DZ of Aorta Flashcards
(55 cards)
1
Q
normal diameter of ascending aorta
A
3cm
2
Q
normal diameter in descending portion
A
2.5cm
3
Q
measurement of aorta in abdomen
A
1.8-2cm
4
Q
why is the aorta prone to injury
A
d/t its constant exposure to high pulsatile pressure and shear stress
-more prone than any other vessel
5
Q
3 layers of the aorta
A
- intima - thin inner layer
- media - thick middle ayer that give the aorta strength, elasticity, and distensibility
- adventitia - thin outer layer
6
Q
2 anatomically into two components
A
- thoracic - within the thorax, above the diaphragm
2. abdominal aorta - section below the diaphragm
7
Q
three segments of thoracic arota
A
- ascending
- aortic arch - has great vessels
- descedning aorta
8
Q
2 segments of ascending aorta
A
- aortic root: lower segment
- begins at the level or the aortic valve
- supports the aortic valve leaflets
- extends into the sinotubular junction
- area where right and left main coronaries arise - ascending aorta - upper segment
9
Q
3 vessles that come off the aortic arch
A
- innominate artery/brachiocephalictrunk
- left CCA
- left subclavian
10
Q
descending thoracic aorta runs how to the diaphragm
A
distally
11
Q
what is the aortic isthmus
A
point at which the aortic arch joins the descending aorta
-vulnerable to trauma
12
Q
abdominal aorta extends from the what
A
from the thoracic aorta at the level of the diaphragm to the bifurcation of the right and left common iliac arteries
13
Q
2 segments of abdominal aorta
A
- suprarenal - segment aboe the renal arteries
2. infrarenal - segment below the reanl arteis
14
Q
aorta as we age
A
- elasticity and distensibility decreases with age
- these changes occur earlier and more rapidly in men tha women - loss of elasticity is accerelated in pts with HTN, hypercholesterolemia, and CAD
15
Q
2 dz of the aorta
A
- aortic aneurysms
- thoracic
- abdominal - aortic dissections
16
Q
what is an aortic aneurysm
A
pathologic dilation of the aorta that can occur anywhere along the course of the aorta
-involves all layers of the vessel
17
Q
2 types of aortic aneursysm
A
- fusiform - affects the entire cirumference of a segment of a vessel
- saccular - involves only a portion of the circumference (outpouching of a vessel)
18
Q
classification of aortic aneurysms
A
determined by locations
- abdominal - below diaphragem
- thoracic - above diaphragem
- thoracolumbar - involves the descending thoracic aorta and abdominal aorta
19
Q
complications of aortic aneurysms
A
dissection
acute ruptrue - greatest fear!!
20
Q
avg growth rate of thoracic aortic aneurysm
A
- 1-0.2cm/year
- those with marfacns syndrome may expand ast a greater rate
21
Q
risk of rupture is related to the
A
size and presence of symptoms
- -2-3% rupture per year when 6.0cm in diameter
- fewer than 1/2 of pts with an acute rupture arrive to the hospital alive
22
Q
etiology of thoracic aortic aneurysms
A
- ascending aortic aneurysms - cystic medial necrosis is most common cause
- aortic arch and descending thoracic aneurysms - atherosclerosis is the most common cause
23
Q
risk factors for thoracic aortic aneurysms
A
- atherosclerosis
- connective tissue disorders - Marfan’s Ehlers-Danlos syndrome
- HTN
- familial thoracic aortic aneurysm syndromes
- infections - syphilis (rare) TB,
- vasculitis
- traumas
24
Q
s/s of thoracic aortic aneurysms
A
most are asymptomatic and found on routine physical exam or chest x ray
-+/- chest and back pain (steady, deep and at times extremely severe
25
if symptoms are present, they coincide with what?
size and location of aneurysm
1. aortic root: CHF, AR
2. aortic arch - compress the trachea and/or recurrent laryngeal nerve
3. descending - compresses esophagus
26
imaging for thoracic aortic aneurysms
1. CXR - widening of mediastinum, displacement or compression of trachea, calcifications of the outline of the aorta, large aortic knob
2. TEE: can assess the proximal ascending aorta and descending thoracic aorta
3. CT scan - MODALITY OF CHOICE
4. MRII AND AORTOGRAPHY - BOTH SENSITIVE AND SPECIFIC TEST
27
TX OF THORACIC AORTIC ANEURYSMS
1. SURGERY -
- AORTIC ARCH/ASCENDING AORTA:OPEN SURGERY REQUIRED - -DESCENDING - ENDOVASCULAR STENT GRAFTING
2. MEDICAL MANAGEMENT
28
indications for surgery in a thoracic aortic aneurysm
1. symptomatic pts
2. ascending aortic aneurysm >5,5-6cm
descending aortic aneurysm >6.5-7cm
aneurysms that have increased >1.0 cm/year
Marfan's syndrome pts: ascending aortic aneurysm >5cm
29
surgical complications of thoracic aortic aneurysm
1. higher morbidity and mortality than AAA
2. paraplegia (4-10% rate foloowing endovascular repair)
3. stroke
30
medical management of thoracic aortic aneurysms
1. indications - asymptomatic pts with aneurysms too small to jusitfy surgery
2. beta blockers - decreased mortality and slow the rate of dilation
3. ACE-I/ARBs - sutdies showiing these reduce the rate of expansion in pts with Marfans' syndomre
31
prognosis of thoracic aortic aneurysms
- survival rate of those not undergoing repair is 20% at 5 eras
- less than 1/2 of the pts with an acute rupture arrive to the hospital alive
32
what is abdominal aortic aneurysms
defined as an aneurysm measuring >=3.0cm
M>F 4:1-90% of AAA are related to atherosclerosis
90% are infrarenal in location
risk of rupture increases as the size increases 5cm: 5 year risk of rupture if 20-40%
33
overall mortality from rupture is
80%
34
approx what % of pts with acute will die b4 receiving med attn
-operative mortality for those reaching hospital is
50%
35
risk factors for abdominal aortic aneurysms
atherosclerosis - MC
- HTN
- smokoking
- hypercholesterolemia
- PVD
- age m>55 W>70
- male gender
- genetics
36
s/s of abdominal aortic aneurysms
asymptomatic mostly
- usually found on exam as a palpable, pulsatile nontender mass or seen incidentally on imaging studies ordered for an unrelated issue
- as the aneurysm expands, pts may feel abdominal or lower back pain
- pain may be constant or intermittent and may be brought on by gentle pressure on the aneurysm
- pain is usually a sign of impending rupture and is a medical emergency
37
dz/imaging for abdominal aortic aneurysm
- pulsatile mass anywhere from the xiphoid process to the umbilicus (abdominal aorta)
- abdominal US - Gold STandard
- xray - calcified outline of aneurysm
- CT - can diagnose and size aneurysm
- contract aortography - invasive and require contract
- MR angiography - extremely accurate, used to plan for surgical repair
38
tx of abdominal aortic aneurysm
surgery - definitive
- indications - any size that is symptomatic
- any aneurysm that is rapidly expanding
- diameter >5.5cm
procedures: insertion of a prosthetic graft (open procedure)
- endovascular stent graft
39
medical tx of abdominal aortic aneurysm
smoking cessation
- aggressive control of HTN
- control of hyperlipidemia
- beta blockers - reduce expansion and rupture
- serial imaging q6months to monitor size and rae of expansion for aneurysms >4 cm or greater
40
prognosis of AAA
if treated surgically - 5 year survival after tx 60%, MI is leading cause of death
-if n surgery 12% annual risk of rupture if>6cm 25% annual risk of rupture if >7cm
41
prevention/screening of AAA
- treat risk factors (HTN, hyperlipidemia)
- smoking cessation
- screening indications - all men age 665-75 yo who have ever smoked, siblings or offspring of people with thoracic aortic or peripheral arterial aneurysm
42
what is an aortic dissection
tear of the intima that results in the formatio of a false channel with in the media layer
43
how does the dissection usually progress
distally down the descending aorta and into ts branches
44
common sites of aortic dissection
1. right lateral wall of the ascending aorta (shear stress is highest)
2. descending thoracic aorta just below the ligamentum arteriosum
45
epidemiology of aoritc dissection
peak incidence in 7th and 8th decades of life
| M>W 2:1
46
risk factors of aortic dissection
- HTN
- age
- bicuspid aortic valve
- marfans' syndrome and Ehlers Danlos syndrome
- infalmmatory aortitis
- pregnancy (3rd tri)
- blunt trauma to aorta
47
two classification of aortic dissectin
1. Debakey classification
| 2. standored classification
48
debakey classification of aortic dissection
- type I - originates in ascending aorta, continues to the aortic arch and many times beyond the arch distally
- type III - originates and is confined to the ascending aorta
- type III - originates in the descending aorta with extension distally
49
stanford classification of aortic dissection
type A - all dissection involving the ascending aorta
| type B - all dissections not involving he ascending aorta
50
symptoms of aortic dissection
- severe, persistent, sudden onset CP most common initial symptom
- pain described as tearing, ripping and sharp
- may localized to the front or back of chest, lower back
- pain may migrate as it progresses
- ascending dissection: neck throat, jaw pain
- descending dissection - chest pain +/- radiation to back, inter scapular or anterior chest
- less common symptoms: dyspnea, syncope, weakness, CHF, CVA, paraplegia, cardiac arrest
51
signs of aortic dissection
HTN, hypotension
aortic regurg
-periph pulses decreased or unequal
-pulm edema
-intestinal ischemia or renal insufficiency
-neuro findings dt carotid artery obstruction (hemiplegia, hemianestheisa)
-paraplegia (spinal cord ischemia)
52
imaging/dx of aortic dissection
1. CXR - may show widened mediastinum and pul edma
- EKG - may be normal, may show LVH, acute changes may develop if it involves the coronary artery
- CT IS DIAGNOSTIC test of coice - should include chest and abdomine
- ECHO and MRI - also diagnositc but not sued first line in an acute setting
53
tx of aortic dissection
goal is to stop the progression of dissection
- medical - BP control is essential
- beta blocker unless contraindicated to get HR down to 60bpm
- sodium nitroprusside to lower SBP
54
surgery for aortic dissection
superior to medical tx in acute proximal dissections
- indications
- acute distal dissections w/ vital organ compromise, rupture or impending rupture
- dissections in Marfans' syndrome or
- continued pain
- involves incising the intimal flap, obliterating the false lumen and placing a graft in the lumen of the vessel
55
what is the largest blood vessel in the body
aorta
