gms | German Medical Science

Objective: Evaluation of the decision making process and of the surgical results in a current vestibular schwannoma (VS) surgery series in NF 2 patients.

Methods: Retrospective study of 34 VS surgeries in NF 2 patients. Analysis of patients' records and interviews, operative records and follow-up data. Outcome was evaluated regarding the completeness of tumor resection on MRI, and functional deficits during neurological examination. In a subgroup additional categories were prospectively analysed including dizziness (DHI), psychological state/depression (BDI) and quality of life (SF-36).

Results: Complete tumor removal was achieved in 53% of all cases. In all other cases, sufficient tumor decompression and opening of the internal auditory canal could be achieved. 43% of cases with preoperative functional hearing (New Hannover classification I-III) had functional hearing after surgery as well. Comparing tumor sizes (timing of surgery), small tumors (Hannover classification I-II, n=9) showed a higher incidence of cases with preoperative functional hearing (89%) followed by postoperative functional hearing (62.5%) than large tumors (Hannover classification III-IV, n=25) with preoperative functional hearing (28%) followed by postoperative functional hearing (57%). Hearing preservation in large tumors was followed by a higher incidence of subtotal tumor resections (40% vs. 22% in small tumors). Dizziness improved over the follow-up period (DHI score preop: 22; postop: 12; follow-up:6). All patients with excellent or good facial nerve function (HB I-III) stayed in the same general functional group (at least HB III) after surgery. The evaluation revealed a significant positive correlation (Spearmann coefficient) between dizziness (p=0.015)/ hearing loss (p=0.045) and depression. SF-36 quality of life examination revealed no postoperative deterioration in the long-term follow-up (mean: 6 months).

Conclusions: In NF 2 patients, preservation of cranial nerve function is the predominant strategy due to the underlying disease constellation. Tumor resection or sufficient decompression can be performed safely via the retrosigmoid approach with good to excellent rates for preservation of auditory and facial nerve function, as well as a significant relief of dizziness. Early surgery in small tumors improves the overall hearing preservation and completeness of tumor removal. Dizziness and hearing loss do have a significant impact on the patients’ psychological state. A custom-tailored microsurgical treatment of vestibular schwannomas can preserve quality of life in NF 2 patients.