Relationship of the location of the ventricular catheter tip and function of the ventriculoperitoneal shunt.

The long-term maintenance of ventriculoperitoneal (VP) shunt function depends on the correct placement of the catheter tip in the lateral ventricle. The relationship between the location of the ventricular catheter tip and VP shunt function was analyzed in 52 patients. The location of the ventricular catheter tip was classified into one of the following five groups: (i) Group A--superior to the foramen of Monro; (ii) Group B--in the center of the lateral ventricle body; (iii) Group C--in the third ventricle; (iv) Group D--contacting the ventricle wall; and (v) Group E--in the septum pellucidum. VP shunt function was defined as well controlled hydrocephalus when the Evan's ratio of the ventricular size was < 0.3. The VP shunt functioned well in 14 of 52 patients (26.9%), the shunt valve pressure was incorrectly set in 21 (40.4%), and irreversible shunt malfunction was identified in 17 (32.7%). Among the 14 patients with a well-functioning shunt, 13 were in Groups A or B with an odds ratio (OR) of 17.875 (p<0.05). In the 17 irreversible shunt malfunctions, 13 were identified in Groups C, D, or E with an OR of 0.123 (p<0.05). Long term VP shunt function or failure due to irreversible malfunction is directly influenced by the position of the ventricular catheter tip. Ideal points for positioning the ventricular catheter tip are superior to the foramen of Monro and in the center of the lateral ventricle body. Early shunt revision may be required for patients in whom the catheter tip contacts the ventricle wall or is located in the septum pellucidum.