Minimally invasive treatment of type II neurofibromatosis

Abstract

Objective To explore the experience of minimally invasive microsurgical treatment for neurofibromatosis type Ⅱ (NF2). Methods The clinical data of 16 consecutively NF2 patients who underwent minimally invasive microsurgical treatment for vestibular schwannoma removal were retrospective analyzing, including tumor enlargement or cystic enlargement 2 sides after gamma knife treatmen. According to the size of the tumor, the degree of hearing damage, the timing of surgical resection and the side of the tumor were selected. The posterior suboccipital sigmoidsinus tran-acoustic approach was used to remove the acoustic neuroma. The facial nerve, trigeminal nerve and auditory brainstem response were monitored. Results Staging side resection of bilateral acoustic neuroma in 9 cases, unilateral acoustic neuroma resection in 7 cases. A total of 25 acoustic neuromas were removed(2 tumors were not operated). The tumor was completely resected on the 22 side (22/25, 88%), and subtotal resection were be done in 3 sides tumor (effective hearing ear only). Intraspinal schwannoma resection in 3 cases, 1 case of intracranial meningioma resection, total resection of the tumor was achieved in all. Three sides of tumor subtotal of the tumor and 2 side tumors without undergoing tumor resection (surviving effective listening), postoperative adjuvant gamma knife treatment. Eleven ears with residual effective hearing before operation, postoperative 5 ears retained different degrees of hearing, the postoperative hearing preservation rate was 45.5% (5/11). Twenty-three sides of the tumor were anatomically preserved facial nerve (23/25, 92%), facial nerve function H-B Ⅰ-Ⅲ level were preserved on the 23 side after 6 months postoperation, H-B Ⅳ 2 sides. No postoperative death and serious complications. Conclusion Minimally invasive surgery for type Ⅱ neurofibromatosis should be based on the size of the bilateral tumor, the level of hearing, the urgency of relieving brain stem compression, the growth rate of the tumor, and whether other tumors are combined, to design an individualized surgical plan, and choose the good timing of tumor resection, tumor side and tumor type. Key words: Vestibular schwannoma; Neurofibromatosis type 2; Minimally invasive technique; Nerve function preservation