2209 Bilateral fronto-parietal subcortical cytotoxic oedema associated with headache and transient neurological symptoms following flow diversion stenting of an anterior cerebral artery aneurysm

Endovascular treatment of cerebral aneurysms with flow diverting stents (FDS) divert blood flow away from an aneurysm and into the native vessel. Complications are less than with surgery¹ but may include haemorrhage, ischemia^2–4 and rarely brain oedema.⁵ A 48-year-old woman underwent a suitability assessment for kidney donation. Multiple aneurysms involving the splenic, superior mesenteric and gastroduodenal arteries were found. Further screening identified a 1.9mm x 2.7mm berry aneurysm of the left distal pericallosal Anterior Communicating Artery. By PHASES criteria, her risk of rupture in five years was 0.9%; however, her actual risk was likely higher given the suspicion for a vascular fragility syndrome. FDS insertion to the left Azygos ACA was performed.

Within twenty-four hours, she developed ataxia, nausea, headache and confusion. MRI demonstrated bilateral fronto-parietal subcortical cytotoxic oedema with perivenular enhancement surrounding the stent. Over four weeks, there was clinical recovery. Repeat imaging at three months showed resolution of enhancement but persistent white matter changes in the left peri-rolandic and parietal lobes. Delayed nonischemic cerebral enhancing lesions are rarely reported after endovascular treatment.⁵ These lesions are attributed to foreign-body emboli and inflammatory reactions. While cerebral oedema has been previously recognised shortly after FDS insertion, often associated with headaches,⁶ our patient demonstrated a more persistent clinical syndrome and inflammatory changes on imaging. This potential complication is important to recognise as anti-inflammatory medication may be considered.⁷ The intensity of reaction observed may relate to her underlying vascular fragility and increased blood-brain barrier disruption.

References

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