Postshunt insertion CSF leaks in infants treated by an adjustable valve opening pressure reduction

Abstract

Objects. Cerebrospinal fluid (CSF) leakages through the operation wound following shunt placement are commonly treated by head elevation when the shunt is patent and signs of infection are absent.

Methods and results. In two cases in which the standard therapy of head elevation failed, the leakage was successfully managed by temporary lowering of the opening pressure of the implanted programmable valve. Case 1 was that of a preterm baby with repaired meningomyelocele and shunted hydrocephalus. A shunt infection made shunt removal necessary. Five days after insertion of a new ventriculoperitoneal shunt, transcutaneous CSF flow occurred. The CSF leak was cured by a temporary reduction of the opening pressure from 70 to 30 mmH₂0. Case 2 was in a 9-month-old child with shunted posthaemorrhagic hydrocephalus. Shunt infection was treated by shunt removal, placement of external ventricular drainage, and antibiotics. CSF leakage through the operation wound developed 24 h after placement of the new ventriculoperitoneal shunt. The CSF leakage was successfully treated by temporarily lowering the opening pressure of the valve from 100 to 50 mmH₂0.

Conclusion. The authors assume that head elevation alone did not generate a sufficient difference between the ventricular and the abdominal pressure for the selected opening pressure of the valve to be exceeded, with the result that CSF flowed around the ventricular catheter and through the operation wound. It is believed that reduction of the opening pressure of the valve led to CSF flow through the shunt and made siphoning possible, resulting in cessation of the transcutaneous CSF flow. The authors propose the prophylactic implantation of a programmable valve in children at high risk of postoperative transcutaneous CSF leakage.