Outcome-based anatomic criteria for defining the hostile aortic neck

Area of Science:

• Vascular Surgery
• Medical Imaging
• Biomedical Engineering

Background:

• Hostile aortic neck anatomy is a known risk factor for poor outcomes in endovascular aortic aneurysm repair (EVAR).
• Existing definitions of hostile anatomy lack standardization, leading to variability in clinical assessment and risk stratification.
• Accurate identification of predictive anatomic criteria is crucial for improving EVAR success rates.

Purpose of the Study:

• To identify specific anatomical criteria of the aortic neck that accurately predict success or failure after EVAR.
• To establish objective thresholds for defining hostile aortic neck anatomy.
• To reduce the incidence of type Ia endoleaks, a common complication of EVAR.

Main Methods:

• Analysis of 221 patients from the ANCHOR clinical trial, enriched for challenging aortic neck anatomy.
• Three-dimensional computed tomography scans were analyzed to assess various aortic neck measurements.
• Receiver operating characteristic (ROC) curve analysis and binary logistic regression were employed to identify predictive variables and optimal thresholds for type Ia endoleaks.

Main Results:

• 45.2% of patients experienced type Ia endoleaks, either intraoperatively or during follow-up.
• Predictive factors for endoleak included increased aortic neck diameter, aneurysm sac diameter, common iliac artery diameters, and conical neck configuration.
• Protective factors against endoleak were increased aortic neck length and the presence of mural thrombus in the aortic neck.

Conclusions:

• Aortic neck diameter and length are independently predictive of type Ia endoleak after EVAR.
• Mural thrombus within the aortic neck demonstrates a protective effect against endoleaks.
• Standardized anatomic criteria with defined thresholds are essential for assessing hostile aortic necks and managing EVAR risks.