Vascular Flashcards
Arterial supply of the lower limb
1) common iliac -> external iliac -> common femoral
2a) common femoral -> profunda femoris -> perforating branches
2b) common femoral -> superficial femoral -> popliteal
3) popliteal -> anterior + posterior tibial
4) anterior tibial -> dorsalis pedis
5) posterior tibial -> peroneal -> medial & lateral plantar
Profunda femoris runs ___, supplies ___ and superficial femoral runs ___, supplies ___
posterolaterally, supplies muscles of thigh
anteromedially, exits femoral triangle into adductor canal, through adductor hiatus into popliteal fossa. Supplies adductor muscles
On angiogram at trifurcation of leg arteries, most lateral to medial ___, ___, ___
anterior tibial
peroneal
posterior tibial
Posterior tibial artery runs ___ and becomes plantar arteries
posterior to medial malleolus
Femoral artery landmark
Mid-inguinal point (b/w pubic symphysis and ASIS)
Popliteal artery landmark
Popliteal fossa, palpate against upper end of tibia
Peripheral artery disease includes disease of all the arteries except ___, ___
coronary arteries and aorta
Intermittent claudication means?
reproducible discomfort of a defined group of muscles that is induced by exercise and relieved by rest
Chronic limb threatening ischemia clinical diagnosis
1) Rest pain requiring opioid analgesia >2 weeks
AND/OR
2) gangrene/ulcers over foot
AND
3) objective indication of poor vascular supply to lower limbs (ABPI <0.5 , toe pressure, TcPO2)
Ischemic rest pain presentation
pain at night during sleep (BP drop, pts not in dependent position)
pain on lying down, relieved by getting up having a short walk
pain aggravated by lifting the limb
Ischaemic ulcers tend to occur on ___ of the foot, tend to be (characteristic)
venous ulcers occur over the ___, tend to be (characteristic)
Neuropathic ulcers occur over ___
lateral malleolus - dry, punctate, deep (punched out, well-circumscribed)
medial malleolus - moist, diffuse, superficial (sloping)
heel, metatarsal heads
Gangrene is ___ tissue that progresses to ___. Caused when ____.
cyanotic, necrosis
arterial pressure falls below minimum required for metabolic functions
Gangrene can be wet or dry
Patients with intermittent claudication tend to have symptomatic stabilisation due to
1) collateral development
2) patient alters gait to use non-ischemic muscles
3) metabolic adaptation of ischemic muscle
Risk factors of peripheral arterial disease
Diseases: diabetes, coronary artery disease, previous stroke
Non-modifiable: age, gender, ethnicity, FH
modifiable: smoking, HT, HLD, diabetes, obesity
Atherosclerosis tends to form at ___
branch points (points proximal to bifurcations), bends & tethered segments
*aortoiliac, femoropopliteal, tibial-peroneal segments
What is Buerger’s disease known as? Main treatment?
Thromboangiitis obliterans
- inflammatory vasculopathy, non-atherosclerotic
main treatment is smoking cessation
What is Leriche syndrome
Occlusion at bifurcation of terminal aorta into common iliac arteries
Pts present with buttock, hip claudication, erectile dysfunction (impotence) Reduced/absent femoral & distal pulses
Tibial-peroneal occlusive disease presents a higher risk of ____ than femoropoliteal occlusive disease due to ___
chronic limb threatening ischemia
lack of collateral blood flow to the foot
Tibial-peroneal occlusive disease patients have absent ___, lack of ___, and ___
dorsalis pedis & posterior tibial pulse
leg hair
shiny skin
Characteristic description of neurogenic vs vascular claudication
neurogenic - pain from “park bench to park bench” (sitting down relieves pain
vascular - pain from “shop window to shop window” (does not have to sit, not walking will relieve pain)
Risk factors for peripheral artery disease
Smoking/ex-smoker
Diabetes
HTN, HLD
Hyperhomocysteinemia
Family history of AAA
What is wet gangrene?
Infected gangrene - blistering, bacterial infection & putrefaction occurs.
Emergency surgical debridement or amputation required
What is diabetic dermopathy?
Atrophic hyperpigmented skin, usually on shin
What do you inspect for when examining PAD patient?
- colour of skin
- trophic changes (loss of hair, thickening of nails, skin dry)
- loss of digits/foot
- presence of ulcers
- presence of gangrene
- diabetic skin changes/joint deformities
Landmark of LL pulses
1) DP: 1/3 way down a line joining midpoint of two malleoli to 1st webspace
2) PT: 1/3 way between medial malleolus and heel
3) Popliteal: patient knee bent, press against superior part of tibia at popliteal fossa
How to perform Buerger’s test
1) Pt lie down. Lift leg straight up until toes turn white
2) Angle at which toes turned white is the Buerger’s angle. Less than 20deg = chronic ischemia
3) Drop patient leg over edge of bed. Should have reactive hyperemia (foot turns purple red)
What clinical classifications are used for Lower Extremity Arterial Disease?
Rutherford (Grade 0-6)
Fontaine (Stage I-IV)
Fontaine classification for LEAD
Stage I: asymptomatic
Stage IIa: mild claudication
Stage IIb: moderate to severe claudication (<200m walk)
Stage III: ischaemic rest pain
Stage IV: ulceration/gangrene
How to measure ABPI
Brachial pressure: higher arm systolic pressure (either left or right)
Ankle pressure: higher of ankle systolic pressure using DP or PT (only the leg you are trying to measure)
ABPI = AP/BP
Interpreting values of ABPI
Normal: >0.9
Claudication: 0.5-0.9
Critical ischemic rest pain: <0.5
>1.4 = non-compressible calcified vessel (perform toe pressure index instead)
Normal arterial waveforms on Arterial Duplex ultrasound are ___
triphasic
mono or biphasic waves are abnormal
What is acute limb ischemia?
Sudden decrease in limb perfusion that threatens limb viability
*ischemic ulcers, gangrene, ischemic rest pain
Risk factors for acute limb ischemia
- ***Arterial embolism - emboli from heart or DVT clots
- *Acute thrombosis - thrombosis of previously stenotic artery (less severe bc collaterals form). Pts tend to have had claudication history
- Arterial trauma
- Dissecting aortic aneurysm
Quickest to slowest tissues affected by ischemia
Nerves > muscle > skin > bone
so numbness comes first, then paralysis, then skin changes
Clinical presentation of ALI (6 Ps)
paresthesia
pain
pallor
poikilothermia (inability to regulate temperature)
pulselessness
paralysis
Acute limb ischemia can be classified using
Rutherford criteria (Stage I-III)
Stage I - viable: no immediate threat of tissue loss
Stage II - threatened: salvageable if properly revascularised
Stage III - non-viable: has to be amputated
Limbs will die after ___ during episode of ALI
6-8 hours
Early ___ is required in acute limb ischemia
anticoagulation with heparin
prevents further clot propagation
How does compartment syndrome occur?
Prolonged ischemia -> delayed reperfusion causes cell membrane damage, leakage of intracellular content out into interstitium -> swelling of muscle compartments
What can carotid artery stenosis lead to?
amaurosis fugax (transient vision loss in one/both eyes)
TIA
ipsilateral ischemic stroke - hemimotor/hemisensory signs, higher cortical dysfunction
Carotid ___ (surgery) is indicated for ___
endarterectomy
symptomatic pts with 70-99% stenosis
symptomatic MALE pts with 50-69% stenosis
asymptomatic with >80% stenosis
What is an arteriovenous access? Two types?
Abnormal connection b/w artery & vein that is surgically created.
AV fistula - connecting native vein to adjacent artery (autogenous)
AV graft - synthetic or biologic grafts
When is AV fistula/graft needed?
Pts with impending/established renal failure requiring chronic haemodialysis
Types of AV fistula
Brescia-Cimino: cephalic vein + brachial artery
Gratz: cephalic vein + radial artery
AV grafts have higher risk of ____ than AV fistulas
thrombosis - 10x risk
Difference between aneurysm & pseudoaneurysm
Aneurysm - intact attenuated vessel where wall is formed by 3 normal elements: intima, media, adventitia
Pseudo - breach to arterial wall, blood accumulates between media and adventitia
True aneurysms can be ___ or ___
saccular: only part of circumference
fusiform: circumferential dilatation
Berry aneurysms occur at ___. Increased incidence in ____.
junction of vessels at Circle of Willis
HTN, PCKD, Ehlers-Danlos Syndrome
What can cause a false aneurysm?
Iatrogenic - needle, endovascular procedures
Trauma
Dissecting aneurysm caused by
intimal tear -> blood flows into media -> forces intima and adventitia apart -> formation of a false lumen
blood will flow back into the true lumen distally OR ruptures externally
What are charcot-bouchard aneurysms?
Microaneurysms that occur at basal ganglia, cerebellum, pons, thalamus
Can cause intracerebral haemorrhage
Most common aneurysm complication above and below inguinal ligament
above: rupture
below: thrombosis & embolism
Abdominal aorta bifurcates at __
L4
trachea: T4
common carotid: C4
Risk factors for aortic dissection
HTN
Age (60-70)
Gender (male)
Collagen conditions - Marfan’s, Ehlers Danlos
Pregnancy
Which part of the aorta most at risk of dissection?
Ascending and proximal descending
Subjected to high pressure blood flow on aortic wall
S___ classification of aortic dissection
Stanford
Stanford A: involves ascending aorta
Stanford B: does not involve ascending aorta
D___ classification of aortic dissection
Debakey
Type I: involves ascending, arch and descending aorta
Type II: involves ascending aorta only
Type IIIa: involves descending only, confined to thoracic
Type IIIb: involves descending, all the way to abdominal aorta
Differential diagnosis for aortic dissection
Heart: myocardial infarction, pericarditis, Aortic aneurysm w/o dissection
Respi: pulmonary embolism
GIT: acute pancreatitis, GERD, perforated ulcer, PUD
Gold standard for diagnosing aortic dissection is ___
CT aortogram
Abdominal aortic aneurysm is when abdominal aorta is ___ larger than normal
50%
normal: 2cm
AAA: >= 3cm
Risk factors for AAA
Modifiable: smoking, HTN, HLD
Non-modifiable: age, gender (M), connective tissue disorders, family history
AAA masses are ___ - fingers are pushed ___ when palpating
expansile
upwards & outwards (contracts and expands)
vs pulsatile (only transmits pulse)
AAA commonly develops (where)___. Should check for concomitant ___ or ___ aneurysm.
below renal arteries
femoral/popliteal aneurysm
Pts at higher risk for AAA rupture
female
COPD
saccular aneurysms
rapid rate of enlargement
Indications for asymptomatic AAA surgery
aneurysm >= 5.5cm
increased diameter >5mm/6 months
Saccular aneurysm
AAA tends to rupture ___ into the ___
posterolaterally
retroperitoneal space
What is permissive hypotension
maintain systolic BP just high enough to maintain clinically alert patient & sufficient end organ perfusion
But not normal BP so can reduce bleeding
Two superficial veins of the leg
great and small saphenous vein
Course of the great saphenous vein
Medial side of the dorsum -> in front of medial malleolus -> medial side of leg -> posterior leg -> medial thigh -> pierces cribiform fascia at saphenofemoral junction, empty into femoral vein (2.5cm inferolateral to pubic tubercle)
What veins join tgt at the saphenofemoral junction?(4)
Great saphenous vein
superficial epigastric vein
superficial circumflex iliac vein
superficial external pudendal vein
Course of small saphenous vein
lateral dorsum -> posterior to lateral malleolus -> midline of calf -> pierces deep fascia over popliteal fossa -> empty into popliteal vein
How does blood get pushed up the veins of the leg?
1) Calf muscle contraction pushes venous sinuses -> squeeze blood into popliteal vein
2) Intramuscular deep veins open during calf relaxation, pulls blood in from superficial veins through communicating veins
3) Valves in communicating and deep veins prevent backflow of blood into superficial veins
Locations of communicating veins
SFJ
mid-thigh (Hunterian perforator)
distal thigh (Dodd’s)
below knee (Boyd’s)
5,10,15cm above medial malleolus (cockett)
Chronic venous insufficiency can result from venous hypertension. Causes of VHT?
1) obstruction to flow: pelvic tumours, pregnancy, DVT
2) failure of venous valves
3) Failure of “venous pump” - inadequate muscle contraction from stroke/muscular weakness
What is telangiectasias
spider veins/venous stars - intradermal veins
What are varicosities and where do they tend to form?
Dilated, tortuous superficial veins
Main tributaries of the saphenous veins - no strong coat of smooth muscle, more superficial
What is corona phlebectatica
network of small dilated venules beneath lateral/medial malleolus with severe venous HTN, indicates severe venous disease
Hallmark of CVI
pitting oedema
Phlegmasia ___ Dolens - caused by ___
Phlegmasia ___ Dolens - caused by ___
Alba - obliterated major deep venous channel (DVT) with sparing of collateral veins. Painful, pitting oedema, blanching (white appearance)
Cerulea - obliterated major deep venous channels + collateral veins. Painful, oedema, cyanotic, arterial insufficiency, venous gangrene (blue appearance)
What is atrophie blanche?
avascular fibrotic scars (ivory white area with hyperpigmented borders)
prone to venous ulcers
What is lipodermatosclerosis
Fibrosing area of subcutaneous tissue - firm area of tender, indurated, hyperpigmented skin
from severe venous HTN. starts at gaiter region and wraps circumferentially around leg
causes “inverted champagne bottle” appearance
Characteristics of venous ulcer
Occurs at gaiter region
sloping edges, shallow, flat, moist
base may be sloughy/granulating
CVI is classified by ___
CEAP
Characteristic
Etiology - congenital, secondary, primary
Anatomy - deep, superficial, perforator
Pathophysiology - reflux, obstruction, both
Risk factors for varicose veins
Age
Obesity, parity
occupation - long standing
posture - crossing legs
increased abdominal pressure
pelvic tumour
family history
what is thrombophlebitis
inflammation of wall of a vein with associated thrombosis
Symptoms of varicose veins
nonspecific pain, tingling, burning, muscle cramps
itchy skin, swelling
worsens throughout course of the day, relieved with compression stockings or elevating legs
What is a saphena varix
compressible lump at the inguinal region that refills when released
landmark of saphenofemoral junction
2.5cm inferolateral to pubic tubercle
Investigations for PAD
ABPI
TBI (<0.7 abnormal)
Arterial duplex ultrasound
Transcutaneous oxygen pressure
Angiogram
What is angiogram with digital subtraction?
Images of underlying bone removed to better visualise arteries
Gold standard for evaluating arterial tree prior to revascularisation
