Aneurysm neck length and mortality after rupture 121114
Supplementary Material
Supplementary Table 1. Variables that are multiply imputed, and details of imputation model used.
All variables are imputed irrespective of the (imputed) neck length. Multiple imputation using chained equations was performed. All imputations were adjusted for the variables listed in Supplementary Table
1 along with the following complete variables: age, sex, vital status at 24 hours, vital status at 30 days, centre, randomised group, treatment commenced. 10 multiply imputed datasets were created and estimates were combined using Rubin's rules [1].
Imputation model Variable
Admission systolic blood pressure
Admission diastolic blood pressure
Admission haemoglobin
Admission creatinine
Lowest recorded systolic blood pressure
Lowest recorded diastolic blood pressure
Volume of IV fluid given (log litres)
Loss of consciousness during care episode
Acute myocardial ischaemia
Reinterventions within 30-days
Maximum Aneurysm Diameter (core lab)
Distal aortic neck angle
Proximal aortic neck angle
Right Common Iliac Diameter
Left Common Iliac Diameter
Aortic neck diameter at distal renal artery (1mm below)
Aortic neck diameter 5mm below lowest renal artery
Neck length (from lowest renal artery to sac)
Aortic neck diameter 10mm below lowest renal artery
Aortic neck diameter 15mm below lowest renal artery
No. (%) missing
8 (1.7%)
8 (1.7%)
4 (0.9%)
10 (2.2%)
29 (6.3%)
33 (7.2%)
206 (45.0%)
20 (4.4%)
37 (8.1%)
5 (1.1%)
31 (6.8%)
49 (10.7%)
52 (11.4%)
54 (11.8%)
55 (12.0%)
84 (18.3%)
101 (22.1%)
49 (10.7%)
135 (29.5%)
180 (39.3%)
Linear regression
Logistic regression
Truncated regression (>0)
Partial mean matching

Aneurysm neck length and mortality after rupture 121114
Supplementary Table 2. Agreement of within liberal IFU and local assessment of suitability for EVAR
Within IFU guidelines?
No
Yes
Local findings: Suitable for EVAR?
No
80 (53%)
40 (20%)
Yes
72 (47%)
162 (80%)
354 patients with complete IFU information were assessed locally for suitability for EVAR.
Total
152 (100%)
202 (100%)

Aneurysm neck length and mortality after rupture 121114
Supplementary Table 3. Aortic morphology and 30-day mortality (with multiple imputation for missing variables). Multivariate model adjusted for all six morphological variables in addition to age, sex,
Hardman Index, lowest recorded systolic blood pressure and randomised group.
Variable EVAR commenced
50 deaths, n=177
Maximum AAA diameter (per
17mm increase)
Top neck diameter
(per 4mm increase)
Odds ratio
(95% CI)
0.97
(0.65, 1.44)
1.16
(0.72, 1.87) p-value
0.88
0.54
Aortic neck length
(per 16mm increase)
Neck conicality
(per 1.6% per mm change increase)
Proximal aortic neck (alpha) angulation
(per 20 degree increase)
Maximum common iliac diameter
(per 9mm increase)
0.82
(0.53, 1.27)
1.24
(0.63, 2.49)
0.92
(0.60, 1.42)
1.41
(0.94, 2.13)
0.38
0.53
0.71
0.095
* Also adjusted for operation commenced
Open commenced
105 deaths, n=281
Odds ratio
(95% CI)
0.82
(0.61, 1.10)
0.91
(0.63, 1.31)
0.66
(0.48, 0.91)
1.07
(0.72, 1.61)
0.89
(0.66, 1.19) p-value
0.19
0.61
0.011
0.73
0.42
1.14
(0.87, 1.48)
0.35
Combined*
155 deaths, n=458
Odds ratio
(95% CI)
0.88
(0.70, 1.11)
1.01
(0.77, 1.34)
0.73
(0.57, 0.93)
1.12
(0.78, 1.61)
0.90
(0.71, 1.15) pvalue
0.28
0.92
0.010
0.53
0.40
1.18
(0.94, 1.47)
0.15

Aneurysm neck length and mortality after rupture 121114
Supplementary Table 4. Aortic morphology and 30-day mortality (complete-case analysis). All models adjusted for age, sex, Hardman Index, lowest recorded systolic blood pressure and randomised group.
Odds ratios are presented per standard deviation increase of morphological parameter.
Variable EVAR commenced
Within liberal IFU (vs outside)
Maximum AAA diameter (per
17mm increase)
Aortic neck diameter at distal renal artery
(per 4mm increase)
Aortic neck length
(per 16mm increase)
Neck conicality
(per 1.6% per mm change increase)
Odds ratio
(95% CI)
0.75
(0.32, 1.79)
N=139
0.92
(0.62, 1.38)
N=144
1.16
(0.72, 1.87)
N=139
0.90
(0.57, 1.43)
N=139
0.82
(0.40, 1.64)
N=139 p-value
0.52
0.69
0.55
0.66
0.59
Proximal aortic neck (alpha) angulation
(per 20 degree increase)
Maximum common iliac diameter
(per 9mm increase)
0.90
(0.59, 1.38)
N=139
1.36
(0.85, 2.19)
N=136
0.64
0.20
* Also adjusted for operation commenced
Open commenced
Odds ratio
(95% CI)
0.70
(0.38,1.30)
N=203
0.81
(0.60, 1.10)
N=214
0.97
(0.68, 1.39)
N=203
0.57
(0.40, 0.82)
N=203
1.06
(0.74, 1.53)
N=203
0.85
(0.63, 1.15)
N=200
1.09
(0.83, 1.43)
N=201 p-value
0.26
0.18
0.89
0.002
0.75
0.30
0.52
Combined*
Odds ratio
(95% CI)
0.70
(0.43, 1.15)
N=342
0.85
(0.67, 1.09)
N=358
1.05
(0.80, 1.40)
N=342
0.67
(0.51, 0.88)
N=342
1.02
(0.73, 1.42)
N=342
0.88
(0.69, 1.12)
N=339
1.13
(0.89, 1.43)
N=337 pvalue
0.16
0.20
0.71
0.005
0.92
0.29
0.32

Aneurysm neck length and mortality after rupture 121114
Supplementary Table 5. Morphology characteristics stratified by men and women; mean (SD).
Max aneurysm diameter, mm
Aortic neck diameter at distal renal artery, mm
Neck Length, mm
Conicality (% change per mm length)
Proximal neck angle, degrees
Maximum Common Iliac diameter, mm
Women
N=94
78.9
(16.1)
24.4
(5.4)
19.4
(16.2)
1.04
(2.49)
35.6
(23.0)
17.9
(5.4)
Men
N=364
87.9
(17.3)
25.9
(4.0)
24.3
(16.0)
0.65
(1.33)
32.0
(19.4)
21.8
(9.4) p-value*
<0.001
0.002
0.010
0.135
0.400
<0.001
* Wilcoxon rank- sum test

Aneurysm neck length and mortality after rupture 121114
Supplementary Table 6. Aortic morphology and the risk of experiencing any reintervention within 30day (with multiple imputation for missing variables). Multivariate model adjusted for all six morphological variables in addition to age, sex, Hardman Index, lowest recorded systolic blood pressure and randomised group. Odds ratios are presented per standard deviation increase of morphological parameter.
Variable
Maximum AAA diameter (per
17mm increase)
Top neck diameter
(per 4mm increase)
Aortic neck length
(per 16mm increase)
Neck conicality
(per 1.6% per mm change increase)
Proximal aortic neck (alpha) angulation
(per 20 degree increase)
EVAR commenced
(23 patients with reinterventions, n=167)
Odds ratio
(95% CI)
0.77
(0.45, 1.33) p-value
0.35
1.06
(0.59, 1.92)
0.87
(0.50, 1.50)
1.04
(0.36, 3.00)
0.78
(0.44, 1.41)
Maximum common iliac diameter
(per 9mm increase)
1.59
(0.97, 2.59)
* Also adjusted for operation commenced
0.84
0.61
0.95
0.42
0.063
Open commenced
(65 patients with reinterventions, n=245)
Odds ratio
(95% CI)
0.73
(0.52, 1.04)
1.09
(0.70, 1.70)
1.05
(0.72, 1.53)
0.62
(0.37, 1.04)
1.20
(0.87, 1.66)
1.20
(0.89, 1.61) p-value
0.078
0.71
0.79
0.072
0.28
0.22
Combined*
(88 patients with reinterventions, n=412)
Odds ratio
(95% CI)
0.74
(0.56, 0.99)
1.04
(0.74, 1.48)
0.99
(0.73, 1.34)
0.69
(0.43, 1.12)
1.08
(0.82, 1.43) pvalue
0.040
0.80
0.94
0.13
0.59
1.27
(1.00, 1.63)
0.055

Aneurysm neck length and mortality after rupture 121114
Supplementary Table 7. Aortic morphology and the risk of experiencing any reinterventions within 30days (complete-case analysis) after exclusion of patients who either did not leave the operating theatre alive (n=41) or had missing re-intervention data (n=5). All models adjusted for age, sex, Hardman Index, lowest recorded systolic blood pressure and randomised group. Odds ratios are presented per standard deviation increase of morphological parameter.
Variable EVAR commenced
Within IFU (vs outside)
Maximum
AAA diameter
(per 17mm increase)
Aortic neck diameter at distal renal artery (per
4mm increase)
Aortic neck length
(per 16mm increase)
Neck conicality
(per 1.6% per mm change increase)
Proximal aortic neck
(alpha) angulation
(per 20 degree increase)
Maximum common iliac diameter
(per 9mm increase)
Odds ratio
(95% CI)
0.49
(0.17, 1.39)
N=132
0.78
(0.45, 1.37)
N=135
1.24
(0.69, 2.23)
N=132
1.06
(0.58, 1.91)
N=132
0.87
(0.35, 2.15)
N=132
0.76
(0.43, 1.34)
N=132
1.30
(0.79, 2.14)
N=130 p-value
0.18
0.39
0.48
0.86
0.76
0.34
0.31
* Also adjusted for operation commenced
Open commenced
Odds ratio
(95% CI)
0.89
(0.43, 1.84)
N=179
0.82
(0.58, 1.15)
N=190
1.20
(0.80, 1.83)
N=179
1.10
(0.76, 1.60)
N=179
0.66
(0.39, 1.12)
N=179
1.26
(0.91, 1.74)
N=176
1.14
(0.85, 1.53)
N=178 p-value
0.76
0.25
0.38
0.61
0.12
0.16
0.38
Combined*
Odds ratio
(95% CI)
0.77
(0.43, 1.39)
N=311
0.81
(0.61, 1.09)
N=325 p-value
0.38
0.17
1.18
(0.84, 1.65)
N=311
0.33
1.06
(0.78, 1.45)
N=311
0.72
(0.47, 1.11)
N=311
1.09
(0.83, 1.44)
N=308
1.19
(0.93, 1.54)
N=308
0.71
0.13
0.53
0.17

Aneurysm neck length and mortality after rupture 121114
References
1 Rubin, D.B. (1987) Multiple Imputation for Nonresponse in Surveys. J. Wiley & Sons, New York.