Baseline characteristics
| Overall n=1555 | Without re-rupture n=1354 | Re-rupture n=201 | P value | |
| Demographic characteristics | ||||
| Female gender, n (%) | 668 (43.0) | 570 (42.1) | 98 (48.8) | 0.089 |
| Initial rupture age, mean (SD) | 25.3 (14.9) | 25.1 (14.7) | 26.6 (15.9) | 0.198 |
| Clinical features | ||||
| Seizure, n (%) | 191 (12.3) | 163 (12.0) | 28 (13.9) | 0.517 |
| Headache, n (%) | 234 (15.1) | 206 (15.2) | 28 (13.9) | 0.712 |
| Neurological complications, n (%) | 298 (19.2) | 256 (18.9) | 42 (20.9) | 0.567 |
| Morphologic features | ||||
| SM grade, n (%) | ||||
| 1 | 273 (17.6) | 259 (19.1) | 14 (7.0) | <0.001 |
| 2 | 551 (35.4) | 500 (36.9) | 51 (25.4) | |
| 3 | 497 (32.0) | 420 (31.0) | 77 (38.3) | |
| 4 | 202 (13.0) | 153 (11.3) | 49 (24.4) | |
| 5 | 32 (2.1) | 22 (1.6) | 10 (5.0) | |
| Ventricular system involvement, n (%) | 1022 (65.7) | 863 (63.7) | 159 (79.1) | <0.001 |
| Deep location, n (%) | 492 (31.6) | 421 (31.1) | 71 (35.3) | 0.262 |
| AVM size, n (%) | ||||
| <3 cm | 956 (61.5) | 872 (64.4) | 84 (41.8) | <0.001 |
| 3–6 cm | 516 (33.2) | 419 (31.0) | 97 (48.3) | |
| >6 cm | 83 (5.3) | 63 (4.7) | 20 (10.0) | |
| Eloquent region, n (%) | 893 (57.4) | 760 (56.1) | 133 (66.2) | 0.009 |
| Angioarchitectural features | ||||
| Feeding artery dilation, n (%) | 537 (34.5) | 453 (33.5) | 84 (41.8) | 0.025 |
| Feeding arteries number, mean (SD) | 2.0 (1.2) | 1.9 (1.1) | 2.5 (1.3) | <0.001 |
| Arterial borderzone, n (%) | 316 (20.3) | 252 (18.6) | 64 (31.8) | <0.001 |
| Associated aneurysm, n (%) | 302 (19.4) | 258 (19.1) | 44 (21.9) | 0.394 |
| Diffuse nidus, n (%) | 699 (45.0) | 615 (45.4) | 84 (41.8) | 0.374 |
| Any deep venous drainage, n (%) | 704 (45.3) | 582 (43.0) | 122 (60.7) | <0.001 |
| Exclusive deep venous drainage, n (%) | 509 (32.7) | 427 (31.5) | 82 (40.8) | 0.011 |
| Number of arteries/venous, mean (SD) | 8.9 (3.2) | 8.8 (3.1) | 9.6 (3.5) | 0.003 |
| Draining vein stenosis, n (%) | 300 (19.3) | 256 (18.9) | 44 (21.9) | 0.366 |
| Venous aneurysm, n (%) | 99 (6.4) | 77 (5.7) | 22 (11.0) | 0.007 |
AVM, arteriovenous malformation; SM, Spetzler–Martin.