Background: Protection techniques using stents or microcatheters allow treatment of aneurysms with complex configurations by coil embolization. However, the application of these techniques is occasionally limited in wide-neck middle cerebral artery (MCA) aneurysms with acute angularity of the efferent branch vessel.
Objective: We describe a looping technique for passage of a microcatheter and microwire into the acutely angled efferent branch vessel without navigating the system through the aneurysm lumen.
Methods: To select the acutely angulated branch, a looped microcatheter was advanced near the orifice of the distal acutely angled branch vessel, followed by microwire passage through the looped microcatheter into the efferent vessel. The microcatheter loop was straightened after the microwire had been sufficiently advanced. The microcatheter was then navigated into the distal branch vessel over the advanced microwire.
Results: A total of 36 wide-neck MCA aneurysms were successfully treated using this looping method. This technique was used to pass the microcatheter for stent protection in 13 patients and for microcatheter protection in 23. The method was most commonly used for aneurysms located at the M1 trunk (n = 21), followed by the MCA bifurcation (n = 15). Complete or near-complete endosaccular occlusion was achieved in 31 aneurysms. There were no complications related to looping the microcatheter.
Conclusion: This microcatheter looping technique facilitates safe entry into the distal branch during coil embolization of wide-neck MCA aneurysms incorporating the origins of acutely angulated branches.