Complications of [thoracic] aneurysm

Most thoracic aneurysms are asymptomatic

Ascending aorta aneurysm may be associated with marked dilatation of the aortic result with subsequent aortic regurgitation

Large mass of aneurysm may compress adjacent structures: tracheal deviation; dysphagia, pulmonary artery stenosis, superior vena caval syndrome

Rupture of thoracic aneurysm results in exsanguination into:

mediastinum, pleural space, tracheobronchial tree, oesophagus or pericardium (resulting in tamponade)

Death usually results from aneurysm rupture

Ascending Aorta Aneurysms

• Often associated with aortic regurgitation
• Frequently site for transverse intimal or medial lacerations
• Death ultimately results from:

1. AR
2. rupture
3. transverse intimal or medial lacerations
4. pressure or erosion into adjacent structures

Transverse Aortic Arch Aneurysms

• May compress airway, pulmonary artery, great veins
• May rupture into airway, pulmonary artery, great veins, pericardium, mediastinum, or pleural cavity

Descending Thoracic Aorta Aneurysms

• May compress or erode adjacent structures: spine, ribs, airway, nerve, oesophagus, lung
• As a consequence: hoarseness, chest pain, cough, haemoptysis, dysphagia, haematemesis
• Aneurysm may rupture into oesophagus, airway, mediastinum, or pleural cavity

Abdominal Aortic Aneurysms

• Death results from rupture into the pleural cavity, oesophagus, duodenum, vena cava, retroperitoneum or abdominal cavity

Aortic Dissections

• External rupture, the most common cause of death, tends to occur through the false channel opposite the entrance tear [at the point of origin of the dissecting process]
• Rupture of the proximal dissection produces hemopericardium and cardiac tamponade
• Haemorrhage into the mediastinum or either pleural space may occur
• Death from external rupture may be abrupt, but in a fair percentage, cessation of haemorrhage occurs secondary to falling aortic pressure and increase tension in the periaortic tissue
• In 50% of proximal dissections, see involvement of aortic valve rendering it incompetent
• Obstruction of a branch vessel of the aorta by aortic dissection occurs in 50% with proximal dissection with catastrophic results: impaired blood supply to heart & brain, kidneys or splanchnic.
• The aortic wall that has been weakened by aortic dissection is often the site of saccular aneurysm formation: rupture of these is a major cause of late death

Complications Acute Aortic Dissection
Aortic valvular insufficiency	Results in heart failure
Aortic rupture	Most common cause of death in acute stage as outer wall of false lumen is thinner than inner wall
Aortic obstruction	False lumen may obliterate true lumen resulting in distal aortic insufficiency
Aortic branch obstruction	Includes coronary, brachiocephalic, visceral & iliac arteries by a combination of extension of dissection, compression and thrombus
Pulmonary artery obstruction	Ascending aorta & Pulmonary artery are adjacent & share common tissue covering within pericardium
Rupture into Heart Chamber	Right atrium & ventricle become adherent to dissecting ascending aorta; if rupture see left to right shunt & heart failure