The authors conclude that ETV presents an effective alternative for the treatment of obstructive hydrocephalus in infants younger than 1 year of age. Age does not present a contraindication for ETV, nor does it increase the perioperative risk. The success of ETV is determined by the cause of the hydrocephalus.

For children with posterior fossa tumors, ETV is not indicated as a standard operation either prior to or following tumor removal. Only six of 52 children presenting with hydrocephalus required a permanent CSF draining procedure. Endoscopic third ventriculostomy may be suitable for patients with fourth ventricle outflow obstruction and persisting or progressive hydrocephalus following tumor removal.

The significant failure rate of fourth ventricle shunts has led to the development of alternative treatment methods. Endoscopic aqueductoplasty or interventriculostomy presents an effective, minimally invasive, and safe procedure for the treatment of isolated fourth ventricle in pediatric patients. Compared with suboccipital craniotomy and microsurgical fenestration, endoscopic aqueductoplasty is less invasive, and compared with fourth ventricle shunts, it is more reliable and effective.

Patients with higher Hunt and Hess grades of subarachnoid haemorrhage who are predominantly intubated and ventilated and most of them suffer from ARDS can receive lung protective ventilation. In our small patient collective, the occurring hypercapnia did not influence (increase) the intracerebral pressure.

The long-term communication following aqueductoplasty is determined by the etiology and morphology of the AS. In patients with a membranous distal AS aqueductoplasty alone will suffice. In patients with tumor-associated AS aqueductoplasty alone will not stay open. Those patients would better be treated with third ventriculostomy. In patients with isolated fourth ventricle the risk of restenosis is high. Therefore, we favor primary stent placement.