BIVENTRICULAR SHUNT
It can be inserted in either the frontal or parietal location. There are three options for the placement of biventricular shunts. The 2 shunts can be treated independently with two tubes tunnelled to the peritoneal cavity. A 'Y' or 'T connector inserted proximal to the valve can connect ventricular catheters. This last is the preferred technique. In the third option a valve can be placed just after the reservoir on each side with the 2 shunts being joined at a more distal location (Fig. 6-12). The most frequent indication to insert second shunt is that a catheter placed on one lateral ventricle initially drains both lateral ventricles satisfactory in case of hydrocephalus caused by a tumour, but then with subsequent tumour growth, the two lateral ventricles become isolated. The patient becomes symptomatic with evidence of raised intracranial pressure or the problem may be detected by routine follow-up CT or MRI. In such a case it is necessary to place a second ventricular catheter and to attach it to the existing shunt.