Influence of On-Call Vascular Surgery Team and Off-Hour Effect on Survival after Ruptured Abdominal Aortic Aneurysm

Abstract

Ruptured abdominal aortic aneurysms (rAAAs) represent a life-threatening emergency and carry a high community and in-hospital mortality, despite treatment and protocol advances. Identifying prognostic factors like the presence of on-call vascular surgery teams at first hospital admissions or times of hospital admissions can modify hospital protocols and mechanisms to ameliorate general outcomes. The aim of this study is to analyze the influence of on-call vascular surgery teams and off-hour admissions on survival after rAAAs in Catalonia, Spain. We used data from public health official registries (based on registration of the minimum basic data set) to collect diagnosed cases of rAAAs (ICD-9-CM [International Classification of Diseases, Ninth Revision, Clinical Modification] 441.3) between January 2008 and December 2017. Variables included patient comorbidities, aneurysm treatment and type (endovascular treatment: ICD-9-CM 39.7 or open surgery: ICD-9-CM 398.44 and 39.25), in-hospital mortality, initial hospital admissions and transfers, days and times of admission, and final treatment received. We compared intervention rates and mortalities in all samples and operated cases, in patients initially admitted into tertiary vascular centers (with on-call vascular surgery teams) and community centers (without on-call vascular surgery teams), and the "off-hour effect" (night [22:00 hr to 8:00 hr] or weekend admissions [Friday to Sunday]) in mortality and type of surgery (open or endovascular repair). Of 717 patients with rAAAs (92% men), 561 (78.2%) were initially admitted into tertiary vascular centers and 156 (21.8%) into community centers. The rate of operated cases and global mortality was higher when cases were initially admitted into tertiary vascular centers (388, 69.2% vs. 46, 29.5%; P<0.001 and 63.6% vs. 88.5%, P<0.001, respectively), but when surgery was performed (excluding palliative nonoperated cases), the postoperative mortality in both groups was comparable (47.4% vs. 60.9%, P=0.085), in both univariate and multivariate analysis. On the other hand, patients admitted during night hours (210, 29.3%) did not reveal noteworthy differences in the overall mortality (68.6% vs. 69.2%, P=0.860) or postoperative mortality compared to those admitted during day hours (61.0% vs. 60.4%, P=0.880). Weekend admissions neither showed worse results (280, 39.1%, admitted during weekend: overall mortality 70.4% vs. 68.2%, P=0.541 and postoperative mortality 51.2% vs. 47.3%, P=0.436). No significant dissimilarities were seen either in the use of endovascular or open repair at night (42.2% vs. 46.1%, P=0.457) or weekend (41.8% vs. 47%, P=0.287). Patients with rAAAs initially admitted into tertiary vascular centers have better overall survival rates than those initially admitted into community centers, mainly because of higher rates of rejected cases in community centers. No differences were seen in terms of mortality or type of surgery in the off-hour admitted cases (night hours or during weekends).