Time Distribution of Mortality After Ruptured Abdominal Aortic Aneurysm Repair

Background: Ruptured abdominal aortic aneurysm (rAAA) repair is still associated with high mortality. The aim of this population-based study was to analyze the time distribution of mortality and short-term mortality trends after rAAA repair. Methods: This was a nationwide retrospective registry study including all patients (n = 3,927) who underwent endovascular (EVAR) (n = 935) or open surgical repair (OSR) (n = 2,992) for rAAA between 2000 and 2018. The National Patient Register was used as a source to extract patient and medical data. The register was cross-linked with the national all-cause mortality registry. The postoperative time of death was divided into <48 hours, 2 to 5 days, 6 to 10 days, 11 to 20 days, 21 to 30 days, and 31 to 90 days during the year intervals 2000-2004, 2005-2009, 2010-2014, and 2015-2018, respectively. The proportion of patients who died within each postoperative time interval was calculated. Results: The overall median age was 75.0 years (interquartile range [IQR] 69.0-80.0) and females were 19.6% (n = 769). The EVAR cohort was older (77 vs. 65 years; P < 0.001) and had significantly more cardiovascular risk factors and a history of malignancy. The overall postoperative 90-day mortality was 33.2%, EVAR 25.7%, and OSR 35.5%. There was an overall improvement in 90-day mortality over time (odds ratio [OR] 0.70; 95% confidence interval [CI] 0.57-0.87; P = 0.001) but not separately for EVAR or OSR. Analyzing all postoperative mortalities within 90 days, 43.4% of deaths occurred within 48 hours followed by 16.3% in 2-5 days. The distribution of mortality proportions in each time interval after OSR was 15.4% in < 48 hours, 7.3% in 2-5 days, 4.4% in 6-10 days, 8.6% in 11-30 days, and 6.0% in 31-90 days and after EVAR 11.1% < 48 hours, 3.6% 2-5 days, 3.1% 6-10 days, 4.6% 11-30 days, and 6% 31-90 days. The overall mortality proportions for patients who died <48 hours after aortic repair had decreased over time (P = 0.024). A logistic regression analysis found the following risk factors associated with mortality <48 hours after rAAA, open repair (OR 1.48; 95% CI 1.17-1.89; P = 0.001), female gender (OR 1.41; 95% CI 1.14-1.75; P = 0.002), and history of heart failure (OR 1.63; 95% CI 1.19-2.22; P = 0.002) or angina pectoris (OR 1.37; 95% CI 1.03-1.81; P = 0.03). The recent operative year interval, 2015-2018, was associated with a lower risk for mortality <48 hours (OR 0.72; 95% 0.53-0.98; P = 0.04) and <90-days (OR 0.63; 95% CI 0.49-0.80; P < 0.001). Conclusions: Overall mortality after rAAA repair had decreased but early deaths remained a significant challenge. The mortality was highest within two days of surgery but the proportion of patients who died <48 hours after aortic repair had decreased in recent years. Open repair, female gender, and cardiovascular comorbidities were associated with mortality within 48 hours after surgery. More focused research in the early postoperative phase after rAAA is warranted.