Origin, Course, and Branches of Anterior and Posterior Intercostal Vessels and Internal Thoracic Vessels

Introduction

The intercostal vessels play a vital role in supplying the thoracic wall and adjacent structures. Understanding their anatomy is crucial for clinicians, surgeons, and medical students.

Course of Internal Thoracic Vessels

The internal thoracic artery originates from the subclavian artery and descends posterior to the sternum, giving rise to several branches before bifurcating into the superior epigastric and musculophrenic arteries.

Branches of Internal Thoracic Artery

• Anterior intercostal arteries (first six intercostal spaces)
• Pericardiophrenic artery
• Musculophrenic artery
• Superior epigastric artery

Anterior and Posterior Intercostal Vessels

These vessels contribute to the vascularization of the intercostal spaces and thoracic wall.

Origin

Posterior intercostal arteries arise from the thoracic aorta, while anterior intercostal arteries branch from the internal thoracic artery.

Course and Distribution

• Posterior intercostal arteries travel along the costal groove with accompanying veins and nerves.
• Anterior intercostal arteries supply the upper six intercostal spaces and anastomose with their posterior counterparts.

Clinical Significance

These vessels are important in surgical procedures like coronary artery bypass grafting (CABG) and contribute to collateral circulation during vascular obstructions.