A challenging case of endoscopic third ventriculostomy

Although controversial, endoscopic third ventriculostomy (ETV) in the management of Myelomeningocele and Chiari type II malformation-related hydrocephalous is gaining wider popularity and use. With variable success rates, it can be proposed as a first or second option after shunt malfunction. ETV in post-infectious hydrocephalus may also be considered as an alternative to shunting. With reported success rates of 50-60%, failure is attributed to anatomical reasons and/or to pathological subarachnoid space scarring that may result from infectious processes. Similarly, ETV in repeated shunt malfunctions is an acceptable option that may offer shunt independency. In all situations, case-by-case selection and discussion are to be considered.

A 5-year-old boy with a history of surgically treated lumbosacral myelomeningocele and ventriculoperitoneal shunting at six months of age is presented. During the course following the initial surgery, he experienced multiple shunt malfunctions, with two episodes of meningitis, leading to 7 shunt revision surgeries. Lately, the patient presented a large peritoneal cyst formation that needed regular evacuations. With a magnetic resonance imaging (MRI)-scan showing a large bi-ventricular hydrocephalus and a trapped third ventricle with multiple septations, surgical options included either ventriculoatrial shunting or third ventriculostomy. The latter option, offering shunt independency, was chosen after family consent and risk explanation. The expected success rate of the procedure was discussed and evaluated to 40-60% on the ETV success score. The video describes a step-by-step procedure with detailed radiological and correlated anatomical annotations of a completely distorted anatomy of a multifactorial hydrocephalous. No scarring at the prepontine cistern was observed. Shunt independency was achieved. However, the patient died from late postoperative status epilepticus and pulmonary complications. Whether these postoperative events are directly related to the procedure is unclear, although technically and clinically successful in the short term.

We believe that ETV should be carefully indicated in selected patients with Chiari II, post-infectious hydrocephalus, by experienced hands, as the surgical anatomy can be extremely complex and misleading.