Baseline characteristics of the patients included in the SVASONA trial
| Programmable valve group (n=71) | Gravitational valve group (n=74) | |
|---|---|---|
| Sex | ||
| Male (n (%)) | 48 (68) | 41 (55) |
| Female (n (%)) | 23 (32) | 33 (45) |
| Age at surgery (years) (mean (SD)) | 71.2 (7.0) | 72.7 (6.7) |
| BMI (mean (SD)) | 28.6 (4.2) | 27.1 (4.1) |
| Evans Index (mean (SD)) | 0.38 (0.06) | 0.37 (0.05) |
| Cortical atrophy, any grade (n (%)) | 61 (86) | 67 (91) |
| Mean intracranial pressure (mm H2O) (mean (SD)) | 9.6 (3.6) | 9.6 (3.1) |
| ASA III patients (n (%)) | 23 (32) | 25 (34) |
| Charlson Comorbidity Index (n) | ||
| Not indicated | 8 | 7 |
| 0 | 18 | 24 |
| 1 | 20 | 20 |
| 2 | 9 | 11 |
| 3 | 7 | 7 |
| 4 | 7 | 5 |
| >4 | 2 | 0 |
| Duration of surgery (min) (mean (SD)) | 60.5 (22.5) | 61.9 (23.7) |
| Duration of hospital stay (days) (mean (SD)) | 7.9 (4.3) | 7.1 (3.9) |
| Gravitational unit opening pressure (mm H2O) (n) | ||
| 200 | 20 | |
| 250 | 34 | |
| 300 | 16 | |
| 350 | 4 | |
| Postoperative CT scan (n (%)) | 70 (99) | 71 (96) |
| Interval to postoperative CT (days) (mean (SD)) | 3.9 (3.7) | 4.2 (4.5) |
ASA, American Society of Anaesthesiologists physical status classification system; BMI, body mass index; SVASONA trial, Shunt Valves plus shunt Assistant versus Shunt valves alone for controlling Overdrainage in idiopathic Normal pressure hydrocephalus in Adults trial.