Module 3 : Vascular Diseases Flashcards
what are 5 conditions that can alter blood flow in and out of organs
- increase in vessel pressures
- thrombosis/tumor invasion
- atherosclerosis
- congenital abnormalities
- aneurysms
what is the normal aortic waveform pattern prox and distal
- prox = moderate
- distal = high resistance
renal artery normal wave form pattern
- low resistance
sma normal wave form patter prandial and postprandial
- pre prandial = high resistance
- post prandial = low resistance
normal portal venous flow
- hepatopedal
- monophasic flow with slight undulations
hepatic veins and ivc normal flow
- phasic flow
- influence by the cardiac and respiratory cycles
- IVC often described as a saw tooth pattern
normal ao prox measuremnt
2-2.5cm
normal ao dist measurement
1.5cm
at what measurement is the ao considered aneurysmal
3cm
ivc size
5-29mm (usually less than 25mm)
when is the IVC considered dilated
> 3.7cm
what is the IVC size on initial inspiration
decreases in size
what is the IVC size on suspended respiration
increases in size
4 indications for arterial assessment
- pulsatile abdominal mass
- abdominal pain
- abdominal buit
- hemodynamic compromise of the lower limbs
definiton of arteriosclerosis
hardening of arteries
definition of atheroma
lipid deposits in arterial intima
atherosclerosis definiton
- form of arteriosclerosis occurring in larger and medium arteries
plaque definiton
platelets forming cap over fatty deposits
characteristics of atheromatous disease (atherosclerosis)
- lipid deposits on intimal lining of any artery
- alteration of lining provokes fibrosis and calcification
what 3 things is atherosclerosis associated with
- hypertension
- smoking
- diabetes
does incidence of atherosclerosis incense or decrease with age
- increase
does atherosclerosis effect females or males more
males
sonographic appearance of atherosclerosis
- wall irregularities
- tortuous vesels
- calcifications
- narrowed vessel lumen
do aneuysms effect only one artery
- no can affect any artery
6 types of aortic aneurysms
- abdominal aortic aneurysms
- splanchnic artery aneurysms (mesenteric)
- renal artery aneurysms
- iliac artery aneurysms
- mycotic aneurysms
- inflammatory aneurysms
what is an abdominal aortic aneurysm
- a weakening of the aortic wall that leads to a focal dilatation
what is a true aneurysms
- involves all 3 layers of the artery wall
what is ectasia
- slight widening of the aorta up to 3cm
where does AAA usually occur
- occur mainly below the level of the renal vessels (infrarenal)
5 causes of AAA
- atherosclerosis MOST COMMON
- syphilis
- systemic infection
- cystic medical necrosis
- other diseases (marfans)
4 increased risk factors for AAA
- men > 60
- hypertenison
- family history
- hypercholesteremia
6 signs and symptoms of AAA
- usually asymptomatic
- palpable mass
- incidental finding on X-ray
- lower back pain
- abdominal pain
- leg pain
two types of AAA
- fusiform
- saccular
fusiform AAA
- uniform tubular dilation
saccular AAA
- sac like protrusion towards one side connected to the aortal
- most often due to trauma or infection
sonographic appearance of a AAA
- dilation of the aorta 3cm or greater
- aorta projects anterior and left (ivc and spine)
- wall irregularities
- ## thrombus on anterior and lateral walls
what is thrombus
- clot attached to the vessel wall
- poorly attached thrombus can result in the release of emboli
what three things cause thrombus
- slowing of the blood stream
- injury to vessel
- alterations to the blood constituents
two associated findings with AAA
- iliac artery aneurysms
- popliteal aneurysms
iliac artery aneurysms
- bilateral
- 2cm or greater
- usually asymptomatic
- older men
- can rupture
- causes hydronephrosis = compress ureters
popliteal aneurysms
- 25% of cases
- >1cm
protocol for measuring AAA
- place callipers outer to outer wall
- measure perpendicular to the vessel
6 things you want to document with AAA
- length, width and AP dimension
- shape
- location in aorta
- does it involve renal or iliac arteries
- describe the wall thickening
- flow pattern
follow up treatment for 3-5cm aneurysm
- increasing in size 2-5mm/year
+ serial ultrasound exams - increasing in size 10mm/year
+ surgery aortic graft
follow up and treatment for 5-6cm aneurysm
- surgery with good prognosis
- at 6cm surgery is considered imperative
follow up and treatment for >7cm aneurysm
- 1 year survival rate 25%
- 75% risk of fatal rupture
- surgery = aortic graft
4 complications with AAA
- stenosis/occlusion MOST COMMON
- rupture
- dissection
- thrombosis
+ with distal emboli
characteristics of AAA rupture
- surgical emergency
- mortality rate >50%
- operative mortality rate >40-60%
signs and symptoms of AAA rupture
- pain
- shock
- expanding abdominal mass
sonographic appearance of AAA rupture
- free fluid in abdomen
- complex fluid collection
- compression/displacement of surrounding structures
two types of AAA repair
- traditional graft
- endovascular aortic stent
traditional graft
- surgical bypass graft
- open repair
- made by flexible synthetic material (teflon or Dacron)
endovascular stent
- less invasive
- stent inserted and ballooned out
- more popular and less invasive quicker recovery
sonographic appearance of end-vascular stent
- ribbed appearance
- straight distinct borders
- increased echoes
- post op = small layer of fluid normal
- graft older than 8 years may bee difficult to see
6 complications of surgical repair
- fluid collection
- hematomas seromas
- abscesses
- pseudoaneurysms
- stenosis
- endoleaks
splanchnic artery aneurysms
- celiac, SMA, IMA
- rare but life threatening
order of arteries effected by splanchnic artery aneurysms
- splenic artery
- hepatic artery
- SMA
underlying causes of splanchnic artery aneurysms
- congenital
- atherosclerosis
- mycotic (fungal/bacterial)
- inflammatory
sonographic appearance of splanchnic artery aneurysms
- anechoic or complex area continuous with the vessel
- doppler signal
- can be mistaken for abscess/cyst/lymph node
renal artery aneurysms
- extra renal location
common underlying cause of renal artery aneurysms
- athersclerosis
- polyarteritis
signs and symptoms of renal artery aneurysms
- palpable mass
- hypertension (kidneys controls blood pressure)
- hematuria
sonographic appearance of renal artery aneurysms
- anechoic mass connected to artery with doppler signal
mycotic aneurysms
- rare
- due to bacterial or fungal infection
- most are saccular with asymmetric wall thickening
- difficult to diagnose with ultrasound alone
inflammatory aneurysms
- uncommon
- dense fibrotic reaction around the aneurysm
- involves retroperitoneum
- high morbidity and mortality rate
- adherent to bowel, ureter, iliac veins and IVC
sonographic appearance of inflammatory aneurysms
- dilated aorta
- wall thick
- hypo echoic mantle around aorta
what is an aortic dissection
- tear of the intimal lignin got the aorta (and sometimes media)
- false lumen created as blood pulsates through the vascular wall layers
- begins at the thorax
- presents typically with chest pain
what are ao dissections related to
- hypertension
3 types of aortic dissections
- involving aortic arch and movie down the aorta
- marfans
+ ascending ao only - dissection of descending ao after origin of left subclavian
+ MOSR COMMON
sonographic appearance of ao dissection
- thin, linear, echogenicity within the arterial lumen
+ flap moves with cardiac cycle - doppler
+ demonstrates blood flow on both sides of the flap
what is a psuedoaneurysms
- blood escapes through a tear in the vessel wall and Is contained by surrounding tissues
causes of pseudo aneurysms
- failed graft
- post angiogram
- trauma
sonographic appearance of pseudoaneurysms
- round/oval appearnce
- blood circulates through in systole
- pulsatile jet entry
- variable waveform
- always identify neck of mass
treatment of pseudoanerysm
- ultrasound guided compression
- ultrasound guided thrombin injection
+ cause blood to clot off - monitored with color doppler imaging
what is an arteriovenous AV fistula
- abnormal communication between and artery and vein
- blood moves from high to low pressure
- most secondary to trauma, can be complication to aortic aneurysm
clinical presentation of AV fistula
- lower back and abdominal pain
- hemodynamics altered
- swelling of lower trunk and extremities
- dilated veins
sonographic appearance of AV fistula
- dilated IVC
- pulsatile IVC
- irregular waveform high velocites
- reduced distal arterial flow
vascular stenosis
- can occur in varying degree
- caused by atherosclerotic plaque
common 2D and doppler findings of vascular stenosis
- narrowed lumen
- post stenotic dilation
- increased velocities at stenosis
- downstream changes
renal artery stenosis
- associated with incontrollable hypertension
- decreased glomerular filtration rate
- causes ischemic renal damage
- commonly at the origin from the aorta within the first 2cm
4 things to look for when assessing the IVC
- changes with respiration
- compressibility
- echo free lumen
- patency
what is a dilated IVC
- caliber increases below the point of obstruction
what is a dilated IVC associated with
- right ventricular failure
4 signs and symptoms of dilated IVC
- abdominal pain
- ascites
- hepatomegaly
- lower extremity edema
characteristics of ivc tumors
- primary metastatic or extension
- present with leg edema, ascites and abdominal pain
primary IVC tumors
- uncommon
- leiomyoma/leiomyosarcoma
+ tumor of smooth muscle
metastatic ivc tumors
- most commonly RCC
sonographic appearance of ivc tumors
- intraluminal ehcogenic foci
- can be isoechoic or heterogeneous
- caliber of ivc increased
- loss of respiratory changes
characteristics of IVC thrombus
- life threatening
- MOST COMMON ABNORMALITY OF IVC
- spreads from other veins
sonographic appearance of IVC thrombosis
- intraluminal filling defect expanding the vessel
- echogenicity of the thrombus depends on its age
- respiratory changes decreased or absent
- color doppler is useful will show no flow in the region of the thrombus
- IVC filters used for treatment
signs and symptoms of IVC thrombus
- leg edema
- lower back pain
- GI complaints
- enlarged liver
- ascites
renal vein thrombosis characteristics
- serious complication in a dehydrated state or septic infant
- in adults occur as result of shock, renal tumor, renal transplants or trauma
- associated with diabetes and high blood pressure
3 signs an symptoms of renal vein thrombosis
- flank pain/mass
- hematuria
- proteinuria
sonographic appearance of renal vein thrombosis
- enlarged kidney hypo echoic
- dilated renal vein
- filing defects of variable echogenicty
- decreased or absent venous signal
congenital abnormalities of the IVC
- most occur at or below level of the renals
what are the most common congenital abnormalities of IVC
- duplication and transposition
when does azygous/hemiazygous abnormality occur
- when hepatic segment of the IVC fails to develop
three types of congenital IVC abnormality
- transposition
- duplication
- azygous continuation
what is hepatic congestion
- passive edema of liver secondary to vascular congestion
- related to heart failure
- blood flow to the right side of heart is impaired
sonographic appearance of acute hepatic congestion
- enlarged liver
- IVC dilated/ no respiratory changes
- hepatic veins = highly pulsatile, flow reversal
- portal vein flow = pulsatile
sonographic appearance of chronic hepatic congestion
- shrunken liver
- hepatic veins distended
- LFT may be altered
what is portal hypertension
- due to increase portal venous pressure
- 2 types based on whether hepatic vein pressure are normal or elevated
2 types of portal hypertension
- presinusoidal
+ normal hepatic vein pressure - intraheptaic
+ abnormal hepatic vein pressure
2 types of presinusoidal hypertension
- extrahepatic
- intrahepatic
extra hepatic presinusoidal hypertension
- PV and SV thrombosis
- results in ascites, splenomegaly, varices
- possible causes
+ malignancy, infection, inflammation, trauma, splenectomy, hypercoaguable states
intrahepatic presinusoidal hypertension
- caused by diseases affecting the portal zones
+ schistosomiasis (panc infection)
+ primary biliary cirrhosis
intrahepatic portal hypertension
- most common in western world = cirrhosis
- normal liver parenchyma is replaced which leads to increased resistance to PV flow and obstruction of HV outflow
- results in ascites, splenomegaly, collaterals
sonographic appearance of both types of portal hypertension
- dilated PV in the early stages \+ upper limit of normal 13mm - collateral flow - patent umbilical vein/coronary vein - ascites - splenomegaly - monophasic >> biphasic>> hepatofugal
5 most common collateral routes
- gastroesophageal \+ fatal hemorrhage - paraumbilical \+ leads to caput medusa - splenorenal/gastrorenal - intestinal - hemorrhoidal
what is portal vein thrombosis
- clot in portal venous system
- can result in cavernous transformation
causes of portal vein thrombosis
- malignancy
- infection/inflammation
- trauma
- splenectomy
why is color doppler important for portal vein thrombosis
- useful in distinguishing benign and malignant thrombi
- acute thrombus may be relatively anechoic
what is cavernous transformation
- formation of venous channels around a thrombodes vein portal vein
what is Budd chairi syndrome
- rare
- obstruction of hepatic veins with possible IVC occlusion
causes of Budd chiari syndrome
- coagulation/congenital abnormalites
- trauma
- ORAL CONTRACEPTIVES
- tumor invasion
sonographic appearance of Budd chiari
- stage dependant
- enlarged liver (acute)
- poor visualization of hepatic veins
- thrombus in IVC
- caudate lobe enlarged/hypoechoic
- HV flow absent or reversed
signs and symptoms of Budd Chiari
- RUQ
- hepatomegaly
- occasionally splenomegaly
treatment of portal hypertension
- portosystemic shunts
portisystemic shunts characteristic
- shunts venous blood flow from congested venous system to a systemic vein
- decompress PV system
- can be placed surgically or percutaneously
- TIPS
TIPS shunt
- trans jugular intrahepatic portosystemic shunt
- stent inserted percutaneously via jugular vein
- inserted HV to PV
- blood flows from PV system into hepatic venous system
what is an infarction
- sudden interruption of blood supply that may lead to encores
splenic infarct
- common cause of focal splenic lesions
- caused by occlusion of the splenic artery
- sudden onset of LUQ pain
- underlying causes = sickle cell anemia
sonographic appearance of splenic infarct
- hypo echoic wedge shaped round area
- echogenicity changes over time (becomes hyperechoic)
renal infarct
- can be segmental or diffuse
- appearance is time dependant
+ early = hypo
+ late = hyper - renal function often remains normal
