Disorders of the Aorta Flashcards
Describe aortic aneurysm
outpouching or dilation of arterial wall
- occur more in men than women and incidence increases with age
- 3/4 occur in the abdominal aorta, 1/4 in thoracic aorta
- most abdominal occur below the renal arteries
Causes of aortic aneurysm
- degrenerative
- congenital
- mechanical (penetrating or blunt trauma)
- inflammatory
- infectious
Risk factors for aortic anurysm
Most 3 important risk factors are- age, male gender, &Tabacco use. Also: hypertension coronary artery disease family Hx high cholesterol lower extremity PAD carotid artery disease previous stroke obese, or excessive weight * white and native americans have higher risk than african americans, hispanics, and asians
aortic aneurysms are linked to what congenital abnormalities?
- bicuspid aortic valve
- coarcation of aorta
- turner syndrome
- autosomal dominant polycystic kidney disease
- specific collagen defects
- premature breakdown of vascular elastic tissue (Marfans, loey-dietz syndrome)
Define true-aneurysm
wall of artery forms the aneurysm with atleast one vessel layer is intact. Further divided into:
Fusiform- circumferential and relatively uniform in shape
Sacular- pouchlike with narrow neck connecting the bulge to one side of the arterial wall.
define false aneurysm (psuedoaneurysm)
is not an aneurysm, but a disruption of all arterial wall layers with bleeding that is contained by surrounding anatomical structures.
- results from trauma, infection, peripheral artery bypass graft surgery, or arterial leakage after removal of cannulae (femoral artery catheters, intra-aortic balloon pump devices)
Clinical Manifestations of Thoracic aortic aneurysms (TAA)
- often asymptomatic
- most common manifestation is deep diffuse chest pain that may extend to interscapular area.
- if in ascending aorta/ aortic arch then there may be angina due to decreased blood flow to coronary arteries and hoarseness of voice from pressure on laryngeal nerve.
- if pressing on superior vena cava there may be decreased venous return–> distended neck veins, edema in face and arms.
Clinical Manifestations of Abdominal Aortic Aneurysm (AAA)
- often asymptomatic (often found during routine exams, xrays, CT)
- may mimic pain assoc with abdominal or back disorders (compression of nearby anatomic structures and nerves)
- may spontaneously embolize plaque–> causing blue toe syndrome (patchy mottling of the feet and toes in the presence of palpable pedal pulse)
Complications of Aortic Aneurysm- rupture into retroperitoneal space
if the rupture occurs into retroperitoneal space, bleeding may be tamponaded by surrounding anatomic structures which can prevent patient from bleeding out and may prevent them from dying. In this case, patient has severe back pain and may or may not have back/flank ecchymosis (Grey Turners sign).
Complications of Aortic Aneurysm- rupture into abdominal cavity/thoracic cavity
- more than 90% of patients die from massive hemorrhage
- if patient reaches hospital, they will be in hypovolemic shock with tachycardia, hypotension, pale clammy skin, decreased urine output, altered LOC, and abdominal tenderness.
X-rays done to diagnose Aortic Aneurysm look at….
- chest: demonstrate mediastinal silhouette and any abnormal widening of thoracic aorta
- abdomen: may show calcification within wall of AAA
when diagnosing an aortic aneurysm, do an ___ to rule out an _______ ________
do an ECG to rule out myocardial infarction
echocardiography for aortic aneurysm
assists in diagnosis of aortic valve insufficiency
ultrasonography for aortic aneurysm
- useful in screening for aneurysms
- monitors size of aneurysm
CT scan fom aortic aneurysm
- most accurate test to determine: anterior-to-posterior length cross sectional diameter presence of thrombus best type of surgical repair
MRI for aortic aneurysm
used to diagnose and assess the location and severity
angiography for aortic aneurysm
used to anatomically map aortic system using contrast
- not reliable method for determining diameter or length
- can provide accurate info about involvement of intestinal renal or distal vessels.
goal for an AA is what?
- prevent aneurysm from rupturing. Early detection and treatment are imperative.
Once an AA is detected, studies are done to determine the size and location. What is the threshold for surgery?
- AAA greater than 5.5 cm diameter or larger. and may occur sooner if patient has
- genetic disorder (Marfans)
- rapidly expanding aneurysm
- is symptomatic
- high rupture risk
- smaller, asymptomatic AAA are managed with risk factor modifications (no tobacco use, lowering BP, optimizing lipid profile)
If an AA ruptures, what happens?
- emergency surgery. 90% mortality rate with ruptured AA
describe aortic resection (also called open aneurysm repair)
- large abdominal incision
- surgeon cuts into diseased aortic segment and removes plaque, then sutures synthetic graft to the aorta proximal and distal to the aneurysm then sutures the native aortic wall back around the graft to serve as a protective cover.
- clamps are used
- takes 30-45 min
- risk of post-op renal complications (acute kidney injury) increases in patients who have has this procedure above the level of renal arteries
describe endovascular graft procedure (EVAR)
- minimally invasive
- placement of sutureless aortic graft into abdominal aorta inside the aneurysm via femoral artery. The graft is a cylinder supported with rings of flexible wire and bifurcated, and delivered through a femoral artery catheter, on each side. when all components are in place, they are released against the vessel wall by balloon inflation. Blood now flows through the graft preventing further expansion of aneurysm.
nursing management for post-op
- ICU monitoring
- monitor for graft patency and renal perfusion (PRIORITY)
- maintenance of an adequate blood pressure is extremely important
- monitor incision site for drainage and infection
- avoid knee flexion positions
- antibiotics
- hourly urine outputs
- freq assessment os peripheral pulse, skin temp and color, capillary refill, sensation and movement in extremities
- no heavy lifting for 6 weeks
monitoring post-op carotid endartectomy
- neurological status–> level of consciousness, pupil size and response to light, facial symmetry, speech, ability to move upper extremities, quality of hand grasps.
What should you include in discharge teaching
- encourage patient to express concerns
- instruct patient to gradually increase activities
- no heavy lifting
- teach about signs and symptoms of complications (infection, neurovascular changes)
define aortic dissection
not a type of aneurysm
- it is a false lumen between the intima (inner lining) and the media (middle layer) of the arterial wall as a result of a tear in the intima. blood surges through tear and causes middle and inner layers to separate
- probably linked to degenerated elastic fibers in arterial wall. Chronic HTN makes this worse.
clincal manifestations of aortic dissection
- pain characterized as sudden, severe in anterior part of chest or intrascapular pain radiating down spine to abdomen or legs
- described as sharp or worst pain ever
- pain may mimic pain of MI
- Cardiovascular, neuro, and respiratory signs may be present.
- is aortic arch is involved then neurologic deficiency may be present.
complications of aortic dissection
- aorta may rupture- results in exsanguination and death
- hemorrhage may occur in mediastinal, pleural, or abdominal cavities
- occlusion of arterial supply to vital organs
diagnostic studies for aortic dissection
- similar to those for an AA
- an ECG can rule out cardiac ischemia
- chest xray will show widening of mediastium and pleural effusion
goal of therapy for aortic dissection
- goal is to lower the HR and BP and manage pain
- accomplished through drug therapy
- surgery is indicated when drug therapy is ineffective or when complications occur
what procedure is done, if necessary, for an aortic dissection?
- endovascular dissection repair (similar to EVAR)
- done for acute descending AD with complications, or chronic descending AD with complications
An acute ascending AD is considered a _______ _________
surgical emergency
surgical therapy is done for an AD when:
- it is an acute ascending AD
- when drug therapy is ineffective or when complications of AD are present
- surgery is delayed for as long as possible to allow edema to decrease to permit clotting of blood in the false lumen
- surgery involves resection of aortic segment and replacement with synthetic graft.
- women experience poorer surgical outcomes and higher mortality than men.
