Aneurysms Flashcards
Abdominal Aortic Aneurysms
Most aneurysms are asymptomatic until rupture
AAAs measuring 5cm are palpable in 80% of patients
Dilatation of the infrarenal aorta is a normal part of aging
AAAs are defined as greater than 3cm, however rupture rarely occurs unless diameter > 5cm or usually greater
2% of men over age 55 have AAAs
Ratio of men to women with AAAs is 4:1
90% of AAAs are below the level of renal arteries which is an important consideration for treatment
Positive correlation b/t smoking and aneurysms
S&S AAA
80% asymptomatic, found coincidentally
If there are symptoms, it is usually pain.
Pain: mild to severe midabdominal pain that radiates to back
Rupture: sudden severe pain with palpable abdominal mass and profound hypotension
Imaging AAA
Abdominal ultrasound = study of choice for initial screening
CT scans provide assessment of aneurysms diameter after initial dx
CT angiograms provide visualization of arteries above and below the aneurysm and helps determine type of repair if pt going to surgery
Surveillance AAA
Once AAA is identified, routine follow-up with ultrasound will determine size and growth rate
aneurysms require ultrasounds every 6 months
Open Resection AAA
Graft suture to nondilated vessels above and below aneurysm
Mortality rate lower in centers with high volume
Older and sicker patients do not do well with open repairs
Endovascular Repair AAA
Stent graft is used to align the aorta and exclude the aneurysm
Reduced operative morbidity and mortality with shorter recovery times
Cannot do endovascular repair if renal arteries are involved
10-15% incidence of continued aneurysm growth post endovascular repair and requires continued surveillance post repair
General Considerations AAA
Refer any patient with a 4cm or grater AAA for evaluation to either cardiology or vascular surgery
Urgent referrals for pain on palpation regardless of size
During surveillance periods, optimal blood pressure control is essential. Keep SBP <130
Thoracic Aortic Aneurysms
Most thoracic aneurysms are asymptomatic
Symptoms depend on size, position and rate of growth of aneurysm
CXR may show calcified outline of aneurysm
CT scan test of choice to demonstrate anatomy and size of aneurysm
Cardiac catheterization and echocardiography used to describe the relationship of the coronary vessels to an aneurysm of the ascending aorta
Tx TAA
Depends on location, rate of growth, associated symptoms and overall condition of patient
>6cm thoracic aneurysms are considered for repair
Descending thoracic aorta-treated routinely by endovascular repair
Aortic arch- need skilled team for complicated procedure in a high volume setting
Ascending thoracic aneurysms- complicated surgery and usually requires open surgery. High risk of morbidity, especially stroke because interruption of arch blood flow required
Aortic Dissection
Spontaneous intimal tear develops and blood flow dissects into the media of the aorta
Mainly related to severe hypertension
Type A dissection- involves the arch proximal to subclavian. Poor prognosis and death can occur in several hours due to rupture of dissection in pericardial sac
Type B – proximal descending thoracic aorta typically beyond the subclavian artery
Blood entering the intimal tear may extend the dissection into the abdominal aorta, lower extremities, carotid arteries, coronary arteries or subclavian arteries
TRUE emergency and requires immediate BP control to limit extent of dissection
S&S Aortic Dissection
Sudden and severe ripping and tearing pain
Severe hypotension
May have syncope, hemiplegia or paralysis of lower extremities
Intestinal ischemia or acute renal insufficiency may develop
Diminished or unequal peripheral pulses
Diastolic murmur
May have signs of cardiac tamponade - tachycardia, hyoptension, pulsis paradoxis
Imaging Aortic Dissection
CTA
TEE - good way to dx, but in acute phase, not recommended
Medical Tx Aortic Dissection
Aggressive measures to lower BP should be started even before diagnostic imaging if dissection is suspected
Intravenous beta blockers are the drugs of choice because they reduce the left ventricular ejection force that that continues to weaken the arterial wall
Labetolol and esmolol are drugs of choice
Morphine for pain control
Surgical Tx Aortic Dissection
Urgent surgical intervention is required for all Type A dissections
Urgent surgical intervention is required for type B dissections if there is compromise resulting in malperfusion of renal, visceral or extremity vessels
Mortality for untreated Type A dissections is 1% per hour for 72 hours
Patients with uncomplicated Type B dissections whose BPs are controlled and who survive the initial episode may have long-term survival without surgical intervention
