548 A 10-Year Longitudinal Cohort Study Assessing Growth Rates and Surveillance Intervals for Common Iliac Artery Aneurysms. (19th August 2022) - Laloo, R
Abstract: Aim: The European Society for Vascular Surgery defines common iliac artery (CIA) aneurysms as greater than 1.8cm in men and 1.5cm in women. Their reported growth rate is 1–4mm/year depending on their diameter. This study aimed to assess the natural history and surveillance intervals for CIA aneurysms as intervention threshold is based on low-quality evidence. Method: Patients diagnosed with an IAA at a single vascular centre between 1 st January 2010 and 31 st August 2021 were identified from a prospectively collected departmental database and Caldicott-approved data collection performed. The primary outcomes included diameter-based mean aneurysm growth rates and median surveillance intervals. Statistical analysis with SPSS® was performed using chi-squared tests. Results: Of the 203 patients included, 90.6% were men and median (IQR) age at detection was 77 (71–83). IAA were located in the CIA (85.2%), IIA (21.7%) and EIA (2.0%) with the majority being asymptomatic (78.8%). CT was most frequently used as the imaging modality for IAA surveillance (66.3%), followed by ultrasound scan (29.8%) and MRA (3.9%). Growth rate for CIA aneurysms measuring 1.0–1.9cm were -2.1mm/year, 2.0–2.9cm were 0.8mm/year, 3.0–3.9cm were 3.5mm/year, 4.0–4.9cm were 9.4mm/year, 5.0–5.9cm were 2.9mm/year and >6.0cm were 13.8mm/year. Median surveillance intervals for CIA aneurysms at 1.0–1.9cm were 12-monthly, 2.0–2.9cm were 11-monthly, 3.0–3.9cm were 5-monthly, 4.0–4.9cm were 5-monthly, 5.0–5.9cm were 5.5-monthly and >6.0cm were 14.5-monthly. Mean(SD) CIA diameter at rupture was 4.6 (2.4)cm. Conclusions: CIA aneurysms demonstrate faster growth rates as they enlarge and may require more frequent clinical assessments, surveillance, and consideration for repair prior to rupture.