By Jenna Koschnitzky, PhD
National Director of Research Programs, Hydrocephalus Association
Is an ETV an option after shunt failure? A study recently published out of the United Kingdom reviewed studies that reported on the effectiveness of endoscopic third ventriculostomy (ETV) after shunt failure in children. The study, by lead author Dr. Mueez Waqar, combined and analyzed the results from 15 studies looking at children under 18 years old. All of the children had previously had a shunt placed for hydrocephalus (primary shunt) and were in shunt failure at the time of the ETV procedure (secondary ETV).
Based on the available data, the authors came to several conclusions.
Overall, in 68.2% of the patients, the secondary ETV effectively treated the hydrocephalus. The average follow-up time in the reviewed studies was 37 months.
Another interesting finding was that, patients who are initially poor candidates for a primary ETV, may have better success rates with a secondary ETV. This includes patients with posthemorrhagic or postinfectious hydrocephalus and those with a chiari malformation or spina bifida. The reason for this is still unclear. It may be due to the narrowing of the pathway between the third and fourth ventricles that can occur after shunt placement.
The authors also recommend complete removal of the existing shunt if it can be done safely.
However, there are many factors to consider with your doctor when considering an ETV procedure for those patients with a failing shunt.
Secondary ETV can be a more challenging surgery due to changes in the ventricular system after long-term shunting. Patients with slit ventricles should be carefully considered, as navigating the narrowed ventricles can be very challenging.
Although secondary ETV worked in 68.2% of the patients studied, it did not work in 31.8% of the patients. That is not an insignificant number of individuals. These patients had to undergo another surgery to divert cerebrospinal fluid.
It is also likely that the patients in each study were already determined to be ‘good candidates’ for secondary ETV. Therefore, these results may not be accurate for the general population.
The authors state that there are many questions remaining as to the appropriate post-surgical care for patients with secondary ETVs and the risk of sudden death after a secondary ETV.