Intradural clinoidectomy and postoperative headache in patients undergoing aneurysm surgery.

Background: The incidence of severe, chronic postoperative headache in patients undergoing elective surgery for unruptured aneurysms is unknown. In addition, no clear risk factors have been identified for the development of postoperative headache.
Objective: To evaluate intradural drilling of the anterior clinoid process as a mechanism for the development of postoperative headache after open aneurysm repair.
Methods: A retrospective review of 128 patients undergoing open surgical treatment for unruptured, proximal carotid aneurysms treated at the University of Texas Southwestern Medical Center between January 2004 and December 2007. Patients who required intradural drilling of the anterior clinoid process were compared with patients in whom additional drilling was not necessary. The presence of postoperative headache and the duration and severity were noted.
Results: In 28% of patients who underwent surgery with intradural clinoidectomy severe headache developed vs 7% of patients without clinoidectomy. This result was statistically significant (P < .05, Fisher exact test).
Conclusion: Intradural drilling of the anterior clinoid process was associated with an increased incidence of postoperative headache compared with no resection. This implicates either the dural manipulation necessary to expose the clinoid and optic strut or the introduction of bone dust into the subarachnoid space as potential risk factors for postoperative headache.