Up to 75% of TRAAs are now treated via an endovascular approach. Benefits include lower morbidity associated with a less invasive procedure, better visceral preservation and lower incidence of complications, which can be as high as 18% in some surgical series (Kok et al., 2016). However, while trans-catheter coil embolization is a safe and effective treatment for narrow-necked saccular aneurysms, wide-necked aneurysms require a more sophisticated techniques such as balloon-assisted coil embolization as described above. This involves temporary inflation of a balloon across the neck of an aneurysm with an unfavourable neck anatomy to avoid the risk of coil herniation into the parent vessel and non-targeted coil embolization (Spiotta et al., 2013).
Embolization of wide-necked renal artery aneurysms in patients with a solitary kidney has been described using flow diversion techniques (Kok et al., 2016), covered stents (Kok et al., 2016) and neck-bridging devices (Maingard et al., 2017). BACE was selected as the preferred technique in this case to immediately occlude the aneurysm, while also preserving the arterial supply to the solitary kidney.
We elected to use a Transend EX 0.014-in. guidewire (Stryker Neurovascular, Fremont, CA) in conjunction with the Scepter C balloon to afford more steerability and more favourable navigation through challenging tortuous arterial anatomy (3,5). Increased steerability is further enhanced by the 5 mm length distal tip of the Scepter C making it easier for the balloon catheter to track across a sharply angulated vessel (Rho et al., 2013). Additionally, the use of a dual-lumen system for both neck remodelling and coil embolization may decrease the risk of thromboembolic complications due to the elimination of the need for two devices and the ability to use a smaller guide sheath or catheter for device delivery (Spiotta et al., 2013).
There are several limitations to BACE of aneurysms including, increased operative complexity owing to a greater number of guidewires and microcatheters required intra-procedurally and vessel dissection or rupture secondary to inflation of the balloon microcatheter in the vicinity of the aneurysm neck (Nelson & Levy, 2001).
The expense of detachable coils used for BACE procedures is also recognised as potentially prohibitive. Simon et al. (Relative cost comparison of embolic materials used for treatment of wide-necked intracranial aneurysms. Simon SD, Reig AS, James RF, Reddy P, Mericle RA, 2010) noted that for aneurysms between 3 and 25 mm in size, the financial cost of of embolization increased exponentially as the size of the aneurysm increased. For example, using Axium coils (eV3 Neurovascular) to embolize a 25 mm intracranial aneurysm could conceivably cost in excess of $50,000 to achieve an optimum packing density of 25%.