Ultrasound-guided puncture of a Dandy-Walker cyst via the lateral and III ventricles

Since the Dandy-Walker syndrome was first described by Dandy and Blackfan, Taggart and Walker, the many variants of posterior fossa anomalies, the appropriate management of these malformations and the clinical outcome have been the subjects of controversy. Surgery of the posterior fossa with membrane excision was initially the preferred method of treatment. Unfortunately, there was a high rate of complications, and many of the patients treated in this way still needed a shunting system. Ventricular-peritoneal and/or cysto-peritoneal shunting is commonly used to treat symptomatic posterior fossa cysts of Dandy-Walker malformations and hydrocephalus. Cysto-peritoneal shunt implantation only was associated with a high rate of complications, and most patients so treated needed a ventriculo-peritoneal shunt in addition. According to the literature, combined ventriculo-peritoneal and cysto-peritoneal shunting is needed for satisfactory decompression of Dandy-Walker cyst and hydrocephalus in between 16% and 92% of cases. We report on a young patient with a Dandy-Walker malformation who needed drainage of the posterior fossa and a ventricular shunt. We decided to drain the cyst and the supratentorial ventricles via a single, especially prepared, catheter with many perforations. The catheter was inserted under ultrasound guidance. The tube was inserted from the left lateral ventricle through the foramen of Monro into the III ventricle and downwards into the cyst. Intraoperatively, an immediate decrease in the size of the cyst and the supratentorial ventricles was observed. Postoperative MRI confirmed the exact position of the catheter and sufficient drainage of the posterior fossa cyst and the ventricles. Six months later the girl was seen in our outpatient department. Clinical examination showed no neurological deficit, and MRI demonstrated sufficient drainage of the ventricles and the Dandy-Walker malformation, and in addition hypoplasia of the corpus callosum. Received: 31 March 1999