Vascular Flashcards
Etiology of peripheral arterial disease
Atherosclerosis
Differentials:
Beurger disease - thromboangiitis obliterans
vasculitis - takayasu arteritis, bechet disease
ergot toxicity
vasospasm
Cystic medial degeneration
Popliteal artery aneurysm - showering of emboli
Fibromyalgia dysplasia
Diagnostic criteria of critical limb ischemia
- rest pain req opioid analgesia
- tissue loss - ulcer, gangrene
- ABI<0.5, TPI<0.3, Toe pressure<30, Ankle pressure<50
for more than 2 weeks
Classification for acute limb ischemia
Rutherford classification I: viable II: threatened (a: marginally, image and revasc urgently b:immediately) - emergency revasc III: Irreversible, non viable - amputation
Sensory, motor, doppler - arterial and venous
Classification of chronic limb ischemia
Fontaine or Rutherford
0 - asymptomatic 1 - mild claud 2- mod claud 3- maj claud 4 - rest pain 5 - minor tissue loss 6 - major tissue loss (more than forefoot)
Investigations for PAD
Anatomical
- arterial duplex (us)
- CT angiogram
- lesser used: bone subtraction angiogram, MRA
Perfusion
- ABPI/ TBI
Management of PAD
Asymptomatic
- lifestyle
- manage various RF (smoking, HTN, DM - HbA1c)
- statins, single anti pat therapy
Claudicants, non debilitating
- supervised exercise therapy (30m, 3x/7, for 12w)
- drugs: naftidrofurul, cilostazol
Claudicants, debilitating; critical limb ischemia:
revascularisation (endoscopic angioplasty/ stenting, subintimal angioplasty vs bypass) - Transatlantic classification
Buerger’s test
significant if pallor when raised <20 deg
venous guttering
reactive hyperaemia when foot placed down from bed
What is a positive exercise test
fall of ABI >0.2 post exercise
When to repair AAA
Asymptomatic: threshold 5.5cm (follow up with u/s) - give statin to slow rate of growth
or >1cm/year or saccular aneurysm (rather than fusiform)
AND patient fit for surgery
Symptomatic: repair ASAP regardless of size - pain or distal embolisation
(optimise for surgery - CVS fx)
Criteria for AAA
Normal Aorta: 2-2.5cm
AAA: >3
Aortic diameter>50% than normal
<50%: ectasia
RF AAA
and
RF for rupture
smoking
male
family hx
disorders: marfan (fibrillin 1), Ehler danlos syndrome IV (type 3 collagen)
others: HTN, HLD, atherosclerosis, advanced age, hyperhomocysteinemia
RF for rupture:
COPD, smoking, larger initial AAA size, female gender, renal transplant, rate of enlargement
Types of rAAA presentation
- Classical: hypotension, shock, pain rad to back, pulsatile ab mass
- Local contained: radicular symptoms to thigh, groin with GI/urinary obstruction
- rupture into IVC (aortocaval fistula): audible ab bruit, venous HTN (swollen cyanotic legs, lower GI bleed, hematuria)
- distal embolisation (thrash foot)
Cx of AAA surgery
Intra-op: haemorrhage, distal embolisation (thrash), distal limb arterial thrombosis
Early: spinal cord ischemia (paralysis), ARF (oliguria), AMI, CVA, acute sigmoid colon ischemia, pneumonia, ARDS
Late: aortoenteric fistula, graft infection (Dacron graft), false aneurysm formation, sexual dysfunction, renal failure
Endovascular (EVAR) vs open AAA sx repair
Short term: endo mortality rate lower, and a/w lower aneurysm relate death
LT (4 y): endo has higher incidence of post op cx and need for re-intervention
endo needs long term follow up with CT angio to check position of stent
Position of SFJ
2.5cm inferolateral to pubic tubercle
How to confirm it is saphena varix
located at SFJ/ inguinal region, soft, compressible
collapsible when lying down, positive cough impulse
grading of chronic venous insufficiency
CEAP classification 0 - normal 1 - telangiectasia (<1mm), reticular veins (1-3mm) 2 - varicose veins (>3mm) 3 - edema 4 a venous eczema/ hyperpigmentation 4 b atrophie blanche, lipodermatosclerosis 5 - healed ulcer 6 - active venous ulcer
Venous ulcer management
first rule out marjolin cancer - biopsy
Conservative: 4 layer compression bandage
- first ensure ABI >0.8
1. non stick wound dressing + wool bandage
2. crepe bandage
3. blue line bandage (elset)
4. adhesive bandage (coban) - aim ankle pressure ~30mmhg
- also give: analgesia, antibiotics (if infx), avoid trauma, elevate legs when resting, compression stockings for life after healed
Surgical: split skin graft, venous sx for underlying pathology
Varicose veins management
- cx of surgery
Conservative:
- lifestyle: change job, avoid standing long durations
- daflon
- graduated compression stockings
Surgical if: 1. cosmesis, 2. symptomatic, 3. cx
- high tie with GSV stripping - stab avulsion (CI if DVT)
(cx: DVT , saphenous nerve injury) - US guided injection foam sclerotherapy
(cx: cutaneous necrosis, hyperpigmentation, telangiectasic matting, thrombophlebitis, allergic reaction, venous
thromboembolism) - endovenous laser/ radiotherapy saphenous vein ablation
(cx: skin burns, DVT, PE, vein perforation & hematoma, superficial thrombophlebitis)
Anatomical relations of GSV, SSV
GSV: passes anterior to medial malleolus, travel with saphenous nerve
SSV: passes posterior to posterior malleolus, travel with sural nerve
Special tests for venous PE
tourniquet test, trendelenburg test, perthes test, doppler ultrasound
arterial supply of LL
aorta > common iliac > int/ext iliac > common femoral
5 br: sup epigastric, sup circumflex art, sup ext pudendal art, deep ext pud art, profunda femoris (3 br: med/lat circumflex fem art, 4 perforating branches)
pop>ant/pos tibial, peroneal arteries
Description of dorsalis pedis
one third of the way down a line joining the midpoint of the two malleoli to the cleft between the first and second toe located between the extensor halluces longus and extensor digitorium longus
location of claudication vs site of dz
- buttock
- thigh
- calf
- foot
buttock/ impotence: stenosis of lower aorta/ common iliac (aortoiliac dz)
thigh: ext iliac, common fem, aortoiliac dz
calf: superficial femoral (femoral-popliteal dz)
foot: tibial peroneal dz
Arterial exam
- inspection
- palpation
- special
Inspect:
- colour (red, white, purple)
- trophic changes: hairless, dry shiny skin, thickened nail
- tissue loss: ulcer/ gangrene/ amputation
- surrounding skin: cellulitis, nec fas, DM dermopathy
- deformities: Charcot
Feel:
- temp, CRT, bogginess, discharge, inguinal LN
- pulses grading
Special: beurger
Complete:
- full neuro LL exam: sensory, motor, peripheral neuropathy
- palpate other peri pulses, auscultate for bruit
- ab for AAA
- ABPI
- neck for carotid art stenosis
Differentiate between art, venous and neuropathic ulcers
pain: ischemic painful
site: distal toes, lat malleolus/ gaiter, medial malleolus/ heel,MT heads
size: vary/ large/ -
shape: defined/ irregular/ punched
edge: punched/ sloping/ clean
base: no gran/ gran
surrounding skin: pale/ venous signs/ normal
temp: cold/ warm/ dry
pulses: absent for art
sensation/reflex/ vibration: loss in neuropathic
bone: in neuro
types of amputations
ray, forefoot, lisfranc (trans MT), Chopard (mid-tarsal), syme (thru ankle), BKA, AKA, through knee, hip disarticulation
ABPI values
TPI values
ABPI
N: >0.9
occlusion: 0.5-0.9
non comp calcified vessel: >1.4
TBI
abN: <0.7
lab Ix to do for asymptomatic patients to check risk of developing PAD
CRP
Best medical therapy for PAD
smoking cessation (bupropion) weight reduction LDL < 2.6, high risk<1.8 (statin) Hba1c<7%, podiatrist BP<140/90, <130/80 if DM or renal dz - ACEi SAPT - clopidogrel 75mg > aspirin 100mg
Indications for amputation
4Ds: dead (ischemic), damaged (trauma), dangerous (gangrene, sepsis, Ca), damn nuisance (infx, neuropathy)
Complications of amputation
Early: - hematoma, wound infx (gas gangrene) - DVT, PE - phantom limb pain - skin necrosis (poor perfusion of stump > refashioning) - psychological/social coping Late - OM - stump ulceration - stump neuroma - fixed flexion deformity - difficulty mobilising - spurs and osteophytes in underlying bone
ddx for acute limb ischemia
acute DVT: phegmasia cerulean dolens
blue toe syndrome: atheroembolism from AAA
purple toe syndrome: cx of wafarin
venous insufficiency
Causes of acute limb ischemia
arterial embolism - cardiac: AF, recent AMI with LV mural thrombus, prosthetic heart valves - non cardiac acute thrombosis - atherosclerosis - hypercoag states: APS, HIT - medium vessel vasculitis arterial trauma dissecting aortic aneurysm
6Ps of acute limb ischemia
pain, paresthesia, pallor (mottled, duskiness, black), pulseless, paralysis, perishingly cold (heavy limb, intrinsic foot muscles > leg muscles)
paresthesia progression: light touch > V >P > deep pain> pressure sense
LeRiche Syndrome
occlusion at bifurcation of terminal aorta
tetrad: buttock claud + impotence in men + absent femoral and distal pulses + aortoiliac bruits
Ls of PAD
Life > Limb > Lifestyle
Embolic vs thrombotic cause of acute limb ischemia
source, claud hx, PE, angio
EMBOLIC: source present - AF, AMI, no claud hx, pale white leg, contra pulses present, no collaterals on angio, sharp cut off, minimal atherosclerosis
THROMBOTIC: no source, claud hx, dusky, contra leg pulses diminished, angio - diffuse atherosclerosis, collaterals well formed, irregular cut off
Management of Acute Limb Ischemia
- Doppler to determine severity via Rutherford Classification
- Prep for op: op bloods, ECG, CXR, call OT, call vascular surgeon
- Early coagulation: IV heparin bolus 70unit/kg, then infusion 15unit/kg/hr - maintain PTT 50-75s (2-2.5x normal)
- improve existing perfusion: dependent position, avoid injuries, heel pressure, extremes of temp, 100%O2, correct hypotension
- surgical emergency (+- fasiotomy) w on table angiogram (confirm occlusion, determine cause - thrombotic vs embolic, level of occlusion, anatomy)
- Post op anti coag w heparin and vasodilators if vasospasm
- mg risk factors (e.g AF)
Surgical options for limb salvage
Open surgical - embolectomy/ thrombectomy - endarterectomy - bypass grafting - fasciotomy - primary amputation Endovascular - thrombolysis - angioplasty - stenting
Intra arterial catheter directed thrombolysis
- how it works
- contraindications
thrombolysis catheter into clot, infuse TPA (alteplase) for 6 hours (in HD) - angioplasty and stent after
Contraindications
Absolute
- CVA within past 2 months
- Active bleeding / recent BGIT past 10 days
- Intracranial haemorrhage/ vascular brain neoplasm/ neuroSx past 3 months
Relative
- CPR past 10 days
- Major Sx / trauma past 10 days
- Uncontrolled HTN
Complications of limb salvage
- Reperfusion injury
- Rhabdomyolysis > (release K, lactic acid, myoglobin, ) hyperkalemia - arrhythmias
tx: hydrate + IV bicarb to alkalinise urine - Compartment syndrome (>30mmhg or within 30 of DBP) - 4 compartment fasciotomy
Differentials for ischemic rest pain
- Diabetic Neuropathy
- Complex Regional Pain Syndrome
- Nerve Root Compression
- Peripheral Sensory Neuropathy (other than diabetic neuropathy) - Night Cramps
- Buerger‟s Disease (thromboangitis obliterans)
locations of communicating veins
- SFJunction (GSV into fem vein)
- Hunterian perforator: mid-thigh
- Dodd‟s perforator: distal thigh
- Boyd‟s perforator: knee
- Cockett (posterior tibial) perforators: at 5, 10, and 15 cm above the medial malleolus (connects posterior arch vein to posterior tibial vein)
Complications of AV access
Mechanical
- Stenosis
- thrombosis
- infx (S aureus)
- aneurysm - rupture, bleeding, ulceration
Functional
- arterial steal syndrome (ischemic pain, neuropathy, ulceration/gangrene)
- venous HTN (skin discolouration, hyperpigmentation, ulceration)
- CCF (increased venous return)
- failure of fistula, graft
AV graft
- advantages
- disadvantages
- large surface area
- easy cannulation
- short maturation time (3-6w)
- easy surgical handling
AV fistula
- types
- advantages
- disadvantages
- suitability
- how to prepare
- Brachio-cephalic, Radio-cephalic, Brachio-Basilic
- long term patency, low infx risk, high blood flow rate, least likely to clot, less arterial steal syndrome
- long maturation time
- presence of vein diameter >4mm (more likely to succeed)
- Prep: avoid blood taking, venipuncture, tight clothing
AV fistula assessment - rule of 6
at 6 w post creation, diameter of fistula body>6mm
depth no more than 0.6cm
blood flow rate >600ml/min
length of fistula 6cm
occlusion of outflow: augmentation of pulse (adequate inflow)
raise arm above heart should collapse fistula (adequate drainage)
Doppler us
Fistula failure definition
fistula that never matured to be useful
difficult to cannulate
not enough blood flow for successful 2 needle dialysis
types of aneurysms
Congenital: berry Acquired: - atheromatous (ab, pop, fem) - mycotic (subacute IE) - syphilitic (thoracic) - dissecting (cx: inferior MI, AR) - false - arteriovenous
