Delayed Inflammatory Reaction after Mechanical Thrombectomy: A Case Report and Literature Review
Stella Uzoewulu, MD1; Katarina Dakay, DO2,3; Umair Afzal, MD2,3; Barry Rabin, MD4; Joshua Billingsley, MD5; Anit Behera, MD, PhD2,3*
1Department of Psychiatry, Advocate Lutheran General Hospital, Park Ridge, IL, USA.
2Department of Neurology, Advocate Lutheran General Hospital, Park Ridge, IL, USA.
3Department of Neurology, Rosalind Franklin University Medical College, Chicago, IL, USA.
4Department of Radiology, Advocate Lutheran General Hospital, Park Ridge, IL, USA.
5Department of Neurosurgery, Advocate Lutheran General Hospital, Park Ridge, IL, USA.
*Corresponding Author: Anit Behera MD, PhD, Department of Neurology, Rosalind Franklin University Medical College, Chicago, IL, USA.
DOI: https://doi.org/10.58624/SVOANE.2026.07.017
Received: May 04, 2026
Published: June 10, 2026
Citation: Uzoewulu S, Dakay K, Afzal U, Rabin B, Billingsley J, Behera A. Delayed Inflammatory Reaction after Mechanical Thrombectomy: A Case Report and Literature Review. SVOA Neurology 2026, 7:3, 124-128. doi.org/10.58624/SVOANE.2026.07.017
Abstract
Mechanical thrombectomy is the standard of care for patients with ischemic stroke due to large vessel occlusion with salvageable penumbra and has resulted in improved outcomes. Mechanical thrombectomy is performed under fluoroscopy and involves the use of microcatheters introduced into the cerebral circulation. A rare side effect of this procedure is granulomatous inflammation due to hydrophilic polymer particles which are part of the composition of the microcatheters and can slough off during their usage resulting in a delayed inflammatory reaction due to the presence of foreign material. We report a case of a 70-year-old woman who presented with a seizure several months after mechanical thrombectomy whose imaging demonstrated vasogenic edema in the territory of her infarct, suggestive of a granulomatous reaction. She was successfully treated with intravenous steroids followed by an oral steroid taper which resulted in clinical improvement and resolution of the lesion. The recognition of this rare condition is important as it can lead to delayed neurological complications, which can be treated with steroids.
Keywords: Mechanical thrombectomy, Cerebral granulomatous inflammation, Hydrophilic polymer embolism, Ischemic stroke
