SURG-14. ENDOSCOPIC SURGERY FOR PEDIATRIC INTRAVENTRICULAR TUMOR WITHOUT HYDROCEPHALUS: INDICATION, SURGICAL TECHNIQUE, AVOIDANCE OF COMPLICATION, AND ITS PROSPECT

INTRODUCTION: Neuroendoscopic surgery is useful for intraventricular tumors accompanied by ventriculomegaly. However, it is often challenging for cases with small ventricles. Our institution is actively performing surgeries for pediatric intraventricular tumors without frank ventriculomegaly. METHODS: Seven cases of intraventricular tumors without ventriculomegaly (5 cases of subependymal giant cell astrocytoma (SEGA) and 2 cases of germ cell tumors (GCTs)) were analyzed. The age ranged between 3 and 14 years (median 5 years). The sizes of SEGA were between 10-27mm, and all the tumors showed an enlargement around the foramen of Monro, which was the indication for surgery. Biopsy and third ventriculostomy were performed for GCTs. For resection, after making a small craniotomy of 2 x 3 cm, ellipse-cone-like sheath with a diameter of 12mm or 17mm was inserted through it to the lateral ventricle, which enabled a wide surgical view. Under a rigid endoscope of 4mm diameter, 2 types of surgical instruments were employed, making the microsurgical procedure like under a microscope, with a wider view, possible. For the cases of tumor resection, septostomy and placement of a drain in the ventricle were performed at the end of surgery. RESULTS: The lesions were safely approached in all the cases. For resection, endoscopic microsurgery was possible, and tumor was totally removed in all the cases. No postoperative complication was observed in any of them. CONCLUSIONS: Our experience shows that tumor resection can be safely achieved with the aid of endoscope even for cases without ventriculomegaly.