One and done? The effect of number of Pipeline embolization devices on aneurysm treatment outcomes.

Abstract

Controversy exists regarding the optimum number of flow diverters for the treatment of intracranial aneurysms. We explored the effect of the number of Pipeline embolization devices (PEDs; Medtronic, Dublin, Ireland) deployed on rates of aneurysm occlusion and complications. Consecutive patients who underwent saccular intracranial aneurysm treatment solely with the PED were included in this retrospective study. Computed tomographic, magnetic resonance, or digital subtraction angiographic images at 6 and 12 months and last follow-up (>12 months) were reviewed for aneurysm occlusion. Complication and retreatment rates were recorded and analyzed statistically. The study included 141 aneurysm treatments in 119 patients. A single PED was deployed in 105 cases, two PEDs in 31 cases, and three PEDs in 5 cases (total = 182 devices). Six-month angiographic data were available for 103 patients. Occlusion rates were 67.1% for single-PED cases and 90.0% for cases with > 1 PED (p = 0.028). The 12-month occlusion rate (follow-up available for 132) for single-PED cases was 74.7% compared to 91.7% for multiple-PED cases (p = 0.04). On multivariate analysis, number of PEDs was an independent predictor of aneurysm occlusion at 12 months (odds ratio 6.3, 95% confidence interval 1.8-22.8, p = 0.005). Thromboembolic complication rates were the same in the single- and multiple-PED treatment groups (2.8%). The retreatment rate was higher in patients treated with a single PED (16.2% vs. 0%, p = 0.01). Deployment of > 1 Pipeline embolization device was associated with higher intracranial aneurysm occlusion and lower retreatment rates. No significant difference was found in complication rates.