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Traumatic aortic rupture, also called traumatic aortic disruption or transection, is a condition in which the aorta, the largest
artery An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the pu ...
in the body, is torn or ruptured as a result of trauma to the body. The condition is frequently fatal due to the profuse bleeding that results from the rupture. Since the aorta branches directly from the
heart The heart is a muscular organ found in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon diox ...
to supply
blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in th ...
to the rest of the body, the pressure within it is very great, and blood may be pumped out of a tear in the blood vessel very rapidly. This can quickly result in shock and death. Thus traumatic aortic rupture is a common killer in automotive accidents and other traumas, with up to 18% of deaths that occur in automobile collisions being related to the injury. In fact, aortic disruption due to blunt
chest trauma A chest injury, also known as chest trauma, is any form of physical injury to the chest including the ribs, heart and lungs. Chest injuries account for 25% of all deaths from traumatic injury. Typically chest injuries are caused by blunt mechanisms ...
is the second leading cause of injury death behind
traumatic brain injury A traumatic brain injury (TBI), also known as an intracranial injury, is an injury to the brain caused by an external force. TBI can be classified based on severity (ranging from mild traumatic brain injury TBI/concussionto severe traumatic b ...
. Aortic rupture can also be caused by non-traumatic mechanisms, particularly abdominal aortic aneurysm rupture.


Symptoms and signs

Symptoms are often unreliable, but include severe tearing chest pain; cough; dyspnea (shortness of breath); dysphagia (difficulty swallowing); back pain; and hoarseness. Blood pressure is usually high in the upper body, but low in the lower body. A widened mediastinum and a massive left hemothorax are often found in an X-ray. There can be bruising of the anterior chest wall, and a systolic murmur can be heard on the bottom of the heart.


Causes

The injury is usually caused by high speed impacts such as those that occur in vehicle collisions and serious falls. It may be due to different rates of deceleration of the heart and the aorta, which is in a fixed position.


Location of rupture

By far the most common site for tearing in traumatic aortic rupture is the proximal descending aorta, near where the left subclavian artery branches off from the aorta. The tethering of the aorta by the ligamentum arteriosum makes the site prone to shearing forces during sudden deceleration. A study of people who died after traumatic aortic rupture found that in 55–65% of cases the damage was at the aortic isthmus and in 10–14% it was in the ascending aorta or aortic arch. An angiogram will often show an irregular outpouching beyond the takeoff of the left subclavian artery at the aortic isthmus, representing an aortic pseudoaneurysm caused by the trauma. Damage can also be in the lower thoracic or abdominal aorta.


Pathology

The aorta is not always torn completely through; it may also tear some but not all layers of the arterial wall, sometimes forming a
false aneurysm A pseudoaneurysm, also known as a false aneurysm, is a locally contained hematoma outside an artery or heart due to damage to the vessel wall. The injury goes through all the three layers of the arterial wall causing a leak, which is contained b ...
. A sub-
intima The tunica intima (New Latin "inner coat"), or intima for short, is the innermost tunica (biology), tunica (layer) of an artery or vein. It is made up of one layer of endothelium, endothelial cells and is supported by an internal elastic lamina. ...
l hemorrhage is the least serious type.


Intimal tear

Being the mildest form, it often does not weaken the wall of the aorta and may heal on its own. Usually, it occurs in the
descending aorta In human anatomy, the descending aorta is part of the aorta, the largest artery in the body. The descending aorta begins at the aortic arch and runs down through the chest and abdomen. The descending aorta anatomically consists of two portions or ...
. It was originally defined as a small intimal flap with less than one centimeter length and with little or no
haematoma A hematoma, also spelled haematoma, or blood suffusion is a localized bleeding outside of blood vessels, due to either disease or trauma including injury or surgery and may involve blood continuing to seep from broken capillaries. A hematoma is b ...
. It is 10-28% of aortic injuries.


Diagnosis

The condition is difficult to detect and may go unnoticed, because many patients have no specific symptoms. Diagnosis is further complicated by the fact that many patients with the injury experienced multiple other serious injuries as well, so the attention of hospital staff may be distracted from the possibility of aortic rupture. In fact most cases occur along with other injuries. A common symptom is unusually high blood pressure in the upper body and very low blood pressure in lower limbs. Another sign is
kidney failure Kidney failure, also known as end-stage kidney disease, is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney failure is classified as eit ...
where the
creatinine Creatinine (; ) is a breakdown product of creatine phosphate from muscle and protein metabolism. It is released at a constant rate by the body (depending on muscle mass). Biological relevance Serum creatinine (a blood measurement) is an import ...
level shoots very high and urine output becomes negligible. In most cases, however, the doctors would misinterpret kidney failure as due to issues with the kidney itself and may recommend dialysis. Though not completely reliable, chest
X-ray X-rays (or rarely, ''X-radiation'') are a form of high-energy electromagnetic radiation. In many languages, it is referred to as Röntgen radiation, after the German scientist Wilhelm Conrad Röntgen, who discovered it in 1895 and named it ' ...
s are the first-line investigation, initially used to diagnose this condition when the patient is unstable and cannot be sent to the CT bay. The preferred method of diagnosis used to be CT angiogram until it was found to cause complications in some people; now it is reserved for when
CT scan A computed tomography scan (CT scan; formerly called computed axial tomography scan or CAT scan) is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers ...
s are inconclusive. The classical findings on a chest X-ray will be widened mediastinum, apical cap, and displacement of the trachea, left main bronchus, or nasogastric tube. A normal chest x-ray does not exclude transection, but will diagnose conditions such as pneumothorax or hydrothorax. The aorta may also be torn at the point where it is connected to the heart. The aorta may be completely torn away from the heart, but patients with such injuries rarely survive very long after the injury; thus it is much more common for hospital staff to treat patients with partially torn aortas. When the aorta is partially torn, it may form a "pseudoaneurysm". In patients who do live long enough to be seen in a hospital, a majority have only a partially torn blood vessel, with the outermost
adventitial The adventitia () is the outer layer of fibrous connective tissue surrounding an organ. The outer layer of connective tissue that surrounds an artery, or vein – the tunica externa, is also called the ''tunica adventitia''. To some degree, its ...
layer still intact. In some of these patients, the adventitia and nearby structures within the chest may serve to prevent severe
bleeding Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethra, vag ...
. After trauma, the aorta can be assessed by a CT angiogram or a direct angiogram, in which contrast is introduced into the aorta via a catheter.


Treatment


Aortic transection

Traumatic aortic rupture is treated with surgery. However,
morbidity A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that ...
and
mortality rate Mortality rate, or death rate, is a measure of the number of deaths (in general, or due to a specific cause) in a particular population, scaled to the size of that population, per unit of time. Mortality rate is typically expressed in units of d ...
s for surgical repair of the aorta for this condition are among the highest of any cardiovascular surgery. For example, surgery is associated with a high rate of
paraplegia Paraplegia, or paraparesis, is an impairment in motor or sensory function of the lower extremities. The word comes from Ionic Greek () "half-stricken". It is usually caused by spinal cord injury or a congenital condition that affects the neu ...
, because the
spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the spin ...
is very sensitive to
ischemia Ischemia or ischaemia is a restriction in blood supply to any tissue, muscle group, or organ of the body, causing a shortage of oxygen that is needed for cellular metabolism (to keep tissue alive). Ischemia is generally caused by problems ...
(lack of blood supply), and the nerve tissue can be damaged or killed by the interruption of the blood supply during surgery. A less invasive option for treatment is endovascular repair, which does not require open
thoracotomy A thoracotomy is a surgical procedure to gain access into the pleural space of the chest. It is performed by surgeons (emergency physicians or paramedics under certain circumstances) to gain access to the thoracic organs, most commonly the hea ...
and can be safer for people with other injuries to organs. Since high
blood pressure Blood pressure (BP) is the pressure of circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term "blood pressur ...
could exacerbate an incomplete tear in the aorta or even separate it completely from the heart, which would almost inevitably kill the patient, hospital staff take measures to keep the blood pressure low. Such measures include giving
pain medication An analgesic drug, also called simply an analgesic (American English), analgaesic (British English), pain reliever, or painkiller, is any member of the group of drugs used to achieve relief from pain (that is, analgesia or pain management). It ...
, keeping the patient calm, and avoiding procedures that could cause gagging or
vomiting Vomiting (also known as emesis and throwing up) is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose. Vomiting can be the result of ailments like food poisoning, gastroenteri ...
.
Beta blocker Beta blockers, also spelled β-blockers, are a class of medications that are predominantly used to manage abnormal heart rhythms, and to protect the heart from a second heart attack after a first heart attack ( secondary prevention). They are ...
s and
vasodilator Vasodilation is the widening of blood vessels. It results from relaxation of smooth muscle cells within the vessel walls, in particular in the large veins, large arteries, and smaller arterioles. The process is the opposite of vasoconstriction ...
s can be given to lower the blood pressure, and
intravenous fluids Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutrie ...
that might normally be given are foregone to avoid raising it. In 1959, Passaro reported the first successful surgical repair of a torn aorta. Kirsh, in 1976, reported a 70% success rate in surgery to repair a torn aorta, based on 10 years of experience as a surgeon. Therefore, for those who make it to the hospital (85% do not), are successfully diagnosed in time and are quickly operated upon, the chances of survival are higher.


Intimal tear

In some cases, intimal tears may resolve on their own. Therefore, conservative treatment like antihypertensives are usually initiated. There is limited data on the treatment of this type of aortic injury. In some places, endovascular repair is also an option for treatment.


Prognosis

Death occurs immediately after traumatic rupture of the thoracic aorta 75%–90% of the time since bleeding is so severe, and 80–85% of patients die before arriving at a hospital. Of those who live to reach a hospital, 23% die at the time of or shortly after arrival. In the US, an estimated 7,500–8,000 cases occur yearly, of which 1,000–1,500 make it to a hospital alive; these low numbers make it difficult to estimate the efficacy of surgical options. However, if surgery is performed in time, it can offer a chance of survival. Though there is a concern that a small, stable tear in the aorta could enlarge and cause complete rupture of the aorta and heavy bleeding, this may be less common than previously believed as long as the blood pressure does not get too high. There have been five rare cases of a traumatic aortic rupture going undiagnosed of more than a year, and presenting with chest and back pain. They had pseudoaneurysms or large aneurysms that caused pain. Asymptomatic chronic traumatic aneurysms are not always a risk for sudden death unless too large. Growing aneurysms, symptomatic or not, have a risk of rupture so the treatment is surgical removal.


See also

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Chest trauma A chest injury, also known as chest trauma, is any form of physical injury to the chest including the ribs, heart and lungs. Chest injuries account for 25% of all deaths from traumatic injury. Typically chest injuries are caused by blunt mechanisms ...
*
Aortic dissection Aortic dissection (AD) occurs when an injury to the innermost layer of the aorta allows blood to flow between the layers of the aortic wall, forcing the layers apart. In most cases, this is associated with a sudden onset of severe chest or ...
*
Pulmonary contusion A pulmonary contusion, also known as lung contusion, is a bruise of the lung, caused by chest trauma. As a result of damage to capillaries, blood and other fluids accumulate in the lung tissue. The excess fluid interferes with gas exchange, po ...


References


External links

{{DEFAULTSORT:Traumatic Aortic Rupture Diseases of the aorta Chest trauma Injuries of abdomen, lower back, lumbar spine and pelvis