Intraluminal thrombosis (ILT) is a significant but underexplored complication in aortic interventions. It is defined as the formation of thrombosis, partially or totally obstructing the lumen, in the surgically treated, stented, or native aorta. In cases of Frozen Elephant Trunk interventions for which are performed regulary for type A dissections, or pathologies such as penetrating aorting ulcers or aneurysm of the distal arch or proximal descending, an ILT can occur early in the postoperative traject and have severe consequences. A recent systematic review and meta-analysis from our group (abstract attached as Annex 1; manuscript pending) analyzed data from 825 patients. and estimated a pooled incidence of ILT of 8.6% [95% CI: 5.7-12.9]. The included studies reported ILT rates ranging from 6.2% to 16.8% (1-4). Patients with ILT had significantly higher risks of dialysis (43% vs. 16%) and mortality (25% vs. 8%). Risk factors included female gender, older age, and concomitant aortic valve replacement. Despite these findings, the underlying pathophysiology and management strategies for ILT in FET remain poorly defined Intraluminal thrombosis (ILT) is a recognized but poorly studied complication following endovascular thoracic aortic repair (TEVAR). Case reports have described its occurrence, particularly in patients with blunt aortic trauma (5-14), and one study suggested a higher risk of intraluminal narrowing among female patients, associated with increased reoperation rates (15). However, no reliable data exist regarding the overall incidence, risk factors, or clinical outcomes of ILT following TEVAR.

A recent systematic review conducted by our group (abstract attached as Annex 2; manuscript pending) identified 10 case reports and three retrospective studies reporting highly variable ILT rates (5-14, 16-18). A study, focusing on blunt aortic trauma patients, found an ILT incidence of 20.6% in a cohort of 34 patients, while another study observed 2 cases in 97 patients (2.06%), and a third study reported 0 cases in 11 patients (0%). The lack of consistent epidemiological data highlights the necessity of a multicenter cohort study to establish a reliable incidence estimate and investigate potential risk factors and clinical outcomes.

This study aims to fill the knowledge gap through a multicenter analysis involving patients treated with FET and TEVAR. By identifying risk factors for ILT, describing related outcomes, and evaluating management strategies, the ultimate goal is to improve clinical care and outcomes for patients undergoing these procedures.

Inclusion Criteria:

• age ≥18 years
• males and females
• presence of pre- and post-operative CT imaging

Exclusion Criteria:

• Patients previously treated with TEVAR or FET

Adult patients undergoing elective and emergency FET and TEVAR procedures between Jan 2010 and June 2025.