Morphometry of pig coronary venous system

Area of Science:

• Cardiovascular Anatomy
• Comparative Physiology
• Hemodynamics

Background:

• Previous studies quantified pig coronary arterial and capillary networks.
• A comprehensive morphometric description of the coronary venous tree was lacking.

Purpose of the Study:

• To provide a complete quantitative description of the pig coronary venous tree.
• To establish a foundation for coronary hemodynamics by integrating venous data with arterial and capillary data.

Main Methods:

• Silicone elastomer casting of five pig hearts.
• Optical sectioning of histological specimens for smaller vessels.
• Analysis of vascular casts for larger vessels.

Main Results:

• Coronary venules exhibit unique elliptical cross-sections and wavy, converging morphology.
• Detailed data on vessel number, dimensions, length, connectivity, and series fractions are presented for sinusal and thebesian veins.
• Blood distribution: 27.4% in arteries, 37.1% in veins, and 35.5% in microcirculation (89.4% of microcirculation in capillaries).

Conclusions:

• The morphometric data of the venous tree complements arterial and capillary data, providing a complete quantitative anatomic foundation for coronary hemodynamics.
• Unique venous morphology and topology are critical factors in understanding coronary blood flow and distribution.