Shunt procedures and patient demographics, by age group, among patients with known age
| Age of patient at time of procedure | |||
| Infant (<1 year) | Children (1 to <17 years) | Adults (≥17 years) | |
| Total no of procedures, n* | 4458 | 8742 | 27 310 |
| Age (years) at primary shunt, median (IQR) | 0.2 (0.1–0.4) | 7.6 (3.2–12.4) | 55.3 (39.3–68.5) |
| Female:male ratio at primary shunt | 5:7 | 6:7 | 6:5 |
| Primary shunt insertions, n (%) | 2756 (61.8) | 2525 (28.9) | 15 263 (55.9) |
| Underlying diagnosis for primary shunt†, n (%) | |||
| Malformations‡ | 934 (33.9) | 411 (16.3) | 1125 (7.4) |
| Perinatal intraventricular haemorrhage | 973 (35.3) | 160 (6.3) | 94 (0.6) |
| Tumour (benign, malignant, unspecified) | 152 (5.5) | 1022 (40.5) | 3750 (24.6) |
| Post-haemorrhagic (AVM, SAH, unspecified) | 28 (1.0) | 48 (1.9) | 2473 (16.2) |
| Idiopathic normal pressure hydrocephalus | 0 (0) | 0 (0) | 2173 (14.2) |
| Idiopathic intracranial hypertension | 10 (0.4) | 122 (4.8) | 1160 (7.6) |
| Infection (meningitis, cerebral abscess, unspecified) | 184 (6.7) | 108 (4.3) | 472 (3.1) |
| Cyst (colloid, arachnoid, unspecified) | 84 (3.0) | 124 (4.9) | 522 (3.4) |
| Trauma | 30 (1.1) | 55 (2.2) | 525 (3.4) |
| Acquired other | 127 (4.6) | 168 (6.7) | 1242 (8.1) |
| Idiopathic other | 22 (0.8) | 26 (1.0) | 162 (1.1) |
| Unknown (diagnosis not specified) | 212 (7.7) | 279 (11.1) | 1565 (10.3) |
| First-year revision rates, n (%)§ | 772 (31.0) | 584 (25.2) | 2406 (17.4) |
| 90-day revision rates, n (%)§ | 591 (21.9) | 462 (18.6) | 1919 (12.8) |
| Reasons for primary shunt revision¶, n (%): | |||
| Underdrainage | 317 (64.9) | 199 (66.3) | 759 (57.2) |
| Shunt infection | 81 (16.5) | 35 (11.7) | 158 (11.9) |
| Disconnection | 25 (5.1) | 12 (4.0) | 93 (7.0) |
| Migration | 17 (3.4) | 6 (2.0) | 101 (7.6) |
| Overdrainage | 7 (1.4) | 24 (8.0) | 101 (7.6) |
| Fracture | 8 (1.6) | 5 (1.6) | 30 (2.2) |
| Wound infection | 3 (0.6) | 1 (0.3) | 8 (0.6) |
| More than one reason | 30 (6.1) | 18 (6.0) | 75 (5.6) |
| Primary shunt revisions that included shunt replacement with external ventricular drain | 55 (5.5) | 21 (2.6) | 106 (3.3) |
*For 526 (1.3%) procedures, in 486 (1.8%) patients, the age of the patient was unknown.
†Including only procedures of primary shunt insertion.
‡Malformations included aqueduct stenosis, Dandy-Walker, Chiari, malformations with spina bifida, unspecified congenital and other malformations.
§First-year and 90-day revision rates were calculated for all patients whose primary shunt was inserted in the study period, and who were followed up for at least 1 year and 90 days, respectively.
¶Excluding revision procedures with unknown/no reason specified. Among the 119 patients with multiple reasons for revision of primary shunt, each reason was present in different percentages, and included underdrainage (74%), disconnection (46%), migration (33%), shunt infection (18%), fracture (15%), overdrainage (11%) and wound infection (2%).
AVM, cerebral arteriovenous malformation;SAH, subarachnoid haemorrhage.