vascular Flashcards
mc cause of arterial stenosis and occlusion
atherosclerosis
mc sites of atherosclerotic plaques
coronary arteries, carotid bifurcation, proximal iliac arteries, and adductor canal region of distal superficial femoral arteries
difference between true and false aneurysms
true-includes dilation of all 3 layers of arterial wall;
false (pseudo)- not all 3 and secondary to trauma, infection, or disruption of an arterial bypass anastomosis
mc site of aneurysms
infrarenal aorta, iliac arteries, and popliteal arteries
most life threatening occurrence of an aneurysm
rupture
best screening test for aneurysm
US
imaging for AAA
confirmed by US then CT; +/- angiography
adv of retroperitoneal incision compared to midline abdominal incision for open surgery for AAA
ease of access to perirenal and suprarenal aorta as well as dec postop pulmonary dysfunction
operative approach for AAA
normal infrarenal aorta and distal arteries are dissected and isolated. After heparinization, the aorta is clamped and the aneurysm incised. A prosthetic graft is sewn in place and covered with the residual aneurysm sac
adv of endovascular repair of AAA
dec periop mortality, dec blod loss, shortened hospital stay, and more rapid return to normal activty
disadv of endovascular repair of AAA
need for reg f/u requiring annual abdominal us or ct, inc rate of secondary interventions to correct problems w fixation of aortic graft, leakage of blood into aortic aneurysm safe, and risk of renal dysfunction secondary to contrast agents
classic triad of AAA
back pain, hypotension, pulsatile abd mass
permissive hypotension
w rupture AAA, restrict volume resuscitation so systolic bp stays between 70-80 w monitoring of mental status and organ perfusion; it minimizes ongoing blood loss through aortic defect
immediate complications of aortic aneurysm repair
MI, renal failure, colonic ischemia, distal emboli, hemorrhage
long term complications of aortic aneurysm repair
aortic graft infx, aortoenteric fistula, and graft thrombosis
pt who experiences diarrhea postop after aortic aneurysm repair should undergo what and why
sigmoidoscopy to eval sigmoid and rectum; can be colonic ischemia from disruption of pelvic arterial collateral flow, ligation of IMA, or period hypotension
sudden upper GI bleeding (“herald bleed”) after AAA replacement w prosthetic grafts
aortoenteric fistula; best imaging is upper endoscopy
endoleak I after repair of aortic or iliac aneurysm
leak at either the proximal or distal attachment site. This is associated with a high rate of expansion and rupture, and should be repaired with either placement of an additional stent graft or replacement of the endovascular graft with an open repair
endoleak II after repair of aortic or iliac aneurysm
persistent flow into and out of the aneurysm sac from lumbar or inferior mesenteric arteries. Generally, type II endoleaks are not treated unless there is expansion of the aneurysm sac or symptoms.
endoleak III after repair of aortic or iliac aneurysm
occur from a modular disconnection between components of the stent graft or a tear in the fabric of the graft. They should be repaired when identified
endoleak IV after repair of aortic or iliac aneurysm
due to diffusion of blood and serum through the graft and generally will resolve once anticoagulation is reversed at the conclusion of the surgical procedure.
PAD is dictated by what
number and severity of occlusions, degree of collateralization, and pt’s tolerance to limitations in walking distance
between the ages of 45-65 what two arteries are more likely to become stenosed or occluded in PAD
aorta and iliac
PAD below the inguinal ligament is known as
femoropopliteal occlusive disease- usually asymp except w extensive exercise
mc site of PAD
distal superficial femoral artery (SFA) within the adductor (hunter’s) canal
PAD below popliteal trifurcation known as
tibial occlusive ds- common in pt w diabetes, end stage renal failure, and adv age
leading cause of development of symptoms of PAD
enlargement of an atherosclerotic plaque
after what % of stenosis can the artery no longer adapt its diameter leading to the dev of stenosis
40%
ischemia of the lower extremity can cause
intermittent claudication, ischemic rest pain, skin ulceration, and gangrene
claudication related to PAD and not meeting the metabolic demands to muscles during exercise result in
conversion to anaerobic metabolism and painful local metabolic acidosis
Leriche syndrome
impotence, lower ext claud, and muscle wasting of buttocks due to aortoiliac occlusion
occlusion of SFA causes claudication where
calf
what does ischemic rest pain indicate
more advanced peripheral ischemia
what is rest pain caused by and what is a temporary relief
caused by nerve ischemia of tissues that are most sensitive to hypoxia; relief by dangling legs over side of bed or walking
arterial ulceration location and presentation
toes/heel/dorsum of foot; painful; ischemic ulcers may have punched out appearance and a pale or necrotic base
location of venous ulcers
medial or lateral malleolus (“gaiter zone”)
dry vs wet gangrene
dry is mummification of digits of foot without assoc purulent drainage or cellulitis; wet is assoc w ongoing infx, malodorous w copious purulent drainage
s/sx of PAD on PE
loss of hair on distal aspect of leg, muscle atrophy, color changes in leg, and ulcers or gangrene; Buerger’s sign
Buerger’s sign
assoc w PAD; dependent rubor; foot dangled, pooling of oxygenated blood in the maximally dilated arteriolar bed distal to an arterial occlusion causes the foot to appear red; when elevated, hydrostatic pressure dec, pooled blood drains and foot becomes white
what should pts w extremity ischemia be examined w
continuous wave doppler us
normally a triphasic waveform is seen on Doppler, what is seen for proximal stenosis
biphasic waveform and as progresses will become wider and monophasic
ankle-brachial index (ABI)
comparison of the systolic blood pressure at the level of the ankle divided by the brachial arterial pressure; this ratio provides an assessment of the degree of lower extremity arterial occlusive disease, with the brachial arterial pressure used as a control
results of ABI
> 0.9 normal,
dx imaging for pt w severe lifestyle limiting claudication, rest pain or gangrene
MRA or CTA; contrast arteriography
leading cause of death for patients with PAD
MI
medical tx PAD
diet modification, exercise, tobacco cessation, antiplatelet therapy, heart rate, and myocardial contractility control w beta blocker, and tx of htn, dyslipidemia, and DM
what has been used to tx short segment stenosis of peripheral arteries
percutaneous transluminal angioplasty (PTA)- balloon inflated for dilation
atherectomy
removal of plaque by using rotational or orbital blades or laser energy
what meds are used after endovascular intervention for SFA stenosis/occlusions to prevent acute thrombosis
clopidogrel, along w aspirin, should be used for at least 1 month, followed by aspirin alone indefinitely
standard operative tx for carotid bifurcation atherosclerosis
endarterectomy- excision of diseased arterial wall, including the endothelium, the occluding plaque, and portion of the media (limited use for PAD)
principal operative tx for PAD
bypass procedures
extra anatomic bypasses
axillary artery to femoral artery bypass grafts and femoral artery to femoral artery bypass grafts
tx pt with ischemic rest pain and occluded superficial femoral arteries w proximal profunda femoral artery stenosis
opening the stenoses by profundaplasty combined with femoral endarterectomy can increase lower leg perfusion through collaterals and relieve most symptoms. However, if the ischemia has progressed to tissue loss or gangrene, it is unlikely that profundaplasty alone can adequately increase arterial inflow into the leg to heal the ulcerative lesions. In this case, arterial bypass must be performed.
tx infrainguinal occlusive ds
bypass to popliteal artery above the knee (better results than below); use saphenous vein
for limb threatening ds such as rest pain, tissue loss, or gangrene what is best tx option
bypass
s/sx chronic intestinal ischemia
postprandial abd pain (1hr) and wl
dx intestinal ischemia
pe, duplex us, cta and mesenteric angiography
tx intestinal ischemia
mesenteric revascularization; prox mesenteric artery balloon angioplasty and stenting; endarterectomy or bypass w synthetic grafts
six P’s of limb threatening acute arterial occlusion
pallor, pain, paresthesia, paralysis, pulselessness, poikilothermia
causes of acute mesenteric ischemia
arterial occlusion (embolus or thrombosis), mesenteric venous occlusion, or nonocclusive mesenteric ischemia
where do most emboli to the SMA lodge
just distal to origin of middle colic artery, approx 5-10cm from origin of SMA
dx mesenteric ischemia
labs, CT w IV contrast- shows thrombus within mesenteric veins as well as thickened bowel wall
tx of acute mesenteric venous thrombosis
anti coat (heparin); prompt surgery w venous thrombectomy only for an acute abdomen
causes of arterial cerebrovascular insufficiency
occlusive, ulcerative, or aneurysmal ds of the carotid or vertebral arteries
most devastating complication of cerebrovascular insufficiency
stroke
what are strokes caused by
infarction or hemorrhage within the cerebral hemispheres; 1/3 by embolism from atherosclerotic plaques in the carotid arteries of the neck
cerebral ischemia and infarction occur after perfusion reaches
ischemia
mc cause of cerebral infarction
atheroembolism
amaurosis fugax
fleeting blindness; transient monocular blindness that is caused by emboli to opthalmic artery (cerebral vasc)
curtain of blindness being pulled down from superior to inferior and involving the eye ipsilateral to carotid lesion
amaurosis fugax
repetitive changes in mentation, vision, or sensorimotor function that completely rev within 24hr
TIA- cerebral artery distribution, pts often have contralateral arm, leg, and facial weakness
cerebrovascular accident
cerebral infarction; permanent neurologic deficit or stroke; region of nonviable cerebral tissue; MRI diffuse weighted imaging
mc involved area causing neurologic deficit with cerebral vasc
middle cerebral artery (parietal lobe); main outflow vessel of carotid artery
what does hypo perfusion of the middle cerebral artery cause
contralateral hemiparesis or hemiplegia and occasionally paralysis of the contralateral lower part of the face
dominant hemisphere involved with cerebral vasc
difficulty with speech (aphasia)
mc finding in a patient with carotid stenosis
cervical bruit (high freq systolic murmur) heard at angle of jaw; pt complain of buzzing or heartbeat in ear
dx carotid artery stenosis
doppler us, duplex scan; definitive dx of extra cranial carotid arterial system is arteriography
medical tx for cerebrovasc ds
control rf (htn, smoking, dm, hyperlipoproteinemia); anticoag (warfarin); anti platelet drugs (aspiring, clopidogrel)
all pt with carotid stenosis whether asymp or symp must be on
antiplatelet (aspirin or clopidogrel) therapy, statins, and beta blockers
risk factors for DVT
virchow’s triad: stasis, venous endothelial injury, and hyper coagulable states
what happens once valves are damaged from DVT
ambulatory venous pressure becomes much higher and results in stasis and venous dissension, which may injure the venous endothelium and allow protein to leak into sub cut tissue causing inflammation in the interstitium
lipodermatosclerosis
end process of damaged valves of DVT; scarring of the sub cut tissue in the limb
s/sx DVT
asym; pain secondary to inflammation and edema; for many the first symptom is pulmonary embolism
which venous system is more commonly the cause of DVT
left iliac venous system because of the potential for compression of left iliac vein by aortic bifurcation and crossing of the right iliac artery
pe findings of DVT
unilateral extremity swelling or pain; calf pain precipitated by dorsal flexion of the foot (Homan’s sign)
dx DVT
duplex us; doppler us; d dimer
primary therapy of DVT
anticoag initially with heparin, then long term w warfarin (coumadin); INR 2-3; +/- thrombolytics
contraindications to anticoag therapy for DVT
bleeding diathesis, gi ulceration, recent stroke, cerebral avms, recent surgery, hematologic disorders, bone marrow suppression
pulmonary embolism
result from migration of venous clots to pulmonary arteries
s/sx pulmonary embolism
pleuritic chest pain, dyspnea, tachypnea, tacycardia, cough, hemoptysis
what is seen on ekg for PE
right sided heart strain
dx PE
ct of chest, ventilation-perfusion lung scan or pulmonary angiogram; wedge shaped or lobar defect
tx PE
anticoag; if unstable then inotropic support; if stable but compromised then thrombolytic therapy; vena caval filters
mc cause of primary varicose veins
dev of incompetence of the venous valve at junction of the saphenous vein w femoral vein in inguinal region
s/sx superficial (primary) varicose veins
heaviness and fatigue after prolonged standing, night cramps, and occasionally ankle edema, superficial thrombophlebitis or hemorrhage from superficial veins
dx superficial veins (primary)
pe; duplex us
tx options for superficial veins (primary)
stripping the saphenous vein; saphenous ligation; endogenous closure w radio frequency ablation (RFA); branch vein excision by micro incision (stab phlebotomy)
chronic venous insufficiency is a direct result of
local venous hypertension
s/sx chronic venous insufficiency
swollen legs, hyperpigmentation, venous ulceration in “gaiter” zone of ankleorange-brown skin discoloration at ankle w hemosiderin deposition, lower extremity edema, superficial varicosities and/or ulceration
dx chronic venous insufficiency
venous duplex us, MRI/MRV or CT venogram
where do chronic venous insufficiency ulcers usually occur
medial and lateral malleoli of ankle; result of venous htn and usually postthrombotic
tx chronic venous insufficiency
gradient compression stocking; if ulcers medicated tightly wrapped compressions; split thickness skin grafting for wound healing
A 68-year-old man comes to the office because he noted a pulsatile bulge in his abdomen for the past 2 years, and it is becoming more prominent. He has a remote history of Ml, and his only risk factors are one pack per day of smoking and hypertension, controlled with a diuretic. His physical exam is normal except for a pulsatile, nontender mass above his umbilicus, which measures 7 cm. What is the best initial test for this patient?
ct scan w contrast of the abdomen and pelvis
A 70-year-old woman responds to an advertisement for cardiovascular screening, which includes an ABI, an EKG, an ultrasound for AAA, and a carotid duplex ultrasound. She is told that she has a stenosis in her left carotid artery of 50% to 70%, and no significant stenosis in the right carotid bulb What should your recommendation to her be?
repeat carotid duplex us
Carotid stenosis Is often found by screening studies but must be confirmed by another diagnostic test before treatment. Of the options available, only repeat duplex ultrasound is a low risk diagnostic test. When a screening study is abnormal, confirmation of the findings with a repeat full-length study Is often the best approach to confirm the findings. An angiogram carries a risk of stroke and has little additional information that cannot be obtained with an MR angiogram or CTA. The decision for treatment in an asymptomatic patient should be preceded by risk factor modification with low dose antiplatelet therapy, statins, and ß-blockers. Carotid stent is not approved in asymptomatic patients and CEA should not be performed in asymptomatic women until their stenosis becomes >80%.
A 50-year-old type 1 diabetic woman has developed an ulcer that penetrates into the fat on the plantar aspect of the left foot, under the ball of her big toe. She has foot swelling so pulses are not palpable, but she has good capillary refill in the toes. The ulcer is not painful and Is not clinically Infected. What is the next best step for this problem?
measure ankle brachial index and toe pressures
This patient has a mal perforans ulcer, which is a neuropathic ulcer on the ball of the foot due to changes in the motor, sensory, and autonomic nerves In the extremity. The absence of ulcer pain, in itself, tells you that she has a severe peripheral neuropathy. She Is at risk for a major amputation unless she has adequate blood supply to heal, good local wound care with offloading of the ulcer, and then good footwear once the ulcer is healed. The presence of blood supply Is critical to preventing amputation, and physical exam Is not accurate for assessing perfusion, so she needs noninvasive testing, Including an ABI, toe pressures, and assessment of tissue perfusion around the ulcer. If she has a significant pressure deficit In the foot, then an angioplasty or bypass is needed to provide enough blood supply to heal the ulcer. Amputation and IV antibiotics will not be effective If there Is Inadequate blood supply.
A 55-year-old man has degenerative hip disease and must undergo a total hip replacement. His BMI is 36.3. He is otherwise healthy and has never had an episode of deep venous thrombosis. The most appropriate DVT prophylaxis for him is: e.
This patient represents a high risk for DVT post-op due to his risk factor of obesity and the procedure that he is undergoing, total hip arthroplasty. Orthopedic procedures carry one of the highest risks of DVT due to the relationship between the procedure and the deep veins and the post-op immobilization often required. Of the options presented, only low molecular weight heparin (LMWH) has been demonstrated to prevent DVT in high-risk patients. Support hose are used primarily in low risk patients. Sequential compression is useful for all patients pre- and post-op, but is not as successful in preventing DVT In high-risk procedures. A venacaval filter does not prevent DVT—it merely protects the patient from DVT progressing to pulmonary embolism. Aspirin is more effective for prevention of arterial thrombosis and has minimal effect on preventing DVT.
A 35-year-old woman comes to the office because of an ulcer on the skin of her left ankle. She developed pigmentation In her left medial ankle several years ago and then developed a superficial, painless ulcer in the center of the pigmented area 2 months ago. She had been in excellent health prior to that. She works as a schoolteacher and is on her feet most of the day. She has been unable to heal it with local wound care and comes to see you for treatment. Which of the following diagnostic tests would be most useful?
A. Ankle brachial index
B. Wound culture
C. Labs tests for autoimmune disease
D. Venous duplex ultrasound
E. Ulcer biopsy
Based on the location and description, as well as the age of the patient and absence of significant other medical problems, this patient has chronic venous insufficiency, the pigmentation represents lipodermatosclerosis, and the venous ulcer is likely due to reflux In the superficial, perforator, and deep venous systems. An ABI is unlikely to be helpful in a woman at her age, with the ulcer in its current location. Wound cultures are helpful occasionally in management of venous ulcers, but not to diagnose them, and the location and age make both serum autoimmune disease tests and biopsies unlikely to make the diagnosis.
A 25-year-old man comes to the office because of right arm weakness. He is an elite swimmer, who Is otherwise healthy, but is now unable to compete due to arm weakness. On exam his left arm is stronger than his right and he has a reduced right radial pulse with shoulder elevation. The best approach to his problem is:
A. physical therapy
B. change in type of physical activity
C. angiogram and arterial repair
D. MRI followed by first rib resection
E. MR venogram, followed by thrombolysis
This patient has signs and symptoms of neurogenic TOS, which is commonly associated with physical activity and repetitive sports. Since he already exercises regularly, physical therapy (PT) is unlikely to help. He is an elite swimmer and is unlikely to give up his lifestyle unless there are no other options. Even though his pulse Is diminished, this is a common finding in many patients and the primary problem is thoracic outlet compression, not Intrinsic arterial disease. MRI can help determine the location of compression and other pathology, such as cervical rib. Following MRI, a first rib resection, with cervical rib removal if present, is a treatment that is likely to return him to normal function. His symptoms are primarily neurogenic, and not venous, which would be arm swelling, arm pain, and prominent veins. Therefore, venography and thrombolysis are unlikely to be needed.
