Aortic Dissection

1. Pathology

   1. AD is tear through the intima into the media of the aorta

   2. Blood goes between the layers of the media

   3. Dissection goes distal or proximal

   4. Common sites

      1. Just above aortic valve near R coronary—point that has most blood force

      2. Just past the ligamentum arteriousum—aorta is fixed there and doesn’t have a lot of give; if too much force, can tear

   5. Injury occurs due to rupture of aortic layers of loss of flow to vital organs (brain, heart

      1. R. coronary artery most commonly affected, can have inferior wall MI

   6. If tears while in pericardium—can cause tamponade

   7. Tear can create 2 lumens—always have multiple re-entry sites

2. Anterior rip can cause:

   1. Aortic insufficiency by damaging aortic valve

   2. Rupture into pleural space

   3. Bleed into pericardium and cause tamponade

   4. Block coronary artery

3. People at risk

   1. Young

      1. Marfan’s syndrome

      2. Ehlers-Danlos

      3. Coarctation of aorta

      4. Bicuspid aortic valve

   2. Older

      1. HTN

      2. M: F 2:1

      3. Peak age 60-75

   3. Either

      1. Recent surgery on aorta or open heart

      2. Trauma

         1. Includes bypass machine

4. Classification

   1. Debakey (old—not used anymore)

      1. I—involves ascending and descending aorta

      2. II—involves ascending and arch

      3. III—descending only

   2. Stanford

      1. A—involves any part of ascending aorta

      2. B—descending only

5. History

   1. PMH

      1. Marfan’s, bicuspid valve, HTN older male

      2. Surgery on aorta

   2. Pain—VERY IMPORTANT

      1. Sudden onset, unbearable, tearing

      2. Location: anterior radiating to back

         1. pain moves in the direction of the tear

      3. Differentiate from heart pain:

         1. Cardiac pain is slower in onset, more of a pressure feeling, heavy weight on their chest

6. Physical exam

   1. HTN

   2. Tamponade

      1. Muffled heart sounds

      2. Decrease BP

      3. Decrease VR causes distended jugular veins

   3. Coronary artery occlusion

      1. Heart pain

      2. Similar findings with MI

   4. Brachiocephalic artery occlusion

      1. Stroke

      2. No radial pulse in side affected

   5. Distal artery occlusion

      1. Diminished or absent peripheral pulses

      2. Belly pain (if occluding mesenteric arteries)

1. Left pleural effusion

   1. Diminished breath sounds

   2. Dullness

2. Expansion of aorta

   1. Hoarseness (impinges on laryngeal nerve)

   2. Horner’s syndrome

3. Aortic regurgitation

   1. Diastolic mummur

   2. Decrease BP, especially diastolic

   3. Widened pulse pressure

1. Screening tests

   1. EKG—can show signs of ischemia

   2. CXR

      1. Pleural effusion

      2. Widened mediastinum

      3. Pericardial effusion—round heart

2. Diagnostic tests

   1. Aortography with coronary arteriography

      1. Takes too long

   2. MRI—good, but takes too long

   3. CT—good way to dx if you’re not really sure

   4. TEE (trans-esophageal echo)—very quick!!

3. Natural history

   1. 25% die within 24 hours

   2. 50% die within 48 hours

   3. 80% die after 1 week

4. Management

   1. Start treating patient before dx is made!

   2. Insert appropriate monitoring lines

   3. Decrease BP and pulse pressure by using beta-blockers (esmolol)

   4. Admit to ICU

   5. Complete dx

   6. Obtain CT and surgical consult

5. Management-specific

   1. Type A

      1. Surgery unless contraindicated (stroke)

   2. Type B

      1. Control using meds unless there are complications

         1. Aneurysm dilation

         2. Bleeding into abdomen or chest

6. Outpatient management

   1. Control BP and pulse pressure

   2. Make pt aware of signs and symptoms of rupture and occlusion

   3. Serial CT or MRI to monitor dilation

      1. >6cm needs repaired

Category: Pathology Notes