Table 1

Hydrodynamic resistance of the opened shunt depends on the preset performance level.

Performance level
Shunt without Catheter
Shunt with catheter (110 cm long, internal diameter 1.1 mm)

30 mmH2O
2.3 mmHg
1.58 (0.3)
4.61 (.71)
70 mmH2O
5.2 mmHg
2.06 (0.41)
5.12 (0.76)
110 mmH2O
8.1 mmHg
2.48 (0.52)
5.62 (0.82)
150 mmH2O
11.1 mmHg
5.18 (0.81)
8.21 (1.01)
200 mmH2O
14.7 mmHg
11.2 (1.31)
14.2 (1.42)

Units are mmHg/ml/min; mean values and standard deviation (in parentheses). Each test was repeated 3 times in 3 valves.

Allin et al. Cerebrospinal Fluid Research 2008 5:8   doi:10.1186/1743-8454-5-8