Table 3.
BAVM morphologic classification associated with unfavorable hemorrhage riska
| Characteristics | Type Ia (n = 30) |
Type Ib (n = 29) |
Type II (n = 52) |
Type III (n = 51) |
|---|---|---|---|---|
| Morphologic Features | ||||
| Nidus location | Periventricular and non-temporal (corpus callosum, basal ganglia or thalamus) | Periventricular and non-temporal (frontal, parietal, occipital lobe or cerebellum) | Non-periventricular or temporal lobe | Non-periventricular or temporal lobe |
| Long pial draining vein | 13 (43.3) | 14 (48.3) | 52 (100.0) | 0 (0) |
| Hemorrhage | ||||
| mRS at bAVM rupture | ||||
| ≤ 2 | 9 (30) | 12 (41.4) | 30 (57.7) | 41 (80.4) |
| >2 | 21 (70) | 17 (58.6) | 22 (42.3) | 10 (19.6) |
| Unfavorable hemorrhage | ||||
| No | 12 (40.0) | 15 (51.7) | 38 (73.1) | 48 (94.1) |
| Yes | 18 (60.0) | 14 (48.3) | 14 (26.9) | 3 (5.9) |
| Follow-up period, patient-years | 367 | 280 | 667 | 711 |
| Annual rate of unfavorable hemorrhage, % | 4.9 | 5.0 | 2.1 | 0.4 |
| Spetzler-Martin Grade | ||||
| I-II | 7 (23.3) | 20 (70.0) | 30 (57.7) | 29 (56.9) |
| III | 11 (36.7) | 6 (20.7) | 14 (26.9) | 18 (35.3) |
| IV-V | 12 (40.0) | 3 (10.3) | 8 (15.4) | 4 (7.8) |
aTable entries are No. (%)