Abdominal Aortic Aneurysm

Posterior rupture of the abdominal aneurysm will have a better surgical outcome.

Anterior rupture results in free bleeding into the peritoneal cavity causing prolonged period of hypotension, and, consequently the results of surgery are poor.

Ans. is `d’ i.e. None of the above 

Ans is d i.e. 50%

In elective surgery of abdominal aortic aneurysm the operative mortality rate approximates 1 to 2% whereas after acute rupture the mortality rate of emergency operation generally approximates 45- 50%.

Abdominal Aortic Aneurysms

• Abdominal aortic aneurysm (AAA) is the most common true arterial aneurysm.
• An aortic aneurysm is defined as a focal dilation of the aorta with a diameter of at least 1.5 times that of the expected normal diameter of that given aortic segment; in the AA, enlargement of the aortic diameter of more than 3 cm is usually considered aneurysmal.
• Most common site is infrarenal.
• More common in males than females.
• Incidence increases with age.
• At least 90% of all abdominal aortic aneurysms >4.0 cm are related to atherosclerotic disease.
• Prognosis is related to both the size of the aneurysm and the severity of coexisting coronary artery and 3 cerebrovascular disease.
• The risk of rupture is directly related to the size of aneurysm.
• An abdominal aortic aneurysm is usually asymptomatic. They are usually detected incidentally on routine clinical examinations or investigation performed for some other reasons.
• As abdominal aortic aneurysms expand, however, they may become painful. Aneurysmal pain is usually a harbinger of rupture and represents a medical emergency. More often, acute rupture occurs without any prior warning, and this complication is always life-threatening.
• Contrast-enhanced CT is investigation of choice. MRI is as sensitive and specific as CECT and is used if use of contrast is precluded. Ultrasound is the screening study of choice and is useful for serial documentation of aneurysm size
• Operative repair of the aneurysm with insertion of a prosthetic graft or endovascular placement of an aortic stent graft is indicated for:

–  abdominal aortic aneurysms of any size that are expanding rapidly or are associated with symptoms.

– for asymptomatic aneurysms, abdominal aortic aneurysm repair is indicated if the diameter is >5.5 cm.

• The decision to perform an open surgical operation or endovascular repair is based in part on the vascular anatomy and comorbid conditions.
• Endovascular repair of abdominal aortic aneurysms has a lower short-term morbidity rate but a comparable long-term mortality rate with open surgical reconstruction. (Harrison 18/e)
• In Elective surgery of abdominal aortic aneurysm the operative mortality, rate approximates 1 to 2% whereas after acute rupture the mortality rate of emergency operation generally exceeds 50%.

Answer is ‘b’ i.e. Emergency surgery complication < 10% ; 'c' i.e. Rarely asymptomatic before rupture 

• Abdominal aortic aneurysms are usually asymptomatic before rupture. They are usually detected incidentally on routine clinical examinations or investigation performed for some other reasons.
• However some aneurysms may cause pain, or a strong pulsatile sensation in the abdomen. Aneurysmal pain is usually a harbinger of acute rupture and represents a medical emergency.
• The risk of rupture is directly related to the size of aneurysm (The 5-year risk of rupture for aneurysm < 5 cm is 1 to 2%, whereas it is 20 to 40% for aneurysm > 5 cm in diameter).
• In Elective surgery of abdominal aortic aneurysm the operative mortality, rate approximates 1 to 2% whereas after acute rupture the mortality rate of emergency operation generally exceeds 50%.

Ans is a i.e.laterally into the left retroperitoneum 

Abdominal aortic aneurysm ruptures most commonly in left retroperitoeum.

Ans. is ‘a’ i.e., Rupture 

Answer- D. Infrarenal aorta

• Ruptured aneurysm is the most common cause of aortic rupture and they are most common in the abdomen.

Answer- A,Surgery is indicated when AAA > 6 cm C,Mortality rate after surgery is > 25% D,Commonly causes colon ischemia

• It is the most common true arterial aneurysm.
• Most common site (85-90%) is infrarenal.

Etiology-

• Atherosclerosis is the most common cause.
• Non-specific aorto-arteritis:- the 2nd most common cause.
• The 5 year risk of rupture of aneurysm of < 5 cm is 1 to 2%, where as it is 20-40% for aneurysm > 5cm.
• Investigation

IOC is CECT

Management-

• Operative repair of the aneurysm with insertion of prosthetic graft or aortic stent graft is indicated for-
• For asymotomatic aneurysms AAA repair is indicated if size > 5.5 cms.
• In elective surgery of AAA the operadve mortality rate approximates about l-2% whereas after acute rupture the mortality rateof emergency surgery generally approximate about 45-50%.

Complications-

• Death (1.8-5% mortality for elective open repair
• Colon ischemia is l% for elective repair 15-20% if the AAA has ruptured

Answer- A, B, C, Most common below renal artery, (B) May presents as pulsatile abdominal mass (C) Atherosclerosis is most common cause

• 9O% of abdominal aortic aneurysm (AAA) of size > 4cm in diameter is due to atherosclerosis.
• Male are more frequently affected than female.
• The aneurysm most commonly arises below the level of renal artery.
• It is usually detected on routine examination as a palpable, pulsatile, expansile, and non tender mass.

Answer- B. Most commonly arises from above the level of renal artery

• 90% of abdominal aortic aneurysm (AAA) of size > 4cm in diameter is due to atherosclerosis.
• Male are more frequently affected than female.
• The aneurysm most commonly arises below the level of renal artery.