Comparison of coil types in aneurysm recurrence

Abstract 

Objective

Coiling of saccular aneurysms may result in recurrence requiring retreatment. Aneurysm recanalization may depend on coil type. Coil variations include bare platinum, polymer coated (Matrix), and hydrophylic gel coated (HydroCoil) coils. The effect of coil type on aneurysm recurrence was evaluated.

Methods

Retrospective analysis of prospectively collected database of 100 consecutive, 4–15mm, coiled, ruptured aneurysms. There were 3 groups based on coil type: (1) bare platinum, (2) HydroCoil, and (3) Matrix. Data collected included age, gender, aneurysm location, follow-up, retreatments and angiographic occlusion and recanalization.

Results

There were 42.4% (n=14) anterior and 57.5% (n=19) posterior circulation aneurysms in the bare platinum, 61.5% (n=16) and 38.45% (n=10) in HydroCoil, and 43.9% (n=18) and 56.1% (n=23) in the Matrix groups. Retreatment was required in 4 (12.1%) bare platinum, 9 (21.9%) Matrix, and 3 (11.5%) HydroCoil groups. On follow-up angiography HydroCoil group had the most number of completely occluded and least number of residual aneurysms (P=0.01), HydroCoils showed the least (n=4), bare platinum an intermediate (n=7), and matrix group the greatest tendency (n=15) to recanalize.

Conclusions

Matrix coils were most likely to need retreatment. Retreatment rates were comparable for bare platinum and HydroCoils. Follow-up angiography demonstrated statistically significant attenuation of residual aneurysms for HydroCoils. Matrix group had the greatest and HydroCoils the least tendency to recanalize. Factors other than coil surface-coating may attenuate aneurysm recurrence.

Keywords: Aneurysm recurrence, Coil compaction, Bare platinum coils, Hydrocoils, Matrix coils