Comparison of baseline, procedural variables and complications among patient groups
| Characteristics | Total | Group 1 | Group 2 | P value | Statistic |
| (n=213) | 1–25 (n=25) | 26–213 (n=188) | |||
| Demographic variables | |||||
| AVM patients treated | 213 | 25 | 188 | ||
| Age, years | 29.45±14.17 | 31.96±16.12 | 29.11±13.90 | 0.346 | t=0.94 |
| Female sex, n (%) | 87 (40.85) | 11 (44.00) | 76 (40.43) | 0.733 | χ²=0.12 |
| Alcohol abuse, n (%) | 21 (9.86) | 5 (20.00) | 16 (8.51) | 0.146 | χ²=2.11 |
| Smoking, n (%) | 38 (17.84) | 5 (20.00) | 33 (17.55) | 0.982 | χ²=0.00 |
| Hypertension | 12 (5.63) | 1 (4.00) | 11 (5.85) | 0.706 | χ²=0.00 |
| Diabetes | 2 (0.94) | 0 (0.00) | 2 (1.06) | 0.604 | – |
| Presentation, n (%) | 0.218 | χ²=3.05 | |||
| Incidental | 10 (4.69) | 0 (0.00) | 10 (5.32) | ||
| Symptomatic | 97 (45.54) | 9 (36.00) | 88 (46.81) | ||
| Ruptured | 106 (49.77) | 16 (64.00) | 90 (47.87) | ||
| Preoperative mRS | 0.693 | – | |||
| 0–2 | 196 (92.02) | 24 (96.00) | 172 (91.49) | ||
| 3–4 | 14 (6.57) | 1 (4.00) | 13 (6.91) | ||
| 5–6 | 3 (1.41) | 0 (0.00) | 3 (1.60) | ||
| AVM variables | |||||
| AVM size, mm | 39.15±15.34 | 44.33±14.48 | 38.47±15.35 | 0.072 | t=1.81 |
| Spetzler-Martin grades | 0.214 | χ²=3.08 | |||
| I–II | 94 (44.13) | 7 (28.00) | 87 (46.28) | ||
| III | 89 (41.78) | 13 (52.00) | 76 (40.43) | ||
| IV–V | 30 (14.08) | 5 (20.00) | 25 (13.30) | ||
| Eloquent location | 120 (56.34) | 15 (60.00) | 105 (55.85) | 0.694 | χ²=0.15 |
| Deep venous drainage | 66 (30.99) | 8 (32.00) | 58 (30.85) | 0.907 | χ²=0.01 |
| Associated aneurysms | 42 (19.72) | 4 (16.00) | 38 (20.21) | 0.818 | χ²=0.05 |
| AVM location, n (%) | 0.354 | – | |||
| Superficial | 160 (75.12) | 17 (68.00) | 143 (76.06) | ||
| Deep | 34 (15.96) | 4 (16.00) | 30 (15.96) | ||
| Cerebellum | 16 (7.51) | 4 (16.00) | 12 (6.38) | ||
| Brainstem | 3 (1.41) | 0 (0.00) | 3 (1.60) | ||
| Embolisation strategy, n (%) | <0.001 | χ²=32.79 | |||
| Curative | 54 (25.35) | 18 (72.00) | 36 (19.15) | ||
| Palliative | 133 (62.44) | 6 (24.00) | 127 (67.55) | ||
| Targeted | 26 (12.21) | 1 (4.00) | 25 (13.30) | ||
| Major complications, n (%) | 78 (36.62) | 13 (52.00) | 65 (34.57) | 0.089 | χ²=2.89 |
| Haemorrhagic events | 13 (6.10) | 3 (12.00) | 10 (5.32) | 0.386 | χ²=0.75 |
| Ischaemic events | 10 (4.69) | 3 (12.00) | 7 (3.72) | 0.182 | χ²=1.78 |
| Intracranial infections | 57 (26.76) | 8 (32.00) | 49 (26.06) | 0.529 | χ²=0.40 |
| Seizure | 7 (3.29) | 0 (0.00) | 7 (3.72) | ＞0.999 | – |
| Blood loss ≥549 mL | 85 (39.91) | 14 (56.00) | 71 (37.77) | 0.080 | χ²=3.06 |
| Blood loss, mL, median (Q₁, Q₃) | 500 (300, 1000) | 750 (500, 1500) | 500 (300, 1000) | 0.135 | Z=−1.49 |
| Unfavourable outcomes, n (%) | 46 (21.60) | 11 (44.00) | 35 (18.62) | 0.004 | χ²=8.40 |
| Worsen mRS | 41 (19.25) | 8 (32.00) | 33 (17.55) | 0.147 | χ²=2.11 |
| Discharge mRS=5–6 | 5 (2.35) | 3 (12.00) | 2 (1.06) | 0.012 | – |
| Discharge mRS score, n (%) | 0.002 | – | |||
| 0–2 | 160 (75.12) | 13 (52.00) | 147 (78.19) | ||
| 3–4 | 48 (22.54) | 9 (36.00) | 39 (20.74) | ||
| 5–6 | 5 (2.35) | 3 (12.00) | 2 (1.06) | ||
| Follow-up time,month | 49.90±20.54 | 72.26±3.83 | 46.00±19.75 | ||
| Follow-up patients | 147 (69.01） | 22 (88.00） | 125 (66.49） | ||
| Follow-up mRS score, n (%) | 0.035 | χ²=6.71 | |||
| 0–2 | 124 (84.35) | 18 (81.82) | 106 (84.80) | ||
| 3–4 | 20 (13.61) | 2 (9.09) | 18 (14.40) | ||
| 5–6 | 3 (2.04) | 2 (9.09) | 1 (0.80) |
–: Fisher’s exact test.
AVM, arteriovenous malformation; mRS, modified Rankin Scale; Z, Mann-Whitney test.