Aortic Dissection

1
Aortic Dissection

• Risk factors age (60-80 yo), poorly controlled
  HNT, collagen disorders (Marfans,
  Ehlers-Danlos), bicuspid aortic valve,
  coarctation of the aorta
• Clinical manifestations severe, sharp,
  tearing chest pain that radiates to the back,
  abrupt in onset
• HTN at initial presentation is more common in
  distal dissection
• Other sequelae acute aortic insufficiency, AMI
  or ischemia due to dissection into the right
  coronary artery, tamponade, hemothorax,
  neurologic deficits, vocal cord paralysis,
  hoarseness due to compression of recurrent
  laryngeal nerve

2
Diagnosis

• One study of 250 pts
• Typical pain
• Wide mediastinum on chest xray
• Pulse or BP differential between R and L arm
• The incidence of aortic dissection was 7 if none
  present, 31 if typical pain, 39 if CXR findings
  present, 83 when differential occurred or if
  pain and CXR finding present, 100 if all three
• Overall incidence of CXR 63 of 464 pts

3
Diagnosis

• To confirm Chest CT, MRI, or TEE
• TEE and MRI superior but depend on availability
  and stability of the pt.
• Chest CT most widely used. Sensitivity/specificit
  y 94 and 87. Disadvantages intimal flap/site
  of entry less often seen (lt75 of the time)
• MRI 98 sensitive, specific and can ID origin
• TEE can ID true and false lumen based on doppler
  flow, can also ID aortic regirg
• Blood tests smooth muscle myosin heavy chain
  assay. Significant elevations occur in first 24
  hours. Sens/spec 90/97.

4
Management

• DeBakey type I involved both ascending/descendin
  g aorta, type II involved ascending only, type
  III descending only
• Daily system type A involves the ascending
  type B does not
• Initial Rx iv Beta blocker to reduce the HR to
  below 60 bpm and reduce SBP to lowest level
  tolerated.
• If you reach 60 bpm and still have systolic gt100,
  add nitroprusside.
• Other vasodilators should not be used as
  monotherapy because of the reflex tachy that
  ensues.

5
Management

• Surgical repair Daily type A or DeBakey I or
  II. Mortality with surgery 7-36, without gt50.
• Stents 19 pts proximal dissection, poor
  surgical candidatecomplete thrombosis 79,
  relief of Sxs 76, morbidity 21 mortality 16
• Stents 12 pts distal dissection medical
  management, morbidity 12 mortality 0, with
  stent morbidity 42 and mortality 33!

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