Pig Heart Comparison

Anatomy of the Pig Heart: Comparisons with Human Cardiac Structure

Overview

• The study focuses on comparing the cardiac anatomy of pigs (Sus scrofa) and humans, emphasizing the structural differences that could impact xenotransplantation efforts.

• Although transgenic technology aims to address immunological challenges of using pig organs in humans, anatomical disparities often necessitate careful consideration.

Pig vs. Human Heart Shape

• Pig Heart: Classic ‘Valentine heart’ shape due to its position in the thorax and unguligrade stance.

• Human Heart: Trapezoidal silhouette reflecting an orthograde posture.

Atrial Differences

• **Morphologically Right Atrium in Pig:

  • Tubular-shaped appendage

  • Superior and inferior caval veins enter at right angles.

  • Prominent left azygous vein drains into coronary sinus.**

• **Human Right Atrium:

  • Triangular appendage

  • Direct line alignment of caval veins.**

Pulmonary Veins

• Porcine Left Atrium: Receives only 2 pulmonary veins.

• Human Left Atrium: Typically has 4 orifices for pulmonary veins.

Right Ventricle Characteristics

• Pig Right Ventricle:

  • Less pronounced inlet to outlet sweep.

  • Prominent muscular moderator band situated higher than in humans.

• Human Right Ventricle: Greater distinction between inlet and outlet components.

Trabeculations

• Pig Ventricles: Apical components display broader trabeculations compared to human ventricles, indicating different muscular architecture.

Aortic-Mitrial Continuity

• Reduced in the outlet component of the porcine left ventricle. Approximately two-thirds of the aortic valve is supported by the left ventricular muscle.

Cardiac Structure Comparison

• General: Pigs' hearts exhibit several morphologic differences from humans, crucial for the understanding of potential xenotransplantation outcomes.

• Studies indicate a substantial need for anatomical insights as techniques evolve in utilizing porcine organs for transplant.

Introduction to Transgenic Pigs in Research

• Establishing the pig as a significant model in cardiovascular research, as it may offer more accurate extrapolation compared to dogs due to lesser anatomical differences with humans.

Methods of Study

• Examination of 27 pig hearts across various ages, ensuring normal conditions free of congenital defects or cardiovascular diseases.

• Detailed gross anatomical analysis and dissection conducted to assess internal structures and compare findings with human hearts.

Gross Morphology Findings

• Porcine hearts demonstrate a consistent morphology, characterized by:

  • Uniquely positioned appendages.

  • Distinct orientation of major vessels and structures.

Significance of Findings

• Highlights crucial differences between porcine and human cardiac anatomy that may complicate transplantation procedures.

• Provides groundwork for future assessments, particularly considering how such morphologies adapt in a new physiological context when transplanted into human bodies.

Conclusion

• Recognizing disparities in anatomy is paramount in discussions about the relevance and viability of using porcine hearts in human xenotransplantation.

• Ongoing research is essential to resolve potential issues related to cardiac function and overall compatibility of organ transplants from pigs to humans.