Ligamentum arteriosum

Systemic & remnants · detail · Was: ductus arteriosus

Short fibrous band from the top of the pulmonary trunk at the origin of the left pulmonary artery to the undersurface of the aortic arch at the isthmus, just distal to the left subclavian artery: the closed ductus arteriosus.

Traced from the start

  1. Placenta
  2. Umbilical vein
  3. Ductus venosusHepatic sinusoids (portal and umbilical mixing)
  4. Right atrium to right ventricle and pulmonary trunk
  5. Ductus arteriosus
  6. Ligamentum arteriosum

Detail

Origin
Ductus arteriosus, anatomically closed by 2-3 weeks and fully fibrosed over 1-3 months
Nerve relation
The left recurrent laryngeal nerve hooks under the arch immediately lateral to the ligamentum before ascending in the tracheo-oesophageal groove
Fixation
Tethers the mobile arch to the pulmonary trunk, so shear forces concentrate at the isthmus during sudden deceleration

When it goes wrong

High-speed deceleration (car crash, fall from height)

Traumatic aortic transection at the isthmus just distal to the left subclavian: widened mediastinum, tracheal deviation to the right and a left apical cap on chest X-ray

Aortic arch aneurysm, left atrial enlargement or ductal surgery

Left recurrent laryngeal nerve palsy with hoarse voice and bovine cough (Ortner syndrome)

Juxtaductal coarctation of the aorta

Upper-limb hypertension with weak, delayed femoral pulses, rib notching from intercostal collaterals and a '3' sign on chest X-ray; ductal tissue in the aortic wall contracts after birth and tightens the narrowing

Practise this structure

3 questions in the bank tagged Thorax.