ObjectiveResorption of autologous bone flap grafts is a known long-term complication of cranioplasty following decompressive craniectomy (DC). We analyzed our data to identify risk factors for bone flap resorption (BFR) following cranioplasty.MethodsA total of 162 patients who underwent cranioplasty following DC due to life-threatening elevated intracranial pressure between October 2003 and December 2012, were included in our investigation. Follow-up exceeded one year.ResultsBFR occurred as a long-term complication in 9 of the 162 patients (5.6%). The affected patients consisted of individuals who had undergone DC for traumatic brain injury (TBI; n=4), for subarachnoid hemorrhage (SAH; n=3), for cerebral infarction (n=1), and intracerebral hemorrhage (n=1). Logistic regression analysis identified no significant risk factors for BFR.ConclusionTBI and SAH as initial diagnoses are more often associated with BFR than other diagnoses. This finding may influence future surgical decision making, especially in patients with possible risk factors for BFR. A prospective study with a large number of patients is needed to identify potential predictors of BFR such as bone flap sterilization and preservation.

Objective: The natural course of unruptured vertebral artery dissection remains unclear. The clinical manifestation of unruptured vertebral artery dissection varies from headache, focal neurologic deficits caused by ischemia to subarachnoid hemorrhage with high mortality. The purpose of this study is to investigate the clinical course of unruptured vertebral artery dissection. Methods: From March 2011 to April 2013, 7 patients with headache or nuchal pain by spontaneous vertebral artery dissection visited our institute were retrospectively reviewed. Their clinical data was obtained by medical records and radiologic studies including computed tomographic angiography, magnetic resonance imaging, magnetic resonance angiography and digital subtraction angiography. Results: No patient experienced fatal outcome by subarachnoid hemorrhage or vertebrobasilar ischemia during follow-up period. Radiologic studies also did not show the evidence of subarachnoid hemorrhage or vertebrobasilar ischemia. Followup angiography showed the decreased size or disappearance of aneurysm in 3 patients. Conclusion: This study suggests that the natural course of unruptured vertebral artery dissection is not aggressive. Patients with unruptured vertebral artery dissection could be managed with conservative treatment including anticoagulants and/or antiplatelet agents. (Korean J Neurotrauma 2013;9:69-73) KEY WORDS: Vertebral artery dissection ㆍSubarachnoid hemorrhage ㆍDissecting aneurysm.