Internal thoracic ( mammary ) artery

Cardiac Surgery
Internal thoracic ( mammary ) artery
ORIGIN and Course Of IMA
BRANCHES
Thymic Artery
The Xiphoid branch
The sternal branches
The Pericardiacophrenic branch 
Anterior intercostal branches
Perforating branches
Musculophrenic artery
Superior Epigastric Artery
Clinical significance

1. The Internal Thoracic ( Mammary ) Artery Cardiac Surgery October / 2017

2. Each of the subclavian arteries is made up of three parts, defined in relation to the  Anterior scalene muscle. First part   lies  medial to the anterior scalene muscle. First part branches include: Vertebral artery , Internal thoracic artery and Thyrocervical trunk S econd Part   lies posterior  to the anterior scalene muscle . It gives rise to the  costocervical trunk  . Third Part  lies lateral to the anterior scalene muscle. Ends at the outer border of the 1st rib by forming the axillary artery

3. ORIGIN and Course Of IMA Originates from 1 st part of the subclavian artery , opposite the thyrocervical trunck and medial to the scalenus anterior muscle. Crossed anteriorly by the brachiocephalic vein before reaching the first rib (risk of injury ). It descends into the thorax behind the 1 st costal cartilage and in front of the pleura. It descends vertically one fingerbreadth lateral to the sternum.

4. It Coveres by the intercostal cartilage and the internal intercostal muscle At the 3 rd intercostal space, it continues to run inferiorly but now superficial to the transversus thoracis muscle . In the 6th intercostal space, it divides into the superior epigastric and the musculophrenic arteries.

5. BRANCHES Thymic Artery Thin artery branches off at the level of the first intercostal space Usually only present in children Turns into a fibrotic residue in adults

6. The Xiphoid branch a small bilateral branch Passes in front of xiphoid  Anastomosis with the opposite artery

7. The sternal branches Distributed in each intercostal space The main source of the sternal blood supply. 

8. The Pericardiacophrenic branch  Accompanies the phrenic nerve Runs toward the diaphragm supplies the pericardium

9. Anterior intercostal branches Arise in the uppermost five intercostal spaces

10. Perforating branches Contribute to the blood supply of the sternum, skin, pectoral muscles, and breast.  accompany the terminal branches of the corresponding intercostal nerves

11. Musculophrenic artery The lateral end branch which runs around the costal margin of the diaphragm supplies the lower intercostal spaces and the diaphragm Superior Epigastric Artery The medial terminal branch enters the rectus sheath of the anterior abdominal wall and supplies the rectus muscle as far as the umbilicus

12. Clinical significance Use in bypass grafts The internal thoracic artery is the cardiac surgeon's blood vessel of choice for coronary artery bypass grafting. The left ITA has a superior long-term patency to saphenous vein grafts and other arterial grafts (e.g. radial artery, gastroepiploic when grafted to the left anterior descending coronary artery, generally the most important vessel, clinically, to revascularize .