Editor's Choice – Prevalence of Smoking and Impact on Peri-Operative Outcomes After Elective Abdominal Aortic Aneurysm Repair

Objective
The contemporary burden of smoking in patients undergoing elective abdominal aortic aneurysm (AAA) repair in the UK is unknown. This study aimed to quantify the prevalence of smoking in patients undergoing AAA repair in the UK and determine the association between smoking and peri-operative outcomes.

Methods
This was an observational cohort study. The National Vascular Registry was interrogated for adults undergoing elective infrarenal AAA repair from 2014 to 2021 for prevalence of current smokers, former smokers, and non-smokers over time. The primary outcomes were post-operative complications by smoking status. Secondary outcomes were variation in smoking rates over time and by hospital, in hospital mortality, and length of stay by smoking status. All analyses were adjusted using the validated British Aneurysm Repair score.

Results
Overall, 26 916 patients undergoing elective AAA repair were included (21.9% smokers, 62.2% former smokers, 15.9% non-smokers). The prevalence of smoking did not change over time, with a 2.4 fold variation between UK hospitals (range 13.0 – 31.8% excluding outliers). In hospital mortality was not significantly different between smokers, former smokers, and non-smokers (p > .050 for all comparisons). Compared with non-smokers, smoking was associated with increased overall (odds ratio [OR] 1.40, 95% confidence interval [CI] 1.24 – 1.57) and respiratory complications (OR 1.98, 95% CI 1.63 – 2.39), limb ischaemia (OR 1.63, 95% CI 1.19 – 2.23), bowel ischaemia (OR 1.64, 95% CI 1.06 – 2.54), return to theatre (OR 1.38, 95% CI 1.11 – 1.71), and intensive care admission (OR 1.43, 95% CI 1.31 – 1.56). Compared with former smokers, smoking was associated with increased overall (OR 1.24, 95% CI 1.14 – 1.36), respiratory (OR 1.44, 95% CI 1.27 – 1.63) and limb ischaemia complications (OR 1.48, 95% CI 1.19 – 1.84), and intensive care admission (OR 1.37, 95% CI 1.28 – 1.46). On analysis of the endovascular aneurysm repair subgroup, active smoking was associated with significantly higher rates of limb ischaemia compared with former and non-smokers (OR 2.12, 95% CI 1.49 – 3.01 and OR 1.94, 95% CI 1.19 – 3.16 respectively).

Conclusion
The prevalence of smoking remains high in patients undergoing elective AAA repair with no evidence of a decline in active smokers from 2014 to 2021 compared with the general UK population. Smoking is associated with increased peri-operative complication rates.