Thoracic aortic aneurysm risk guidelines have changed in recent years. Most heart specialists learned during training that thoracic aneurysms do not require treatment unless larger than 5.5 cm, or 5 cm for Marfan syndrome patients. However, we now know there's more to it than that.
At the Thoracic Aneurysm Surveillance Program, we have determined the following risks based on our experience performing risk assessments for patients with thoracic aneurysm. They are listed below in order of decreasing importance.
Risk Assessment for Thoracic Aortic Aneurysm
1. Symptoms that may indicate an acute aortic dissection or rupture in a person with a thoracic aneurysm.
When symptoms occur in a patient with an ascending aneurysm who has high blood pressure, urgent surgery might be needed.
Aortic dissection or rupture symptoms typically include:
- Central chest pain that may radiate and sometimes includes the throat or the upper back
- Chest pain with the above characteristics that comes on suddenly and is very severe
2. Symptoms in patients with a thoracic aortic aneurysm not as dramatic as those in acute aortic dissection, but that recur from time to time.
These symptoms are not explained by other conditions (such as coronary artery disease, esophageal disorders or musculoskeletal trauma). In these patients, elective aneurysm surgery should be strongly considered.
- If symptoms occur with straining (e.g., heavy lifting or during difficult bowel movements) or episodes of high blood pressure, the potential for a complication to occur is potentially higher. In these cases, an urgent evaluation for surgery may be recommended.
3. Situations in which the relative aortic size exceeds published guidelines.
The relative aortic size compares the size of the aneurysm with overall body size. For instance, a 5 cm aneurysm should represent a different risk to a petite (short stature) lady, as compared with an NBA center — especially if she has a genetic syndrome associated with aggressive aneurysm behavior.
- Certain patients whose relative aortic size is larger than published guidelines could be considered for surgery, particularly if that patient has recurring chest and back symptoms.
4. Family history of thoracic aortic aneurysm, aortic dissection or rupture, or unexpected death of a first-degree relative (mother, father or sibling) at a young age without a known cause.
Aneurysms tend to run in families, and familial aneurysm is recognized as a subcategory of aneurysm patients that rupture or dissect at smaller sizes. By the time an aneurysm reaches 5 cm, we sometimes recommend surgery to patients without symptoms who have confirmed or strong suspicion of familial aneurysm.
5. Aortic stenosis or insufficiency in addition to an aneurysm.
The aortic root and proximal ascending aorta are anatomically associated with the aortic valve. As the aneurysm grows, it may stretch apart the leaflets of the valve, causing leaking of blood back into the ventricle during the ventricle’s relaxation phase. This may lead to symptoms of fatigue and shortness of breath with exertion, and in extreme causes, congestive heart failure symptoms.
- If a person with moderate or worse aortic insufficiency has the above symptoms, we may recommend elective surgery to treat both the aortic valve and the aneurysm. Often, leaking aortic valves associated with aneurysm can be treated with aortic valve repair, as opposed to replacement.
6. Young patients with aortic root aneurysm who could be candidates for valve-sparing aortic root surgery, also known as the David procedure.
The procedure’s creator, Dr. Tirone David, recommends surgery at a root size of 5 cm (vs. current guidelines of 5.5 cm). Allowing root aneurysms to become much larger could make it no longer possible to preserve the patient's aortic valve and require a replacement instead. Valve-sparing aortic root surgery is the favored treatment for younger patients with root aneurysm according to current guidelines.
7. Lifestyle or occupational risk that involves heavy lifting or straining.
Individuals with aneurysm should refrain from activities that involve heavy lifting or straining. Or, they should modify them in such a way to minimize strain, which can cause significant spikes in blood pressure and heart rate, even in people without high blood pressure.
These activities include the following:
- Patients with severe constipation or urinary obstruction who use the Valsalva maneuver, which involves closing the vocal chords at the same time as bearing down
- Patients whose profession requires them to strain on the job (e.g., heavy lifting or manual labor)
Ideally, patients should avoid the above lifestyle or job-related activities. However, if a patient cannot avoid these activities, we might (in rare instances) recommend elective surgery. In these cases, patients would have an anticipated return to work of approximately three months.