Quantitative evaluation of aortic arch development using digital-image analysis.

Area of Science:

• Human Embryology
• Cardiovascular Anatomy

Background:

• Understanding fetal cardiovascular development is crucial for diagnosing congenital heart defects.
• The aortic arch is a key component of the fetal circulatory system, and its dimensional changes provide insights into normal development.

Purpose of the Study:

• To quantitatively analyze the growth of the human aortic arch.
• To establish normative data for aortic arch diameter, length, and volume during specific gestational periods.
• To investigate the relationship between aortic arch dimensions and fetal age.

Main Methods:

• Dissection of 80 formalin-preserved human fetuses (17-27 weeks gestation) with latex-injected arteries.
• Digital imaging and a custom computer program for precise measurement of aortic arch diameter, length, and volume.
• Statistical analysis to assess growth patterns and differences between age groups.

Main Results:

• Aortic arch diameter ranged from 2.5-4.1 mm and length from 6.7-10.3 mm, showing statistically significant linear growth with fetal age.
• Volumetric growth followed a square root function, ranging from 35.7-136.8 mm3, also statistically significant.
• The aortic isthmus diameter was measured and compared to ascending and descending aorta diameters, indicating a narrowing trend.

Conclusions:

• Fetal aortic arch dimensions exhibit significant, predictable growth patterns correlated with gestational age.
• The aortic isthmus demonstrates a relative narrowing during fetal development, suggesting adaptive changes in circulation.
• These findings provide valuable reference data for fetal cardiovascular development and anomaly assessment.