Jessica Moser &
Jenna Koschnitzky, PhD
National Director of Research Programs

The study:
The International Infant Hydrocephalus Study (IIHS), gathering data from more than 20 hospitals around the world, compared the effectiveness of shunts versus endoscopic third ventriculostomies (ETVs). This study started in 2005 and these are the five year outcomes. The study enrolled children under 2 years old who had hydrocephalus due to aqueductal stenosis. The study measured how well the patients were doing in regards to their overall health and quality of life five years after treatment.

Why this matters:
Shunt and ETV are the two most common treatments for hydrocephalus, but studies directly comparing the long-term outcomes of shunts to ETVs are rare. When asked about this study, lead author, Dr. Abhaya Kulkarni said, “We have often wondered how well patients fared long term with an ETV versus the more traditional shunt procedure. This new study offers us a clearer picture and hopefully will help families make a more informed decision about which treatment option is best for their child.”

What they did:
The infants in this study received either a shunt or an ETV upon diagnosis. Five years after their treatment, a parent filled out two questionnaires to measure the child’s overall health and quality of life. One questionnaire, the Health Utilities Index – 2 (HUI-2), measures the overall health of a child by assessing how well the child can move and take care of themselves, if they are in pain, and if they have emotional, cognitive, or sensory challenges. The other questionnaire, the Hydrocephalus Outcome Questionnaire (HOQ), measures quality of life, such as how social the child is and their emotional, physical, and cognitive health.

What they found:
Of the 178 patients who enrolled in the study, 78 completed the questionnaires five years later; 19 had shunts and 61 had ETVs. Overall, the children in this study scored well on both questionnaires, indicating that these children had good overall health and a high quality of life. There was no difference in scores between those with shunts and those with ETVs on either questionnaire. This means that the type of treatment did not influence the child’s overall health or quality of life.

What it means:
The results of this study are positive as they show treatment type did not impact five year outcomes for children with aqueductal stenosis and hydrocephalus. These results are significant for parents considering either a shunt or an ETV. Since the overall health and quality of life of the children were similar, other factors may play a larger role in the decision-making process.

However, this study only included children with aqueductal stenosis, and these children generally scored well on both questionnaires. Therefore, the results may be different for children with other causes of hydrocephalus. Furthermore, it is still unknown how well the children in this study will do later in life such as in high school or college, although the future looks promising.

Lead author, Dr. Abhaya Kulkarni, is a professor at the University of Toronto and pediatric neurosurgeon at the Hospital for Sick Children. Dr. Kulkarni is also a principal investigator for the Hydrocephalus Clinical Research Network ( and a member of the Hydrocephalus Association Medical Advisory Board.

For information on this study and other outcomes of the International Infant Hydrocephalus Study follow the links below:

5 year outcomes

Outcome of treatment after failed ETV

Initial results of the IIHS

IIHS concept and rationale


Author Jessica Moser is a high school senior. She enjoys playing the harp and reading. In the future, Jessica hopes to pursue a career in neuroscientific research.