Aorta is the main and the largest artery in the human body. It originates from the left ventricle of the heart and extends down to the abdomen. There it splits into two smaller arteries known as the common iliac arteries. The main work of the Aorta is to supply oxygenated blood to all parts of the body through the systemic circulation. But when the Aorta is enlarged or bulged to over 1.5 times normal size then that condition is known as Aortic Aneurysm. According to Medical professionals, it is better to indicate it as a bulge rather than an enlargement because only a small part of the vessel is affected. This condition can be life threatening because there are no noticeable symptoms until the vessel gets ruptured. However there can be certain symptoms like abdominal, back, or leg pain which people usually ignore. In a simplified way, actually the pressure of blood flowing through the Aorta may cause a bulge at some weak spot. It makes the wall of the Aorta weaker which increases risk of a rupture. It is just like an over inflated cycle tyre tube. In the beginning the bugle is small but with increasing pressure on the same spot, the size starts to increase. It can be of risk to life because if the bulge ruptures then it can cause internal bleeding which is a life threatening situation. If immediate treatment is not done in this condition then the patient may suffer from shock or may die. According to reports, almost 152,000 people died in 2013 because of Aortic Aneurysm while around 100,000 had lost their life to aortic aneurysm in 1990.
It is important to understand that the bulge can be created in any artery of the body. It is also common in the brain artery. Most aneurysms are in the aorta which is the main artery that runs from the heart through the chest and abdomen. However there are two types of aortic aneurysm. The first one is Thoracic aortic aneurysms (TAA) that occurs in the Aorta which runs through the chest. Similarly the second kind of aortic aneurysm occurs in the part of the aorta running through the abdomen. The bulging can be divided into 3 different types which are true aneurysm, false aneurysm, or dissection. All three layers of the blood vessel wall are involved in true aneurysm. The two outer layers of the blood vessel help to contain the false aneurysm. In this condition there is high chance of bursting so it is dangerous at this level.
Signs and symptoms of Aortic Aneurysm
Every disease and medical conditions are known to have signs and symptoms because of which we can get proper treatment on time but in case of Aortic Aneurysm, there are no identified direct signs or symptoms. In some cases, abdominal pain and back pain can be prevalent but it is not always the case. Sometimes leg pain or numbness can be caused because of compression of the nerves. If untreated on time the aneurysms can grow bigger with time. However the exact rate of growing is not known. It can’t be predicted because individual cases can be different. When the clotted blood lining around aortic aneurysms break off, then it may result in an embolus. Aneurysms can only be found by physical examination. It is usually detected when screening for some other problem. Regular screening is advised for any person aged 65-75 if they have family history of Aortic Aneurysm. Chain smokers are also at high risk of this condition in that age group.
Abdominal aortic aneurysm
Abdominal aortic aneurysm is more common type of aortic aneurysm compared to Thoracic aneurysm. The main cause of it is that in case of Abdominal aorta, elastin which is the principal load-bearing protein present in the aorta wall , is reduced in the abdominal aorta compared to the thoracic aorta. The abdominal aorta also does not have vasa vasorum which is the nutrient supplying blood vessels within the aorta wall. Most of the abdominal aortic aneurysms are true aneurysms which involve 3 layers involving tunica intima, tunica media and tunica adventitia. The chances of abdominal aortic aneurysm are high at the age of 65-75. The risk of rupture is related to size and shape of the aneurysm. Shorter ad bulbous aneurysm has more risk of rupture. In case of a rupture, it has classic symptoms of abdominal pain which is severe, constant, and radiating to the back. An ultrasound can diagnose the rupture and presence of free fluid in the abdomen may also indicate the rupture. The aortic rupture is an emergency case and there is high mortality even if treatment is provided on time.
Causes of aortic aneurysm
There can be various causes related to aortic aneurysm. It can happen because of trauma, infection, or, most commonly, from an intrinsic abnormality in the elastin and collagen components of the aortic wall. Genetic abnormalities in genetic syndromes like Marfan, Elher-Danlos and others are also related to aortic aneurysm. Risk factors also include different factors like Coronary artery disease, Hypertension, Loeys-Dietz Syndrome, Hypercholesterolemia, Hyperhomocysteinemia, Elevated C-reactive protein, Tobacco use, Peripheral vascular disease, Marfan syndrome, Ehlers-Danlos type IV, Bicuspid Aortic Valve, Syphilis and IgG4-related disease.
Patient’s blood pressure, smoking and cholesterol levels should be controlled to prevent aortic aneurysm. Men over the age of 65 should regularly do ultrasoud to check the conditions. Different drugs like tetracycline antibiotic doxycycline is being tested to prevent this condition. Similarly fluoroquinolones antibiotics are also being studied in that regard.
The possible treatment of aortic aneurysms is by open or endovascular surgery. For smaller aneurysms or for elderly and frail patients medical treatment can be done because the surgical repair has higher risks compared to non-operative therapy. Medical theraphy involves strictly controlling the blood pressure. It can’t treat the aortic aneurysm but it can be helpful to decrease the rate of expansion of the aneurysm. For smaller aneurysms or weak patients cessation of smoking, blood pressure control, use of statins and occasionally beta blockers is recommended. It is necessary to follow the condition of the aneurysm with regular ultra sound studies in every (6-12) month. If a person has severe cardiovascular disease then the aneurysm would not be repaired because the risk of treatment is much higher than the risk of rupture itself. There can be cardiac complications in that case which is to be seriously considered while making a decision of repairing an aortic aneurysm with a surgery. There are various risks involved in a surgery, first there are risks involved immediately after or during the surgery. Secondly it should be carefully considered if the surgery would provide a long term solution.
Endovascular aneurysm repair is considered a less invasive procedure which is related with less short term risks but it involves secondary procedures during long term follow up. Surgical or endovascular repair is the treatment for aortic aneurysm but it is difficult to determine the surgical option. The medical team will carefully consider the procedural risk compared to the chances of a rupture. Other conditions such as, presence or absence of Marfan Syndrome, Ehlers–Danlos Syndrome or similar connective tissue disorders, and other co-morbidities are all taken into consideration before making a final decision. If an aneurysm is growing at a rapid speed then immediate surgical intervention may be necessary but a slowly developing aneurysm can be scanned and monitored on a regular basis by routine diagnostic testing which is CT scan or ultrasound. In case of abdominal aneurysms, according to the treatment guidelines, elective surgical repair is suggested when the diameter of the aneurysm is greater than 5 cm (2 in). Medical management for abdominal aneurysms with a diameter of less than 5.5 cm is suggested to patients aged 60-76. Open surgery or the Endovascular treatments of aortic aneurysms are two different procedures which is to be determined by the team of medical professionals while treating conditions with aortic aneurysms.