694 Morphological Differences of Ruptured Versus Unruptured Wide Neck Aneurysms: Insights From the EVERRUN Registry

Abstract

INTRODUCTION: Wide neck aneurysms (WNAs) have been defined as having a neck width >4 mm (N > 4) and/or dome-to-neck ratio <2 (DTNR < 2). Despite literature detailing treatment options for WNAs, there has been less study on the natural history of WNAs. METHODS: Ruptured and unruptured, saccular, not previously treated WNAs (N > 4, DTNR < 2, or both) were included. Differences in WNA morphology and patient demographics were compared between ruptured (R) and unruptured (U) cohorts. Statistical significance set at p < 0.05. All analysis performed using R(v.4.2.1). RESULTS: There were 310 WNA (87 R vs. 223 U). There were more females in both groups (R: 80.5%, U: 75.8%). Ruptured WNA were smaller (neck size R: 3.72 ± 1.39 mm, U: 4.5 ± 1.78 mm; dome width R: 5.04 ± 2.39 mm, U: 6.29 ± 3.37 mm, p < 0.05) with a trend towards reduced height (R: 5.04 ± 2.16 mm, U: 5.74 ± 3.01 mm) (p = 0.05). Ruptured aneurysms had higher rates of DTNR<2 alone (R: 60.9%, U: 42.2%) and unruptured aneurysms had higher rates of combined DTNR <2 and N >4 (R: 34.5%, U: 50.7%, p < 0.05). N > 4 alone was more prevalent in the unruptured cohort (R: 4.6%, U: 7.2%). ICA-Pcomm location (R: 21.1%, U: 9.4%) and AComm (R: 24.1%, U: 15.2%) were more common in the ruptured cohort. ICA-Oph location was more common in the unruptured cohort (R: 2.3%, U: 17.0%) (p < 0.05). Higher percentages of Asian (A), African American (AA), and Hispanic (H) patients were in the ruptured cohort compared to Caucasian (C) patients (A, R: 6.9%, U:0.9%; AA, R: 12.6%, U: 7.2%; H,R: 35.5%, U: 29.6%; C,R: 42.5%,U: 60.1%) (p < 0.05). CONCLUSIONS: Ruptured WNAs tend to be smaller with unfavorable DTNR whereas unruptured WNAs tend to be larger with a favorable DTNR. Higher rates of Pcomm/Acomm location in ruptured WNA are consistent with previous studies of all aneurysms. The significant racial disparity in ruptured vs. unruptured WNAs highlights the need to examine the biological and societal risks underlying these results.