Relationship Between Muscle Dissection Method and Postoperative Muscle Atrophy in the Lateral Suboccipital Approach to Vestibular Schwannoma Surgery

BackgroundVarious techniques are available for occipital skull exposure with muscle dissection, as well as different types of skin incisions in the lateral suboccipital approach to vestibular schwannoma (VS) surgery. The skin incisions are generally classified as S-shaped, J-shaped, or C-shaped. In each method, the technique used for muscle dissection differs in terms of cut, single layer, and multiple layers. This study was performed to identify the relationships among muscle dissection method, skin incision type, and muscle atrophy in the lateral suboccipital approach to surgery for VS.MethodsBetween 2002 and 2011, we performed surgical resection in 53 patients with VS at Shinshu University Hospital. Of these 53 patients, 35 with radiographic annual follow-up for >3 years after surgery were evaluated retrospectively. These patients included 14 who underwent an S-shaped incision, 6 with a J-shaped incision, and 15 with a C-shaped incision. Bilateral areas of the skin and occipital muscles were measured, and rates of atrophy were calculated and compared among the 3 methods.ResultsPostoperative muscle atrophy was significantly advanced in the second postoperative year, but did not tend to develop further after the third year. The postoperative muscle atrophy ratio was significantly lower in the C-shaped incision group (mean ± SD, 4.0% ± 6.9%) compared with the S-shaped (17.1% ± 9.8%) and J-shaped (17.6% ± 10.0%) incision groups within 2 years after surgery (P < 0.05).ConclusionsThe C-shaped skin incision with multilayer muscle dissection was associated with significantly reduced postoperative muscle atrophy compared with the other methods.