Management of posthaemorrhagic ventricular dilatation (PHVD) in preterm infants is still under discussion. The most important benefit of CSF drainage is the avoidance of compromise of the cerebral circulation resulting from increased ICP. Therefore, we inserted a silastic subcutaneous ventricular catheter reservoir to perform serial CSF punctures and to measure intracranial pressure (ICP). The reservoir was inserted when on ultrasound the ventricular diameter was >2SD above P97 of the Levene curve1. CSF punctures were performed twice daily. Before and at 30′ minutes after CSF removal cerebral blood flow velocity (CBFV) was measured in the anterior and mid cerebral artery. ICP was measured at the moment of puncturing the reservoir and at the end of the CSF removal procedure. A CSF removal volume of 5ml/kg bodyweight was chosen for each puncture. Tapping continued untill normalisation of ventricular diameter or untill a ventricular-peritoneal shunt could be inserted. Measurements were obtained on 43 occasions in 12 preterm infants with PHVD. The mean decrease in ICP after tapping was 40%, with a concomitant decrease in Pulsatility Index of 6.6%. The latter was mainly caused by an increase in end diastolic blood flow velocity of 33%. The resulting increase in mean CBFV was 22%.
Conclusion: repeated tapping of CSF via a subcutaneous ventricular catheter is associated with a significant improvement in CBFV, probably caused by a reduction in ICP. Frequency and volume of tapping can be determined by ICP and CBFV in combination with ultrasound measurement of ventricular diameter in expectation of insertion of a permanent ventricular-peritoneal shunt or, even, normalisation of the ventricular size.
