Incomplete stent expansion in flow-diversion treatment affects aneurysmal haemodynamics: a quantitative comparison of treatments affected by different severities of malapposition occurring in different segments of the parent artery

Comaneci stent-angioplasty for the optimization of inadequately deployed flow diverter stents

BACKGROUND AND PURPOSE

In endovascular procedures, inadequate deployment of a flow diverter stent is a highly concerning technical complication that can lead to acute parent vessel occlusion and ischaemic events. This study aimed to assess the off-label use of the Comaneci device in managing technical difficulties associated with flow diversion.

MATERIALS AND METHODS

We conducted an analysis of all flow diverter procedures documented in our prospectively collected database. Our objective was to identify patients with inadequately deployed implants who underwent Comaneci stent-angioplasty. Both Comaneci 17 and Comaneci 21 devices were utilized to address and remediate technical complications related to stent deployment. We reviewed anatomical features, technical details, intraprocedural complications, as well as clinical and angiographic outcomes.

RESULTS

Thirty-one Comaneci devices were employed to remediate 31 inadequately deployed flow diverter stents. Successful resolution of technical complications associated with flow diverter placement was achieved in all attempted cases. No clinically significant complications were attributed to the technique, and no mortality was observed during the study.

CONCLUSION

Technical issues arising from flow diverter stent deployment are formidable complications. Familiarity with appropriate corrective manoeuvres is essential to achieve successful outcomes. The Comaneci device can be safely and effectively incorporated into the range of techniques used to rectify inadequately deployed stents.

How to perform intra-aneurysmal coil embolization after Pipeline deployment: a study from a hemodynamic viewpoint

BACKGROUND

Pipeline embolization device (PED) deployment combined with coil therapy for large complex intracranial aneurysms is effective and considered superior to PED deployment alone. However, the optimal strategy for use of coils remains unclear. We used patient-specific aneurysm models and finite element analysis to determine the ideal packing density of coils after PED placement.

METHODS

Finite element analysis was used to provide a higher-fidelity model for accurate post-treatment computational fluid dynamics analysis to simulate the real therapeutic process of PED and all coils. We then calculated and analyzed the reduction ratio of velocity to identify the hemodynamic change during PED deployment and each coil embolization.

RESULTS

Sixteen consecutive patients underwent PED plus coil procedures to treat internal carotid artery intracranial aneurysms. After PED deployment, the intra-aneurysmal flow velocity significantly decreased (15.3 vs 10.0 cm/s; p<0.001). When the first coil was inserted, the flow velocity in the aneurysm further decreased and the reduction was significant (10.0 vs 5.3 cm/s; p<0.001). Analysis of covariance showed that the effect of the reduction ratio of velocity of the second coil was significantly lower than that of the first coil (p<0.001)-that is, when the packing density increased to 7.06%, the addition of coils produced no further hemodynamic effect.

CONCLUSION

Adjunct coiling could improve the post-PED hemodynamic environment in treated intracranial aneurysms. However, dense packing is not necessary because the intra-aneurysmal hemodynamics tend to stabilize as the packing density reaches an average of 7.06% or after insertion of the second coil.