MV

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.