AORTIC ANEURYSM and DISSECTION

 

Acute Dissecting Aneurysm:

Etiology:

  1. HTN (in 90% of cases), Marfan, any pathology that causes medial layer necrosis.

Classification:

  1. Debakey's  I= ascending and arch.
  2. Debakey's II= ascending only (not the arch).
  3. Debakey's III= distal, just beyond the SC artery and may be all the way down till iliac arteries.

S & S:

  1. Severe Chest pain radiating to the back, but if location of tear is more proximal pain can radiate to neck & jaw.
  2. Renal/Visceral ischemia in 50% (hematuria/GI bleed).
  3. Pulmonary edema in 20%.
  4. Stroke, Paraplegia 2ry to dissection into carotid or spinal vessels in 5%. Horner's syndrome is another presenting possibility.
  5. MI 2ry to propagation into coronaries (usually RCA and gives IWMI).
  6. Murmur 2ry to AI in 40-60%.
  7. Pericardial tamponade.
  8. Discrepancy in BP of > 20mmHg and in pulses between two arms.
  9. Delayed and decreased peripheral pulses.
  10. Rarely hoarseness, SVC syndrome, airway obstruction can be the presenting S&S.

DX:

    1. EKG abnormal but not contributory.
    2. CXray :
      1.   Wide mediastinum is seen in 80% of initial xray.
      2.   Deviated trachea or NGT to R.
      3.   Elevation of R bronchus.
      4.   Depressed L bronchus.
      5.   this is followed by ANGIO.
    3. TEE is an excellent study. It can be done in ER @ bed side and has accuracy similar to ANGIO.
    4. ANGIO  is a gold standard

Treatment:

  1. Type & Cross x 6U
  2. Nitroprusside 0.1 - 10mcg/kg/min IV
                        PLUS
    Beta-Blocker (propranolol, atenolol, esmolol, metaprolol).
  3. Pt unable to tolerate beta-blockers (COPD, Bradycardia, CHF) is given Trimethaphan 1 - 4mg/min instead of  Nitroprisside and  beta-blocker.
  4. Once the pt is stabilized  ® OR  for Type I&II. Type III is treated medically.

 

Thoracic Aortic Aneurysm

Etiology:

  1. syphilis, trauma, atherosclerosis.

S & S:

  1. 50% have cough, dysphagia, hemoptysis. Other 50% have incidental findings.

DX:

  1. CXray, CT, Angio.

Treatment:

  1. Asymptomatic  ® provide F/U
  2. Symptomatic ®  surgical repair.

 

Abdominal Aortic Aneurysm

Etiology:

  1. Atherosclerosis.

S & S:

  1. 95% are below the kidneys. 85% are asymptomatic.
  2. can have a chronic  course characterized by  low abdominal pain.
  3. if pt presents with symptoms these are: sudden onset pain in abdomen or low back that can be radiating to testis or groin, abdominal mass (frequently pulsatile), hypotension ( in 60% of cases), neurological  findings 2ry to femoral or sciatic compression. Hematuria is present in 30% of cases.

Treatment:

  1. If there is above presentation pt should go to the OR  STAT.
  2. If  OR not available ® IVF, PRBC, MAST trousers, Thoracotomy to clamp thoracic aorta.

In other situations: Cross Table Lateral Xray (60% will show calcifications), US, CT.

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