@article {Brinjikji, author = {W. Brinjikji and P.M. White and H. Nahser and J. Wardlaw and R. Sellar and H.J. Cloft and D.F. Kallmes}, title = {HydroCoils Reduce Recurrence Rates in Recently Ruptured Medium-Sized Intracranial Aneurysms: A Subgroup Analysis of the HELPS Trial}, year = {2015}, doi = {10.3174/ajnr.A4266}, publisher = {American Journal of Neuroradiology}, abstract = {BACKGROUND AND PURPOSE: The HydroCoil Endovascular Aneurysm Occlusion and Packing Study (HELPS) was a randomized, controlled trial comparing HydroCoils with bare-platinum coils. The purpose of this study was to perform a subgroup analysis of angiographic and clinical outcomes of medium-sized aneurysms in the HELPS trial. MATERIALS AND METHODS: Patients with medium-sized aneurysms (5{\textendash}9.9 mm) were selected from the HELPS trial. Outcomes compared between the HydroCoil and bare-platinum groups included the following: 1) any recurrence, 2) major recurrence, 3) retreatment, and 4) mRS score of <=2. Subgroup analysis by rupture status was performed. Multivariate logistic regression analysis adjusting for aneurysm neck size, shape, use of adjunctive device, and rupture status was performed. RESULTS: Two hundred eighty-eight patients with medium-sized aneurysms were randomized (144 in each group). At 15{\textendash}18 months posttreatment, the major recurrence rate was significantly lower in the HydroCoil group than in controls (18.6\% versus 30.8\%, P = .03, respectively). For patients with recently ruptured aneurysms, the major recurrence rate was significantly lower for the HydroCoil group than for controls (20.3\% versus 47.5\%, P = .003), while rates were similar between groups for unruptured aneurysms (16.7\% versus 14.8\%, P = .80). Multivariate analysis of patients with recently ruptured aneurysms demonstrated a lower odds of major recurrence with HydroCoils (OR = 0.27; 95\% CI, 0.12{\textendash}0.58; P = .0007). No difference in retreatment rates or mRS of <=2 was seen between groups. CONCLUSIONS: HydroCoils were associated with statistically significant and clinically relevant lower rates of major recurrence for recently ruptured, medium-sized aneurysms in the HELPS trial. Because this was not a prespecified subgroup analysis, these results should not alter clinical practice but, rather, provide insight into the design of future clinical trials comparing bare platinum with second-generation coils. Abbreviation HELPSHydroCoil Endovascular Aneurysm Occlusion and Packing Study}, issn = {0195-6108}, URL = {https://www.ajnr.org/content/early/2015/03/12/ajnr.A4266}, eprint = {https://www.ajnr.org/content/early/2015/03/12/ajnr.A4266.full.pdf}, journal = {American Journal of Neuroradiology} }