Vascular surgery Flashcards
You are evaluating a liver transplant in a patient that received the organ yesterday. The resistive index (RI) for the hepatic artery is 0.9. Which of the following best describes the findings?
A. the resistive index is abnormally increased and any value greater than 0.6 indicates irreversible rejection
B. the resistive index is abnormally increased and should be reported as a critical finding of suspected rejection
C. the resistive index indicates normal resistance to flow in the liver parenchyma
D. the resistive index is abnormally increased, but this can be a normal finding in immediate post-op patients
D
If the immediate post-op patient there can be increased hepatic pressure usually secondary to edema. This can cause the RI values to be elevated. Serial exam should be performed to monitor the expected increase in diastolic flow and decline in RI values. Resistive Index (RI) >0.6-0.8 Normal.
A patient presents for a 3 month follow-up on his aortic endograft. The aortic sac has increased in size by 0.8cm since the last ultrasound evaluation performed 2 months ago. No endoleak was detected on ultrasound or CT evaluation. What is the most likely cause for the diameter change? A. endotension B. May Thurner syndrome C. graft migration D. reactive hyperemia
A
Endotension - no leak present but there is continued expansion of the aneurysm sac greater than 5mm; sometimes referred to as Type V Endoleak.
When performing serial exams on an in situ venous bypass graft, __________ indicates significant graft failure.
A. conversion of the waveform from triphasic to biphasic
B. an increase in end diastolic velocity greater than 30cm/s from the last exam
C. a decrease in peak systolic velocity of 30cm/s from the last exam
D. a decrease in ABI of 0.10 from the last exam
C
Serial exams that demonstrate a decrease in the PSV or 30cm/s or more and/or a decrease in the ABI of 0.15 or more indicate poor performance of the graft on the current exam.
What native artery is commonly used for the arterial anastomosis in a renal transplant when the external iliac artery is not available? A. internal iliac artery B. common iliac artery C. external iliac vein D. aorta
A
The external iliac artery is most commonly used as the arterial anastomosis for the allograft artery. The internal iliac artery is commonly used for the arterial anastomosis when the external iliac artery is not available.
What is the most common complication of an in situ vein graft? A. thrombosis B. AV fistula C. infection D. rupture
B
An AV fistula is the most common complication of an in situ vein graft. Because the vein is left in its normal position and attached to the arterial system at each end, some side branches persist as residual arteriovenous fistulae.
Arterial flow proximal to an AV fistula will be \_\_\_\_\_\_\_\_\_\_. A. phasic B. laminar C. high resistance D. low resistance
D
Arterial flow proximal to an AV fistula will be low resistance.
Retained valve cusps are a complication of: A. reversed cephalic graft B. in situ saphenous graft C. reversed saphenous graft D. Brescia-Cimino graft
B
An in situ saphenous vein graft is performed by disconnecting the proximal GSV from the common femoral vein to connect to the arterial system proximal to an obstruction. The GSV is then ligated distal to the obstruction and the distal end of the in situ graft if attached to the artery just distal to the obstruction. The valves must be removed from the graft or they will prevent arterial blood flow from moving down the leg. Retained cusps can lead to stenosis or thrombosis in the graft.
Which of the following will decrease with acute renal allograft rejection?
A. echogenicity
B. diastolic flow in the segmental arteries
C. resistive index from the arcuate arteries
D. kidney size
B
Acute renal rejection will result in an enlarged kidney with increased echogenicity of the renal cortex. Doppler evaluation will demonstrate increased resistance in the parenchymal arteries and increased resistive index. This will decrease the amount of diastolic flow in the cortical arteries.
Where is the most common location for the surgeon to place a renal allograft? A. 2-4cm below the umbilicus B. right iliac fossa C. left iliac fossa D. 2-4cm above the urinary bladder
B
The right iliac fossa is the most common site for placement of a renal allograft.
Which of the following is a common occurrence after an endarterectomy? A. neointimal hyperplasia B. congestive heart failure C. intracranial hemorrhage D. intimal dissection
A
Neointimal hyperplasia refers to the overgrowth of normal tissue in response to the endarterectomy. This is a common cause of re-stenosis of a vessel that previously underwent endarterectomy.
Which of the following techniques is used to monitor flow during a fem-pop bypass procedure? A. duplex ultrasound B. pulse volume recording C. segmental pressures D. B mode ultrasound
A
Segmental pressures and PVR exams require the use of pressure cuffs that cannot be used during the surgery. AFTER the surgery would be fine. Intraoperative duplex ultrasound can be used during the procedure to assess flow.
Which of the following patients would benefit from intraoperative TCD monitoring of the left MCA? A. right carotid endarterectomy B. left IJV thrombosis C. left carotid endarterectomy D. right ICA stent placement
C
Flow from the left ICA enters the left MCA. If a piece of plaque breaks off during the endarterectomy and escapes into the ICA, it can cause stroke symptoms. Monitoring is used to detect emboli.
A fem-fem graft is used to treat: A. unilateral femoral stenosis B. bilateral popliteal stenosis C. unilateral iliac stenosis D. bilateral iliac stenosis
C
A fem - fem graft can be used to correct unilateral iliac stenosis. Blood is passed from the patent femoral artery through the graft to the contralateral femoral artery at a point distal to the stenosis.
Color Doppler evaluation of an aortic endograft:
A. can be limited by twinkle artifact and color flash artifact
B. should be performed with increased wall filter and velocity scale settings with reduced color priority
C. is the most accurate method for diagnosis of an endoleak
D. cannot be performed on patients who are less than 3 months post-op due to the risk of cavitation and graft migration
A
Calcification in the aortic wall can cause twinkle artifact on color Doppler evaluation. Because color velocity and filter settings are set to lower levels to detect the lower velocity flow in the aorta, color flash artifact is common with patient movement and respiration. PW Doppler is necessary to confirm the diagnosis of a suspected endoleak seen on color Doppler. Follow up exams for an aortic endograft are usually performed at 1 month post-op, then at 3, 6, 9, 12 and 18 months, followed by annual assessment after the first year.
If a patient had surgery to correct an occlusion of the right external iliac vein, which of the following pathways could be used?
A. redirect flow from the right common iliac vein to the right femoral vein
B. redirect flow from the right femoral vein to the left popliteal vein
C. redirect flow from the left femoral vein to the right femoral vein
D. redirect flow from the right femoral vein to the left femoral vein
D
Blood is moving cephalad in the venous system. If the right EIV is blocked, flow can be bypassed from the right femoral vein to the left femoral vein.
The type of dialysis graft where the cephalic vein is anastomosed to the radial artery is called? A. TIPS graft B. synthetic loop graft C. straight graft D. Brescia-Cimino graft
D
The cephalic vein is anastomosed to the radial artery in a Brescia-Cimino graft. Straight Synthetic graft connects from the radial artery at wrist to an antecubital vein. Looped Synthetic graft connects from the brachial artery to antecubital vein. TIPS is a type of shunt used to bypass the liver.
Which of the following statements is true regarding Doppler flow evaluation of a rejected renal allograft?
A. rejected allograft waveforms will demonstrate high resistance flow
B. rejected allograft waveforms will demonstrate low resistance flow
C. rejected allograft waveforms will demonstrate low RI and PI values
D. renal allograft waveforms normally demonstrate arterial flow that varies with respiration
A
Doppler waveforms from arteries in a rejected allograft will demonstrate high resistance flow. The RI values for the parenchymal vessels will be elevated above 0.70.
You are performing an ultrasound on a fem-pop PTFE graft in a lower extremity and you suspect a stenosis at the distal anastomosis. How will you calculate the velocity ration in this patient?
A. divide the velocity in the native popliteal artery by the velocity in the distal graft
B. divide the velocity in the native popliteal artery by the velocity in the native femoral artery
C. divide the velocity at the distal anastomosis by the velocity in the distal graft
D. divide the velocity at the distal anastomosis by the velocity in the proximal anastomosis
C
The velocity ratio is calculated by dividing the velocity at the stenosis (distal velocity) by the velocity just proximal to the stenosis.
When evaluating a patient for placement of a hemodialysis graft, what is the minimum acceptable diameter for the native artery where the graft will be connected? A. 2mm B. 3mm C. 4mm D. 5mm
A
Hemodialysis requires native vein > 2.5mm for AVF; native artery > 2mm; native vein >4mm for synthetic graft.
A fem - tib graft is used to treat: A. unilateral distal femoral stenosis B. bilateral popliteal stenosis C. unilateral iliac stenosis D. bilateral iliac stenosis
A
A fem - tib graft can be used to correct unilateral distal femoral or popliteal stenosis.
A patient presents for evaluation of their hemodialysis graft. The proximal anastomosis demonstrates a velocity of 130cm/s. The mid graft velocity is 275cm/s and the distal anastomosis velocity is 50cm/s. What is your conclusion about the findings on the exam?
A. the venous outflow is most likely thrombosed
B. there is stenosis of the mid graft segment
C. there is stenosis of the proximal anastomosis and the mid graft segment
D. the Doppler evaluation is normal
B
Flow velocities that double between segments indicate graft stenosis. The velocity increases by more than 2X at the mid segment. The velocity at the proximal anastomosis is normal as flow within the grafts is usually high velocity.
When continuous TCD monitoring is used to assist with a carotid endarterectomy, when is the TCD device first activated to begin monitoring the patient?
A. within 24hrs after the endarterectomy was performed
B. immediately after the endarterectomy was performed but before the wound closure is performed
C. within 1-2 hours after the endarterectomy was performed
D. just before the surgery starts
D
The patients intracranial blood flow is monitored closely to identify and count any embolic signatures that may occur during the endarterectomy, and closing phase of the surgery, as well as in the recovery room.
How does the imaging protocol differ when evaluating a hemodialysis graft versus a hemodialysis fistula?
A. a graft has two anastomotic sites and the fistula only has one
B. the outflow vein must be evaluated with a graft but is not required for fistula evaluation
C. a graft has one anastomotic site and the fistula has two
D. the outflow vein must be evaluated with a fistula but is not required for graft evaluation
A
A hemodialysis graft involves a synthetic graft attached to an artery at one end and a vein at the other end. Both anastomotic sites must be evaluated in a complete exam. The hemodialysis fistula connects a native artery and vein at a single anastomotic site. The standard protocol includes evaluation of the native artery proximal to the anastomosis, the anastomotic site(s) and the outflow vein just distal to the anastomosis.
Which of the following describes the importance of the TCD monitoring during a carotid endarterectomy?
A. to evaluate the potential complication of the development of a subarachnoid hemorrhage during the procedure
B. to evaluated the presence of embolic events during the surgery to predict the risk of postoperative stroke
C. the evaluate the presence of associated atherosclerotic intracranial disease
D. to evaluate the potential complication of vasospasm caused by the development of a subarachnoid hemorrhage during the procedure
B
The exam performed to evaluate the presence of associated atherosclerotic intracranial disease should be done before the surgery is scheduled. TCD monitoring provides monitoring for emboli and can be used to evaluate collateral formation.
Which native vessel is the renal allograft artery commonly attached to?
A. SMA or IMA
B. native ipsilateral renal artery
C. aorta
D. external iliac or internal iliac artery
D
The renal allograft artery is most commonly attached to the native external iliac artery and the internal iliac artery is used as an alternative.
Which of the following is not an expected complication in a 3 week post-op liver transplant patient? A. hepatic artery atherosclerosis B. portal vein thrombosis C. biloma D. hepatic vein thrombosis
A
Atherosclerosis formation is a chronic process. Thrombosis and biloma formation are acute complications that can be seen with a recent liver transplant.
Which of the following is considered a normal finding in a patient with a brachiobasilic hemodialysis graft?
A. continuous flow in the basilic vein proximal and distal to the graft anastomosis
B. triphasic flow in the brachial artery proximal to the graft and monophasic flow in the brachial artery distal to the graft
C. increased resistance and velocity with a loss of flow in diastole in the brachial artery proximal and distal to the graft
D. dilated brachial artery proximal to the graft with low resistance monophasic flow
D
The connection between the artery and the vein will cause the resistance in the brachial artery to decrease and become monophasic. The basilic vein will exhibit pulsatile, high velocity venous flow in the area of the graft due to the arterial inflow.
A “snuffbox” fistula connects what two vessels?
A. brachial artery connects to the basilic vein in the upper arm
B. radial artery connects to the basilic vein in the forearm
C. radial artery connects to the cephalic vein in the radial fossa
D. brachial artery connects to the basilic vein at the elbow
C
The anatomical snuffbox is also called the radial fossa. It is a triangular depression on the lateral aspect of the dorsum of the hand. The radial artery, a branch of the radial nerve, and the cephalic vein are found in the snuffbox. Radial artery is connected to the cephalic vein at distal wrist. Because the artery courses directly over the vein in this location, little vessel movement is required during surgery.
Patient presents 9 months after endarterectomy with an approximate 40% recurrent stenosis. What is the most likely cause? A. neointimal hyperplasia B. polycythemia vera C. lack of Warfarin treatment post op D. fibromuscular dysplasia
A
Neointimal hyperplasia is the most common cause of re-stenosis of a vessel that has a history of the endarterectomy procedure. It can be described as thickening of the vessel wall or over-healing after the procedure. Atherosclerosis can also cause re-stenosis but takes a much longer time to reoccur in the vessel.
Which of the following vascular complications is treated with a fasciotomy? A. pseudoaneurysm B. dissection C. anterior compartment syndrome D. popliteal entrapment
C
Blood leaks into the muscle compartment of the calf causing increased pressure. If the fasciotomy is not performed to relieve the pressure, damage to the nerves and tissues can occur.
A patient presents with a radiocephalic hemodialysis fistula in the left arm. Doppler evaluation of which of the following vessels will be used to rule out steal syndrome?
A. distal inflow artery, within 2cm below the fistula
B. cephalic vein at the wrist
C. proximal inflow artery, within 2cm above the fistula
D. cephalic vein at the shoulder
A
Doppler evaluation of the inflow artery <2cm distal to the fistula is used to diagnose steal syndrome. If flow is moving retrograde in the distal radial (inflow) artery, then flow is moving toward the hand in the ulnar artery, through the palmar arch and then toward the upper arm in the radial artery. Normal flow in the radial and ulnar arteries should move toward the hand and into the palmar arch.
After an endarterectomy or carotid stent placement, the first follow up exam should be performed:
A. within one month after the procedure
B. within 5 days of the procedure
C. on the 1 year anniversary date of the procedure
D. immediately following the procedure
A
A patient that has had an endarterectomy or carotid stent placement is usually evaluated within first month following the procedure. If performed too soon after the endarterectomy or other open surgical procedure, artifacts produced by air in the patch or graft may inhibit the exam.
You are performing a carotid duplex on a patient that had a carotid endarterectomy 6 years ago. There is homogeneous material lining the ICA and bulb. The Doppler evaluation demonstrates turbulence and elevated velocities. Which of the following is the most likely cause for these findings?
A. intimal flap and dissection
B. progression of atherosclerotic disease
C. residual blockage from suboptimal surgical techniques
D. neointimal hyperplasia
B
Within the first month post-op, restenosis is attributed to suboptimal surgical techniques. Narrowing over the first 24 months after CEA is attributed to neointimal hyperplasia. After 2 years, stenosis occurs due to progression of atherosclerotic disease.
You are performing a carotid duplex on a patient that had a carotid endarterectomy 2 weeks ago. There is homogeneous material lining the ICA and bulb and Doppler demonstrates turbulence and elevated velocities. Which of the following is the most likely cause for these findings?
A. neointimal hyperplasia
B. intimal flap and dissection
C. residual blockage from suboptimal surgical techniques
D. progression of atherosclerotic disease
C
Within the first month post-op, restenosis is attributed to suboptimal surgical techniques. Narrowing over the first 24 months after CEA is attributed to neointimal hyperplasia. After 2 years, stenosis occurs due to progression of atherosclerosis disease.
In a patient with a patent brachiobasilic AV graft, the axillary vein will:
A. demonstrate a loss of spontaneous and phasic flow and will require distal augmentation to assess patentcy
B. demonstrate biphaisc flow with the majority of antegrade flow occurring during diastole
C. demonstrate high velocity pulsatile flow
D. demonstrate low velocity continuous flow
C
The basilic vein connects to the axillary vein in the upper arm/axilla. The arterial inflow into the basilic vein from the AVG will transmit a pulsatile waveform with high velocities into the axillary vein.
Which of the following is a normal finding when evaluating a hemodialysis graft? A. aneurysm B. thrombosis C. arteriovenous fistula D. pseudoaneurysm
C
A hemodialysis graft is the surgical creation of an AV fistula (connection of an artery and vein). Complications of a hemodialysis graft include thrombosis of the graft, stenosis/occlusion, aneurysm of the graft, pseudoaneurysm caused by needle puncture for dialysis, CHF due to increased flow in venous return to heat, a and distal ischemia.
The most common cause of hemodialysis graft failure is \_\_\_\_\_\_\_\_\_\_. A. acute rejection B. anastomosis rupture C. thrombosis formation D. arterial stenosis
C
The most common cause of hemodialysis graft failure is thrombus formation.
