Crutchlike Incision Along the Mastoid Groove and Above the Occipital Artery Protects the Lesser Occipital Nerve and Occipital Artery in Microvascular Decompression Surgery

BACKGROUND: Patients who have had microvascular decompression (MVD) surgery often report sensory discomfort around the surgical area. In most cases, injury of the lesser occipital nerve (LON) is responsible for this postoperative complication. This study aimed to explore an effective method to protect the LON and reduce postoperative discomfort. METHODS: Doppler was used to determine the course of the occipital artery (OA) and the incision. Direct LON identification and a novel crutchlike incision were performed from January 1, 2016, to February 1, 2017, to reduce postoperative sensory disturbance. Postoperative sensory disturbance was evaluated and retrospectively analyzed compared with previous linear incision cases (from January 1, 2015, to December 31, 2015). Anatomic information at the lateral occiput was measured and recorded. RESULTS: The difference in the amount of postoperative sensory disturbance at 3-month follow-up was significant (P = 0.008). Sensory disturbance was significantly lower in patients who had crutchlike incision (P = 0.002) and patients with direct LON identification (P = 0.035) compared with the previous linear incision cases. The distance from OA to the projection of the transverse sinus was 3.2 +/- 0.6 cm at the mastoid groove and 2.5 +/- 0.4 cm at a site 0.5-1.0 cm from the mastoid groove. CONCLUSIONS: A crutchlike incision at the mastoid groove superior to the OA reduced the incidence of postoperative sensory disturbance and OA injury. The mastoid groove and OA are simple landmarks for determination of the incision in microvascular decompression.