Aortic Aneurysm Index Calculator

Aortic Aneurysm Index Equation:

\[ AAI = \frac{Aortic\ Diameter\ (cm)}{BSA\ (m²)} \]

Aortic Aneurysm Index (AAI):

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1. What is the Aortic Aneurysm Index?

The Aortic Aneurysm Index (AAI) is a calculated value that normalizes aortic diameter to body surface area, providing a more accurate assessment of aneurysm size relative to patient body size. It helps in risk stratification and surgical decision-making.

2. How Does the Calculator Work?

The calculator uses the AAI equation:

\[ AAI = \frac{Aortic\ Diameter\ (cm)}{BSA\ (m²)} \]

Where:

\( Aortic\ Diameter \) — Maximum aortic diameter measured by imaging (cm)
\( BSA \) — Body Surface Area calculated using standard formulas (m²)

Explanation: The AAI accounts for patient body size, making aneurysm assessment more personalized and comparable across different patient populations.

3. Importance of AAI Calculation

Details: AAI provides better risk stratification than absolute aortic diameter alone, especially in smaller or larger-bodied individuals. It helps determine the true relative size of the aneurysm and guides timing of surgical intervention.

4. Using the Calculator

Tips: Enter aortic diameter in centimeters and body surface area in square meters. Both values must be positive numbers. BSA can be calculated using Mosteller, DuBois, or other standard formulas.

5. Frequently Asked Questions (FAQ)

Q1: Why use AAI instead of absolute aortic diameter?
A: AAI normalizes for body size, providing a more accurate assessment of aneurysm severity, especially in patients with extreme body habitus.

Q2: What are normal AAI values?
A: Normal AAI values vary by aortic segment, but generally values above 2.1-2.5 cm/m² for the ascending aorta may indicate pathology.

Q3: How is BSA calculated?
A: BSA is typically calculated using formulas like Mosteller (√[height(cm)×weight(kg)/3600]) or DuBois (0.007184×height(cm)^0.725×weight(kg)^0.425).

Q4: Which aortic segments can AAI be applied to?
A: AAI can be calculated for ascending aorta, aortic arch, descending thoracic aorta, and abdominal aorta.

Q5: Does AAI replace absolute diameter measurements?
A: No, AAI complements absolute measurements and provides additional context for clinical decision-making.