LAUSR

BACKGROUND Aneurysm recurrence after Pipeline Embolization Device (PED) placement can be caused by oversizing of the stent as well as poor wall apposition, both factors of which can lead to elongation. The objective of this study was to assess whether a novel parameter for measuring device elongation based on two-dimensional imaging could be predictive for persistent aneurysm filling after treatment with the PED. METHODS A retrospective cohort analysis was initially completed on 41 aneurysms from Institution A, examining demographic, aneurysmal, and device measurements. Device measurements, including the ratio of the measured length to the nominal length (ML/NL) of the PED, were taken by reviewers blinded to the primary end-point, which was aneurysm occlusion status on 6 month catheter angiogram. Findings were then externally validated against 30 aneurysms (supraclinoid only) from Institution B. RESULTS Data from Institution A demonstrated 61% complete aneurysm occlusion at 6 months, and was lower for aneurysms in the supraclinoid region. For supraclinoid aneurysms alone, combined data from both institutions showed higher rates of non-occlusion with aneurysm neck size greater than 4mm (p=0.008) and a trend towards significance in aneurysms with a branch vessel (p=0.051). The mean ML/NL ratio was significantly larger in the non-occluded group compared with the occluded group at both Institution A (Ratio=1.37 vs 1.10, p=<0.001) and Institution B (Ratio=1.36 vs 1.11, p=0.002). CONCLUSION Our data suggests that a novel parameter based on two-dimensional angiography may serve as a rapid technique to measure device elongation and predict occlusion of supraclinoid aneurysms after PED placement.