• Finnish Medical Society Duodecim. Aortic aneurysm and dissection. In: EBM Guidelines. Evidence-Based Medicine [Internet]. Helsinki, Finland: Wiley Interscience. John Wiley & Sons; 2004 Feb 26 [Various].

Note: This guideline has been updated. The National Guideline Clearinghouse (NGC) is working to update this summary.

• Aortic aneurysm, including abdominal aortic aneurysm and aneurysm of the thoracic aorta
• Aortic dissection (type I, II, and III)

Diagnosis
Evaluation
Management
Treatment

Cardiology
Family Practice
Internal Medicine

Health Care Providers
Physicians

Evidence-Based Medicine Guidelines collect, summarize, and update the core clinical knowledge essential in general practice. The guidelines also describe the scientific evidence underlying the given recommendations.

Patients with or suspected of having aortic aneurysm or aortic dissection

Diagnosis/Evaluation

Aortic Aneurysm

1. Evaluation of signs and symptoms
2. Abdominal x-rays or urography films
3. Ultrasonography as indicated

Aortic Dissection

1. Evaluation of signs and symptoms
   • Check for pulse asymmetry
   • Blood pressure
2. Electrocardiogram
3. Chest x-ray
4. Transoesophageal echocardiography
5. Computed tomography (CT), magnetic resonance imaging (MRI), or angiography

Treatment/Management

Aortic Aneurysm

1. Treat hypertension and other cardiovascular risk factors
2. Monitor aneurysms with diameter >3 cm with ultrasonography
3. Surgery for aneurysms with diameter >5.5 cm or that extend into the chest cavity

Aortic Dissection

1. Lower systolic blood pressure
   • Nifedipine (chewed)
   • Nitrate (or nitroprusside) infusion
   • Beta-blocker
   • Analgesia
2. Immediate surgery for dissection of ascending aorta
3. Conservative treatment (e.g., reduce blood pressure and heart rate) for dissection of descending aorta

• Mortality
• Familial risk for abdominal aortic aneurysms

Hand-searches of Published Literature (Primary Sources)
Hand-searches of Published Literature (Secondary Sources)
Searches of Electronic Databases

The evidence reviewed was collected from the Cochrane database of systematic reviews and the Database of Abstracts of Reviews of Effectiveness (DARE). In addition, the Cochrane Library and medical journals were searched specifically for original publications.

Not stated

Weighting According to a Rating Scheme (Scheme Given)

Levels of Evidence

1. Strong research-based evidence. Multiple relevant, high-quality scientific studies with homogenic results.
2. Moderate research-based evidence. At least one relevant, high-quality study or multiple adequate studies.
3. Limited research-based evidence. At least one adequate scientific study.
4. No research-based evidence. Expert panel evaluation of other information.

Review of Published Meta-Analyses
Systematic Review

Not stated

Not stated

Not applicable

A formal cost analysis was not performed and published cost analyses were not reviewed.

Peer Review

Not stated

Note: This guideline has been updated. The National Guideline Clearinghouse (NGC) is working to update this summary. The recommendations that follow are based on the previous version of the guideline.

The levels of evidence [A-D] supporting the recommendations are defined at the end of the "Major Recommendations" field.

Basic Rules

• Diagnose aortic aneurysm before rupture: nearly all aneurysms can be treated surgically. Monitor a small aneurysm, found incidentally or through screening, until it reaches a size where the benefit of surgical repair outweighs the risks associated with such surgery.
• It is easy for a general practitioner to learn the diagnosis of abdominal aortic aneurysm with ultrasonography.
• Remember the possibility of aortic dissection in a patient with severe pain suggestive of acute myocardial infarction (AMI) but without clear electrocardiogram (ECG) findings.
• Patients with aortic dissection must be referred to a hospital immediately.

Aortic Aneurysms

Abdominal Aortic Aneurysm

• Atherosclerosis is the most important causative factor.
• 85% of the patients are men. An aneurysm is found in 10% of men aged 75 years or more.
• A palpable, pulsating mass in the upper or middle abdominal region is a typical finding. Most aneurysms are found accidentally.
• The patient may complain of pain which may resemble pain originating from the ureter or spinal cord. The pain often radiates to the back. Pain indicates an expanding aneurysm that needs surgery.
• Sometimes a calcified aneurysm can be recognised on plain abdominal x-rays or urography films.
• The diagnosis is confirmed by ultrasonography (which can be performed by a general practitioner familiar with the examination).
• Treatment
  • Hypertension and other cardiovascular risk factors should be treated effectively.
  • An aneurysm with a diameter of over 3 cm is monitored with ultrasonography every 12 months. When the diameter of the aneurysm has reached 5 cm in a man or 4.5 cm in a woman the ultrasonographic checks are carried out every 6 months (Powell & Greenhalgh, 2003).
  • Surgery is indicated when the diameter of the aneurysm exceeds 5.5 cm (UK Small Aneurysm Trial, 1998) [B].
    • About 1% of aneurysms with diameter of 4 cm rupture annually compared with 10% of aneurysms with a diameter of 6 cm or more. The mortality from a ruptured aneurysm is 90%.
  • Aneurysms extending into the chest cavity should be operated on.
  • Elderly brothers of patients with known aneurysms should be screened with ultrasonography (Salo et al., 1999) [C].

Aneurysm of the Thoracic Aorta

• Usually asymptomatic. Pain suggests expansion.
• Aortic regurgitation (with symptoms related to it) (See the Finnish Medical Society Duodecim guideline "The Most Common Acquired Adult Valvular Heart Diseases and Associated Murmurs.")
• Tracheal or bronchial compression or phrenic nerve paralysis
• Sometimes the neck veins are dilated due to the compression caused by the aneurysm.
• May be visible as an incidental finding on a chest x-ray
• Treatment is either surgical or conservative.

Aortic Dissection

• The typical locations are the ascending (type I and II) and descending thoracic aorta (type III). Type I is confined to the ascending aorta. Dissections of the other types may extend into the abdominal aorta.
• As the tunica interna ruptures, the blood rushes into the layers of the tunica media. The aorta is often (but not always) dilated and may be visible on a chest x-ray.
• Marfan's syndrome is often associated with dissection or annuloaortic ectasia and aortic regurgitation.
• The incidence of aortic dissection is about 10/million inhabitants/year.

Symptoms

• Suspect aortic dissection in a patient with sudden excruciating pain without ECG findings suggestive of AMI.
• The patient is usually a hypertensive male.
• The location of the pain may change as the dissection advances.
• The pain radiates in the same way as pain associated with AMI, including the jaw and sometimes the palate. Pain is often also felt in the back.
• The associated symptoms include those resulting from the occlusion of aortic branches, i.e. ischaemic symptoms of the brain, heart, kidneys, and intestines.
• Acute aortic regurgitation may occur (a new murmur).

Findings

• Even though pulse asymmetry is presented only in a minority of patients it is worth checking for. A murmur from aortic regurgitation or bruits may be heard.
• Blood pressure is high, particularly in distal dissection.
• ECG will not be indicative of AMI but may show left ventricular hypertrophy, an old infarction, or ischaemia (AMI is sometimes possible when the dissection occludes a coronary artery).
• A chest x-ray may show a dilated aortic arch, but often the x-ray is nearly normal.
• Transoesophageal echocardiography is a good primary investigation. Computed tomography, magnetic resonance imaging (MRI), or angiography is often needed for final diagnosis.

Treatment

• The systolic blood pressure should be lowered quickly to around 100-120 mmHg. First aid treatment includes nifedipine 10 mg chewed, nitrate (or nitroprusside) infusion, a beta-blocker, and effective analgesia.
• Dissection of the ascending aorta should be operated on immediately. Prognosis without surgery is very poor.
• The immediate treatment of a dissection of the descending aorta is conservative (i.e. reduction of blood pressure and heart rate).
• Thrombolysis is contraindicated.

Definitions:

Levels of Evidence

1. Strong research-based evidence. Multiple relevant, high-quality scientific studies with homogenic results.
2. Moderate research-based evidence. At least one relevant, high-quality study or multiple adequate studies.
3. Limited research-based evidence. At least one adequate scientific study.
4. No research-based evidence. Expert panel evaluation of other information.

None provided

Concise summaries of scientific evidence attached to the individual guidelines are the unique feature of the Evidence-Based Medicine Guidelines. The evidence summaries allow the clinician to judge how well-founded the treatment recommendations are. The type of supporting evidence is identified and graded for select recommendations (see the "Major Recommendations" field).

Appropriate diagnosis and treatment of aortic aneurysm and aortic dissection

Not stated

Thrombolysis is contraindicated as a treatment for aortic dissection.

An implementation strategy was not provided.

Getting Better

Effectiveness

• Finnish Medical Society Duodecim. Aortic aneurysm and dissection. In: EBM Guidelines. Evidence-Based Medicine [Internet]. Helsinki, Finland: Wiley Interscience. John Wiley & Sons; 2004 Feb 26 [Various].

Not applicable: The guideline was not adapted from another source.

2004 Feb 26

Finnish Medical Society Duodecim - Professional Association

Finnish Medical Society Duodecim

Editorial Team of EBM Guidelines

Primary Author: Editors

Not stated

Note: This guideline has been updated. The National Guideline Clearinghouse (NGC) is working to update this summary.

None available

None available

This summary was completed by ECRI on August 30, 2005.

This NGC summary is based on the original guideline, which is subject to the guideline developer's copyright restrictions.