The Source for Neurovascular News and Education

June 13, 2024


Although more complex, the addition of coiling may help achieve earlier and more complete occlusion.


Combining flow diversion and adjunctive coiling results in better outcomes without significantly increasing morbidity in patients with large or giant aneurysms, according to the results of a case series published online in the Journal of NeuroInterventional Surgery.

Matthew T. Bender, MD (Johns Hopkins University School of Medicine, Baltimore, MD), and colleagues report on three techniques for combining adjunctive coiling and flow diversion in a single stage that “hopefully makes more interventionists comfortable using this treatment,” he told Neurovascular Exchange.

According to Bender, some literature exists on the technique known as Pipeline adjunctive coiling (PAC), but no prior article has provided a detailed explanation of the alternative techniques, which differ from stent-assisted coiling.

“A coil-through technique in which the aneurysm is accessed through a previously placed stent is common for stent-assisted coiling, but isn’t possible for PAC,” Bender explained.

The retrospective cohort study included 72 PAC procedures performed in 69 patients using a Pipeline Embolization Device (PED; Medtronic) and a “light coil pack” with an average packing density of 14%. Bender noted that the researchers were surprised that the coil density was this high, but said that it trended down slightly over time as they became more comfortable with the technique.

The average size of the aneurysms was 11.0 mm, and the majority were wide-necked. Patients were treated using three progressively complex techniques: sequential (38%), jailed single-intermediate (32%), and bifemoral jailed microcatheter (31%). As the complexity of the technique increased so did aneurysm dome (P = 0.0223) and neck size (P = 0.001). There was also a trend toward increased procedure length, radiation exposure, and stent thrombosis with increased technique complexity.

Overall, procedural success was achieved in 97% of cases. Complete occlusion was achieved in 85% at 6 months and 96% at 12 months. Only three major complications occurred: one with the jailed single-intermediate approach and two with femoral jailed microcatheter.


Using PAC

According to Bender, PAC is used in 5% to 10% of flow-diversion cases, but it “really depends on aneurysm location and morphology.”

Some might argue for the use of multiple devices to improve occlusion outcomes rather than PAC, he noted. While that “may work well for on-label proximal carotid aneurysms in which you don’t have to worry about covered branch occlusion,” Bender said, “we find that in more distal and branch vessel locations, PAC can improve occlusion outcomes without increasing metal coverage across important side branches.”

Bender and colleagues acknowledge that PAC is a technically challenging procedure with unique risks that have not been well described, including an increased risk for intra-procedural stent thrombosis. The three techniques used in their analysis involve escalating challenges and should be used in differing clinical circumstances, he said.

The sequential, single-intermediate technique is simplest and works well for narrow-necked aneurysms that are large, raising concerns about delayed rupture, or in aneurysms that have significant irregularity where clinicians want earlier occlusion, Bender said.

“The dual-microcatheter, single-intermediate technique works well for wide-necked aneurysms in which the PED helps reconstruct the neck, but that are located along straight anatomy and significant intermediate catheter manipulation isn’t necessary for PED opening and apposition,” he added.

Finally, the bifemoral, dual-intermediate technique is the most technical. This technique is appropriate for wide-necked aneurysms located along complex anatomy where clinicians cannot risk intermediate catheter manipulations necessary for PED opening translating to the jailed coiling microcatheter.



Bender MT, Jiang B, Campos JK, et al. Single-stage flow diversion with adjunctive coiling for cerebral aneurysm: outcomes and technical considerations in 72 cases. J NeuroIntervent Surg. 2018;Epub ahead of print.



Bender reports no relevant conflicts of interest.