Frequency of hemorrhage as a function of angioarchitectural features in pediatric arteriovenous malformations
| Feature | Subgroup | Total No | No with hemorrhage (%) |
| Location | Superficial | 117 | 72 (61.5) |
| Deep | 18 | 14 (77.8) | |
| Supratentorial | 119 | 72 (60.5) | |
| Infratentorial | 16 | 14 (87.5) | |
| Size (cm) | <3 | 88 | 64 (72.7) |
| 3–6 | 43 | 21 (48.8) | |
| >6 | 4 | 1 (25.0) | |
| Venous drainage | Superficial only | 82 | 49 (59.8) |
| Deep only | 23 | 20 (87.0) | |
| Both | 30 | 17 (56.7) | |
| Associated aneurysm | Intranidal | 7 | 6 (85.7) |
| Prenidal | 4 | 3 (75.0) | |
| None | 124 | 76 (61.8) | |
| Venous pouch | Present | 15 | 8 (53.3) |
| None | 120 | 78 (65.0) | |
| Draining veins | Single | 66 | 47 (71.2) |
| Multiple | 69 | 39 (56.5) | |
| Venous ectasia | Present | 5 | 3 (60.0) |
| None | 130 | 83 (63.9) | |
| Angiographic venous stenosis | Present | 24 | 17 (70.8) |
| None | 111 | 69 (62.2) | |
| Functional venous stenosis | Present | 18 | 15 (83.3) |
| None | 117 | 71 (60.7) | |
| Nidus morphology | Compact | 91 | 49 (53.8) |
| Diffuse | 33 | 30 (90.9) | |
| Fistulous | 10 | 6 (60.0) |