Safety and Outcomes of the Off-Label treatment of Intracranial Aneurysms with Pipeline Embolization Device: A Systematic Review and Meta-analysis

Off-label use of pipeline embolization device (PED) has been increasingly used for endovascular treatment of intracranial aneurysms. Numerous articles have highlighted the safety and effectiveness of PED placement from independent centres for both on and off-label indications. There remains a paucity of information that considers overall safety and efficacy of off-label PED placement across the existing literature. Our objective is to systematically review the safety and occlusion outcomes of PED off-label use in intracranial aneurysm embolization. A systematic search of PubMed and Embase was performed to identify for studies on off-label use of PED. The selected studies provided relevant information, including study characteristics, patient demographics, clinical outcomes, peri-procedural complications, and long-term outcomes, which were subjected to meta-analysis. Twelve studies met the inclusion and exclusion criteria. There were 747 patients and 791 aneurysms included for analysis. Among the patient, 69.2% were female, with an age range of 16 to 80s. The overall incidence rates for ischemic and hemorrhagic complications were 7% (95% CI; 4%-10%) and 2% (95% CI; 0%-4%), respectively. The mortality rate was 1% (95%CI; 0%-4%). The occlusion rates of aneurysm at initial follow up and one year follow up were 82% (95% CI; 72%-91%) and 81% (95%CI; 75%-86%), respectively. Meta-regression analysis indicated no correlated between occlusion rate and factors such as age, gender, aneurysm size, location, morphology, rupture, or history of treatment. Despite variations in results observed in single center studies, this meta-analysis provides evidence supporting the safety and efficacy of PED off-label use.