Temporal Trends and Management of Acute Aortic Occlusion: A 21 Year Experience

Abstract

The aim was to study patients with acute aortic occlusion (AAO), a rare and life threatening event, in a population based cohort and the outcome of surgical treatment. The Swedish nationwide vascular database (Swedvasc) was used to identify cases, and the population registry to study long term survival. Variables associated with outcome were tested with the chi-square test and analysis of variance. During the 21 year study period (1994-2014), 693 cases of surgical treatment for AAO were included, with a yearly incidence of 3.6 per million inhabitants. Mean±SD age was 69.9±11.2 years, 352 patients (50.8%) were women, and mean±SD length of follow up was 5.2±5.5 years. Most patients presented with bilateral acute limb ischaemia (596 patients, 86.0%). The aetiology of AAO was native artery thrombosis in 458 patients (66.1%), saddle embolus in 152 (21.9%), and occluded graft/stent/stent grafts in 83 (12.0%). The proportion of occluded grafts/stent/stent grafts increased during the study period (n=14 [6.7%] in 1994-2000 vs. n=45 [17.4%] in 2008-2014; p<.001) with a simultaneous reduction of arterial thrombosis (n=149 [71.6%] in 1994-2000 vs. n=158 [61.2%] in 2008-2014; p <. 001). Major amputation above the ankle was performed in 39 patients (8.5%), and 140 patients died within 30 days of surgery (20.2%). Thirty day mortality rate was lower after occluded grafts/stents/stent grafts (eight patients [9.6%]) and higher after saddle embolus (47 patients [30.9%]); p<.001). There was a reduction in overall 30 day mortality over time (n=53 [25.5%] in 1994-2000 vs. n=40 [15.5%] in 2008-2014; p=.007). Long term survival revealed significant differences between the subgroups, although the difference occurred early after the event (p<.001). Mortality after surgical treatment of AAO is improving over time, yet a significant mortality rate was observed throughout the study period. The proportion of AAO secondary to occluded grafts/stents/stent grafts increased over time.