Introduction: The main concern with using the pipeline embolization device (PED) in treating cerebral aneurysms is the occurrence of hemorrhagic and thromboembolic complications. The aim of this study is to investigate whether monitoring platelet inhibition using P2Y12 Reaction Units (PRU) is warranted in predicting hemorrhagic and thromboembolic complications after treatment with PED and to find an optimal range of pre-procedural PRU values.

Methods: 231 patients with 248 cerebral aneurysms treated with the PED were retrospectively identified. Patients were started on dual antiplatelet therapy at least 10 days before the intervention. PRU values were checked. Univariate and multivariate logistic regression was performed. Youden Indices were calculated to determine cutoffs for optimal PRU values.

Results: Mean patient age was 57 years. Mean last pre-procedural PRU was 132 (range: 1-382). The combined rate of symptomatic hemorrhagic complications (4%) and symptomatic thromboembolic complications (5.6%) was 9.6%. Analysis using Youden indices suggested an optimal PRU range of 70 to 150 with higher odds of complications outside this range (P=0.01, OR=3, [1.2-7.5]). PRU<60 was a significant predictor of any hemorrhagic complication (P=0.04, OR=2.45, [1.01-5.9]) and PRU>240 was a significant predictor of any thromboembolic complication (P=0.04, OR=3.6, [1.04-12]), and cerebral thromboembolic complications (P=0.02, OR=4, [1.2-14]).

Conclusions: PRU monitoring prior to treatment with the PED has a significant effect on the occurrence of hemorrhagic and thromboembolic complications. Target pre-operative PRU values should be between 60 and 240 and ideally between 70 and 150. Values below this range and above it carry higher odds of hemorrhagic and thromboembolic complications, respectively.

Patient Care: Monitoring PRU values prior to intervention with the pipeline embolization device can significantly affect the hemorrhagic and thromboembolic complications observed with this device and can lead to a better safety profile.

Learning Objectives: To assess the role of monitoring PRU values prior to aneurysm treatment with the pipeline embolization device

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