Abstract Number ‐ 115: A Case of Post‐Pipeline Headache : New Post‐Flow Diversion Headaches for Intracranial Aneurysm
Authors: Darici Didem , Karadeli Hasan Huseyin 
Published: April 2023

Introduction
Flow diversion using devices such as the “pipeline” stent is now a common treatment for unruptured intracranial aneurysms. Though much is known about the efficacy of the device, less is reported regarding potential side effects. We aimed to describe a case of giant aneurysm with new onset and severe headache Post‐ Pipeline flow diversion stent application.

Methods
A 70‐year‐old female patient was admitted to the neurology outpatient clinic with complaints of diplopia and drooping of the left eyelid that started three months ago. Neurological examination revealed decreased visual acuity and total ophthalmoplegia in the left eye. In neuroimaging,semi‐thrombosed aneurysm, 20*25*20 mm in size, compressing the optic nerve and cavernous structures was observed in the left internal carotid artery cavernous segment. In digital subtraction angiography, a narrow neck, 20*25*22 mm giant aneurysm was observed in the left ICA C4 segment in three‐dimensional imaging. In premedication, were started seven days ago acetylsalicylic acid 100 mg 1*1 and 48 hours ago ticagrelol 2*90 mg and Pipeline 4.25*30 mm flow diverter was applied to cover the aneurysm neck under general anesthesia. One day after the procedure, the patient developed a new headache behind the left eye, throbbing, sensitive to sound and light, unresponsive to paracetamol and non‐steroidal anti‐inflammatory agents.In contrast‐enhanced cranial MRI, an aneurysm causing a central thrombosed hypointense mass effect was observed in the left cavernous structure neighbor with a peripheral enhanced, hyperintense T2 Flair sequence compatible with peripheral vasogenic edema. Pulse 1 gram/day steroid treatment was applied to the patient for three days.The patient’s headache completely regressed at the end of the third month, and perianeurysmal inflammation disappeared in the same contrast‐enhanced cranial MRI.In the 12th month post‐procedure imaging of the patient, it was observed that the aneurysm was completely occluded.

Results
In the case, we reporta patient with neurologic worsening after flow‐diverter treatment for unruptured cerebral aneurysms. We found MR imaging evidence of perianeurysmal brain inflammation after the therapeutic thrombosis of the sac to be the main cause explaining clinical aggravation. Consequently, we may consider a perianeurysmal brain inflammation when encountering the association of a postprocedure headache with an increase in previous compressive signs, possibly associated with MR imaging signs of inflammation1,2. We tried pulse steroid therapy, which is accepted as the first‐line treatment for postimplantation syndrome after endovascular repair of aortic aneurysms in the literature for a patient who did not respond dramatically to nonsteroidal anti‐inflammatory therapy3.We experienced a significant improvement in the patient’s clinical findings and contrast‐enhanced MRI findings after steroid treatment.

Conclusions
An inflammatory reaction may aggravate, transiently, clinical symptoms after aneurysm treatment with a flow‐diverter device. Further research is needed to better understand the underlying mechanisms as well as to achieve better prevention strategies.