Endoscopic third ventriculostomy in children with third ventricular pressure gradient and open ventricular outlets on MRI

Objective Patients with non-communicating hydrocephalus due to aqueductal stenosis are often successfully treated with endoscopic third ventriculocisternostomy (ETV). In hydrocephalus, due to other locations of obstruction of the major CSF pathways, endoscopic treatment may also be a good option. We investigated our cohort of patients treated by ETV with patent ventricular outflow but pressure gradient signs at the third ventricle in a single-center retrospective study. Methods We retrospectively reviewed records and imaging studies of 137 patients who underwent an ETV in our department in the time period of June 2010 to March 2018. We included patients who showed the following findings in MRI: 1st: open Sylvian aqueduct, 2nd: open outlets of the 4th ventricle, 3rd: open spinal canal, 4th: intra-/extraventricular pressure gradient seen at the 3rd ventricle and excluded patients with history of CSF infection or hemorrhage. Perioperative clinical state and possible complications or reoperations were recorded. Shunt dependency and changes in ventricular dilatation were measured as frontal and occipital horn ratio (FOHR) before surgery and during follow-up. Results A total of 21 patients met the defined criteria. During the mean follow-up time of 40.7 +/- 30 months (range; 5-102 months), two children had to undergo a re-ETV, and six children (all < 1 year of age) received a VP shunt. ETV shunt-free survival was 100% for children > 1 year of age. The ventricular width measured as FOHR was significantly reduced after ETV 0.5 +/- 0.08 (range 0.42-0.69; p < 0.05). FOHR was significantly reduced at last follow-up shunt independent patients (0.47 +/- 0.05; range 0.41-0.55; p < 0.001) Conclusion We conclude that ETV seems to be a successful treatment option for patients with MRI signs of intra-/extraventricular pressure gradient at the 3rd ventricle and patent aqueduct and fourth ventricular outlets in children older than 1 year of age. This condition is observed only rarely and warrants further research on a multicenter basis in order to get more solid data of its pathophysiology.