Vascular Diseases Flashcards
1
Q
What is Morbidity Rate?
A
The frequency with which a disease appears in a population.
2
Q
What is Mortality Rate?
A
Death rate to a specific cause.
3
Q
What is Mural?
A
Relates to the wall of any cavity.
4
Q
What are emboli/embolus?
A
A blockage causing material that moves within a vessel (can be clot/fat/air).
5
Q
What are thrombi/thrombus?
A
A blood clot inside a vessel.
6
Q
What is a true aneurysm?
A
A true aneurysm is a bulging in a vessel that involves all three layers of the vessel being weakened and dilated.
7
Q
What is a false aneurysm?
A
A pseudoaneurysm is when a tear in the vessel wall allows blood to pool between the layers.
8
Q
What is a stenosis?
A
The abnormal narrowing of a blood vessel.
9
Q
How does the flow pattern of the aorta change?
A
Proximal (above renals) = Moderate/Low waveform
Distal (below renals) = High resistance waveform
10
Q
What is the flow pattern of the renal arteries?
A
Low resistance
11
Q
How does the flow pattern of the SMA change?
A
Pre-pandial = high res
Post-prandial = low res
12
Q
What does hepatofugal mean?
A
Away from the liver
13
Q
What does hepatopedal mean?
A
Towards the liver
14
Q
What is normal portal venous flow?
A
- Hepatopedal
- Monophasic with slight undulations
15
Q
What is the normal flow of the hepatic veins and IVC?
A
- Phasic
- “sawtooth”
16
Q
What is the normal measurement of the Aorta?
A
2-2.5 cm
17
Q
What is the normal measurement of the distal aorta?
A
1.5 cm
18
Q
When is an aorta considered aneurysmal?
A
AP of 3cm or greater
19
Q
What is the usual size of the IVC?
A
Less than 25 mm
20
Q
When is the IVC considered dilated?
A
3.7cm
21
Q
How does respiration affect the size of the IVC?
A
Initial inspiration = decreases
Suspended respiration = IVC increases
22
Q
What are the indications for an arterial assessment?
A
- Pulsatile abdominal mass
- Abdominal pain
- Abdominal bruit
- Hemodynamic compromise of the lower limbs
23
Q
What is a bruit?
A
The abnormal sound generated by turbulent flow of blood in an artery.
24
Q
What is Arteriosclerosis?
A
Hardening of the arteries
25
What is Atheroma?
Lipid deposit in the arterial intima
26
What is Atherosclerosis?
A form of Arteriosclerosis effecting large and medium arteries where the artery is narrowed due to plaque build up.
27
What is plaque?
Platelets forming a cap over a fat deposit
28
What is another name for Atherosclerosis?
Atheromatous Disease
29
What is atheromatous disease?
Lipid deposits on the intimal lining of any artery alter the lining and provoke fibrosis and calcification.
30
What is atheromatous disease associated with?
Hypertension, smoking and diabetes.
31
What increases the incidence of atheromatous disease?
Age
32
Who does atheromatous disease more commonly effect?
Males
33
How does atheromatous disease appear on US? (4)
- Irregular walls
- Tortuous vessel
- Calcifications
- Narrowed lumen
34
What arteries can aneurysms affect?
Any artery
35
What is AAA?
Abdominal Aortic Aneurysm
A weakening of the aortic wall that leads to focal dilation.
36
What is ectasia?
A slight widening of the aorta up to 3 cm.
37
Where do AAA most commonly occur?
Below the level of the renals
38
When is an AAA more difficult to treat?
When is occurs above the renal vessels
39
What is the main cause of AAA?
Atherosclerosis
40
What are some other causes of AAA?
- Syphilis
- Systemic infections
- Cystic medial necrosis
- Other diseases (Marfan's)
41
What is marfan's disease?
Genetic disorder of connective tissue
42
What are the risk factors of AAA? (5)
- Men over 60
- Hypertension
- 1st degree family history
- Hypercholesterolemia
- Smoking
43
What is Hypercholesterolemia?
High cholesterol
44
What are the signs/symptoms of AAA? (5)
Generally asymptomatic but:
- Palpable mass
- Low back pain
- Abd pain
- Leg pain
- Incidental find on x-ray
45
What are the types of AAA?
1. Fusiform - uniform dilation
| 2. Saccular - Protrusion on one side
46
What is saccular AAA usually due to?
Trauma or infection
47
What is the most common type of AAA?
Fusiform
48
What is the typical location of thrombus in AAA?
Anterior and left
49
What are the US features of AAA?
1. 3 cm or greater
2. Wall irregularities
3. Thrombus
50
What is thrombus?
Clot attached to the vessel wall seen on US as medium to low level echoes.
51
What is thrombus caused by?
Slowing of the blood stream, injury to the vessel and alterations to the blood constituents.
52
How do platelets affect clotting?
More platelets = more clotting
53
Why is thrombus concerning?
Poorly attached thrombus can result in the release of emboli.
54
What are common associated findings of AAA?
1. Bilateral iliac artery aneurysms of 2 cm or greater
| 2. Popliteal aneurysms greater than 1 cm
55
How often are popliteal aneurysms seen in conjunction with AAA?
25% of cases
56
What is the average rate of growth for AAA?
2-5 mm per year
57
What is important to do when imaging AAA? (7)
1. Outer to outer wall meas
2. Meas perpendicular to vessel
3. 3 planes
4. Note shape (sac vs fus)
5. Image renals and iliacs
6. Describe wall thickening/thrombus
7. Document flow pattern
58
What is the follow-up/treatment on a 3-5cm aneurysm?
If it is increasing 2-5mm/year then serial US exams
If it is increasing 10 mm/year then surgery aortic graft
59
What is the follow-up/treatment on a 5-6 cm aneurysm?
Surgery with good prognosis
60
When is surgery considered imperative on a AAA?
6cm
61
What is the follow-up/treatment on a AAA greater than 7cm in size?
Surgery-aortic graft asap
62
What is the prognosis of a AAA greater than 7 cm with no surgery?
75% fatal rupture
25% will survive one year
63
What are the complications of AAA? (4)
- Stenosis/occlusion (distal)
- Rupture
- Dissection
- Thrombosis (distal)
64
What is aortic dissection?
When the aortic intima (and sometimes media) tears allowing blood to surge through the layers creating a false lumen.
65
What is the mortality rate of an AAA rupture?
Greater than 50 % (will die)
66
What is the operative mortality rate of a AAA rupture?
Greater than 40-60% (will die)
67
What are the signs/symptoms of a AAA rupture? (3)
1. Pain
2. Shock
3. Expanding abdominal mass
68
What is the sonographic appearance of AAA?
- Free fluid in abdomen
- Complex fluid
- Compression/displacement of surrounding structures
69
What are the options of AAA repair?
1. Traditional graft
| 2. Endovascular aortic stent
70
What is a traditional graft?
A way to repair the aorta by using a surgical bypass graft using a flexible synthetic material.
71
What materials are bypass grafts made out of?
Teflon or Dacron
72
What is an endovascular stent?
A less invasive way to repair a AAA by inserting a stent and ballooning it out.
73
How will a repaired AAA appear on US? (5)
1. Ribbed appearance
2. Straight distinct borders
3. Increased echoes
4. Difficult to visualize after 8 years
5. Small layer of fluid post-op (normal)
74
What are common complications of AAA repair? (5)
1. Fluid collections
2. Hematomas, seromas
3. Abscesses
4. Pseudoaneurysms
5. Stenosis
75
What complication of AAA repair occurs with endovascular repairs only?
Endo-leaks
76
What arteries do splanchnic artery aneurysms affect?
Celiac(splenic, hepatic, gastric), SMA, IMA
77
What is another name for splachnic artery aneurysms?
Mesenteric aneurysms
78
What is the most common artery effected by splanchnic artery aneurysms?
Splenic artery
79
What artery is second most commonly effected by splanchnic artery aneurysms?
Hepatic
80
What artery is least commonly effected by splanchnic artery aneurysms?
SMA
81
What are the underlying causes of splanchnic artery aneurysms? (4)
- Congenital
- Atherosclerosis
- Mycotic
- Inflammatory
82
What is mycotic?
An bacterial infection of the arterial wall.
83
How common is splanchnic artery aneurysms?
Rare but life threatening
84
What is the US appearance of splanchnic artery aneurysms?
Anechoic or complex area continuous with the vessel that has a doppler signal
85
Where are renal artery aneurysms located?
Extra-renal
86
What are common underlying causes of renal artery aneurysms?
Atherosclerosis and polyarteritis
87
What are the signs/symptoms of renal artery aneurysms? (3)
- Palpable mass
- Hypertension
- Hematuria
88
What is the US appearance of a renal artery aneurysm?
An anechoic mass connected to artery with a doppler signal
89
How do iliac artery aneurysms typically present?
- Asymptomatic
- Bilateral
- In older men
90
What are iliac artery aneurysms assoicated with?
AAA and popliteal artery aneurysms
91
Why are iliac artery aneurysms concerning?
They can rupture
92
What can iliac aneurysms cause?
Hydronephrosis due to the compression of ureters
93
What are mycotic aneurysms?
Rare aneurysms that are due to bacterial or fungal infections.
94
How do most mycotic aneurysms appear?
Saccular with asymmetric wall thickening
95
What are inflammatory aneurysms?
Uncommon aneurysms involving the retroperitoneum that have a dense fibrotic reaction around the aneurysm.
96
What is retroperitoneal fibrosis?
A fibrotic reaction in the peritoneum but does NOT relate to an aneurysm.
97
What are inflammatory aneurysms adherent to?
Bowel, ureter, iliac veins and IVC.
98
What is the US appearance of inflammatory aneurysms?
- Dilated aorta
- Thick wall
- Hypoechoic mantle around aorta
99
What is aortic dissection frequently related to?
Hypertension
100
Where does aortic dissection begin?
Thorax
101
What is the symptom of aortic dissection?
Chest pain
102
What are the 3 types of aortic dissection?
1. Involving the arch and moving down the aorta
2. Marfan's - involving ascending aorta only
3. Involving the descending aorta after the subclavian
103
What is the most common aortic dissection?
Involving the descending aorta after the subclavian.
104
What is the US appearance of aortic dissection?
Thin, linear echogenicity within the arterial lumen that has a flap that moves with the cardiac cycle.
105
How can you determine aortic dissection with doppler?
Demonstrate blood flow on both sides of flap.
106
What are the causes of a pseudoaneurysm?
1. Failed graft, post angiogram
| 2. Trauma
107
What is the appearance of a pseudoaneurysm on US? (4)
- Round/oval protuberance
- Blood circulates through in systole
- Pulsatile entry jet
- Variable waveform
108
What is important to identify on a pseudoaneurysm?
The neck of the mass
109
What is the treatment of a pseudoaneurysm?
1. US guided compression
| 2. US guided thrombin injection
110
What is an AV fistula?
An arteriovenous fistula is an abnormal communication between an artery and a vein where the blood moves from high to low pressure.
111
What are the causes of AV fistulas?
1. Trauma
| 2. Complication of AAA
112
What is the clinical presentation of AV fistulas? (5)
1. Low back pain
2. Abd pain
3. Hemodynamics altered
4. Swelling of lower trunk and extremities
5. Dilated veins
113
What is the US appearance of AV fistulas? (4)
1. Markedly dilated IVC
2. Pulsatile IVC
3. Irregular waveform
4. Reduced distal arterial flow
114
What is vascular atherosclerosis caused by?
Atherosclerotic plaque
115
What is the US appearance of vascular stenosis? (4)
- Narrowed lumen
- Post-stenotic dilation
- Increased velocities at stenosis
- Downstream changes
116
What is renal artery stenosis associated with?
Uncontrollable hypertension
117
What does renal artery stenosis cause?
- Decreased glomerular filtration rate
| - Ischemic renal damage
118
Where are renal artery stenosis's commonly found?
Origin from the aorta or within the first 2 cm
119
When assessing the IVC what 4 things do we look for?
1. Patency
2. Compressibility
3. Echo-free lumen
4. Changes with respiration
120
What is IVC dilation associated with?
Right ventricle failure
121
What are the signs/symptoms of IVC dilation?
1. Abd pain
2. Ascites
3. Hepatomegaly
4. Lower extremity edema
122
What are the types of IVC tumours?
They can be primary, metastatic or extensions.
123
What conditions indicate an IVC tumour?
Leg edema, ascites, abd pain
124
What are primary IVC tumors?
Uncommon tumors, leiomyoma or leiomyosarcoma
125
What does leio mean?
"Smooth" (muscle)
126
Where do IVC tumors most commonly metastasize from?
RCC
127
What is the sonographic appearance of IVC tumours? (4)
1. Intraluminal echogenic foci
2. Isoechoic or heterogenous
3. IVC dilated
4. Loss of respiratory changes
128
What is the most common abnormality of the IVC?
IVC thrombosis
129
How does IVC thrombosis occur?
Spreads from another vein
130
Why is IVC thrombosis concerning?
It's life threatening
131
What are the signs/symptoms of IVC thrombosis?
Same as IVC dilation but also GI complaints
132
What is the treatment of IVC thrombosis?
IVC filter
133
What is renal vein thrombosis a serious complication of?
Dehydrated or septic infant
134
What does renal vein thrombosis occur as a result of in adults? (4)
- Shock
- Renal tumour
- Renal transplants
- Trauma
135
What is renal vein thrombosis associated with?
Diabetes and high blood pressure
136
What are the signs of renal vein thrombosis?
- Flank pain/mass
- Hematuria
- Proteinuria
137
What is the sonographic appearance of renal vein thrombosis? (4)
- Enlarged kidney, hypoechoic
- Dilated renal vein
- Filling defects of variable echogenicity
- Decreased or absent venous signal
138
Where do the congenital abnormalities of the IVC occur?
At or below the renals
139
What are the most frequent congenital abnormalities of the IVC?
Duplication and transposition
140
What are the 3 congenital abnormalities of the IVC?
1. Transposition
2. Duplication
3. Azygous Continuation
141
When does azygous continuous occur?
When the hepatic segment if the IVC fails to develop
142
What is transposition of the IVC?
The IVC is located on the left side until the level of left renal vein where it crosses anteriorly to join with a normal pre-hepatic IVC.
143
What is duplication of the IVC?
IVC is normal on the right side but is also duplicated on the left side below the left renal vein.
144
What is azygous continuation of the IVC?
The absence of the hepatic IVC causing the hepatic veins to join and empty into the right atrium directly.
145
What is hepatic congestion?
Passive edema of the liver secondary to vascular congestion.
146
What is hepatic congestion related to?
Impairing blood flow to the right heart causing heart failure.
147
What is the US appearance of acute hepatic congestion? (4)
- Enlarged liver
- IVC dilated/no respiratory changes
- Hepatic veins highly pulsatile with flow reversal
- Portal vein flow is pulsatile
148
What is the US appearance of chronic hepatic congestion? (3)
- Shrunken liver
- Ditented hepatic veins
- LFT's altered
149
What is portal hypertension due to?
Increased portal venous pressures
150
What are the two types of portal hypertension and what are they based on?
1. Presinusoidal
2. Intrahepatic
Based on whether hepatic vein pressure is normal or elevated
151
What are the two types of pre-sinusoidal portal hypertension?
1. Extrahepatic
| 2. Intrahepatic
152
What is extra-hepatic presinusoidal portal hypertension marked by?
Portal vein and splenic vein thrombosis
153
What is extra-hepatic presinusoidal portal hypertension caused by? (5)
- Malignancy
- Infection/inflammation
- Trauma
- Splenectomy
- Hypercoagulable states
154
What does extra-hepatic presinusoidal portal hypertension result in? (3)
- ascites
- splenomegaly
- varices
155
What is intra-hepatic presinusoidal portal hypertension caused by?
Diseased affecting the portal zones:
1. Schistosomiasis
2. Primary biliary cirrhosis
156
What is the most common cause of intrahepatic portal hypertension in the western world?
Cirrhosis
157
What is cirrhosis?
When normal liver parenchyma is replaced which leads to increased resistance to PV flow and obstruction of HV outflow.
158
What does intrahepatic portal hypertension lead to?
- Ascites
- Splenomegaly
- Collaterals
159
What is the US appearance of portal hyper tension? (6)
- Dilated portal veins
- Collateral flow
- Patent umbilical/coronary vein
- Ascites
- Splenomegaly
- Changes in portal flow from monophasic to biphasic to hepatofugal
160
What is the upper limit of normal for the main portal vein diameter?
13 mm
161
What are the 5 most common collateral routes?
1. Gastroesophageal (fatal hemorrhage)
2. Paraumbilical
3. Splenorenal/gastrorenal
4. Intestinal
5. Hemorrhoidal
162
What is a portal vein thrombosis?
Clot in the portal venous system
163
What are the causes of portal vein thrombosis? (4)
- Malignancy
- Infection/inflammation
- Trauma
- Splenectomy
164
Why is colour doppler important in imaging portal vein thrombosis?
1. Can tell between benign and malignant thrombi (malignant will have flow)
2. Acute thrombus may be anechoic and get overlooked
165
What can portal vein thrombosis result in?
Cavernous transformation
166
What is cavernous transformation?
The formation of venous channels around a thrombosed portal vein
167
What is Budd-Chiari Syndrome?
A rare syndrome where the hepatic veins are obstructed with possible IVC occlusion
168
What are the causes of Budd-Chiari syndrome?
- Coagulation/congenital abnormalities
- Trauma
- Oral contraceptives
- Tumor invasion
169
What type of tumour invasion may cause Budd-Chiari Syndrome?
Hepatocellular carcinoma
170
What is the sonographic appearance of Budd-Chiari? (5)
Depends on stage
- Enlarged liver (acute)
- Poor visualization of the hepatic veins
- Possible thrombus in the IVC
- Caudate lobe enlarged/hypoechoic
- Hepatic vein flow absent or reversed
171
What are the signs/symptoms of Budd Chiari? (3)
- RUQ pain
- Hepatomegaly
- Occasionally splenomegaly
172
What is the treatment of portal hypertension?
Portosystemic shunts
173
What are portosystemic shunts?
Shunts used to shunt blood from congested venous system to a sytemic vein in order to decompress the PV system
174
How can portosystemic shunts be placed?
Surgically or percutaneously (through skin).
175
What is TIPS?
Transjugular Intrahepatic Portosystemic Shunt = shunt inserted percutaneously via jugular vein to hepatic vein to portal vein
176
What is an infarction?
Sudden interruption of blood supply that may lead to necrosis
177
What is a splenic infarct?
Loss of flow to spleen due to occluision of the splenic artery
178
What does splenic infarct cause?
Focal splenic lesion
179
What is the underlying cause of the occlusion that causes splenic infarct?
Variety
One may be sickle cell anemia
180
What is a sign of splenic infarct?
Sudden onset of LUQ pain
181
What is sickle cell anemia?
Red blood cells have abnormal sickle shape that cause them to break down easy and do not allow them to carry proper amount of O2 (causing clots).
182
What is the sonographic appearance of splenic infarct?
Hypoechoic wedge shaped/round area that becomes more hyperechoic over time
183
How can renal infarct vary?
- It can be segmental or diffuse
| - Appearance depends on time: Early = hypo, resolving = echogenic
184
How does renal infarct affect renal function?
Often remains normal
