symptoms and those using hormone replacement therapy, there was a trend toward an increased perioperative stroke rate. They concluded that CEA provides a long-term reduction in stroke risk and improved stroke-free survival rates for both men and women.9

The main problem while evaluating the outcome of surgery for female gender will be the high population of male gender in carotid disease patients.21 In many studies, as it is in our study, the ratios of men to women are higher than 2:1 or 3:1 and the number of CEAs in women hospitalized for carotid artery stenosis or its complications is fewer than in men.1, 2, 22 The relatively lower number of women was consistent in every age group and in nearly all studies.2 With the pre-assumption of male and female populations at age groups being the same, this may lead to a false idea that carotid arteries are less affected in women from atherosclerosis. In fact, this idea has not been thoroughly investigated, but it is a well known issue that physicians prefer to treat female carotid artery patients conservatively. Although there is significant variability in cardiac risk factors and presentation, female gender is not a risk factor for stroke, death, or cardiac morbidity after CEA.11

In our study, there was no hospital mortality in female group, and neurological outcomes or rates of postoperative complications of women were comparable to men. Although most of the results were not statistically significant, many complications like postoperative hematoma, cranial verve injury, myocardial ischemia, low cardiac output, or need of IABP were observed in men whereas no woman had these complications.

In our clinic, carotid duplex is preferred for evaluating patients with symptoms of coronary artery disease, and because of the huge number of these patients who attended our hospital, in our series the detection rates of asymptomatic carotid stenosis compared with symptomatic carotid stenosis in patients with CAD are higher.

The results of our study challenge the conclusions from the ACAS and NASCET regarding the benefits of CEA in women. Furthermore, larger comparative studies are necessary to understand the benefit of CEA in women, but the results of our study suggest that the early and late outcomes are comparable in symptomatic or asymptomatic men and women. Female gender does not adversely affect early or late survival after CEA.

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Conclusion 

CEA can be performed safely in women with asymptomatic and symptomatic carotid artery disease, and physicians should expect comparable benefits and outcomes in women and men undergoing CEA. Women should not be excluded from the benefits of CEA on the basis of perceived increased complication rates, and gender should not be a consideration in the decision to perform CEA.

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References 

  1. Sarac TP, Hertzer NR, Mascha EJ, et al. Gender as a primary predictor of outcome after carotid endarterectomy. J Vasc Surg. 2002;35:748–753
  2. Kapral MK, Redelmeier DA. Carotid endarterectomy for women and men. J Womens Health Gend Based Med. 2000;9:987–994
  3. Weise J, Kuschke S, Bähr M. Gender-specific risk of perioperative complications in carotid endarterectomy patients with contralateral carotid artery stenosis or occlusion. J Neurol. 2004;251:838–844
  4. North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. N Engl J Med. 1991;325:445–453
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  18. Dick P, Sherif C, Sabeti S, et al. Gender differences in outcome of conservatively treated patients with asymptomatic high grade carotid stenosis. Stroke. 2005;36:1178–1183
  19. Comerota AJ, Salles-Cunha SX, Daoud Y, et al. Gender differences in blood velocities across carotid stenoses. J Vasc Surg. 2004;40:939–944
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PII: S0890-5096(10)00086-5

doi:10.1016/j.avsg.2010.02.017

Annals of Vascular Surgery
Volume 24, Issue 6 , Pages 775-785, August 2010

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