Vascular Flashcards
1
Q
What are the structures within the carotid sheath?
A
carotid artery, internal jugular vein, vagus nerve
2
Q
What are the segments of the vertebral arteries?
A
- V1: origin off subclavian to foramina of C6
- V2: foraminal from C6-C2
- V3: foramen of C2 to dura
- V4: intra-cranial
3
Q
What structure overlies the bifurcation of the carotid?
A
the facial vein off the IJ
4
Q
What is the first branch of the external carotid?
A
the superior thyroid artery
5
Q
How does the flow of the internal and external carotids differ?
A
- internal is low resistance with biphasic, forward flow
- external is high resistance with triphasic flow and brief flow reversal
6
Q
Can the external carotid be ligated?
A
yes
7
Q
What is the first branch of the internal carotid?
A
the ophthalmic artery
8
Q
What likely happened if a patient is hoarse after carotid endarterectomy?
A
likely clamped the vagus along with the carotid and injured the nerve
9
Q
What likely happened if a patient has tongue deviation after carotid endarterectomy?
A
ipsilateral deviation is a sign of hypoglossal nerve injury, it lies just cephalic to the carotid bifurcation so can easily be damaged
10
Q
What likely happened if a patient has mouth droop after carotid endarterectomy?
A
likely caused a marginal mandibular injury from retraction on the mandible while repairing a high lesion
11
Q
What nerves run near the carotid artery bifurcation?
A
the vagus nerve is within the sheath, the hypoglossal runs just cephalad to the bifurcation and the glossopharyngeal nerve runs cephalad to that
12
Q
Describe the course of the glossopharyngeal nerve. Damage results in what?
A
- deep to the posterior belly of the digastric
- damage can result in disabling dysphagia
13
Q
What layers are removed during an endarterectomy?
A
the intima and part of the media
14
Q
Where is the typical location of carotid atherosclerosis?
A
the bifurcation since there is turbulent flow
15
Q
What are the indications for performing carotid endarterectomy?
A
- symptomatic with 50-70% stenosis
- asymptomatic with > 80% stenosis (EDV > 140)
16
Q
How should you manage a patient with symptoms of carotid stenosis but < 50% stenosis on US?
A
medically with ASA, plavix, statin
17
Q
How should you manage a patient who suffers a stroke and is found to have complete occlusion of carotid?
A
medically with AC to prevent progression, no benefit to revascularization
18
Q
What is an indication for emergent carotid endarterectomy?
A
crescendo TIAs
19
Q
What is the most common non-stroke cause of morbidity and mortality following CEA?
A
MI
20
Q
When should you operate on a symptomatic carotid?
A
- within two weeks once symptoms resolved for a small stroke or TIA
- at 6-8 weeks after a hemorrhagic stroke
21
Q
What is the best next step if a patient has symptoms of stroke in PACU after CEA?
A
suggestive of intimal flap or thrombus requiring RTOR, start with US
22
Q
When would you consider carotid stenting rather than endarterectomy?
A
- those with severe cardiac disease and prohibitive peri-operative risk
- those with a history of neck dissection or radiation
- those with recurrent carotid disease
23
Q
Which carotid revascularization option has the lowest stroke rate?
A
TCAR (transcarotid artery revascularization)
24
Q
How should an asymptomatic blunt trauma carotid dissection be treated?
A
- start anticoagulation/anti-platelet with either heparin or plavix
- repeat imaging prior to d/c
25
How should a symptomatic blunt trauma carotid dissection be treated?
likely needs a covered stent
26
How are carotid body tumors managed?
- all require resection
- consider embolization pre-op given risk of bleeding
27
Name the structures of the thoracic outlet from anterior to posterior.
- subclavian vein
- phrenic nerve
- anterior scalene
- subclavian artery
- brachial plexus
- middle scalene
- first rib
28
What anatomic anomaly puts patients at risk for thoracic outlet syndrome?
a cervical rib
29
What type of thoracic outlet syndrome is most common and what are the symptoms?
- most commonly neurogenic
- presents with pain, weakness, numbness, and ulnar deviation of the hand worse with elevation of the arm
30
How is neurogenic thoracic outlet syndrome treated?
- physical therapy is first line
- if this fails, get a scalene nerve block or conduction test to confirm the diagnosis
- then consider first rib resection and scalenectomy with neurolysis
31
A swimmer presents with a blue swollen arm, what is this and how is it managed?
- subclavian vein thrombosis (aka Paget-Schroetter syndrome)
- treat with catheter directed thrombolysis followed by first rib resection
32
How is arterial thoracic outlet syndrome treated?
- usually an anomalous cervical rib leading to aneurysm of subclavian
- treatment is first rib resection with interposition graft
33
What is subclavian steal?
a proximal subclavian narrowing results in flow reversal in the vertebral artery which can lead to vertebrobasilar symptoms
34
How is subclavian steal syndrome treated?
with endovascular recanalization and stenting or potentially a carotid-subclavian bypass
35
Why are tunneled HD catheters worse than an AVF/AVG?
because they have a higher infection rate and a higher risk of central venous stenosis
36
How long should a temporary HD catheter be left in?
less than 3 weeks
37
What is the ideal location for an HD catheter?
in the R IJ where flow to the right atrium is more direct
38
Why should an HD catheter be placed on the opposite side as a planned AVF?
because it will lead to central venous stenosis and failure of permanent access
39
What is the most common reason for AVF failure?
venous outflow problems
40
How is AVF venous outflow stenosis treated?
with balloon angioplasty
41
What is the problem if a patient has high venous return pressures and increased bleeding after dialysis?
this is venous outflow stenosis
42
What is the rule of 6s for fistulas?
ready to use when 6mm in diameter, < 6mm deep, and with > 600mL/min of flow
43
How long should it take for an AVF to mature?
- less than 6 weeks
- more than this and you should investigate
- likely an inflow problem with stenosis at anastomosis or competing flow from side branches
44
What is the indication for prophylactic fasciotomies?
acute limb ischemia > 4 hours
45
What nerve can be injured when making a lateral fasciotomy incision?
the superficial perineal nerve leading to difficulties with foot eversion and numbness over the lateral leg
46
How do you release the deep posterior compartment of the lower extremity during fasciotomies?
take the soles off the tibia
47
Where are most thoracic aortic injuries located?
just distal to the subclavian artery in the descending artery at the ligament arteriosum
48
What are the size criteria for treating descending thoracic aortic aneurysms?
- greater than 5.5cm if endovascular repair is possible
- greater than 6.5cm if open
49
What is the risk of paraplegia with thoracic aortic repair?
- 20% for open
- less than 5% for endovascular
50
What steps are taken to reduce the risk of paraplegia after a thoracic aortic repair?
- endovascular approach
- lumbar drains (lower the spinal drain to reduce ICP and increase spinal perfusion pressure)
- maintain normo to hypertension
51
What are the four types of acute mesenteric ischemia?
- embolic
- thrombotic
- venous thrombosis
- non-occlusive
52
What is the best test to diagnose mesenteric ischemia?
CT angio
53
How does the distribution of embolic and thrombotic mesenteric ischemia differ?
embolic has skip lesions since it affects distal branches whereas thrombotic is more likely to occur at the ostium/takeoff
54
Which is more likely to require bypass, those with embolic or thrombotic acute mesenteric ischemia?
those with thrombotic
55
How do you identify the SMA?
- lift the transverse colon cephalad
- go to the base of the mesocolon
- the SMA will be just to the right of Treitz
56
What are the features of mesenteric venous thrombosis?
- sub-acute presentation with days of pain and bloody diarrhea
- usually have a history of hypercoagulability
- CTA shows wall thickening, mesenteric edema, and venous thrombus
57
How does the treatment of venous thrombus mesenteric ischemia differ from that of inflow problems?
venous thrombus rarely requires surgery, just need heparin and operative intervention for dead bowel
58
What are the watershed areas of the bowel that are most threatened by non-obstructive mesenteric ischemia?
the splenic flexure and superior rectum
59
Does thrombotic and embolic mesenteric ischemia spare the jejunum?
embolic since it usually lodges distal to the first branch of the SMA
60
What is the most common site of upper extremity embolus?
brachial artery bifurcation
61
What is the most common site for a lower extremity embolism to lodge?
the CFA bifurcation
62
Where should you get proximal control for an emergent AAA rupture repair?
the supra celiac aorta
63
What is the BP goal for a ruptured AAA pre-operatively?
permissive hypotension with SBP 80-100
64
What is the most common organism for vascular graft infection?
Staph epidemidis
65
What is the treatment for popliteal entrapment syndrome?
resect the medial head of the gastrocnemius
66
How is fibromusuclar dysplasia treated?
usually with balloon angioplasty of the affected vessels
67
What are the indications for hepatic/SMA aneurysm interventions?
resect if > 2cm
68
What is the size criteria for treating iliac artery aneurysms?
stent if > 3.5 cm
69
What is the size criteria for treating femoral artery aneurysms?
resect if > 3.5cm
70
What is the usual complication of a femoral artery aneurysm?
embolus or thrombus (unlikely to rupture)
71
What is the size criteria for treating popliteal artery aneurysms?
treat if > 2cm or symptomatic
72
If a patient is found to have a popliteal artery aneurysm, what other screening do they need?
work up for possible AAA
73
What is the size criteria for treating the following:
- TAA
- AAA
- iliac
- femoral
- popliteal
- TAA: >5.5 cm if endovascular or > 6.5 cm if open
- AAA: > 5.5 cm in males, > 5.0 cm in females, > 1cm growth/year, symptomatic, infected
- iliac: > 3.5 cm
- femoral: > 3.5cm
- popliteal: > 2cm or symptomatic
74
What is the size criteria for treating AAAs?
- greater than 5.5 cm for males
- greater than 5.0 cm for females
- more than 1.0 cm growth/year
- symptomatic or infected
75
What is the preferred method for treating popliteal artery aneurysms?
open repair with venous interposition graft or bypass
76
What vein is at risk for injury in an open AAA repair when getting proximal control?
the left renal vein
77
How is chylous ascites treated?
a low-fat, high protein diet with medium-chain fatty acid supplementation
78
What is the best next step if a patient develops abdominal pain and bloody diarrhea after a AAA repair? How is this managed?
- sigmoidoscopy to evaluate for colonic ischemia
- can usually manage non-op with antibiotics, IVF, and serial abdominal exams
79
What is the appropriate interval for surveillance imaging for AAA?
- get an annual US if < 4.0 cm
- get an US every 6 months if > 4
80
What is the preferred treatment for an infrarenal aortic graft infection?
bilateral axillary to femoral bypass with aortic graft excision
81
What are the anatomic criteria for EVAR?
- neck less than 32mm
- neck angle less than 60 degrees
- neck length of at least 10mm
- iliac diameters of at least 7mm
- lack of thrombus or calcification in infrarenal neck
82
What are the types of endoleaks and their treatments?
- type I: poor seal at either end, requires repair with placement of a cuff
- type II: back flow into sac, only needs repair if it grows and can do so with coil embolization
- type III: components of endograft aren't sealed, requires re-inforcement with bridge across connection
- type IV: porosity of graft, may need to re-line
83
How is ABI calculated?
take the highest pedal pressure (DP/PT) and divide by the highest brachial pressure (L/R)
84
What is a normal ABI?
0.9 - 1.4
85
At what ABI will you see claudication, rest pain, and tissue loss?
- claudication: 0.5-0.9
- rest pain: 0.3-0.5
- tissue loss: less than 0.3
86
What is the value of a toe-brachial index?
these vessels are generally free from calcification and more reliable in patients with non-compressible, calcified vessels
87
What are the mainstays for medical treatment of claudication?
smoking cessation, exercise, statin therapy
88
What are the indications for surgical intervention in someone with claudication?
- lifestyle limitation that failed to improve with medical management
- tissue loss
- rest pain
89
Why is conventional angiography better in some cases than a CTA?
- angiography allows for visualization of more distal vessels
- angiography can use less contrast and even CO2 if renal function is very poor
90
Generally, endovascular revascularization is better than open under what circumstances?
short lesions that are not heavily calcified
91
Why is the CFA usually treated in an open fashion?
because it is in a highly mobile area and endovascular fixes are likely to kink
92
What is Leriche syndrome?
a syndrome of buttock claudication, impotence, and absent femoral pulses that arises due to thrombotic disease of the distal aorta
93
How does the treatment differ for a thrombus versus an embolus in the distal aorta?
- embolus: amenable to embolectomy
- thrombus: usually requires bilateral aorta-femoral bypass
94
Where do the arteries of the lower extremity run?
- the AT is in the anterior compartment
- the PT and peroneal are in the deep posterior
95
Which renal vein can you ligate?
the left if proximal to the the gonadal vein
96
What is the most common location of a DVT?
- iliofemoral DVTs are most common
- with a preponderance for the left
97
A provoked DVT should be treated with what duration of anti-coagulation?
three months
98
How long should a DVT be treated in someone with cancer?
until they are cured
99
How is the supra celiac artery exposed in a trauma patient?
enter the lesser sac through the gastrohepatic ligament, divide the posterior crus of the diaphgram
100
What is the biggest risk factor for ischemic colitis in a patient with ruptured aneurysm?
pre-operative hypotension
101
What is the most common organism found in mycotic aneurysms?
Staphylococcus
