Œdème cérébral vasogénique par syndrome de reperfusion post-endartérectomie carotidienne

Extra-aneurysmal flow modification following pipeline embolization device implantation: focus on regional branches, perforators, and the parent vessel

BACKGROUND AND PURPOSE

Flow-diverter technology has proved to be a safe and effective treatment for intracranial aneurysm based on the concept of flow diversion allowing parent artery and collateral preservation and aneurysm healing. We investigated the patency of covered side branches and flow modification within the parent artery following placement of the Pipeline Embolization Device in the treatment of intracranial aneurysms.

MATERIALS AND METHODS

Sixty-six aneurysms in 59 patients were treated with 96 Pipeline Embolization Devices. We retrospectively reviewed imaging and clinical results during the postoperative period at 6 and 12 months to assess flow modification through the parent artery and side branches. Reperfusion syndrome was assessed by MR imaging and clinical evaluation.

RESULTS

Slow flow was observed in 13 of 68 (19.1%) side branches covered by the Pipeline Embolization Device. It was reported in all cases of anterior cerebral artery coverage, in 3/5 cases of M2-MCA coverage, and in 5/34 (14.7%) cases of ophthalmic artery coverage. One territorial infarction was observed in a case of M2-MCA coverage, without arterial occlusion. One case of deep Sylvian infarct was reported in a case of coverage of MCA perforators. Two ophthalmic arteries (5.9%) were occluded, and 11 side branches (16.2%) were narrowed at 12 months' follow-up; patients remained asymptomatic. Parent vessel flow modification was responsible for 2 cases (3.4%) of reperfusion syndrome. Overall permanent morbidity and mortality rates were 5.2% and 6.9%, respectively. We did not report any permanent deficit or death in case of slow flow observed within side branches.

CONCLUSIONS

After Pipeline Embolization Device placement, reperfusion syndrome was observed in 3.4%, and territorial infarction, in 3.4%. Delayed occlusion of ophthalmic arteries and delayed narrowing of arteries covered by the Pipeline Embolization Device were observed in 5.9% and 16.2%, respectively. No permanent morbidity or death was related to side branch coverage at midterm follow-up.

Brain Edema after Carotid Revascularization: Benign Syndrome or Prelude to Hemorrhage?

Brain edema (BE) post carotid revascularization (CR) is considered a benign presentation of the hyperperfusion syndrome. Its physiopathology has been related to production of vasogenic edema that tends to progressive spontaneous resolution. Its relation with post-CR hemorrhage remains unclear. Three cases of BE post-CR are described and compared to controls. Clinical evolution, medical management, and plain-CT and perfusion-CT (PCT) results are analysed. Two cases of BE had a benign course, with a progressive resolution of edema and disappearance of neurologic deficits. Effective blood pressure control was achieved in these patients. The third case suffered massive hemorrhage 24h after initial BE and died. This patient reached peak systolic levels of 220 mmHg before conversion to hemorrhage. Plain-CT and PCT findings were similar in the three patients with BE. CT showed signs of hemispheric brain swelling ipsilateral to CR. PCT showed low MTT and high CBF values on the hemisphere ipsilateral to CR compared to the contralateral hemisphere, with symmetric CBV values. Plain-CT and PCT in controls showed no abnormalities. BE post CR can be reversible but may also herald a hemorrhagic complication. A common physiopathology of post-CR BE and hemorrhage is suggested by PCT findings, related to failure of autoregulation and secondary blood-brain-barrier dysfunction. Spontaneous resolution of BE post-CR should not be routinely expected in clinical practice. Conversion to hemorrhage might be related with deficient blood pressure control and secondary rupture of the already damaged vessel wall.