Protocol-based medical management for inflammatory abdominal aortic aneurysms: a five-year single-center experience

Inflammatory abdominal aortic aneurysm (IAAA), a distinct clinical entity characterized by dense periaortic fibrosis and elevated inflammatory markers, lacks a consensus-driven optimal management strategy. While medical therapy is often utilized, comparative data against surgical or endovascular interventions remain limited. We report our experience with a standardized medical protocol for the management of IAAAs.

We conducted a retrospective cohort study of 27 consecutive patients diagnosed with IAAA between 2012 and 2019. Predefined diagnostic criteria for IAAA included an ESR>100 mm/h, aortic wall thickness >10 mm, and inflammatory symptoms. Risk of rupture was assessed using a PET-CT scan for patients with a maximal aortic diameter exceeding 5.5 cm. A standardized medical protocol was used for low rupture risk patients including IV methylprednisolone followed by oral prednisone taper. Methotrexate was introduced for steroid-refractory cases. Endovascular or open aortic repair was used for patients with high risk of rupture.

Patients had a mean age of 62.3 years, and 70.4% were male. The mean baseline aortic diameter was 48±5 mm (95% CI 46.0-50.0). Twenty-three patients (85.2%) were treated initially with corticosteroids. At the 3-month mark, 69.6% of medically treated patients achieved an acceptable response with steroids alone. Five steroid-refractory patients received methotrexate and demonstrated clinical improvement. ESR normalized in 95.7% of medically treated patients. During five-year follow-up, no medically managed patient required emergency surgical intervention. Eleven patients required temporary steroid reintroduction at 3 years, with sustained stability at 5 years. Three patients underwent EVAR with favorable outcomes. One patient underwent open repair, which was associated with significant perioperative morbidity and late mortality.

In selected patients with low risk of aortic rupture, protocol-based medical therapy for IAAA is safe and effective with minimal risk upon mid-term follow-up. PET-CT scan assessment for risk of immediate rupture is appropriate for patients with aortic diameter between 5.5 to 6.5 cm. Methotrexate introduction may be effective for steroid-refractory cases. Endovascular repair remains a suitable option when intervention is required. Larger prospective studies are needed to establish definitive management guidelines for IAAAs.