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A Murine Model of Stent Implantation in the Carotid Artery for the Study of Restenosis
Published on: May 14, 2013
Longitudinal Stent Malapposition After Microcatheter Removal Is Associated With Incomplete Occlusion After Pipeline
Kazuaki Okamura1, Yoichi Morofuji1,2, Nobutaka Horie3
1Department of Neurosurgery, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
Background And Objectives:
Flow diversion is an established treatment strategy for intracranial aneurysms; however, incomplete aneurysm occlusion remains a clinically relevant challenge. Adequate stent-vessel wall apposition is considered critical for aneurysm healing, yet the impact of longitudinal malapposition on long-term outcomes has not been well defined. We aimed to evaluate whether longitudinal stent malapposition detected on cone-beam computed tomography (CBCT) after microcatheter removal is associated with incomplete aneurysm occlusion after Pipeline flow diversion.
Methods:
We retrospectively analyzed 54 intracranial aneurysms treated exclusively with the Pipeline embolization device between 2019 and 2024. In coil-assisted cases, coils were delivered through a jailed 0.0165-inch microcatheter (SL-10). CBCT was routinely obtained immediately after microcatheter removal and before angioplasty to assess intrinsic stent configuration. Longitudinal malapposition was defined as incomplete stent-vessel wall apposition measuring ≥5 mm. The primary end point was aneurysm occlusion at 12 months graded by the O'Kelly-Marotta (OKM) scale. Incomplete occlusion was defined as OKM grades A-C.
Results:
At 12 months, complete occlusion (OKM D) was achieved in 36 aneurysms (67%), whereas 18 (33%) demonstrated incomplete occlusion. Longitudinal malapposition ≥5 mm was identified in 7 aneurysms (13%). Incomplete occlusion occurred in 71% of aneurysms with malapposition compared with 28% without malapposition (odds ratio 6.5, 95% CI 1.1-37.8; P = .03). In coil-assisted cases, malapposition was observed in 4 of 31 aneurysms (13%), all of which resulted in incomplete occlusion.
Conclusion:
Longitudinal malapposition ≥5 mm detected on CBCT after microcatheter removal was significantly associated with incomplete aneurysm occlusion at 12 months after Pipeline flow diversion. This association was particularly evident in coil-assisted procedures. These findings suggest that longitudinal malapposition may represent a clinically relevant and potentially modifiable procedural factor, and that CBCT assessment after catheter removal may help guide procedural optimization and risk stratification.
