Life-threatening allergic vasculitis after clipping an unruptured aneurysm: Case report, weighing the risk of nickel allergy

BACKGROUND: This case report represents one of the estimated 17,000 aneurysms clipped annually in the United States, often with nickel-containing clips. The authors highlight the development of life-threatening allergic vasculitis in a 33-year-old woman after aneurysm clipping. CASE DESCRIPTION: After suffering subarachnoid hemorrhage, the patient had coil embolization at another facility for rupture of a right internal carotid artery (ICA) aneurysm. An incidental finding, an unruptured left posterior communicating artery aneurysm unamenable to coiling, was then successfully clipped via a left pterional craniotomy. Arriving in our emergency department 11 days later, she progressively declined during the next weeks, facing deteriorating clinical status (i.e. seizures) and additional infarctions in the left frontal lobe, midline shift, and new infarctions in the bilateral frontal lobe, right sylvian, right insular regions, and posterior cerebral artery distribution. During decompressive surgery, biopsy findings raised the possibility of lymphocytic vasculitis; consultations with rheumatology, allergy, and immunology specialists identified that our patient had a nickel allergy. After reoperation to replace the nickel-containing clip with one of a titanium alloy, the patient had an uncomplicated postoperative course and was discharged 6 days later to a rehabilitation facility. CONCLUSIONS: Nickel-related allergies are more common than appreciated, affecting up to 10% of patients. Fortunately, severe reactions are rare; nevertheless, vascular neurosurgeons should be aware of this potential complication when using cobalt alloy aneurysms clips. The use of titanium alloy clips eliminates this risk.