Inflammation of the aortic wall is a determinant of postoperative aortic surgery outcomes and it is detectable by positron emission tomography imaging

Background The impact of aortic wall inflammation on postoperative aortic surgery outcomes and its diagnostic methodology is unclear and not addressed in the current guidelines(1). Purpose To verify if aortic inflammation affects the outcomes after aortic surgery, and the diagnostic potential of positron emission tomography (PET) imaging. Methods This is a retrospective and prospective study performed on the aortic histology of adult patients who underwent aortic surgery in a single centre, from 2000 to 2023. Exclusion criteria were: active infection. All the histologies were analyzed and classified according to the literature consensus(2). Variables included patients’ demographics, cardiovascular risk factors and indication for surgery. Primary outcomes were death or reintervention on remnant native aorta. The relationship between aortic inflammation and cardiovascular risk factors was tested with Logistic Regression, as odds ratio (OR) and 95% confidence interval (CI95%). The Cox regression evaluated the primary outcomes related to inflammation, as hazard ratio (HR) and 95%CI. The Kaplan-Meier curves stratified by inflammation were compared with the Tarone-Ware test. A sub-analysis was conducted on preoperative and postoperative PET to verify his potential in detecting aortic inflammation. Results Data concerning 2365 patients’ histology were gathered: 227(9.6%) had aortic inflammation. The main histological subgroups were: 167 giant cell patterns (73.6%), 31 lymphoplasmacytic patterns (13.7%), 18 IgG4-related aortitis (7.9%), 11 mixed patterns (4.8%). The median follow-up was 5 years (Interquartile 2-9 years). The inflammation was independently associated with females (OR3.5 CI95% 1.9-6.2 p<0.01), age (OR1.05 CI95% 1.01-1.08 p<0.01), and aneurysmatic aorta (OR1.08 CI95% 1.05-1.1 p<0.01), not with aortic dissection (OR0.47 CI95% 0.19-1.10 p=0.08). Inflammation was a strong independent risk factor for reintervention on the remnant native aorta (HR2.85 CI95%1.8-4.4 p<0.01). It was statistically nearly associated with increased mortality (HR 1.47, CI 95% 0.9-2.2, p=0.053). No differences in the outcomes impact were found in the different subclasses of inflammation. The Kaplan-Meier curves confirmed that an inflamed aorta provided lower freedom from reintervention than one without inflammation (Figure1, Tarone-Ware Test p<0.001). Of the patients with histologically confirmed aortic inflammation, preoperative PET was available in 18, revealing aortic wall hypermetabolism in 16 cases. Postoperative PET imaging was performed in 35 patients, with hypermetabolism in 23. 3 patients treated with high-dose corticosteroids showed complete resolution at 6-month follow-up(Figure2). Conclusions Aortic wall inflammation is associated with age, female gender, and aneurysmatic aortic pathology. The inflammation strongly increases the risk of reintervention in the remnant native aorta. PET promises to be a good tool to detect it.