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To The Editor: We are interested in the article by Sughrue et al.2 (Sughrue ME, Yang I, Aranda D, et al: Beyond audiofacial morbidity after vestibular schwannoma surgery. Clinical article. J Neurosurg 114:367–374, February 2011).
Vestibular schwannomas (VSs) are located in the cerebellopontine angle, close to cerebrovascular structures, cranial nerves, the brainstem, and the cerebellum. Traditional surgical treatment of these lesions carries high risks for morbidity and some risks for mortality, even for well-trained neurosurgeons. The complications of cerebrospinal fluid leakage, vascular injury, neurological deficits, and postoperative infection have been reported.2 Recent advances in stereotactic radiosurgery (SRS) have greatly reduced the risks of morbidity and mortality associated with the management of VSs. Lee et al.1 reported no radiosurgery-related instances of morbidity or mortality associated with Gamma Knife stereotactic radiosurgery (GKS). However, an adverse radiation effect was found, with perifocal edema, tumor enlargement, and cyst enlargement identified at a median of 26 months (range 3 months–6 years) after GKS.
Using PubMed, Sughrue et al.2 summarized the results of microsurgery from various institutions. In this study, the authors reviewed 100 articles providing information on 32,870 patients; their analysis showed an overall mortality rate of 0.2% (95% confidence interval [CI] 0.1%–0.3%). Twenty-two percent of patients (95% CI 21%–23%) suffered from at least 1 microsurgery-related complication other than those affecting cranial nerve VII or VIII. Cerebrospinal fluid leakage was a complication in 8.5% of patients (95% CI 6.9%–10.0%). This complication rate was significantly increased when the translabyrinthine approach was used but was unaffected by the size of the tumor. Vascular complications, such as ischemic injury or hemorrhage, were found in 1% of patients (95% CI 0.75%–1.2%). Neurological complications developed in 8.6% of cases (95% CI 7.9%–9.3%) and were less likely to occur with resection of smaller tumors (p < 0.0001) and use of the translabyrinthine approach (p < 0.0001). Infections happened in 3.8% of cases (95% CI 3.4%–4.3%), and 78% of these were meningitis. These results were significantly higher than those associated with SRS.
The contribution made by Sughrue et al.2 in pointing out instances of morbidity beyond audiofacial complications after VS surgery alerts neurosurgeons to take great precautions during decision making before choosing a treatment modality. Contemporary advances in SRS have resulted in a reduction of morbidity in the treatment of VSs. Therefore, comparisons of complications related to SRS and microsurgery should be carefully considered during the decision-making process.
There is one minor concern that we have about this retrospective study. Patient demographic data should be stratified based on patient age, sex, and underlying comorbidities when performing a univariate and/or multivariate analysis of these morbidities, because advanced age carries higher risks of morbidity than younger age.
Despite these limitations, the study by Sughrue et al.2 provides significantly potent evidence for neurosurgeons to use in advising patients on the published risks of complications other than injury to audiofacial nerves following microneurosurgery for VS. Further large scale, prospective studies are mandatory to better address the potential risks of surgery for VS.