Aortic dissection resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Chetan Lokhande, M.B.B.S [2]

Definition

A tear in the layers of the aorta especially in the intima leading to bleeding and separation of the layers of the aorta from within which creates a false lumen. Aortic dissction can be further defined as:

1. Acute dissection- Dissection occurring within 2 weeks of onset of pain
2. Subacute dissection-Dissection occurring witin 2-6 weeks of onset of pain
3. Chronic dissection- Dissection occurring within 6 weeks of pain.

Classification

Aortic dissection can be classified into four types. DeBakey and Daily (Stanford) systems are the commonly used systems used to classify aortic dissection.

• Stanford system classifies dissection into the following two types based on whether ascending aorta is involved or not.

1. Ascending aortic dissection or type A
2. All other dissections or type B

• DeBakey system classifies dissection according to location of the tear.

1. Type I- Starts at ascending aorta and extension upto the aortic arch
2. Type II- Starts and is limited till the ascending aorta
3. Type III- Starts in the descending aorta and progresses proximally or distally
   1. Type III A - Restricted till the descending thoracic aorta
   2. Type III B - Dissection extending below the diaphragm

• The third type of classification divides aortic dissection according to the proximity

1. Proximal- Ascending aortic involvement
2. Distal- Descending aortic involvement distal to left subclavian artery

Causes

Life Threatening Causes

Aortic dissection is a life-threatening condition and must be treated as such irrespective of the causes. Life-threatening conditions may result in death or permanent disability within 24 hours if left untreated.

Common Causes

• Atherosclerosis
• Complication of cardiac procedures
• Chest trauma
• Connective tissue disorders
• Hypertension
• Vasculitis

Management

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Obtain a detailed history:
❑ Past medical history

❑ Hypertension

❑ Pheochromocytoma

❑ Family history

❑ Aortic disorder^*

❑ Connective tissue disorder^*

❑ Anatomic deformities

❑ Aortic valve disease^*

❑ Thoracic aortic aneurysm^*

❑ Coarctation of aorta

❑ Polycystic kidney disease

❑ Iatrogenic

❑ Recent aortic manipulation^*

❑ Chronic steroid usage

❑ Immunosuppressive therapy

❑ Lifestyle

❑ Cocaine abuse

❑ Heavy weight lifting

❑ Trauma
❑ Genetic

❑ Marfan's syndrome^*

❑ Ehlers-Danlos syndrome

❑ Turners syndrome

❑ Biscuspid aortic valve

❑ Loeys-Dietz syndrome

❑ Familial thoracic aneurysm and dissection syndrome

❑ Inflammatory vasculitis

❑ Takayasu arteritis

❑ Giant cell arteritis

❑ Behcet's arteritis

❑ Pregnancy

❑ Infections involving the aorta }} {{familytree | | | | | | | | B01 | | | |B01=

Examine the patient:

❑ General examination:

❑ Pulse rate - ↑

❑ Blood pressure - ↑ or ↓

❑ Respiratory rate - ↑

❑ Wide pulse pressure

❑ Difference in the blood pressure in both extremities^*

❑ Increased sweating or anhidrosis

❑ Signs of shock (hypoperfusion)^*

❑ Pulse deficit involving carotid, femoral or subclavian arteries^*

❑ Head/neck examination:

❑ ↑ JVP

❑ Signs of vocal cord paralysis

❑ Pemberton's sign (SVC)

❑ Venous distention in the neck and distended veins in the upper chest and arms (SVC)

❑ Cardiovascular examination:

❑ Diastolic murmur suggestive of aortic regurgitation^*

❑ Wheeze (cardiac asthma) (CHF)

❑ Pericardial friction rub

❑ Respiratory examination

❑ Crackles/crepitations/rales

❑ Decreased movement of the chest on affected side

❑ Stony dullness to percussion

❑ Diminished breaths sounds

❑ Decreased vocal resonance and fremitus

❑ Pleural friction rub.

❑ Abdominal examination:

❑ Ascites

❑ Claudication of buttocks

❑ Absent femoral pulses

❑ Neurological examination:

❑ Altered mental status^*

❑ Signs of peripheral neuropathy

❑ Signs of stroke^*

❑ Extremity examination:

❑ Pedal edema

❑ Ophthalmological examination

❑ Miosis

❑ Ptosis

❑ Assess the severity by counting the high risk features marked in bold and by *

❑ Consider close differential diagnoses:

❑ Myocardial infarction due to an acute coronary syndrome with or without ST segment elevation

❑ Aortic regurgitation without dissection

❑ Aortic aneurysm without dissection

❑ Pericarditis

❑ Atherosclerotic or cholesterol embolism

❑ Pulmonary embolus

❑ Pleuritis

❑ Cholecystitis

❑ Peptic ulcer disease or perforating ulcer

❑ Acute pancreatitis

❑ Esophageal perforation/rupture

❑ Musculoskeletal pain

❑ Mediastinal tumors

Characterize the symptoms: ❑ Cardiac ❑ Chest pain described as tearing, ripping, sharp or stabbing* ❑ Abrupt onset of pain and increasing in intensity* ❑ Chest pain worsened by deep breathing or cough and relieved by sitting upright ❑ Anxiety ❑ Palpitation ❑ Fainting ❑ Sweating ❑ Pale skin ❑ Rapid, weak pulse ❑ Shortness of breath ❑ Peripheral edema ❑ Rapid breathing ❑ Orthopnea ❑ Extra cardiac ❑ Abdominal pain or back pain ❑ Flank pain ❑ Lower and upper extremity weakness, numbness and tingling ❑ Nausea and vomiting ❑ Symptoms suggestive of stroke ❑ Swallowing difficulties due to pressure on the esophagus ❑ Gastrointestinal bleeding ❑ Altered mental status ❑ Feeling of impending doom ❑ Hemoptysis ❑ Drooping of eyelids ❑ Decreased or no sweating ❑ Haematemesis ❑ Hoarseness of voice