A novel method to estimate iliac tortuosity in evaluating EVAR access

Area of Science:

• Vascular Surgery
• Medical Imaging
• Radiology

Background:

• Abdominal aortic aneurysms (AAA) require careful preoperative planning for endovascular repair.
• Assessing iliac artery tortuosity is crucial for successful endovascular aneurysm repair (EVAR) access.
• Existing methods for evaluating iliac artery tortuosity have limitations.

Purpose of the Study:

• To evaluate subjective and objective methods for preoperative assessment of iliac artery tortuosity in AAA patients.
• To compare the accuracy and reliability of different tortuosity measurement techniques.
• To identify an optimal method for clinical use in EVAR planning.

Main Methods:

• Retrospective analysis of 188 AAA patients who underwent preoperative CT scans.
• Evaluation of iliac artery tortuosity using subjective grading, modified iliac tortuosity index, and a novel shortest aortic bifurcation-common femoral artery (CFA) distance method.
• Assessment of intra- and interobserver agreement and correlation between methods.

Main Results:

• Subjective grading demonstrated substantial agreement (κ=0.71) but showed variations in tortuosity index calculations.
• The iliac tortuosity index showed strong intra- and interobserver correlations (r=0.94, r=0.79).
• The novel shortest aortic bifurcation-CFA distance method correlated well with the iliac tortuosity index (r=0.78) and effectively categorized tortuosity.

Conclusions:

• Subjective grading is not recommended as a substitute for the tortuosity index in access evaluation.
• The iliac artery tortuosity index is accurate but complex and time-consuming.
• The shortest aortic bifurcation-CFA distance on axial CT scans is a practical and accurate alternative to the tortuosity index for clinical EVAR planning.