Terminology

Procedure

Outcomes

Definitions

• Acute aortic syndromes: Spectrum of abnormalities that acutely compromise aortic wall integrity
  • Thoracic aortic dissection (AD): Intimal tear extends into aortic wall; blood flows between/separates wall layers
    • Blood flow separates aortic wall structures, producing "true" & "false" lumina
      • Aortic branch vessel perfusion may be compromised; end-organ ischemia may result
    • Weakened aortic wall may rupture; high mortality
      • Chronic dissection may progress to aneurysm
  • Intramural hematoma (IMH): Hemorrhage within aortic wall media without initial intimal disruption
    • May occur as primary event in hypertensive patients
      • Spontaneous bleeding from vasa vasorum into aortic media causing hematoma formation
    • May result from penetrating atherosclerotic ulcer (PAU)
    • IMH weakens aortic wall
      • May spontaneously progress to AD if intimal layer ruptures ("entry tear")
      • Increased risk of aortic rupture
      • Association with ulcer-like projection in arch or ascending aorta, indicative of intimal disruption
    • May resolve over time, persist, or evolve into aneurysm or PAU
    • Prognosis worsens if associated with ulcer-like projection, IMH > 2 cm thick, aortic diameter > 5 cm, or pleural or pericardial effusion
  • PAU: Plaque rupture through aortic internal elastic membrane
    • Often in patients with extensive intimal calcifications & atherosclerotic plaques
    • Ulcer/hematoma weakens aortic wall
      • May progress to AD
      • May form saccular pseudoaneurysm
      • Increased risk of acute rupture
    • May be single or multiple
    • Often with associated IMH
• Thoracic aortic aneurysm (TAA): Aortic dilatation exceeding normal diameter by > 50%
  • Various etiologies
    • Degenerative: Commonly due to atherosclerosis
      • Abnormal matrix metalloproteinase activity
      • Etiology in 75% of TAAs
    • Connective tissue disorders: Genetic conditions associated with acute aortic syndromes/aneurysms
      • Ehlers-Danlos syndrome: Type IV vascular subgroup characterized by generalized vascular fragility; frequent arterial ruptures
      • Loeys-Dietz syndrome: Phenotypically similar to Ehlers-Danlos type IV subgroup
      • Marfan syndrome: Cystic medial degeneration; usually involves aortic root (annuloaortic ectasia)
      • Cystic medial necrosis
    • Infection (mycotic): Localized infection weakens/compromises integrity of aortic wall
      • Typically saccular configuration
    • Pseudoaneurysm: Disruption of ≥ 1 arterial wall layers; forms contained rupture
      • May be due to aortic injury following penetrating or blunt trauma (e.g., deceleration injury)
      • Also associated with infectious, inflammatory, & neoplastic disease
  • Increased rupture risk if TAA > 5-cm diameter or growth of > 1 cm per year
    • Rupture risk doubles per 1-cm aneurysm increment
  • Great vessel aneurysms: Account for only 1-3% of all arterial aneurysms
    • Brachiocephalic artery most commonly involved
      • Same etiologies as TAAs
• Stenoses/occlusions of thoracic aorta & great vessels
  • Atherosclerosis: Most common cause
    • Severe stenoses may progress to chronic occlusion
    • Often occur at/near origins from thoracic aorta
  • Coarctation: Congenital condition in which thoracic aorta narrows in region where ductus arteriosus inserts; 3 subtypes
    • Preductal: Occurs proximal to ductus arteriosus
      • Due to decreased left heart blood flow from fetal cardiac anomaly; leads to hypoplastic aorta
      • Aortic perfusion distal to narrowing relies on ductus arteriosus; can be life threatening if severe
      • Occurs in ~ 5% of infants with Turner syndrome
    • Ductal: Narrowing at ductus arteriosus insertion
      • Usually appears when ductus arteriosus closes
    • Postductal: Narrowing distal to ductus arteriosus
      • Likely due to contraction & fibrosis of ductus arteriosus at birth, subsequently narrowing aorta
      • Most common type in adults
  • Pseudocoarctation: Rare congenital anomaly in which kinking/buckling of thoracic aorta occurs; resembles true thoracic coarctation on imaging
    • Involves descending thoracic aorta immediately distal to left subclavian artery origin
    • Differentiated from true coarctation by absence of significant hemodynamic obstruction
  • Subclavian steal syndrome: Retrograde flow in vertebral &/or internal mammary artery due to proximal subclavian artery stenosis or occlusion
    • Can cause posterior fossa ischemia resulting in ataxia, dizziness
    • May also present with arm claudication
• Vasculitis
  • Giant cell arteritis (GCA): Vasculitis affecting medium- to large-caliber arteries; similar to Takayasu arteritis & may represent single disease spectrum
    • Age at onset often used to classify patients
      • GCA affects older population (> 50 years)
      • Classically involves temporal arteries &/or cervical carotid arteries
    • 20-30% of patients with GCA have involvement of aorta & primary branches
      • May cause long stenoses of mid/distal subclavian arteries, extending into axillary arteries; seen more frequently in GCA than in Takayasu
    • Diagnosis confirmed by arterial biopsy
      • Typically biopsy of temporal artery; easily accessible & usually involved when disease present
      • Mononuclear cell infiltration/granulomatous inflammation with multinucleated giant cells
  • Takayasu arteritis: Large-vessel granulomatous inflammatory vasculitis
    • Affects people younger than 40 years
      • Often occurs between 15-30 years
    • Classically characterized by 3 stages
      • Active inflammation; constitutional symptoms
      • Vascular inflammation; vessel pain/tenderness
      • Vascular fibrosis or degeneration causing ischemia or aneurysms
    • Involves thoracoabdominal aorta &/or primary branches, pulmonary arteries

Pertinent Vascular Anatomy

• Brachiocephalic (innominate) artery: 1st branch of thoracic aorta; divides into right common carotid & right subclavian arteries
  • Right common carotid artery: Supplies face & right cerebral hemisphere; divides into external & internal carotid arteries
  • Right subclavian artery: Supplies right arm with some branches to head & thorax; becomes axillary artery at lateral margin of 1st rib
    • Vertebral artery: Supplies cerebellum
    • Internal mammary artery: Yields anterior intercostals, breast perforators; terminates as superior epigastric & musculophrenic arteries
    • Costocervical trunk: Divides into supreme intercostal & deep cervical arteries
    • Thyrocervical trunk: Divides into inferior thyroid, suprascapular & transverse cervical arteries
    • Dorsal scapular artery: Supplies levator scapulae, rhomboid & trapezius muscles
• Left common carotid artery: 2nd branch of thoracic aorta; divides into external & internal carotid arteries
• Left subclavian artery: 3rd branch of thoracic aorta; yields same branches as right subclavian artery

Significant Variant Vascular Anatomy

• Aberrant right subclavian artery: Arises as last branch of aortic arch; most common clinically significant aortic arch malformation (0.4-2.3% incidence)
  • Usually passes posterior to trachea & esophagus
    • Patients rarely symptomatic; can cause stridor &/or swallowing difficulties (dysphagia lusoria)
  • Diverticulum of Kommerell: Conical dilatation of aberrant right subclavian artery origin
    • Represents distal remnant of right aortic arch
    • Large diverticulum can be symptomatic
      • 19% present with rupture
      • Can also present with distal embolization
• Right aortic arch
  • With aberrant left subclavian artery: Most common type of right aortic arch (0.1% incidence)
    • Arch courses over right mainstem bronchus but may descend on either side of spine; left subclavian artery is last aortic branch
    • Associated with diverticulum of Kommerell
    • Associated congenital heart disease in 5-10%
      • Tetralogy of Fallot (71%)
      • Atrial or ventricular septal defect (21%)
      • Aortic coarctation, rarely (7%)
  • With mirror image branching: Descending aorta almost always courses to right of spine
    • Left innominate artery followed by right carotid & right subclavian arteries; no retroesophageal vessel
    • Associated congenital heart disease in 90-95%
      • Tetralogy of Fallot (90%)
      • Truncus arteriosis (6%)
      • Tricuspid atresia (5%)
• Double aortic arch
  • Most common vascular ring
    • Aortic arches pass on both sides of trachea, join posterior to esophagus
      • Right arch larger & higher, supplies right subclavian & common carotid arteries
      • Smaller & lower left aortic arch supplies left subclavian & common carotid arteries
  • Rarely associated with congenital heart disease
    • Clinical symptoms of dysphagia &/or stridor
• Cervical aortic arch
  • Rare anomaly; usually asymptomatic
    • May present as pulsating supraclavicular mass
    • May rarely produce vascular ring, compress airway
  • Right-sided location in > 80%
    • Branching may be normal or mirror image

Indications

Contraindications

Preprocedure Imaging

Getting Started

Patient Position/Location

Procedure Steps

Alternative Procedures/Therapies

Complications

Expected Outcomes