Abdominal Aortic Aneurysm (AAA)

· A potentially life-threatening condition, abdominal aortic aneurysm is characterized by a ballooning of a section of
the wall of the aorta
· The aorta is the largest artery in the body, and it has the thickness of a common garden hose
· The aorta is the main blood vessel that supplies the body’s circulation system with oxygenated blood
· The aorta originates from the top-most portion of the heart, and ends at about the level of the umbilicus (belly
· An aneurysm can develop anywhere along the course of the aorta
· This topic however focuses on the clinical manifestations related to the portion of the aorta that is located
within the abdominal cavity
· Abdominal aortic aneurysm is a relatively common disease affecting roughly 15,000 persons per year in the United
States alone

· Most cases are asymptomatic (absence of signs and symptoms) and thus are discovered incidentally when seeking
medical attention for other reasons such as a routine physical examination
· When signs or symptoms are present (but in the absence of a rupture), any of the following may be noted
· Abdominal pain
· Middle back pain
· Flank pain
· Characterized by pain beginning along the back below the ribs or sides of the body, and radiates down
towards the front near the groin area
· A pulsating abdominal mass may or may not be present
· In the presence of a rupture, any of the following may be noted
· Severe abdominal pain
· Severe middle back pain
· Severe flank pain
· Grey Turner sign (bruising along the flanks; retroperitoneal hemorrhage) a sign of bleeding behind the
peritoneal membrane
· The peritoneal membrane forms the lining of the abdominal cavity and covers abdominal organs
· The function of the peritoneal membrane is to provide a mechanism for peritoneal fluid transport, to
provide a pressure gradient within the abdominal cavity, and it may also serve as a natural prevention
against visceral (internal organ) adhesion formation following surgery
· A pulsating abdominal mass is more commonly seen with a ruptured abdominal aorta
· Syncope (partial or complete loss of consciousness due to very low blood pressures) and collapse

· Signs and symptoms consistent with hypovolemic shock may also be seen, including:
· General weakness
· Lightheadedness, confusion
· Pallor, clammy skin
· Low blood pressure
· Decreased or no urine output
· Rapid breathing
· Sudden death
· Other non-specific signs and symptoms may be seen, including
· Fever
· Fatigue
· Early satiety
· Nausea, vomiting
· Groin pain
· Leg pain or weakness with walking (claudication)

· Structural protein failure of the vessel wall has been attributed to many
factors, including
· Genetic predisposition
· Vessel wall inflammatory processes
· Biomechanical forces as would occur in a motor vehicle accident

· Risk factors for this condition have been well established, and include
· Family history (genetic predisposition)
· Caucasian race followed by African Americans
· This condition is not as common in other racial groups (Hispanics,
Asians, Native Americans)
· Current or past smoking
· Advanced age
· Hypertension (abnormally high blood pressure)
· Hyperlipidemia (abnormally high levels of fats or lipids in the blood)
· Obesity
· There tends to be a male predilection up to 70 years of age (2:1 vs
· Gender predilection disappears after 70 years of age
· Other vascular disorders can also increase risk
· Risk for rupture increases when the following are present
· Aneurysm diameter exceeds 5 cm
· Fast rate of expansion (more than 0.5 cm in six months)
· Female gender

· Complications depend on the location and size of the aneurysm; also listed are some complications that may stem
from surgical intervention
· Heart attack
· Infection
· Pulmonary embolism (blood clot in the lungs)
· Aortoenteric fistula
· An uncommon and catastrophic complication
· Due to pressure, the aneurysm of the aorta erodes the bowel wall of the abutting intestine
· Patients may present with minor traces of blood in the stool, and recurrent septicemia (bacterial
infection in the blood)
· The aortoenteric fistula may also cause massive, life-threatening bleeding
· This complication may present as a primary manifestation from a growing aneurysm, or it may occur as a
secondary process following aneurysmal repair
· Graft or stent (surgical treatment) failure
· Treatment-induced vasculopathy (injury to the aorta and/or iliac/femoral arteries due to treatment; iatrogenic)
· Spinal cord ischemia
· This is due to decreased distal aortic perfusion pressure or surgical intervention
· Blood flow interruption of segmental spinal arteries causes tissue death of the affected spinal cord section
· May lead to
· Lower extremity paralysis (loss of ability to move)
· Lower extremity motor and sensory deficits (partial loss of motor and/or sensory nerve function)
· Loss of bladder and bowel control
· Erectile dysfunction
· Mesenteric ischemia
· Embolus, or clot, to the mesenteric arteries impeding blood supply to the affected region of the intestines
· May cause tissue death of the affected region of the intestine
· Kidney damage
· Contrast-induced nephropathy (kidney exposure to contrast media can lead to kidney damage)
· Stent-induced inflammatory changes
· Perianeurysmal fibrosis of ureteric vessels
· Scaring around the aneurysm affecting ureteric vessels can reduce blood supply to the kidney
· Lower extremities
· Distal embolization (clot) of atherosclerotic (fatty) debris
· May lead to livedo reticularis of the feet (mottled discoloration of the skin of the feet
· Livedo reticularis also known as “blue toe syndrome”
· There is a high mortality rate with rupture of an abdominal aortic aneurysm

· In non-ruptured cases, surgical repair may be required if signs and symptoms are present, and if optimization of
medical therapy has failed
· More than 80% of patients who experience a rupture outside of the hospital do not survive

· Reduce risk by focusing on modifiable risk factors
· Quit smoking
· Consume a healthy diet
· Exercise regularly