title: Bipolar radiofrequency ablation of aneurysm remnants after coil embolization can improve endovascular treatment of experimental bifurcation aneurysms.
abstract: OBJECTIVE Endovascular treatment of aneurysms may result in incomplete initial occlusion and aneurysm recurrence at angiographic follow-up studies. This study aimed to assess the feasibility and efficacy of bipolar radiofrequency ablation (RFA) of aneurysm remnants after coil embolization. METHODS Bipolar RFA was accomplished using the coil mass as 1 electrode, while the second electrode was a stent placed across the aneurysmal neck. After preliminary experiments and protocol approval from the Animal Care committee, wide-necked bifurcation aneurysms were constructed in 24 animals. Aneurysms were allocated to 1 of 3 groups: partial intraoperative coil embolization, followed by RFA (n = 12; treated group) or without RFA (n = 6; control group 1); or attempted complete endovascular coil embolization 2-4 weeks later (n = 6; control group 2). Angiographic results were compared at baseline, immediately after RFA, and at 12 weeks, using an ordinal scale. Pathological results and neointima formation at the neck were compared using a semiquantitative grading scale. RESULTS Bipolar RFA was able to reliably target the aneurysm neck when the coil mass and stent were used as electrodes. RFA improved angiographic results immediately after partial coiling (p = 0.0024). Two RFA-related complications occurred, involving transient occlusion of 1 carotid artery and 1 hemorrhage from an adventitial arterial blister. At 12 weeks, angiographic results were improved with RFA (median score of 0), when compared with controls (median score of 2; p = 0.0013). Neointimal closure of the aneurysm neck was better with RFA compared with controls (p = 0.0003). CONCLUSIONS Bipolar RFA can improve results of embolization in experimental models by selectively ablating residual lesions after coil embolization.
authors.affiliation: Centre Hospitalier de l'Université de Montréal Research Centre (CRCHUM), Notre-Dame Hospital, Interventional Neuroradiology Research Laboratory, Montreal, Quebec.
authors.forename: Xavier
authors.initials: X
authors.lastname: Boileau
authors.affiliation: Centre Hospitalier de l'Université de Montréal Research Centre (CRCHUM), Notre-Dame Hospital, Interventional Neuroradiology Research Laboratory, Montreal, Quebec.
authors.forename: Han
authors.initials: H
authors.lastname: Zeng
authors.affiliation: Centre Hospitalier de l'Université de Montréal Research Centre (CRCHUM), Notre-Dame Hospital, Interventional Neuroradiology Research Laboratory, Montreal, Quebec.
authors.forename: Robert
authors.initials: R
authors.lastname: Fahed
authors.affiliation: Centre Hospitalier de l'Université de Montréal Research Centre (CRCHUM), Notre-Dame Hospital, Interventional Neuroradiology Research Laboratory, Montreal, Quebec.|Centre Hospitalier de l'Université de Montréal (CHUM), Notre-Dame Hospital, Department of Radiology, Service of Neuroradiology, Montreal, Quebec.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Bing
authors.affiliation: Centre Hospitalier de l'Université de Montréal Research Centre (CRCHUM), Notre-Dame Hospital, Interventional Neuroradiology Research Laboratory, Montreal, Quebec.
authors.forename: Alina
authors.initials: A
authors.lastname: Makoyeva
authors.affiliation: University of Alberta Hospital, Mackenzie Health Sciences Centre, Department of Surgery, Division of Neurosurgery, Edmonton, Alberta.
authors.forename: Tim E
authors.initials: TE
authors.lastname: Darsaut
authors.affiliation: Institute of Biomedical Engineering, École Polytechnique de Montréal; and.
authors.forename: Pierre
authors.initials: P
authors.lastname: Savard
authors.affiliation: Centre Hospitalier de l'Université de Montréal (CHUM), Notre-Dame Hospital, Department of Medicine, Service of Cardiology, Montreal, Quebec, Canada.
authors.forename: Benoit
authors.initials: B
authors.lastname: Coutu
authors.affiliation: Centre Hospitalier de l'Université de Montréal Research Centre (CRCHUM), Notre-Dame Hospital, Interventional Neuroradiology Research Laboratory, Montreal, Quebec.
authors.forename: Igor
authors.initials: I
authors.lastname: Salazkin
authors.affiliation: Centre Hospitalier de l'Université de Montréal Research Centre (CRCHUM), Notre-Dame Hospital, Interventional Neuroradiology Research Laboratory, Montreal, Quebec.|Centre Hospitalier de l'Université de Montréal (CHUM), Notre-Dame Hospital, Department of Radiology, Service of Neuroradiology, Montreal, Quebec.
authors.forename: Jean
authors.initials: J
authors.lastname: Raymond
mesh_terms: D000818:Animals; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000379:methods*; D002533:Cerebral Angiography; D004621:Embolization, Therapeutic / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000628:therapy*; D008297:Male; D008955:Models, Cardiovascular; D000078703:Radiofrequency Ablation / Q000379:methods*; D015607:Stents; D013552:Swine; D016896:Treatment Outcome
keywords: RF = radiofrequency; RFA = RF ablation; ROI = region of interest; animal model; endovascular therapy; intracranial aneurysm; radiofrequency ablation; stent; vascular disorders