Proximal Landing Zone Growth after Thoracic Endovascular Aortic Repair

This retrospective, cohort study aimed to quantitatively evaluate the growth of the proximal landing zone (PLZ), to identify the main predictors influencing the progression of the diameter of the PLZ, and to evaluate their influence on the adverse events associated with the PLZ.

All consecutive patients who underwent a fenestrated, branched, or standard thoracic endovascular aortic repair (TEVAR) and had a PLZ in native aorta (aortic arch and proximal descending aorta), classified as Ishimaru 0 - 4, between April 2018 and January 2022 were included in the study. PLZ diameter changes over time were assessed using longitudinal mixed effects models. Risk factors for PLZ growth were evaluated by uni- and multivariable analyses. Associations between PLZ growth and adverse events were examined using Cox regression.

Seventy-six patients were included, with a mean follow up of 24.2 ± 20.7 months. The average PLZ growth was 1.7 mm/year (95% confidence interval [CI] 1.1 - 2.3; p < .001), which was statistically significantly greater than the growth observed in the unstented native aorta proximal to the tip of the endoprosthesis, averaging 0.7 mm/year (95% CI 0.46 - 0.96; p < .001). In the multivariable analysis time (β = 1.7, 95% CI 1.08 - 2.33; p < .001), pre-operative PLZ diameter (β = 0.92, 95% CI 0.78 - 1.1; p < .001), oversizing (β = 0.08, 95% CI 0.02 - 0.14; p = .016), and age (β = -0.06, 95% CI -0.11 - 0.01; p = .015) were identified as significant risk factors for growth. Growth was significantly associated with type Ia endoleak (hazard ratio 1.25, 95% CI 1.1 - 1.4; p < .001) and migration ≥ 10 mm (hazard ratio 1.19, 95% CI 1.07 - 1.33; p = .001).

Growth of the PLZ after TEVAR exceeds that of the native aorta proximal to the endograft, with progression influenced by both anatomical and procedural factors. Significant PLZ growth is associated with an increased risk of type Ia endoleaks and migration, emphasising the importance of regular follow up and optimised personalised procedure planning.