The authors evaluated the outcome of radical microsurgery via an osteoblastic retrosigmoid approach in a consecutive series of 442 patients with vestibular schwannomas (VSs) between 1-3cm out of our 1100 VSs.
The authors performed a retrospective study of 257 patients with VSs between 1-2 cm in maximal intra/extrameatal diameter were included in this retrospective Study over a 5 year period (Group A). The group was compared with a matched group of 167 patients with VSs between 2-3 cm (Group B). Patient records, operative reports, follow-up data, and neuroradiological findings were analyzed. In all cases the retrosigmoid approach in semisitting position was performed. Outcome measures included completeness of tumor removal, facial nerve function, hearing function , and the surgery-related complication rate.
The mean tumor size in Group A was 1.7 cm and in Group B was 2.6 cm. Total removal was achieved in all patients in two groups. The anatomical integrity of the facial nerve was preserved in 100 % of our study group A and 100 % of group B. At last follow- up 94% of the patients in group A had excellent (grade 1 H&B) and 6 % good facial nerve and in 51% of patients in group A preoperative hearing level preserved. Newly developed lower cranial nerve dysfunction occurred in 0% of patients . A CSF leak developed in 3 % of patients. Compared with Group B, a significant difference was found in the rates of the following parameters: excellent facial nerve function (H&B gradeI) (78% in group B) and preservation of preoperative hearing (34% in group B) (p < 0.05). The perioperative mortality rate in both group was 0% and surgery related complication rate was the same in two groups.
The goal of VS treatment should be total removal in one stage and preservation of neurological function, as they mainly determine a patient’s quality of life. This goal can be safely and much more successfully achieved using the retrosigmoid approach while tumor size is between 1-2 cm . In patients with the tumor size between 1-2 cm in comparison with the patients with the tumor size between 2-3 cm, total tumor removal can be achieved with low morbidity rate, especially with regards to facial nerve and Hearing excellent function preservation. Any changes in tumor size even in the small tumors significantly correlates with postoperative outcome of facial and hearing preservation.