Endoscopic cerebral aqueductoplasty: a trans-fourth ventricle approach

Abstract

Object: Advances in endoscopic technology have afforded the neurosurgeon new avenues in the treatment of hydrocephalus, rendering many patients independent of shunts, thus averting shunt complications and failure. Cerebral aqueductoplasty has gained popularity as an effective treatment for membranous and short-segment stenoses of the sylvian aqueduct. Traditionally, this procedure has been performed via a coronal approach, passing through the lateral ventricle, foramen of Monro, and third ventricle into the aqueduct. The authors report on the success of a novel technique for this operation, in which they use a suboccipital foramen magnum trans-fourth ventricle approach.

Methods: A retrospective chart review was performed to document the success of cerebral aqueductoplasty procedures via the foramen magnum trans-fourth ventricle approach in patients who had membranous or short-segment stenosis of the cerebral aqueduct. Nine patients underwent 11 cerebral aqueductoplasty procedures. At a mean of 21 months of postoperative follow up, all patients demonstrated resolution of their preoperative symptoms. The only surgical complication was transient vertical diplopia or upgaze weakness in two patients. There was no permanent morbidity. Recurrent aqueductal stenosis developed in one patient twice, requiring the placement of an aqueductal stent via the same approach.

Conclusions: The authors state that in their experience, performing cerebral aqueductoplasty via the foramen magnum trans-fourth ventricle approach is both effective and safe. They advocate the use of this technique, if performed by an experienced neuroendoscopist, for select cases involving membranous or short-segment stenosis of the cerebral aqueduct, a trapped fourth ventricle, or aqueductal stent placement.