Endoscopic third ventriculostomy for hydrocephalus in a patient with achondroplasia: a case report and literature review.

Hydrocephalus, a complication of achondroplasia, requires treatment when it is symptomatic. Hydrocephalus associated with achondroplasia is often treated with ventriculoperitoneal shunting, and endoscopic third ventriculostomy (ETV) is rarely performed in these patients. Here, we report the case of an 18-month-old boy with achondroplasia and progressive hydrocephalus who underwent ETV. He had a family history of achondroplasia and was diagnosed with achondroplasia at birth. Magnetic resonance imaging (MRI) at the age of 1 month showed no hydrocephalus. At the age of 15 months, he was admitted to our hospital due to increased head circumference. He had developmental delays, and MRI showed hydrocephalus with ballooning of the third ventricle. The ETV success score was 80 points; therefore, we performed ETV. Postoperatively, the progression of head circumference increase was controlled. The ventricular size remained unchanged on MRI at 13 months after surgery. Recently, an association between non-communicating hydrocephalus and achondroplasia has been reported. Depending on age and imaging findings, ETV may be effective in some patients with achondroplasia with hydrocephalus.