Objective: To demonstrate a causal relationship between bone dust and the development of headache after retrosigmoid removal of acoustic neuromas.
Study design: The study design was both retrospective (group I) and prospective (groups 2 and 3).
Setting: Tertiary Care Referral Center/Outpatient Data Collection.
Patients: Eighty-four consecutive patients underwent surgery at the Mount Sinai Medical Center in New York by the same surgical team.
Intervention: All patients underwent retrosigmoid removal of acoustic neuromas via the following methods: group 1, standard excision; group 2, excision and cranioplasty; group 3, excision, cranioplasty, and residue trapping.
Main outcome measure: Presence or absence of postoperative headache.
Results: In all, 43 patients (51%) reported postoperative headache. By groups, headache incidence was 64% for group 1 (43% grade 3-4), 81% for group 2 (37% grade 3-4), and 10% (all grade 1) for group 3. Differences with respect to headache incidence and severity were statically significant between groups 1 and 3, and between groups 2 and 3 (p < 0.001).
Conclusions: Free circulation of bone dust into the posterior fossa during intradural drilling of the internal auditory canal may be the most important factor in the development of headache after this surgical procedure.