The aortic arch immediately following the origin of left subclavian showed marked stenosis with mild post-stenotic dilatation. The three aortic arch branches are dilated, more evident at the innominate (23 mm) and left subclavian arteries (17 mm). The left vertebral artery is seen arising directly from the aorta proximal to the left subclavian artery. The diameter of the aorta before the interruption measures 24 mm. The diameter of the aorta after the interruption measures 28 mm. the descending aorta is supplied by the multiple peri-vertebral and mediastinal collaterals. The rest of descending thoracic artery is of normal course and caliber measuring 19 mm. No PDA noted.
Extensive collaterals are seen at the perivertebral and mediastinal regions. Dilated internal mammary arteries anatomizing with inferior epigastric arteries are seen on both sides. Also, posterior intercostal arteries on both sides are dilated to anastomose with anterior intercostal arteries of internal mammary arteries. Evident collaterals are also seen around both scapulae connecting subclavian artery branches with intercostal arteries. Dilated left gastric artery is seen anastomosing with the left internal mammary artery.