Neurologia Medico-Chirurgica (Oct 2023)

Possible Delayed Foreign Body Reactions against Titanium Clips and Coating Materials after Unruptured Cerebral Aneurysm Surgery

  • Ryota TATEZAWA,
  • Taku SUGIYAMA,
  • Shuho GOTOH,
  • Takafumi SHINDO,
  • Hiroshi IKEDA,
  • Masaaki HOKARI,
  • Katsumi TAKIZAWA,
  • Naoki NAKAYAMA,
  • Miki FUJIMURA

DOI
https://doi.org/10.2176/jns-nmc.2023-0116
Journal volume & issue
Vol. 63, no. 10
pp. 482 – 489

Abstract

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Delayed foreign body reactions to either or both clipping and coating materials have been reported in several small series; however, studies in the titanium clip era are scarce. This study aims to survey the contemporary status of such reactions to titanium clips and coating materials. Among patients who received a total of 2327 unruptured cerebral aneurysmal surgeries, 12 developed delayed intraparenchymal reactions during outpatient magnetic resonance imaging (MRI) follow-up. A retrospective investigation was conducted. The patients' average age was 58.6 (45-73) years, and 11 were women. The aneurysms were located in the middle cerebral artery (n = 7), internal carotid artery (n = 4), or anterior communicating artery (AComA, n = 1). In 10 patients, additional coating with tiny cotton fragments was applied to the residual neck after clipping with titanium clips; however, only the clipping with titanium clips was performed in the remaining two. The median time from surgery to diagnosis was 4.5 (0.3-60) months. Seven (58.3%) patients were asymptomatic, and three developed neurological deficits. MRI findings were characterized by a solid- or rim-enhancing lobulated mass adjacent to the clip with surrounding parenchymal edema. In 11 patients, the lesions reduced in size or disappeared; however, in one patient, an AComA aneurysm was exacerbated, necessitating its removal along with optic nerve decompression. In conclusion, cotton material is a strongly suspected cause of delayed foreign body reactions, and although extremely rare, titanium clips alone may also induce such a reaction. The prognosis is relatively good with steroid therapy; however, caution is required when the aneurysm is close to the optic nerve, as in AComA aneurysms.

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