Endoscopic third ventriculostomy: a study of intracranial pressure vs. haemodynamic changes.

Fourteen paediatric patients with obstructive hydrocephalus were studied. They underwent endoscopic third ventriculostomy under general anaesthesia. Their ages ranged from 1 to 144 weeks (mean 34+/-36 weeks) and weight from 2 to 22 kg (mean 10.2+/-5.4 kg). In an attempt to identify the possible mechanisms of the intraoperative haemodynamic changes associated with endoscopic third ventriculostomy, we studied the intracranial pressure measured in the third ventricle versus the haemodynamic changes. The intracranial pressure was measured using a pressure transducer attached at one end to the endoscope and the other end to the monitor. The mean third ventricle pressure value was 10.2 mmHg (+/-3.5). Bradycardia occurred in six (43%) of our patients. The mean value of the lowest heart rate reading intraoperatively was 81 beats/min (+/-31.8). Negative correlation was obtained between the intracranial pressure and the haemodynamic changes. Alerting the surgeon to perforate the floor of the third ventricle or withdraw the scope away from it was sufficient to resolve the bradycardia. We concluded that serious dysrhythmias might occur during endoscopic third ventriculostomy, the majority of which can be resolved without medications.