I’ve previously explained how disease in the abdominal aorta, the main blood vessel, can lead to formation of a red balloon, an aneurysm, which can fatally rupture if not treated. Aneurysms occur in other anatomical locations, as well.
Aneurysms are often asymptomatic until bursting, so prevention or diagnosis is critical. Blood flows from the heart via a succession of ever-smaller arteries, delivering oxygen and nutrients. These muscular tubes withstand pulsatile flow—at 70 beats per minute: 2.9 billion in an 80-year lifespan. High blood pressure increases the likelihood of a rupture, another good reason to maintain a healthy weight and exercise regularly. Smoking also damages arterial walls, as do cholesterol deposits, so avoid tobacco and have your blood lipid levels checked.
Inside the brain, aneurysms resembling berries on a stem (artery) are the most common mischief-maker. Some people are born with one or more; they may be associated with family history, certain rare diseases like Marfan or Ehlers-Danlos syndromes, or as a sequel to cocaine use or a head injury. Although only 1 to 5 percent of people develop one, and only approximately 1 percent of these burst, aneurysms are a serious matter. Larger ones may cause symptoms including persistent headache behind or above the eye, altered vision, difficulty speaking, or enlarged pupils. A sudden, severe headache—associated with nausea, vomiting, stiff neck, light sensitivity, loss of consciousness, or seizure—merit immediate hospitalization, as this suggests rupture and escaped blood irritating the brain. This is one form of stroke and, if not fatal, can cause impaired movement, sensation, speech, or cognition.
If a berry aneurysm is a possibility, diagnosis is confirmed with CAT or MRI scan, together with contrast injection to outline brain blood flow. Treating ruptured berries is a surgical emergency and the techniques are the same for an unruptured aneurysm. The brain is accessed by removing a piece of the skull, then a metal clip is placed where berry meets vine. Alternatively, small coils are inserted into the aneurysm via a tube introduced from a large artery and steered into the brain—the aneurysm fills with clot, which then becomes a scar. Flow diversion, by placing a stent, achieves the same goal, allowing the aneurysm to wither on the vine. Any hypertension or raised cholesterol is medically treated and lifestyle changes implemented. Other therapy—physical, occupational, or speech—may be required for symptoms resulting from the stroke.
From an aeromedical perspective, if detected pre-rupture, and smaller than 5 millimeters with no evidence of leak, an aneurysm can be followed annually with vascular studies, but if larger, must be fixed for certification to be possible. And that makes medical sense, too. If ruptured, FAA stroke protocol is followed: grounding for at least two years, evaluation for other aneurysms, and neurological and neuropsychological tests.
The thoracic aorta is the first part of this major blood vessel as it emanates from the heart. Aneurysms here have the same causes, although heart valve issues, some infections, or prior trauma can initiate damage that becomes apparent later. These aneurysms often grow slowly and are usually asymptomatic but may cause chest or back pain, cough, or hoarseness. Any family history or symptoms merit a visit to your doctor. Clots can form inside aneurysms and because thoracic aorta branches serve the brain, liberated clots can travel there and cause a stroke. Sometimes on rupture, a tear in the arterial wall—a dissection—occurs; blood flows into this false channel and leads to a widespread, life-threatening problem.
Diagnosis is made with a scan, ultrasound of the chest (echocardiogram), or may even be seen on a routine chest X-ray. Treatment of an unruptured aneurysm involves controlling high blood pressure and choosing the right time to intervene by replacing the diseased segment of aorta either surgically or by inserting a cleverly folded stent graft via a large groin artery.
If detected pre-rupture, and 4.5 centimeters or larger, an aneurysm is disqualifying; for all classes, a dissecting ascending aortic aneurysm is also disqualifying. A history of aortic aneurysm, treated or untreated, requires a complete cardiovascular evaluation. Once successfully treated and the evaluation is negative, a medical certificate may be considered. For continued airman certification/air traffic control specialist clearance, no follow-up is required unless there is an adverse change or positive findings of coronary artery disease.
Nena’s song states, “Set them free at the break of dawn, ’Til one by one, they were gone.” Do all you can to avoid aneurysms and if present, set them free.
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