CELL-MEDIATED ALLERGY TO A CEREBRAL ANEURYSM CLIP - CASE-REPORT

BACKGROUND AND IMPORTANCE: Titanium aneurysm clips have superior imagi ng characteristics and have been supplanting their stainless steel cou nterparts. We report the case of a 36-year-old woman with a histologic ally demonstrated cell-mediated reaction to a cobalt alloy aneurysm cl ip. CLINICAL PRESENTATION: The patient underwent a craniotomy and clip placement for a ruptured cerebral aneurysm. Both the aneurysm clip an d the wires used to fix the craniotomy were made of stainless steel (c obalt and nickel) alloys. Postoperatively, the patient was plagued by intense pruritus. INTERVENTION: Skin patch testing revealed a severe r eaction to nickel and cobalt. Surgical removal of the aneurysm clip an d wires resulted in the disappearance of the patient's symptoms. A his tological analysis of the tissue adjacent to the clip and wives was co nsistent with Type IV delayed type hypersensitivity. CONCLUSION: Stain less steel surgical implants in the head can cause diffuse, severe pru ritus in susceptible individuals. Although the role of the aneurysm cl ip, as opposed to the more superficial wires, in the genesis of the pa tient's symptoms is not certain, this case demonstrates that a cobalt alloy aneurysm clip can activate T cells and cause an immunological re action in the central nervous system.