Retrospective Cohort Study
Copyright ©The Author(s) 2021.
World J Clin Cases. Dec 16, 2021; 9(35): 10816-10827
Published online Dec 16, 2021. doi: 10.12998/wjcc.v9.i35.10816
Table 1 Characteristics of the patients at baseline

Total
WOPC group
PC group
P
No. of cases20616640
Age (yr)62.0 ± 7.261.6 ± 7.363.5 ± 6.80.151
Sex 0.616
Male 175 (84.95%)140 (84.34%)35 (87.50%)
Female 31 (15.05%)26 (15.66%)5 (12.50%)
BMI (kg/m2)25.33 ± 2.8925.25 ± 2.8525.63 ± 3.040.461
Smoking history118 (57.56%)97 (58.79%)21 (52.50%)0.470
ASA grade0.521
Grade II157 (81.07%)136 (81.93%)31 (77.50%)
Grade III39 (18.93%)30 (18.07%)9 (22.50%)
Preoperative combined diseases
Hypertension 146 (70.87%)114 (68.67%)32 (80.0%)0.157
Diabetes mellitus74 (35.92%)61 (36.75%)13 (32.50%)0.615
Heart disease56 (27.18%)40 (24.10%)16 (40.0%)0.042a
Respiratory disease11 (5.34%)10 (6.02%)1 (2.50%)0.374
Neurological disease96 (46.60%)78 (46.99%)18 (45.0%)0.821
Kidney disease4 (1.94%)4 (2.41%)0 0.321
Degree of carotid artery stenosis on the surgical side0.449
Mild/moderate stenosis3 (1.46%)2 (1.20%)1 (2.5%)
Severe stenosis201 (97.57%)163 (98.19%)38 (95.0%)
Occlusion2 (0.97%)1 (0.60%)1 (2.50%)
Degree of carotid artery stenosis on the contralateral side0.146
Mild/moderate stenosis169 (85.35%)132 (83.02%)37 (94.87%)
Severe stenosis21 (10.61%)19 (11.95%)2 (5.13%)
Occlusion8 (4.04%)8 (5.03%)0
Operating time (min)141.33 ± 40.96138.39 ± 38.78153.57 ± 47.620.129
Duration of carotid artery occlusion (min)22.00 (18.0–44.0)22.00 (17.0–43.0)27.0 (18.50–49.50)0.328
Anesthesia method
TIVA163 (79.13%)129 (77.71%)34 (85.0%)0.309
Combined intravenous–inhalation anesthesia 43 (20.87%)37 (22.29%)6 (15.0%)
Intraoperative intake and output volume (mL)897.57 ± 333.40911.85 ± 331.01839.75 ± 341.010.221
meanSBP128.82 ± 12.92128.37 ± 12.77130.69 ± 13.540.309
SDSBP20.26 ± 4.9120.09 ± 5.0120.93 ± 4.480.333
CVSBP0.16 ± 0.040.16 ± 0.040.16 ± 0.030.550
meanDBP69.61 ± 7.8369.80 ± 7.7768.82 ± 8.140.480
SDDBP10.23 ± 2.7010.18 ± 2.8110.42 ± 2.260.612
CVDBP0.15 ± 0.040.15 ± 0.040.15 ± 0.040.372
Intraoperative use of vasopressors84 (40.78%)65 (39.16%)19 (47.50%)0.335
Intraoperative use of antihypertensive agents73 (35.44%)63 (37.95%)10 (25.0%)0.124
Table 2 Outcome variables, stratified by major postoperative complications

Total
WOPC group
PC group
P
No. of cases20616640
Major postoperative complications40 (19.42%)0 40 (100%)
Neurological complications 16 (7.77%)0 16 (40.0%)< 0.001a
Cardiac complications6 (2.91%)0 6 (15.0%)< 0.001a
Respiratory complications14 (6.80%)0 14 (35.0%)< 0.001a
AKI9 (4.37%)0 9 (22.50%)< 0.001a
Fever10 (4.85%)4 (2.41%)6 (15.0%)< 0.001a
Surgical site infections3 (1.46%)1 (0.60%)2 (5.0%)0.097
Urinary infections3 (1.46%)1 (0.60%)2 (5.0%)0.097
DVT5 (2.43%)1 (0.60%)4 (10.0%)< 0.001a
Length of stay in the ICU (d) 1.0 (0–1.0)1.0 (0–1.0)1.0 (1.0–1.0)0.055
Hospitalization stay (d)15.56 ± 4.3015.16 ± 3.6317.20 ± 6.170.105
Cost of hospitalization (CNY)24085.15 (21694.72–28395.65)23786.67 (21568.68–27139.36)27127.94 (22326.75–31629.55)< 0.001a
Table 3 Risk factors associated with major postoperative complications

Statistical value
Post-CEA major complications
P
Age (yr)62.0 ± 7.21.04 (0.99, 1.09)0.151
Sex0.616
Male 175 (84.95%)1.0
Female 31 (15.05%)0.77 (0.28, 2.15)
BMI (kg/m2)25.33 ± 2.891.05 (0.93, 1.17)0.459
ASA grade0.522
Grade II167 (81.07%)1.0
Grade III39 (18.93%)1.32 (0.57, 3.05)
Anesthesia methods0.312
TIVA163 (79.13%)1.0
Combined intravenous–inhalation anesthesia 43 (20.87%)0.62 (0.24, 1.58)
Degree of carotid artery stenosis on the surgical side
Mild/moderate stenosis3 (1.46%)1.0
Severe stenosis201 (97.57%)0.47 (0.04, 5.28)0.538
Occlusion2 (0.97%)2.00 (0.05, 78.25)0.711
Degree of carotid artery stenosis on the contralateral side
Mild/moderate stenosis169 (85.35%)1.0
Severe stenosis21 (10.61%)0.38 (0.08, 1.69)0.201
Occlusion8 (4.04%)0 (0, Inf)0.986
Operating time (min)141.33 ± 40.961.01 (1.0, 1.02)0.038a
Intraoperative intake and output volume (mL)897.57 ± 333.401.00 (1.0, 1.00)0.221
Duration of carotid artery occlusion22.0 (18.0–44.0)1.01 (0.99, 1.03)0.327
CVSBP0.16 ± 0.0416.36 (0.00, 150500.70)0.548
CVDBP0.15 ± 0.0440.21 (0.01, 132798.95)0.372
Preoperative NLR2.08 ± 0.941.21 (0.87, 1.69)0.264
NLR within 24 h after CEA 5.68 (3.93–8.91)1.09 (1.01, 1.17)0.026a
Table 4 Correlation between neutrophil to lymphocyte ratio within 24 h after carotid endarterectomy and major postoperative complications
Exposure factors
Unadjusted
P value
Model I
P value
Model II
P
NLR1.09 (1.01, 1.17)0.026a1.08 (1.00, 1.16)0.041a1.15 (1.03, 1.29)0.014a
NLR tertile groups
Low NLR group1.01.01.0
Middle NLR group1.60 (0.63, 4.09)0.3221.52 (0.59, 3.92)0.3863.99 (1.03, 15.49)0.046a
High NLR group2.92 (1.21, 7.02)0.017a2.88 (1.17, 7.09)0.022a8.47 (2.20, 32.63)0.002a
Table 5 Outcome variables, stratified by NLR ratio tertile groups

Total
Low NLR group
Middle NLR group
High NLR group
P
No. of cases206686969
Major postoperative complications40 (19.42%)8 (11.76%)11 (15.94%)21 (30.43%)0.015a
Neurological complications 16 (7.77%)4 (5.88%)4 (5.80%)8 (11.59%)0.346
Cardiac complications6 (2.91%)0 (0.00%)3 (4.35%)3 (4.35%)0.218
Respiratory complications14 (6.80%)2 (2.94%)5 (7.25%)7 (10.14%)0.242
AKI9 (4.37%)2 (2.94%)1 (1.45%)6 (8.70%)0.089
Fever10 (4.85%)1 (1.47%)2 (2.90%)7 (10.14%)0.040a
Surgical site infections3 (1.46%)1 (1.47%)1 (1.45%)1 (1.45%)1.000
Urinary infections3 (1.46%)0 (0.00%)1 (1.45%)2 (2.90%)0.367
DVT5 (2.43%)2 (2.94%)1 (1.45%)1 (1.45%)0.766
Length of stay in the ICU (d) 1.0 (0–1.0)1.0 (0–1.0)1.0 (0–1.0)1.0 (1.0–1.0)0.079
Hospitalization stay (d)15.56 ± 4.3015.44 ± 4.4015.28 ± 4.2715.96 ± 4.260.627
Cost of hospitalization (CNY)26886.26 ± 11277.4924371.70 ± 5233.7326837.07 ± 12681.3429413.56 ± 13520.490.032a