To the Editor:
We read with interest the article by Aydin et al1 describing their strategy for treating wide-necked intracranial bifurcation aneurysms using both stent and balloon assistance. The authors described their adaptation of a traditional stent-assisted coiling technique in 61 patients, in which complete occlusion was achieved in almost 90% of cases at long term follow-up, with a retreatment rate of 1.8%, a permanent morbidity of 3.3%, and periprocedural complications in 11.5%.
In contrast to Y-stenting, this modified technique requires the placement of 3 microcatheters—one in the distal vessel that is to be stented, one in the aneurysm, and a balloon microcatheter in the second daughter branch. In fact, the technique could be accomplished with 2 if the stent is first placed, then the stent microcatheter is used to cross the stent into the aneurysm. Still, as described, there are 3 microcatheters placed at the same time within the parent intracranial vessel, which may contribute to an increased risk of thrombus formation, and increased difficulty in manipulating microcatheters around or between those already placed in the daughter vessels or in the aneurysm itself. It would be helpful to learn which guide catheter was used that is large enough to accommodate 3 microcatheters; where the guide was positioned to provide adequate support; and whether bilateral femoral access was required for access in some cases.
Doubtless, wide-necked bifurcation aneurysms are challenging aneurysms to treat endovascularly. However, there is an ever-increasing array of endovascular options for the interventionalist to consider, and comparing the outcomes between these is not straightforward. Dual-microcatheter, simple balloon-assisted or stent-assisted coiling all have a clear application in a variety of wide-necked aneurysms. Y- or X-stenting has reported complete occlusion at follow-up in 75% to 88% of cases.2-5 The authors of the study have also recently reported their experience with T-stenting, a technique that aims to avoid overlapping stent segments, with occlusion and safety results similar to the current cohort.6 Scaffold devices such as the PulseRider (J&J Medical Devices),7 and newer devices such as adjustable, retrievable stents (Comaneci device; Rapid Medical) can also be used, albeit with potentially slightly lower rates of long-term complete occlusion (∼65%).8 Intrasaccular devices, such as the Woven EndoBridge (WEB; Terumo), appear to be very safe, with rates of adequate occlusion approaching 85%, but may have lower real-world complete occlusion rates.9 For wide-necked anterior communicating artery (AComA) aneurysms, flow diverting stents may be effective even without fully covering the neck of the aneurysm by virtue of their flow modification effect on inflow into the AComA complex.10
Over half the aneurysms in the present series were located in the middle cerebral artery (MCA), presumably at the MCA bifurcation. Surgical treatment, even for wide-necked aneurysms incorporating branches from their base, is feasible and safe. In modern series, a clip-first policy for MCA aneurysms has been reported to result in a >98% complete occlusion rate, with a permanent morbidity rate of 4.6%, 0% retreatment rate, and an 11.0% overall rate of complications.11 In a direct comparison in a “coil-first” modern practice, clipping resulted in a higher immediate and long-term occlusion rate with similar safety outcomes.12 In the real-world BRAT (Barrow Ruptured Aneurysm Trial) trial, wide-necked aneurysms were significantly more likely to cross over to the clipping group, with significantly lower rate of retreatment required among those patients who underwent clipping.13 Safe surgical treatment may be the optimal treatment for some wide-necked aneurysms in other locations in the anterior circulation as well.
It is a truism that you will become facile at what you do often. No doubt the balloon-assisted or stent-assisted coil technique described by Aydin et al has a place in the endovascular armamentarium, and may be the best choice for some wide-necked aneurysms. However, modern cerebrovascular and endovascular surgeons must remain hypervigilant about the safety of their chosen techniques, particularly in the treatment of unruptured intracranial aneurysms, and recognize that any new technique must be measured against the most effective, and safest, options available that include not just other endovascular strategies, but surgery as well.
This study did not receive any funding or financial support.
The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article.
1. Aydin K, Stracke P, Berdikhojayev M, et al. Safety, efficacy, and durability of stent plus balloon-assisted coiling for the treatment of wide-necked intracranial bifurcation aneurysms. Neurosurgery. 2021;88(5):1028-1037.
2. Chen Y, Zhang Y, Chao Y-J, et al. Stent-assisted coiling embolization of middle cerebral artery trifurcation wide-necked aneurysms. Eur Rev Med Pharmacol Sci. 2017;21(19):4346-4349.
3. Bartolini B, Blanc R, Pistocchi S, Redjem H, Piotin M. “Y” and “X” stent-assisted coiling of complex and wide-neck intracranial bifurcation aneurysms. AJNR Am J Neuroradiol. 2014;35(11):2153-2158.
4. Durst CR, Starke RM, Gaughen JR Jr, et al. Single-center experience with a dual microcatheter technique for the endovascular treatment of wide-necked aneurysms. J Neurosurg. 2014;121(5):1093-1101.
5. Chalouhi N, Starke RM, Koltz MT, et al. Stent-assisted coiling versus balloon remodeling of wide-neck aneurysms: comparison of angiographic outcomes. AJNR Am J Neuroradiol. 2013;34(10):1987-1992.
6. Aydin K, Stracke CP, Barburoglu M, et al. Long-term outcomes of wide-necked intracranial bifurcation aneurysms treated with T-stent-assisted coiling [published online ahead of print: December 6, 2019]. J Neurosurg. doi:10.3171/2019.9.JNS191733.
7. Pranata R, Yonas E, Vania R, Sidipratomo P, July J. Efficacy and safety of PulseRider for treatment of wide-necked intracranial aneurysm—a systematic review and meta-analysis. Interv Neuroradiol. 2021;27(1):60-67.
8. Sirakov A, Minkin K, Penkov M, Ninov K, Karakostov V, Sirakov S. Comaneci-assisted coiling as a treatment option for acutely ruptured wide neck cerebral aneurysm: Case series of 118 patients. Neurosurgery. 2020;87(6):1148-1156.
9. Arthur AS, Molyneux A, Coon AL, et al. The safety and effectiveness of the Woven EndoBridge (WEB) system for the treatment of wide necked bifurcation aneurysms: final 12-month results of the pivotal WEB Intrasaccular Therapy (WEB-IT) study. J NeuroIntervent Surg. 2019;11(9):924-930.
10. Cagnazzo F, Limbucci N, Nappini S, et al. Flow-diversion treatment of unruptured saccular anterior communicating artery aneurysms: a systematic review and meta-analysis. AJNR Am J Neuroradiol. 2019;40(3):497-502.
11. Rodriguez-Hernandez A, Sughrue ME, Akhvan S, Habdank-Kolaczkowski J, Lawton MT. Current management of middle cerebral artery aneurysms: surgical results with a “clip first” policy. Neurosurgery. 2013;72(3):415-427.
12. Pflaeging M, Kabbasch C, Schlamann M, et al. Microsurgical clipping versus advanced endovascular treatment of unruptured middle cerebral artery bifurcation aneurysms after a “coil-first” policy. World Neurosurg. 2021;149:e336-e344.
13. Mascitelli JR, Lawton MT, Hendricks BK, Nakaji P, Zabramski JM, Spetzler RF. Analysis of wide-neck aneurysms in the Barrow Ruptured Aneurysm Trial. Neurosurgery. 2019;85(5):622-631.