Endovascular treatment of paraclinoid aneurysms: modified classification based microcatheter shaping technique

Abstract

Objective To develop a modified classification to guide microcatheter shaping in endovascular management for paraclinoid aneurysms and to evaluate the efficiency of this technique.Methods From January 2009 to December 2011,consecutive 126 patients with 142 saccular paraclinoid aneurysms were treated with endovascular embolization at our institute.Paraclinoid aneurysms were classified as Type Ⅰ (ophthalmic artery aneurysms) and Type Ⅱ (superior hypophyseal artery aneurysm).Each type was further divided into two subtypes according to their relative position to an imaginary bisector that separated the origin of ophthalmic artery and posterior communicating artery.Ⅰ a and Ⅱ a referred to aneurysms arising from ICA proximal to the bisector,and Ⅰ b and Ⅱb referred to those aneurysms arising distal to the bisector.Recommended shapes of microcatheter for each subtype of the aneurysins were Ⅰ astraight,Ⅰ b-S shaped,Ⅱ a-C shaped (＜ 90 °) and Ⅱ b-primary curve (≥ 90°).The maneuverability of microcatheters was evaluated with an arbitrary score system.Results Of the 142 aneurysms,56 (39.4％)aneurysms were Type Ⅰ,while 86 (60.6％) were Type Ⅱ.24 aneurysms (16.9％) were managed with coil embolization,and 118 (83.1％) with stent-assisted coiling technique.Immediate angiography demonstrated complete occlusion in 62 (43.7％),neck remnant occlusion in 47 (33.1％) and residual aneurysm occlusion in 33 (23.2％) aneurysms.The microcatheter maneuverability scores ranked as Ⅰ b ＞Ⅱ a ＞ Ⅰ a ＞ Ⅱ b.The maneuverability of microcatheters in Type Ⅰ b was the least satisfactory (P ＜ 0.01).Conclusions A modified classification system of paraclinoid aneurysms may be used to guide microcatheter shaping during endovascular treatment. Key words: Paraclinoid aneurysms ; Endovascular treatment; Classification; Microcatheter