Combined intra- and extra-endoscopic techniques for aggressive resection of subependymal giant cell astrocytomas

Although neuroendoscope is widely used, endoscopic removal of intraventricular solid tumors has rarely been reported. Most reported procedures were performed with special endoscopic instruments through the endoscope's working channel--intra-axial endoscopic procedures. We report two cases of combined intra-/extra-axial endoscopic procedures--intraventricular solid tumor resection for subependymal giant cell astrocytoma.

In 2007, two patients with subependymal giant cell astrocytoma with a long history of tuberous sclerosis underwent solely endoscopic, minimally invasive intraventricular tumor resection. Through a precoronal transcortical approach, intra-axial endoscopic techniques were used to biopsy tumors. After a 1- to 1.5-cm in diameter corridor was formed inside the frontal lobes, extra-axial endoscopic techniques were used to explore the tumors and resect them. During extra-axial procedures, microneurosurgical instruments were used around the endoscope.

In both patients, gross total resection of the tumors was achieved safely. Pathologic diagnoses were subependymal giant cell astrocytoma. There were no complications from surgery, and no neurological deficits. Patients were doing well and shunt free during the 8-month postoperative follow-ups. Postoperative magnetic resonance images showed minimal approach-related trauma along the surgical corridor.

In the present report endoscopic minimally invasive neurosurgery (EMIN) was defined as procedures in which the endoscope was used independently as the only optical device, for both illumination and visualization. Depending on the relationship between surgical instruments and the endoscope, EMIN was classified as intra-axial and extra-axial procedures. EMIN is a completive, safe procedure for intraventricular subependymal giant cell astrocytoma.