NMS Vascular Flashcards
definition of TIA, how do you manage it
transient neuro findings < 24 h usually 2/2 embolus from carotid bifurcation;
mgmt: need to do duplex u/s of carotids, followed by carotid endarterectomy if >70% stenosis; may need echo if heart murmur
when is Carotid endarterectomy indicated
if > 70% stenosis in symptomatic patient; in asymptomatic patient, less well-defined; definitely carotid endarterectomy if >80% stenosis, maybe if >60% stenosis
what precautions needed to prevent stroke during carotid endarterectomy procedure
intraop EEG monitoring , bp control
what possible complications with carotid endarterectomy (3)
1) hypoglossal nerve injury
2) mandibular branch of facial nerve injury
3) vagus nerve injury
tx of amaurosis fugax
same as carotid endarterectomy: carotid duplex –> carotid endarterectomy if >70% stenosis
what to do if amaurosis fugax or TIA with PERSISTENT neuro findings (ie, stroke)
OBSERVE for 2-4 wks, then carotid endarterectomy when stable
what are 6 P’s of acute arterial occlusion
Pain Pallor Pulselessness Poikilothermia Paralysis* Paresthesias* (these last 2 steps happen first; nerves most sensitive to anoxia)
how does acute arterial occlusion happen? how do you tx it
embolus from heart (70%) or artery/aneurysm (30%); treatment is revascularization in OR for balloon catheter embolectomy
what is dangerous finding postop with balloon catheter embolectomy for acute arterial occlusion
COMPARTMENT SYNDROME resulting from ischemia-reperfusion injury –> edema
what are 3 classifications of acute arterial occlusion? how do you know if limb is not salvagable
1) viable
2) threatened
3) irreversible (no dopplerable venous pulses, paralyzed, insensate)
what is most common site of acute arterial occlusion
lower extremity, specifically common femoral artery
how do you work up intermittent claudication
look for ulcers, skin changes, neuro deficits; TESTS include ABI (ankle brachial index, determines severity) and DOPPLER waveforms (normally triphasic)
most common site and findings with intermittent claudication
superficial femoral artery at adductor hiatus –> loss of popliteal and pedal pulses
when to do angiogram in claudication
ONLY as preop test (ie if you dont plan to operate, dont do an angiogram)
what is normal ABI
> 1 ( i saw >0.9, but >1.2 can be pathologic/sign of severe hardened arteries 2/2 atherosclerosis)
how to treat patients with intermittent claudication
operate only if grossly disturbing patients lifestyle; if with activity and mildly aggravating, treatment is EXERCISE + lifestyle modification
what does claudication + absent femoral pulses suggest? how does that change mgmt
suggests AORTOILIAC DISEASE; more progressive than distal disease, so SURGERY should be considered if symptoms progress
what are the tx options for aortoiliac dz? when do you pursue each (2)
1) BYPASS: if multiple or long segments of disease
2) PTA (angioplasty): if single, short segment
how do you work up pt with PVD and ULCER? when to tx? what options
key is adequacy of blood supply; if SBP > 65 (or 90 in DM), supply should be adequate for healing; if NOT, tx surgically; ANGIOGRAM to define anatomy (remember this is preop test) –> graft vs. angioplasty/stent
what longterm tx do most pts with PVD receive
ASA
what is a “trash foot” (complication of PVD repair)? how is it managed
ischemic digit 2/2 atheroembolization –> blue, painful toe; TREATMENT is heparin and long term antiplatelet therapy
what major risk associated with surgery in pt with vascular disease? how to work up preop
CARDIAC dz often a/w vascular dz (MI risk during op) –> need CARDIAC WORKUP: stress test/thallium –> angiogram if positive treat with CABG/PTCA if dz; if testing negative, do operation with intraop monitoring if pt has other risk factors (sick, old)
mgmt of AAA
elective repair if > 5 cm; observe if < 5 cm
three big complications associated with AAA repair
1) ISCHEMIC BOWEL: presents with diarrhea +/- blood in first 3d, 2/2 sigmoid ischemia from IMA occlusion
2) VASCULAR GRAFT INFECTION: from graft seeding with skin flora, but may not present for months-years
3) AORTOENTERIC FISTULA: grossly bloody stool, usually from fistula between aorta and duodenum
treatment of three big complications of AAA repair
1) ISCHEMIC BOWEL: need sigmoidoscopy to determine depth of ischemia; if superficial treat with bowel rest; full thickness, resect + colostomy
2) VASCULAR GRAFT REPAIR: remove graft, debride tissue, extra anatomic bypass, long-term abx
3) AORTOENTERIC FISTULA: 3 steps:
I) remove graft
II) repair GI
III) extra anatomic aortic graft
Presentation, workup and tx of chronic mesenteric ischemia
PRESENTS: with post-prandial pain and resultant weight loss; WORKUP: with angiogram (b/c of intent to operate); TREAT: with surgical bypass (aorta –> vessel)
types of aortic dissection and management (3)
TYPE 1: ascending only (OPERATE)
TYPE 2: ascending + descending (OPERATE)
TYPE 3: descending only (MED MGMT); control htn with all types
tx for DVT? how long
anticoagulation (heparin –> warfarin) x 3-6 m
what is low dose heparin (LDH) therapy
prophylactic heparin for high risk pts: 5000 U subq heparin q8-12 hrs post-op
ABG findings in PE
decreased PCO2 due to hyperventilation
what is tx of PE
SAME AS DVT (anticoagulation x 3-6m)
what is phlegmasia cerulea dolens? how to tx
acute obstruction of venous outflow –> DANGEROUS (can cause sensorimotor loss and eventually gangrene) –> URGENT TX (anticoagulation, leg elevation); VENOUS THROMBECTOMY RARELY INDICATED
if TIA untreated what are chances of recurrences
40% chance of another TIA or stroke in 2 yrs
tests to eval TIA
carotid bruits, neuro exam, murmurs, echocardiogram, Duplex ultrasound of carotids
what % stenosis of carotids does better with surgery
70% stenosis 3x more effective than aspirin in preventing strokes
additional preop for carotid endarterectomy
bp control, cardiac eval
perioperative risk for major stroke for carotid endarterectomy
1-3%
nerves to avoid during carotid endarterectomy
hypoglossal, vagus, marginal branch of facial nerve
what imaging do you do to make sure carotid endarterectomy is perfect
on table angiogram or duplex ultrasound
what is risk % for carotid narrowing on operated side
13% over 5 years
what drug to take post op for carotid endarterectomy
asa
what are carotid endarterectomy pts most likely to die from
MI bc TIA is a sign of atherosclerosis. should take up exercise regimen, lifestyle changes, lipid control
name of ophthalmic finding with amaurosis fugax
Hollenhorst Plaque
what eval do you do if a person has a stroke and it’s not a TIA
carotid duplex, observation for improvement, operate after patient stable; usually 2-4 weeks post stroke or when neuro status stabilizes
at what % carotid stenosis should asymptomatic pts get surgery ?
65%; in a 2 yr period, 2.5% of pts had stroke compared to 11% of ASA pts.
6 Ps for acute arterial occlusion of extremity
pain, pallor, paresthesia, paralysis, pulselessness, poikilothermia
when do you operate on acute occlusion of leg? what do you give them immediately
ASAP. within 6 hrs. give heparin
what is surgical procedure for acute occlusion
Fogarty catheter embolectomy (balloon catheter)
complications of acute reperfusion
compartment syndrome
at what pressure can compartment syndrome get dangerous
20-40 mm Hg: ischemic injury of muscles and nerves
3 most common sites for lower limb embolus
femoral, then iliac, then aortic saddle, then popliteal
long term care for post fasciotomy
coumadin, ECHO, CT to search for embolic source
2 common causes for acute arterial ischemia
- femoral arterial puncture: raise intimal flaps, dislodge emboli, cause local thrombosis
- aortic dissection where false lumen extends to femoral artery
workup for claudication
pulses, bruits, thrills, skin exam for ulcerations, sensory and motor function exam, dependent rubor, history of DM, cardiovascular dz
where in superficial femoral artery is there most likely to be occlusion
at adductor hiatus
if you dont get pulses in some places, what test do you do
ABI with Doppler tracing
what are worrisome signs with claudication
rest pain, ischemic ulceration
what are ranges of normal and abnormal ABI values
normal: 0.9-1.1
mild claudication: 0.6-0.8
severe claudication: < 0.3
in what type of patients can ABI be artificially high
diabetics (bc they have calcified vessels)
what happens to Doppler waveforms with claudication
triphasic –> biphasic –> monophasic
why wouldn’t you operate on claudication
risk-benefit. dangers of arteriogram, possibility of thrombosis, infection, amputation, unfavorable medical condition such as CAD. exercise seems to help
how many claudicators get better
1/3 get better, 1/3 same, 1/3 deteriorate
why would you operate quicker on aortoiliac dz than just a plain old claudication
progresses faster!
how can you tell if a diabetic foot ulcer is likely to heal or not
ankle systolic BPs in torr; nondiabetics probable healing 55-65. diabetics probable healing 80-90.
why would we do non-preop arteriogram for diabetics with claudication
bc it changes our strategy for operation or not
which arteries are given preference when doing femorodistal bypass
popliteal, anterior and posterior tibial, then peroneal (fibular artery)
what f/u procedures after a bypass
frequent duplex of graft for patency, ASA, lipid control, foot care
what is Leriche syndrome
aortoiliac dz; claudication + atrophy + impotence (occlusion of internal iliac that gives rise to pudendal)
treatment for short segment iliac stenosis
percutaneous transluminal angioplasty
surgery for b/l aortoiliac dz
aortobifemoral bypass. if at risk for complications or poor general health, ax-fem-fem may be better
–> i dont fully know what this is?
surgery for unilateral aortoiliac dz
fem-fem
what part of aortobifem bypass graft surgery has greatest risk?
anesthesia induction and during hemorrhage/stress; during clamping: high afterload, must manage bp; during unclamping sudden decrease of afterload possible hypotension and decreased CO.
Unclamping flushes blood from lower body that could have become acidotic and hyperkalemic, causing arrhythmia
what is trash foot
microvessel occlusion following revascularization from fibrin, platelets, atherosclerotic debris that travels down to toes. with good pulses, it should heal!
post op for aortoiliac dz
heparin bridge to coumadin, assess toes for necrosis, watch for evidence of infection, ASA
cardiac morbidity perioperatively in major vessel reconstruction
up to 10%
cardiac mortality post operatively in major vessel reconsturction
2-3%
substance used for stress echo
regadenosone or dobutamine
how to use Eagle’s criteria
for prediction of perioperative cardiac morbidity:
age>70, angina, diabetes, DTS redistribution, ventricular arrhythmia, Q waves on EKG.
0 risk factors: 3% risk of MI. operate
1-2 risk factors: 15% risk of MI. do DTS testing.
3 risk factors: 50% risk of MI. do coronary angiography and revascularize heart if necessary.
DTS= dipyrimadole thallium scanning (scintigraphy; imaging with radioisotopes)
AAA imaging modalities
US or CT
AAA more common in who
4:1 males, 11x first degree relatives, 50% pts with popliteal aneurysms
When should AAA be repaired
> 0.5 cm growth per year or > 5 cm in size
Post-op complications of AAA
- third spacing of fluids. increase fluid requirements
2. third day mobilization of fluids, need diuresis and fluid restriction or else pulmonary edema
why might a AAA pt get impotence after surgery
damage to hypogastric circulation or autonomic nerves on anterior surface of aorta near IMA
what % ruptured AAA die
more than half
What are 5 yr rupture rates for AAA
7 cm: 95%
should the ER resuscitate fluids in ruptured AAA
no, do it after you’ve clamped the aorta in the OR
complications of aortic replacement
- ischemic colitis in rectosigmoid due to interruption of IMA flow: do sigmoidoscopy, bowel rest, NPO, GI decompression, abx, frequent reexamination, fill thickness involvement requires resection and colostomy;
- vascular graft infection due to S.epidermidis or S.aureus; remove, debride, do extra anatomic bypass, long term abx
- upper GI bleed from aortoenteric fistula in 3rd or 4th part of duodenum. remove, repair, GI tract, extraanatomic bypass
how to manage mesenteric ischemia
mesenteric angiogram, bypass graft from aorta to distal obstruction, could be obstruction of celiac axis or SMA (usually)
symptoms of aortic dissection
tearing chest pain, back pain, severe htn, tachycardia, diaphoresis
imaging for aortic dissection
TEE, MRI, CT, arteriography
Types of dissections and treatments
Type A: ascending involvement. operate
Type B: descending only. BP control with beta blockers.
sx of lower extremity DVT
pain with movement esp dorsiflexion (Homan’s sign), leg swelling, palpable cord (thrombosed superficial vein)
how to dx a DVT
Duplex ultrasound
how to treat DVT
Heparin 70-100 U/kg bolus then maintenance of 15-25 U/kg/hr for 5-7 days. bridge to warfarin within first few days, continue 3-6 months.
heparin mxn
activates antithrombin which inactivates II, VII, IX, X
goals of heparin tx for DVT
PTT 1.5 to 2x normal and INR 2-3, follow platelet counts for HIT
why do we bridge to coumadin
because warfarin inhibits protein C and S synthesis, a relatively hypercoagulable state. gotta wait till the effects kick in.
what is post-thrombotic syndrome and how do we treat
after DVT treatment: 10% get edema, skin ulceration, venous claudication for chronic venous HTN. treat with support hose
Virchow triad
venous stasis, hypercoagulable state, endothelial injury
some dvt risk factors
over 40, recent surgery, obesity, smoking, previous hx, cancer, PV, MM, MI, CHF, COPD, pregnancy, DIC, HIT, SLE
what is preventive heparin
5000 U subQ preop and every 8-12 hours postop until ambulatory. dont forget to raise legs and give pneumatic compression devices.
workup for suspected PE
abg, ekg, cxr, pulse ox, v/q scan, CT if necessary (CTA), DVT hx
how to treat PE
same as treating DVT. heparin bolus and drip and bridge to coumadin
how to treat recurrent PE
IVC filter with heparin failure or complications such as HIT
what to do if someone has GI bleeding with heparin
d/c, put in IVC (greefield) filter, antiulcer tx
suspected dx with severe DVT and advanced pelvic ca? tx?
Phlegmasia Cerulea Dolens.
acute interruption of venous outflow due to malignancy. anticoagulate and elevate leg. duplex and CT afterward
