Predictors of Clinical Outcome After Treatment of Intracranial Aneurysms with the Pipeline Embolization Device

BACKGROUND: Flow-diverting stents have revolutionized the endovascular treatment of intracranial aneurysms. The purpose of this study is to identify predictors of adverse outcomes associated with the pipeline embolization device (PED). METHODS: A retrospective analysis of all patients treated with PED at a single high-volume center from January 2014 to September 2018. Patient outcomes, neurologic morbidity/mortality, and other clinical variables were analyzed. RESULTS: We treated 204 aneurysms in 170 patients with PED. Mean length of follow-up was 11 months. Most (181) aneurysms (89%) were located in the anterior circulation, and 23 (11%) were found in the posterior circulation. Most aneurysms were saccular (82%), followed by fusiform (11%), blister (4%), and dissecting pseudoaneurysms (3%). Mean aneurysm size was 8.2 + 5.7 mm with 145 (71%) small aneurysms (<= 10 mm), 53 (26%) large aneurysms (between 10 and 25 mm), and 6 (3%) giant aneurysms (>= 25 mm). Ninety-two percent of aneurysms were unruptured, and 8% were ruptured. The overall major neurologic morbidity/mortality was 4.7% and 1.8%, respectively. The all-cause mortality was 2.9%. Predictors of neurologic morbidity/mortality included the baseline modified Rankin Scale (P = 0.001), aneurysm neck size (P = 0.003), aneurysm size (P = 0.006), anterior versus posterior location (P = 0.02), and rupture at presentation (0.006). The P2Y12 Reactivity Unit, parent vessel diameter, and patient age did not correlate with adverse events. CONCLUSIONS: The PED has a satisfactory safety profile in both on- and off-label indications. A poor clinical patient baseline, wider aneurysm neck or larger size, and rupture predict an increased risk of an unfavorable outcome.