Vascular Flashcards
Location of superficial peroneal nerve
lies within the septum of anterior and lateral compartment of lower leg
function of superficial peroneal nerve
sensation to dorsum of foot, except for first web space
Young female patient presents with unilateral lower extremity swelling, discoloration and paresthesias. What does she have
Phlegmasia Cerulean Dolens, likely has extensive DVT
when can you use catheter directed thrombolysis in limb ischemia?
when it is chronic or sub-acute (i.e. without limb threatening ischemic symptoms)
location of great saphenous vein compared to common femoral vein
superficial and medial on US
Recommendation for AAA screening per vascular surgery guidelines
one time US for men 65-75 with history of smoking
landmarks used to place a subclavian line
sternal notch
deltopectoral groove
at midclavicular line
most likely artery to remain patent in diabetic vasculopath, lower leg
Peroneal artery
- secondary to deep anatomic location
when planning a bypass to a peroneal artery, what must you ensure
The tibioperitoneal trunk is patent
Initial treatment for venous mesenteric ischemia, in a stable patient without peritonitis
anticoagulation
what ABI would be considered a contraindication to compression therapy for venous hypertension?
< 0.7
what constitutes telangiectasisas
venous structures with diameter < 3 mm
treatment for telangiectasias
sclerotherapy injection into feeding vein (reticular vein)
what kind of block would you do for an upper extremity AVF
- supraclavicular block into brachial plexus
what growth rate would warrant surgical intervention on a AAA
0.5 cm of growth in 6 months
OR
1 cm of growth in 1 year
what symptoms would warrant surgical repair of AAA
- back or abdominal pain, not explained by another cause
- embolic phenomenon
- rupture
what is the classic pattern of injury secondary to acute mesenteric ischemia?
- ischemic bowel from distal jejunum to transverse colon
most common site of peripheral arterial emboli
at bifurcations
How do you test for popliteal arterial entrapment
- active ankle plantar flexion
- passive ankle dorsiflexion
what is the preferred approach for fibromuscular dysplasia of the carotid artery
balloon angioplasty
Grade 1 blunt aortic injury
intimal tear
Grade II blunt aortic injury
intramural hematoma
Grade III blunt aortic injury
pseudo-aneurysm
Grade IV blunt aortic injury
rupture
Which blunt aortic injuries can be safely observed with proper pharmacotherapy
Grades I and II
smokers develop PDA in what artery preferentially
Superficial femoral artery
diabetic patients develop PAD in what artery preferentially
infrapopliteal arteries
what is a fundamental principle of popliteal artery aneurysm repair
typically treated with a bypass to a patent runoff vessel identified with angiography
for a patient in ESRD what kind of long term anti-coagulation should you use?
Warfarin
first sign of compartment syndrome?
pain
what study would you use to confirm the presence of a pseudo aneurysm
arterial duplex
when performing decompression of the thigh, which compartment can be omitted?
medial compartment
where can the below-knee popliteal artery be found on cut down?
- cut down on medial lower leg
- expose medial head of gastroc and retract posteriorly
- popliteal artery will be located in deep posterior compartment posterior to tibia
you are performing a cut down on the below-knee popliteal artery, how would you expose the proximal tibioperoneal trunk?
divide the soleus muscle
what nerve do you need to ligate during an above-the-knee amputation?
sciatic nerve
why do you ligate nerves during amputations
- prevent neuroma formation
- prevent neuropathic pain post-op
which renal artery is more amenable to a retroperitoneal approach when repairing in conjunction with a AAA
left renal artery
why isn’t the right renal artery easily accessible from a retroperitoneal approach
IVC is on top of it
what is required for all blunt cerebrovascular injuries
anticoagulation to reduce risk of embolic events
man s/p AAA repair now with leukocytosis, lower abdominal pain, and some bloody stools. What is likely going on
possible colonic ischemia
patient should get a sigmoidoscopy to check
at what size would you electively repair a popliteal aneurysm
2 cm
how do you treat a popliteal aneurysm
its treated with a bypass, ideally an autograft from the contralateral saphenous vein
what nerve is located posterior to the common carotid artery
Vagus nerve
what does injury of the Vagus nerve, during a CEA, lead to?
ipsilateral vocal cord paralysis
what is the surgical approach for a left subclavian artery injury
left anterolateral thoracotomy
avoid a trap door incision because of the morbidity associated with that surgical approach
what US characteristic reliably distinguishes the internal jugular vein from the carotid artery
Waveform with respiratory variation on spectral analysis
indications for repairing an SFA aneurysm
- size > 3 cm
- sxs (pain, ischemia)
- intraluminal thrombus
- saccular morphology
what it the main reason autogenous AVFs don’t mature
venous outflow obstruction, usually from stenosis
what is the treatment of choice for fibromuscular dysplasia
angioplasty is typically sufficient
At what size would you intervene on a hepatic artery aneurysm
2 cm or larger
what 3 US findings would suggest renal artery stenosis?
- flow velocity ratio > 3.5 (renal artery/aorta)
- flow > 180 m/s
- narrowing > 50%
how should you treat greater saphenous vein thrombosis
Fondaparinux (ppx dose of 2.5 mg/day)
- trying to prevent a DVT from developing
if you have embolic ischemia in a leg, where does the emboli usually lodge itself
at bifurcation sites
aortic bifurcation
femoral bifurcation
popliteal bifurcation
What differentiates Class IIa from Class IIb ischemia? (Rutherford classification)
- Class IIa: threatened limb with minimal sensory loss (toes) NO motor loss
- Class IIb: threatened limb with BOTH sensory loss (more than toes) and motor dysfunction (but not profound)
acute limb ischemia with sensory loss at toes and no motor dysfunction = what class of acute limb ischemia?
Class IIa
acute limb ischemia with sensory loss above toes and mild motor dysfunction = what class of acute limb ischemia?
Class IIb
what is the increase in energy requirement after a BKA
increase of 10-40% percent to ambulate
what are the two agents approved by the FDA for sclerotherapy in vascular surgery
- Polidocanol
- Sodium tetradecyl sulfate
after a right sided carotid endarterectomy patient presents in follow up clinic with right tongue deviation, what nerve was injured?
ipsilateral hypoglossal nerve
you are dissecting down to the profunda artery and notice dark blood. What have you hit?
lateral femoral circumflex vein
chronic wounds are arrested at what phase of wound healing
inflammatory
When performing extra-anatomical bypass to the femoral arteries, which vessel is preferred as the inflow vessel and why?
- Right axillary artery
keeps away from left flank to allow for retroperitoneal approach in the future
laterally located venous ulcers are connected to what larger drainage vessel
small saphenous vein
medially located venous ulcers are connected to what larger drainage vessel
great saphenous vein
Segment V1 of vertebral artery
origin to foramen of C6
Segment V2 of vertebral artery
transverse foramen of C6 to transverse foramen of C2
Segment V3 of vertebral artery
Transverse foramen of C2 to dura
Segment V4 of vertebral artery
Dura to confluence at basilar artery
When performing an Above-knee amputation, which nerve should you identify and ligate
Sciatic nerve (within the posterior thigh)
what is the current minimum diameter of the iliac artery to accommodate a fenestrated device for a AAA repair?
7.5 mm
which vascular graft material has been associated with degenerative pseudoaneursym
Dacron grafts
Argatroban
synthetic direct thrombin inhibitor
mechanism of action for Argatroban
binds reversibly to activation site of thrombin
Mechanism of action for heparin
binds to antithrombin and inhibits the effects of downstream enzymes of the clotting cascade
Main Targets of antithrombin
Factor IIa (thrombin)
Factor Xa
Another name for enoxaparin
low molecular weight heparin
AKA: lovenox
how does enoxaparin differ from heparin mechanistically
it is a smaller molecule and therefore when it binds to antithrombin it cannot also bind to thrombin as effectively as heparin can
enoxaparin has a greater inhibitory effect on Factor Xa than thrombin
Mechanism of action of Apixaban
direct Factor Xa inhibitor
Pradaxa is what drug?
dabigatran
eliquis is what drug?
apixaban
Protamine use
reversal of unfractionated heparin
how does protamine work
forms a salt aggregate with unfractionated heparin
What is the technical name for the colloquial “heparin”
unfractionated heparin
what muscle is involved in popliteal artery entrapment
gastrocnemius
You identify a patient with popliteal aneurysm thrombosis and lack of flow distally, what Rutherford class is this?
IIA - limb marginally threatened can be salvaged
Next step - patient with pain for 3 hours found to have popliteal aneurysm thrombosis and no distal flow
Heparinize and angiography
- patient will ultimately need a bypass of the thrombosed aneurysm but you’re trying to prevent progression of disease and also (with Angio) find a distal target for your bypass
most common reason AVFs fail to mature
venous outflow stenosis or obstruction from previous IV sites
Land marks delineating superior and inferior borders of CFA
superior: take off of superficial epigastric and circumflex iliac arteries
inferior: bifurcation into SFA and profunda
When would you do an emergent TEVAR for a type B aortic dissection?
Free rupture or malperfusion of end organs
minimum size for AVF of artery and vein
artery - 2 mm
vein - 3 mm
patient gets a brachial plexus nerve block prior to UE vascular surgery with tourniquet. He starts to complain of pain at the tourniquet…what nerve did we not account for
Intercostobrachial nerv e (T1-T2)
innervates inner upper arm and is not targeted by brachial plexus nerve block
what is more taxing Aorta-to-SMA bypass or an Iliac artery-to-SMA bypass, and why
Aorta-to-SMA, because you have to clamp the Aorta to do your bypass
What is the 30-day mortality rate for critical limb ischemia if no intervention is undertaken
60%
Why are autogenous fistulas preferred over non-autogenous grafts for HD
- lower complication rate
- better cumulative patency rates
