Clinical commentaryBalloon-in-stent assisted coiling for treatment of intracranial overwide and undertall aneurysms

•Balloon-in-stent assisted coiling is a therapeutic alternative for overwide and undertall aneurysms.•Balloon-in-stent assisted coiling is a viable option for the treatment of tiny and recurrent aneurysms.•Balloon-in-stent assisted coiling should be used prudently for ruptured internal carotid artery aneurysms.

This study reports our experience of balloon-in-stent assisted coiling for the treatment of morphologically unfavorable aneurysms located in the internal carotid artery (ICA). From July 2007 to April 2014, twelve patients with twelve aneurysms located in the ICA were coil embolized by simultaneously using balloon and stent assistance. Five aneurysms were ruptured and seven were unruptured. All the aneurysms were overwide (dome-to-neck ratio ⩽1.2) and undertall (aspect ratio ⩽1.2) anatomically. The procedure-related adverse events, clinical and angiographic results were retrospectively analyzed. Intraprocedural aneurysmal bleeding occurred for one unruptured aneurysm but was stopped immediately after the balloon was inflated. Periprocedural thromboembolism occurred for two ruptured aneurysms, leading to death in one patient and severe neurological deficit for the other one. Procedure-related permanent morbidity and mortality rates were 8.3% (1/12) and 8.3% (1/12). Satisfactory (total and subtotal) occlusion was obtained immediately in 11 (91.7%) cases. Nine aneurysms received digital subtraction angiography follow-up (mean 25.1 months, range 6-55), and all of them except one were totally obliterated. No aneurysmal bleeding occurred during a mean period of 59.1 months, clinical follow-up for eleven patients. Balloon-in-stent assisted coiling might be a therapeutic alternative to prevent growth or rupture of overwide and undertall aneurysms. Nevertheless, it should be used prudently for ruptured ICA aneurysms, for its disadvantage of technical complexity and relatively high rate of adverse events.