[Spontaneous third ventriculostomy in obstructive hydrocephalus with composed aetiology: a case report].

Third ventriculostomy (TV) is the most common neuroendoscopic procedure for restoration of near physiological circulation of cerebrospinal fluid in obstructive hydrocephalus. Among 70 adults operated on using this technique, the authors encountered one case of spontaneous TV. Only a few case reports of spontaneous ventriculostomy revealed by ventriculography, flow-sensitive phase-contrast cine magnetic resonance imaging (MRI) or at autopsy have been published. A 43-year-old woman with symptoms of hydrocephalus and signs of chronic obstructive hydrocephalus secondary to aqueductal stenosis on MRI was qualified for TV. Enlarged infundibulo-mammillary triangle with perforation was noted intraoperatively. During the postoperative course, the condition of the patient partially improved although radiological appearance remained unchanged. Three weeks later symptoms of hydrocephalus recurred and the patient underwent an infusion test which revealed increased cerebrospinal fluid outflow resistance. Implantation of a ventriculo-peritoneal shunt yielded stable improvement. Spontaneous TV should be taken into consideration during selection of patients for TV, especially in cases with chronic obstructive hydrocephalus.