Table 3.
Comparison of pre- and postoperative radiological characteristics of 319 CSDH patients undergoing burr hole evacuation with and without drain insertion
| Total (n = 319) | No drain inserted* (n = 45) | Drain* (n = 272) | p value | |
|---|---|---|---|---|
| CSDH density on initial CT scan | 0.27 | |||
| Hypodense | 89 (27.9) | 17 (37.8) | 71 (26.1) | |
| Isodense | 60 (18.8) | 7 (15.6) | 53 (19.5) | |
| Mixed | 170 (53.3) | 21 (46.7) | 148 (54.4) | |
| Presence of membrane on CT scan | 0.22 | |||
| Yes | 133 (41.7) | 15 (33.3) | 117 (43.0) | |
| No | 186 (58.3) | 30 (66.7) | 155 (57.0) | |
| Preoperative maximal width (mm) | ||||
| Overall | 25 (18–32) | 20 (14–26) | 25 (19–32) | < 0.01 |
| Unilateral cases | 22 (17–28) | 20 (12–23) | 23.5 (18–29) | < 0.01 |
| Bilateral cases | 34 (25–42) | 33.5 (19–37) | 34 (25–43.5) | 0.27 |
| Preoperative midline shift (mm) | ||||
| Overall | 8 (4–11) | 7 (4–10) | 8 (4–12) | 0.09 |
| Unilateral cases | 9 (6–12) | 7 (5–11) | 9.5 (6–13) | 0.01 |
| Bilateral cases | 3 (0–6) | 3 (0–7) | 3 (0–6) | 0.67 |
| Time to operation (days) | 1 (1–3) | 2 (1–6) | 1 (1–3) | 0.09 |
| Days between operation and postoperative scan (median; IQR) | 2 (1–4) | 2 (1–3.5) | 2 (1–4) | 0.50 |
| Postoperative maximal width (mm) | ||||
| Overall | 14 (9–21) | 15 (10–22) | 14 (9–21) | 0.36 |
| Unilateral cases | 13 (8–19) | 15 (9–22) | 13 (8–18.5) | 0.14 |
| Bilateral cases | 20 (12.29) | 20 (12–28) | 20.5 (12.5–29) | 0.93 |
| Change in maximal width (mm) | ||||
| Overall | ||||
| Median (IQR) | 10 (5–15) | 6 (2–9) | 11 (6–16) | < .01 |
| Reduced width | 288 (90.9) | 35 (77.8) | 253 (93.0) | |
| Same or increased width | 29 (9.2) | 10 (22.2) | 19 (7) | |
| Unilateral cases | ||||
| Median (IQR) | 9 (5–14) | 4 (0–8) | 10 (6–15) | < 0.01 |
| Reduced width | 202 (90.6) | 26 (74.3) | 176 (93.6) | |
| Same or increased width | 21 (9.4) | 9 (25.7) | 12 (6.4) | |
| Bilateral cases | ||||
| Median (IQR) | 13 (7–20) | 8 (6–9) | 14 (7–20) | 0.08 |
| Reduced width | 79 (91.9) | 9 (90.0) | 70 (92.1) | |
| Same or increased width | 7 (8.1) | 1 (10.0) | 6 (7.9) | |
| Change in midline shift (mm) | ||||
| Overall | ||||
| Median (IQR) | 4 (1–6) | 3 (0–4) | 4 (2–7) | < 0.01 |
| Reduced shift | 256 (80.8) | 32 (71.1) | 224 (82.4) | |
| Same or increased shift | 61 (19.2) | 13 (28.9) | 48 (17.7) | |
| Unilateral cases | ||||
| Median (IQR) | 0 (0–1) | 3 (0–4) | 5 (2–8) | < 0.01 |
| Reduced shift | 192 (86.1) | 25 (71.4) | 167 (88.8) | |
| Same or increased shift | 31 (13.9) | 10 (28.6) | 21 (11.2) | |
| Bilateral cases | ||||
| Median (IQR) | 0 (0–1) | 2.5 (0–5) | 2 (0–4) | 0.84 |
| Reduced shift | 56 (65.1) | 7 (70.0) | 49 (64.5) | |
| Same or increased shift | 30 (34.9) | 3 (30.0) | 27 (35.5) | |