Oxygen diffusion and consumption of aortic valve cusps

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Tissue Engineering

Background:

• Normal aortic valves possess a vascular network to ensure tissue oxygenation.
• Limited data exists on the metabolic activity and oxygen demands of valve tissue, crucial for tissue-engineered heart valve development.

Purpose of the Study:

• To quantify oxygen diffusivity (DO(2)) and oxygen consumption (VO(2)) in porcine aortic valve cusps.
• To model oxygen tension within valve tissue to assess viability for tissue engineering.

Main Methods:

• In vitro measurement of DO(2) and VO(2) in seven porcine aortic valve cusps at 37°C using a Clark oxygen sensor.
• Mathematical modeling of a three-layered valve structure with defined surface oxygen conditions.

Main Results:

• Mean DO(2) was 1.06 x 10(-5) cm(2)/s and mean VO(2) was 3.05 x 10(-5) x ml O(2).ml tissue(-1)xs(-1).
• Modeled central mean oxygen tension (PO(2)) was 27 mmHg (range 0-50 mmHg).
• DO(2) is comparable to other vascular tissues, but in vitro VO(2) may underestimate in vivo requirements.

Conclusions:

• The study provides foundational data on oxygen diffusion and consumption in aortic valve tissue.
• These findings are essential for understanding oxygen supply limitations and metabolic needs in developing avascular tissue-engineered heart valves.
• Further research is needed to determine in vivo oxygen requirements for functional engineered valves.