MS-04A NOVEL MINIMALLY INVASIVE APPROACH FOR THE RESECTION OF INTRAVENTRICULAR TUMORS

The endoscopic management of intraventricular pathology is effective and safe. However, there are limitations to this method including: the size and type of lesion that can be treated, hemostasis and visualization in a fluid medium, and, in particular, the lack of bimanual dexterity. Recently, a minimally invasive integrated systems approach to the subcortical space has been developed that addresses these issues. With this technique, termed Six Pillar, a 15 mm outer diameter cylindrical retractor is inserted through a sulcus to the target along a trajectory specifically planned to minimize disruption of white matter fiber tracts. The authors operated on six intraventricular tumors using this method: two colloid cysts, two subependymomas, one grade two astrocytoma, and one metastatic tumor with intraventricular extension. A gross total resection was achieved for the colloid cysts, the astrocytoma, and one subependymoma. For the metastatic tumor, the intraventricular portion was completely resected. No patient experienced a new postoperative deficit. Historically, approaches to intraventricular abnormalities were transcortical or transcallosal. The endoscope offered less invasive ventricular access but with documented limitations in the published literature such as hemostasis, and management of fibrous and larger lesions. Most importantly, though, is the inability to operate with both hands. The Six Pillar approach does not have these limitations. The operation is conducted through an air medium, improving hemostasis and visualization. Because the inner diameter of the cylindrical retractor is 13 mm, standard bimanual microneurosurgical technique is employed. This means a larger variety of intraventricular pathologies are amenable to surgical resection, not just biopsy. Because advances in imaging permit identification of white matter fiber tracts, safe surgical corridors to the entire ventricular system can be created. The authors conclude that the Six Pillar approach to intraventricular tumors is an important addition to the neurosurgical armamentarium.