Temporal changes of aortic neck morphology in abdominal aortic aneurysms

Area of Science:

• Vascular Surgery
• Medical Imaging
• Aneurysm Research

Background:

• Abdominal aortic aneurysms (AAA) require monitoring for growth and changes.
• The infrarenal neck morphology is critical for endovascular repair suitability.
• Understanding natural history of AAA neck changes is essential for patient management.

Purpose of the Study:

• To characterize temporal changes in the infrarenal aortic aneurysm neck.
• To assess changes in neck diameter and length in small, untreated AAAs.
• To identify factors influencing neck morphology changes over time.

Main Methods:

• Retrospective review of contrast-enhanced CT scans from patients with infrarenal AAA.
• Measurement of infrarenal neck diameter, length, and aneurysm diameter.
• Analysis of changes between serial CT scans and correlation with clinical factors.

Main Results:

• Sixty patients with a median follow-up of 3.4 years showed neck expansion (proximal: 1.1 mm, distal: 1.0 mm) and shortening (4 mm).
• 17% of patients initially had neck length <15 mm.
• Patients with initial neck lengths of 15-20 mm were at risk of losing neck length, impacting suitability for endovascular repair. Diabetes correlated with slower neck shortening.

Conclusions:

• The natural history of the AAA neck involves expansion and shortening.
• Most patients under surveillance will not be significantly affected by these changes.
• Marginal neck lengths (<15-20 mm) at initial imaging predict potential loss of suitability for endovascular repair.