Endovascular Treatment of Spontaneous and Isolated Infrarenal Acute Aortic Syndrome with Unibody Aortic Stent-Grafts.

Introduction: Spontaneous acute aortic syndrome (IAAS) is rarely localized in the infrarenal aorta. The endovascular approach is preferred over conventional open surgery with fewer complications. However, dedicated endovascular devices for IAAS treatment are unavailable. The aim was to report a large single-center experience using unibody stent-grafts to address IAAS.

Methods: From April 2016 to March 2019, a retrospective analysis of patients presenting spontaneous and isolated IAAS was performed. Patients addressed with the unibody stent-graft (AFX endovascular AAA system; Endologix Inc., Irvine, CA) were included in the study. Indications to IAAS treatment were persistent symptoms and/or dilated abdominal aorta (>3 cm). The measured outcomes were technical success; early outcomes (<30 days) including mortality, morbidity, symptoms recurrence, and endoleak occurrence; and late outcomes (>30 days) including mortality, symptoms recurrence, endoleak occurrence, stent-graft patency, and survival. Median follow-up was 23.77 ± 10 months.

Results: Twenty-one patients with IAAS were included. Indications to treatment were symptoms in 14 (67%) patients and dilated abdominal aorta in 7 (33%). Technical success was achieved in all cases. No perioperative mortality and 1 (4.8%) early femoral access complication was encountered. During the follow-up were registered 1 (4.8%) aortic unrelated death and 1 (4.8%) stent-graft limb stenosis. The 36 months estimated survival and freedom from reintervention were 92% (CI: 37-43; SE: 1.7) and 94% (CI: 37-44; SE: 1.7), respectively.

Conclusions: The endovascular treatment of IAAS with unibody stent-graft (AFX endovascular AAA system; Endologix Inc.) is safe and effective with promising mid-term outcomes. The use of unibody stent-grafts expands the endovascular indication, despite the usual anatomic IAAS features. Larger studies with longer follow-up are required to validate the outcomes of the reported technique.