Proximal Seal After Emergency EVAR for Ruptured Abdominal Aortic Aneurysm and its Clinical Implications

OBJECTIVE: Endograft apposition can predict failure after elective endovascular aneurysm repair (EVAR), but its role in ruptured EVAR (rEVAR) has not been investigated separately. This study evaluates early to mid-term outcomes after rEVAR, including proximal apposition and its changes over time. METHODS: In this retrospective, observational, dual-centre study of consecutive rEVAR patients, treated between January 2015 and December 2024, aortic morphology and proximal endograft apposition were analysed. Shortest apposition length (SAL) was measured on early (<3 months) and last postoperative computed tomography angiography (CTA). Records were reviewed for baseline characteristics, complications, and reinterventions. SAL changes were assessed and compared between patients with and without type 1a endoleak (T1aEL). Overall survival was estimated using Kaplan-Meier analysis. Cumulative incidences of T1aEL and reinterventions were assessed using competing risk analysis accounting for mortality. RESULTS: Included were 89 patients. Median follow-up was 47 months (95% Confidence Interval [CI], 37 - 71 months). Thirty-four patients (38%) were treated outside of the instructions for use (IFU) for the proximal neck. Median SAL was 13.7 mm (6.4, 21.8 mm), with 39% (n = 35) having a SAL of <10 mm, as measured on the early CTA. SAL on the early CTA did not differ significantly between patients with and without mid-term T1aEL (10.7 mm [6.5, 19.7 mm] vs. 15.1 mm [8.1, 22.4 mm], p = 0.544). For mid-term T1aEL patients, SAL had diminished and was shorter on the pre-endoleak CTA compared to the SAL on the last CTA of patients without mid-term T1aEL (4.2 mm [0.0, 7.6 mm] vs. 18.5 mm [11.5, 27.0 mm], p = 0.014). CONCLUSIONS: Short proximal SAL (<10 mm) occurred frequently; however, due to the limited number of mid-term T1aELs, no statistical association could be confirmed between initial short SAL and mid-term type IA endoleaks. A low SAL combined with a decrease during follow-up appeared to be linked to the development of mid-term T1aELs. Serial CTA-applied SAL assessment may help identify patients at risk for T1aEL, guide follow-up, and improve long-term outcomes after rEVAR.