Results

Following the table with patients characteristics at admission and AVM surgery

Characteristic Overall
N = 64
1-2
N = 38
3
N = 17
4-5
N = 9
p-value
Sex (male) 36 (56%) 21 (55%) 9 (53%) 6 (67%) 0.876
Age at AVM diagnosis (years) 39.64 ± 19.09 42.68 ± 20.86 37.47 ± 16.93 30.89 ± 11.96 0.264
Clinical Presentation



0.124
    Hemorrhage 37 (58%) 26 (68%) 7 (41%) 4 (44%)
    Unruptured 27 (42%) 12 (32%) 10 (59%) 5 (56%)
Glasgow Coma Scale on Admission



0.450
    3-8 12 (19%) 8 (21%) 4 (24%) 0 (0%)
    9-13 4 (6.3%) 2 (5.3%) 2 (12%) 0 (0%)
    14-15 47 (75%) 28 (74%) 11 (65%) 8 (100%)
Modified Rankin Scale on Admission



0.426
    0-1 40 (63%) 22 (59%) 11 (65%) 7 (78%)
    2-3 6 (9.5%) 5 (14%) 0 (0%) 1 (11%)
    4-6 17 (27%) 10 (27%) 6 (35%) 1 (11%)
Previous Treatments



0.027
    None 21 (33%) 17 (45%) 4 (24%) 0 (0%)
    Embolization 40 (63%) 19 (50%) 13 (76%) 8 (89%)
    Other 3 (4.7%) 2 (5.3%) 0 (0%) 1 (11%)
Time from Diagnosis to Surgery



<0.001
    0-1 year 31 (60%) 26 (84%) 3 (25%) 2 (22%)
    > 1 year 21 (40%) 5 (16%) 9 (75%) 7 (78%)
Age at Surgery (years) 41.13 ± 18.38 43.45 ± 20.37 39.88 ± 16.47 33.67 ± 10.31 0.368
AVM Site



0.907
    Cerebellar 8 (13%) 6 (16%) 1 (5.9%) 1 (11%)
    Frontal 27 (42%) 17 (45%) 7 (41%) 3 (33%)
    Parietal 9 (14%) 6 (16%) 2 (12%) 1 (11%)
    Temporal 15 (23%) 7 (18%) 5 (29%) 3 (33%)
    Other 5 (7.8%) 2 (5.3%) 2 (12%) 1 (11%)
AVM Side



0.707
    left 41 (64%) 23 (61%) 11 (65%) 7 (78%)
    right 23 (36%) 15 (39%) 6 (35%) 2 (22%)
AVM Localization



0.759
    infratentorial 8 (13%) 6 (16%) 1 (5.9%) 1 (11%)
    supratentorial 56 (88%) 32 (84%) 16 (94%) 8 (89%)
Presence of Perforating Arterial Branches 9 (14%) 6 (16%) 2 (13%) 1 (11%) >0.999
Presence of Aneurysm 14 (22%) 9 (24%) 2 (12%) 3 (33%) 0.421
Aneurysm Location



0.811
    pre-nidus 3 (21%) 3 (33%) 0 (0%) 0 (0%)
    pre-intra-nidus 1 (7.1%) 1 (11%) 0 (0%) 0 (0%)
    intra-nidus 10 (71%) 5 (56%) 2 (100%) 3 (100%)
AVM Morphology



0.117
    compact 42 (67%) 23 (61%) 14 (88%) 5 (56%)
    diffuse 21 (33%) 15 (39%) 2 (13%) 4 (44%)
AVM volume (cm³) 6.08 (0.90-11.60) 1.30 (0.50-6.08) 9.84 (7.44-11.86) 28.00 (11.60-43.70) <0.001
Spetzler-Martin Size score



<0.001
    1 33 (52%) 30 (79%) 3 (18%) 0 (0%)
    2 26 (41%) 8 (21%) 13 (76%) 5 (56%)
    3 5 (7.8%) 0 (0%) 1 (5.9%) 4 (44%)
Spetzler-Martin Drainage score



<0.001
    0 45 (70%) 32 (84%) 12 (71%) 1 (11%)
    1 19 (30%) 6 (16%) 5 (29%) 8 (89%)
Spetzler-Martin Eloquence score



<0.001
    0 33 (52%) 27 (71%) 3 (18%) 3 (33%)
    1 31 (48%) 11 (29%) 14 (82%) 6 (67%)
Lawton-Young Grade



0.805
    1 3 (4.7%) 1 (2.6%) 2 (12%) 0 (0%)
    2 10 (16%) 7 (18%) 2 (12%) 1 (11%)
    3 33 (52%) 18 (47%) 9 (53%) 6 (67%)
    4 18 (28%) 12 (32%) 4 (24%) 2 (22%)
Lawton-Young Age score



0.189
    1 12 (19%) 7 (18%) 4 (24%) 1 (11%)
    2 20 (31%) 9 (24%) 5 (29%) 6 (67%)
    3 32 (50%) 22 (58%) 8 (47%) 2 (22%)
Lawton-Young Bleeding score



0.036
    0 39 (61%) 28 (74%) 8 (47%) 3 (33%)
    1 25 (39%) 10 (26%) 9 (53%) 6 (67%)
Lawton-Young Compactness score



0.102
    0 43 (67%) 23 (61%) 15 (88%) 5 (56%)
    1 21 (33%) 15 (39%) 2 (12%) 4 (44%)
Supplemented grade



<0.001
    2-5 35 (55%) 31 (82%) 4 (24%) 0 (0%)
    6 17 (27%) 7 (18%) 9 (53%) 1 (11%)
    7-8 12 (19%) 0 (0%) 4 (24%) 8 (89%)
Emergency Surgery



0.083
    0 45 (70%) 24 (63%) 12 (71%) 9 (100%)
    1 19 (30%) 14 (37%) 5 (29%) 0 (0%)
AVM closure 58 (97%) 34 (94%) 15 (100%) 9 (100%) >0.999
Post-surgery complications 26 (41%) 8 (21%) 10 (63%) 8 (89%) <0.001
Post-surgery deficit



<0.001
    none 35 (56%) 29 (78%) 5 (31%) 1 (11%)
    minor 12 (19%) 4 (11%) 5 (31%) 3 (33%)
    major 15 (24%) 4 (11%) 6 (38%) 5 (56%)
Modified Rankin Scale at Discharge



0.860
    0-1 42 (67%) 25 (66%) 10 (63%) 7 (78%)
    2-3 6 (9.5%) 4 (11%) 1 (6.3%) 1 (11%)
    4-6 15 (24%) 9 (24%) 5 (31%) 1 (11%)
Modified Rankin Scale at Follw-up



0.576
    0-1 49 (88%) 30 (86%) 11 (85%) 8 (100%)
    2-3 3 (5.4%) 3 (8.6%) 0 (0%) 0 (0%)
    4-6 4 (7.1%) 2 (5.7%) 2 (15%) 0 (0%)
Follow-up (years) 5.36 (1.75-7.29) 5.73 (1.94-7.15) 5.36 (1.69-7.60) 5.09 (0.23-6.02) 0.550
Discharge - Admission MRS difference -0.05 ± 1.46 -0.27 ± 1.57 0.31 ± 0.95 0.22 ± 1.72 0.068
Follow-up - DischargeMRS difference -0.75 ± 1.22 -0.86 ± 1.38 -0.77 ± 1.09 -0.25 ± 0.46 0.591
Follow-up - Admission MRS difference -0.80 ± 1.68 -1.12 ± 1.82 -0.38 ± 1.12 -0.13 ± 1.64 0.057

Figure shows the change in the percentage of patients by mRS grading from admission to last Follow-up

Figure shows the change in distribution of mRS grading between Admission and Discharge (A) and Admission and Follow-up (B). The red points indicate mean values (the p-value is referred to a Wilcoxon signed-rank test)

Figure shows the proportion of patient by Spetzler-Martin and Lawton-Young Grade

MRS difference models

Table linear regression for Discharge - Admission MRS difference (S-M categories 1-2, 3, 4-5)

The presence of perforating branches is associated with an increase in mRS between Discharge and Admission, while the hemorrhage at onset is associated with a decrease. R2 = 0.2622366

Characteristic Beta 95% CI1 p-value
Sex (male) 0.58 -0.10, 1.3 0.093
Age at Surgery (years) 0.01 -0.01, 0.03 0.3
Onset


    Unruptured
    Hemorrhage -0.97 -1.8, -0.17 0.019
GCS on Admission 0.04 -0.05, 0.14 0.4
Perforating branches 1.0 0.08, 2.0 0.034
Aneurysm -0.40 -1.2, 0.39 0.3
Diffuse 0.40 -0.39, 1.2 0.3
S-M grade


    1-2
    3 0.38 -0.44, 1.2 0.4
    4-5 0.56 -0.43, 1.5 0.3
1 CI = Confidence Interval

Table linear regression for Followup - Admission MRS difference (S-M categories 1-2, 3, 4-5)

GCS at admission and presence of perforating branches are associated with a worsening of mRS between Follow-up and Admission, while the hemorrhage at onset is associated with an improvement. R2 = 0.3952541

Characteristic Beta 95% CI1 p-value
Sex (male) 0.42 -0.34, 1.2 0.3
Age at Surgery (years) 0.02 0.00, 0.04 0.10
Onset


    Unruptured
    Hemorrhage -1.0 -1.9, -0.10 0.030
GCS on Admission 0.16 0.05, 0.27 0.004
Perforating branches 1.1 0.12, 2.2 0.030
Aneurysm -0.45 -1.3, 0.40 0.3
Diffuse 0.12 -0.77, 1.0 0.8
S-M grade


    1-2
    3 0.17 -0.76, 1.1 0.7
    4-5 0.81 -0.33, 2.0 0.2
1 CI = Confidence Interval

Table linear regression for Discharge - Admission MRS difference (AVM Volume - Only Volumes > 1 cm3)

Male sex and presence of perforating branches are borderline associated with an increase in mRS between Discharge and Admission, while the hemorrhage at onset is associated with a decrease. R2 = 0.4380805

Characteristic Beta 95% CI1 p-value
Sex (male) 0.87 0.15, 1.6 0.020
Age at Surgery (years) 0.02 0.00, 0.04 0.12
Onset


    Unruptured
    Hemorrhage -1.4 -2.2, -0.53 0.002
GCS on Admission 0.00 -0.11, 0.11 >0.9
Perforating branches 1.0 0.16, 1.9 0.022
Aneurysm -0.57 -1.4, 0.22 0.15
Diffuse 0.61 -0.18, 1.4 0.13
AVM volume (cm³) 0.01 -0.01, 0.03 0.4
1 CI = Confidence Interval

Table linear regression for Followup - Admission MRS difference (AVM Volume - Only Volumes > 1 cm3)

Age, GCS at admission, presence of perforating branches and (borderline) volume are associated with a worsening of mRS between Follow-up and Admission, while the hemorrhage at onset and the presence of aneurysm are associated with an improvement. R2 = 0.5416528

Characteristic Beta 95% CI1 p-value
Sex (male) 0.23 -0.43, 0.89 0.5
Age at Surgery (years) 0.02 0.01, 0.04 0.013
Onset


    Unruptured
    Hemorrhage -1.0 -1.8, -0.26 0.011
GCS on Admission 0.14 0.03, 0.25 0.011
Perforating branches 0.93 0.13, 1.7 0.024
Aneurysm -0.84 -1.6, -0.11 0.025
Diffuse 0.56 -0.19, 1.3 0.14
AVM volume (cm³) 0.02 0.00, 0.04 0.060
1 CI = Confidence Interval

Deficit models

Table logistic regression for presence of Deficit (S-M categories 1-2, 3, 4-5)

Only S-M grading is associated with a higher risk of post surgery deficit

Characteristic OR1 95% CI1 p-value
S-M grade


    1-2
    3 14.0 3.17, 80.8 0.001
    4-5 25.7 3.37, 563 0.007
Sex (male) 1.30 0.34, 5.11 0.7
Age at Surgery (years) 1.00 0.96, 1.04 >0.9
Onset


    Unruptured
    Hemorrhage 1.75 0.37, 9.85 0.5
GCS on Admission 1.12 0.92, 1.41 0.3
Perforating branches 1.51 0.23, 9.07 0.7
Aneurysm 1.75 0.34, 9.04 0.5
1 OR = Odds Ratio, CI = Confidence Interval

Table logistic regression for presence of Deficit (Supplementary grading categories 2-5, 6, 7-8)

Only S-M grading is associated with a higher risk of post surgery deficit

Characteristic OR1 95% CI1 p-value
Supplemented S-M grade


    2-5
    6 10.7 2.30, 71.7 0.006
    7-8 42.2 5.92, 895 0.002
Sex (male) 1.22 0.31, 4.82 0.8
Age at Surgery (years) 0.97 0.93, 1.01 0.2
GCS on Admission 1.06 0.88, 1.31 0.6
Perforating branches 1.57 0.25, 8.95 0.6
Aneurysm 1.45 0.28, 7.31 0.6
1 OR = Odds Ratio, CI = Confidence Interval

The figure shows the ROC curves for the two logistic models. The model with the Supplemented grading shows a slightly better AUC values not significantly different from the Original S-M model

Deficit models (major vs others)

Vedi considerazioni modelli precedenti

Table logistic regression for presence of Deficit (S-M categories 1-2, 3, 4-5)

Characteristic OR1 95% CI1 p-value
S-M grade


    1-2
    3 20.8 2.97, 248 0.006
    4-5 76.4 7.02, 1,630 0.001
Sex (male) 0.37 0.07, 1.74 0.2
Age at Surgery (years) 1.03 0.98, 1.08 0.3
Onset


    Unruptured
    Hemorrhage 2.71 0.41, 25.0 0.3
GCS on Admission 1.02 0.80, 1.32 0.9
Perforating branches 0.00
>0.9
Aneurysm 4.21 0.56, 40.6 0.2
1 OR = Odds Ratio, CI = Confidence Interval

Table logistic regression for presence of Deficit (Supplementary grading categories 2-5, 6, 7-8)

Characteristic OR1 95% CI1 p-value
Supplemented S-M grade


    2-5
    6 15.7 2.32, 178 0.010
    7-8 57.9 7.59, 753 <0.001
Sex (male) 0.38 0.06, 1.95 0.3
Age at Surgery (years) 0.99 0.94, 1.04 0.8
GCS on Admission 0.96 0.75, 1.25 0.8
Perforating branches 0.00
>0.9
Aneurysm 3.77 0.47, 39.2 0.2
1 OR = Odds Ratio, CI = Confidence Interval

Logistic regression for surgical complications

Vedi considerazioni modelli precedenti

(S-M categories 1-2, 3, 4-5)

Characteristic OR1 95% CI1 p-value
S-M grade


    1-2
    3 8.33 2.20, 37.3 0.003
    4-5 25.3 3.47, 534 0.006
Sex (male) 0.89 0.24, 3.26 0.9
Age at Surgery (years) 1.01 0.98, 1.05 0.5
GCS on Admission 1.13 0.94, 1.41 0.2
Perforating branches 1.56 0.27, 8.37 0.6
Aneurysm 1.05 0.20, 4.98 >0.9
1 OR = Odds Ratio, CI = Confidence Interval
Characteristic OR1 95% CI1 p-value
Supplemented S-M grade


    2-5
    6 12.9 2.70, 89.9 0.003
    7-8 51.2 7.05, 1,108 <0.001
Sex (male) 0.88 0.21, 3.58 0.9
Age at Surgery (years) 0.98 0.93, 1.02 0.4
GCS on Admission 1.10 0.91, 1.38 0.4
Perforating branches 1.90 0.30, 11.0 0.5
Aneurysm 0.85 0.14, 4.49 0.9
1 OR = Odds Ratio, CI = Confidence Interval

(Supplementary grading categories 2-5, 6, 7-8)

Characteristic OR1 95% CI1 p-value
Supplemented S-M grade


    2-5
    6 12.9 2.70, 89.9 0.003
    7-8 51.2 7.05, 1,108 <0.001
Sex (male) 0.88 0.21, 3.58 0.9
Age at Surgery (years) 0.98 0.93, 1.02 0.4
GCS on Admission 1.10 0.91, 1.38 0.4
Perforating branches 1.90 0.30, 11.0 0.5
Aneurysm 0.85 0.14, 4.49 0.9
1 OR = Odds Ratio, CI = Confidence Interval

Analysis patients with S-M 3

Characteristic All 3s
N = 17
Other 3s
N = 6
3+
N = 11
p-value
Sex (male) 9 (53%) 3 (50%) 6 (55%) >0.999
Age at AVM diagnosis (years) 37.47 ± 16.93 33.33 ± 16.71 39.73 ± 17.42 0.450
Clinical Presentation


0.304
    Hemorrhage 7 (41%) 1 (17%) 6 (55%)
    Unruptured 10 (59%) 5 (83%) 5 (45%)
Glasgow Coma Scale on Admission


0.467
    3-8 4 (24%) 1 (17%) 3 (27%)
    9-13 2 (12%) 0 (0%) 2 (18%)
    14-15 11 (65%) 5 (83%) 6 (55%)
Modified Rankin Scale on Admission


0.333
    0-1 11 (65%) 5 (83%) 6 (55%)
    2-3 0 (0%) 0 (0%) 0 (0%)
    4-6 6 (35%) 1 (17%) 5 (45%)
AVM volume (cm³) 9.84 (7.44-11.86) 10.71 (5.97-11.80) 9.60 (7.90-11.86) >0.999
Previous Treatments


>0.999
    None 4 (24%) 1 (17%) 3 (27%)
    Embolization 13 (76%) 5 (83%) 8 (73%)
    Other 0 (0%) 0 (0%) 0 (0%)
Time from Diagnosis to Surgery


>0.999
    0-1 year 3 (25%) 2 (33%) 1 (17%)
    > 1 year 9 (75%) 4 (67%) 5 (83%)
Age at Surgery (years) 39.88 ± 16.47 36.83 ± 14.82 41.55 ± 17.76 0.546
AVM Site


0.762
    Cerebellar 1 (5.9%) 0 (0%) 1 (9.1%)
    Frontal 7 (41%) 2 (33%) 5 (45%)
    Parietal 2 (12%) 0 (0%) 2 (18%)
    Temporal 5 (29%) 3 (50%) 2 (18%)
    Other 2 (12%) 1 (17%) 1 (9.1%)
AVM Side


>0.999
    left 11 (65%) 4 (67%) 7 (64%)
    right 6 (35%) 2 (33%) 4 (36%)
AVM Localization


>0.999
    infratentorial 1 (5.9%) 0 (0%) 1 (9.1%)
    supratentorial 16 (94%) 6 (100%) 10 (91%)
Presence of Perforating Arterial Branches 2 (13%) 2 (33%) 0 (0%) 0.125
Presence of Aneurysm 2 (12%) 1 (17%) 1 (9.1%) >0.999
Aneurysm Location


>0.999
    pre-nidus 0 (0%) 0 (0%) 0 (0%)
    pre-intra-nidus 0 (0%) 0 (0%) 0 (0%)
    intra-nidus 2 (100%) 1 (100%) 1 (100%)
AVM Morphology


0.500
    compact 14 (88%) 6 (100%) 8 (80%)
    diffuse 2 (13%) 0 (0%) 2 (20%)
Lawton-Young Grade


>0.999
    1 2 (12%) 1 (17%) 1 (9.1%)
    2 2 (12%) 1 (17%) 1 (9.1%)
    3 9 (53%) 3 (50%) 6 (55%)
    4 4 (24%) 1 (17%) 3 (27%)
Lawton-Young Age score


0.819
    1 4 (24%) 2 (33%) 2 (18%)
    2 5 (29%) 2 (33%) 3 (27%)
    3 8 (47%) 2 (33%) 6 (55%)
Lawton-Young Bleeding score


0.620
    0 8 (47%) 2 (33%) 6 (55%)
    1 9 (53%) 4 (67%) 5 (45%)
Lawton-Young Compactness score


0.515
    0 15 (88%) 6 (100%) 9 (82%)
    1 2 (12%) 0 (0%) 2 (18%)
Supplemented grade


>0.999
    2-5 4 (24%) 2 (33%) 2 (18%)
    6 9 (53%) 3 (50%) 6 (55%)
    7-8 4 (24%) 1 (17%) 3 (27%)
Emergency Surgery


0.102
    0 12 (71%) 6 (100%) 6 (55%)
    1 5 (29%) 0 (0%) 5 (45%)
AVM closure 15 (100%) 6 (100%) 9 (100%) >0.999
Post-surgery complications 10 (63%) 4 (67%) 6 (60%) >0.999
Post-surgery deficit


>0.999
    none 5 (31%) 2 (33%) 3 (30%)
    minor 5 (31%) 2 (33%) 3 (30%)
    major 6 (38%) 2 (33%) 4 (40%)
Modified Rankin Scale at Discharge


0.281
    0-1 10 (63%) 4 (67%) 6 (60%)
    2-3 1 (6.3%) 1 (17%) 0 (0%)
    4-6 5 (31%) 1 (17%) 4 (40%)
Modified Rankin Scale at Follw-up


>0.999
    0-1 11 (85%) 5 (83%) 6 (86%)
    2-3 0 (0%) 0 (0%) 0 (0%)
    4-6 2 (15%) 1 (17%) 1 (14%)
Follow-up (years) 5.36 (1.69-7.60) 5.27 (3.27-7.60) 6.72 (0.93-8.07) 0.886
Discharge - Admission MRS difference 0.31 ± 0.95 0.50 ± 1.38 0.20 ± 0.63 0.904
Follow-up - DischargeMRS difference -0.77 ± 1.09 -0.67 ± 1.21 -0.86 ± 1.07 0.527
Follow-up - Admission MRS difference -0.38 ± 1.12 -0.17 ± 0.41 -0.57 ± 1.51 >0.999

Volume threshold analysis

Analysis for surgical complications

Analysis for deficit (major vs other)

Characteristic OR1 95% CI1 p-value
Volume


    <11.115
    >11.115 4.13 1.17, 16.0 0.032
1 OR = Odds Ratio, CI = Confidence Interval

Characteristic OR1 95% CI1 p-value
Volume


    <11.115
    >11.115 2.94 0.76, 12.3 0.12
1 OR = Odds Ratio, CI = Confidence Interval