Chronic ischemia Flashcards
What is the main cause of chronic limb ischemia?
ATHEROSCLEROSIS
there is time for collaterals to develop
What are the non- atherosclerosis causes related to chronic limb ischemia?
BURGER’S DISEASE (thromboangitis obliterans)
What is the pathogenesis of atherosclerosis?
endothelial injury –> PDGF –> monocytes attach to injured endothelium –> migrate into subendothelial layer –> macrophages ingulf fat and become foam cells –> smooth muscle cells are stimulated to migrate into intimal layers –> fibrous plaques become part of fatty streaks
- adventitia layer is completely normal
- purely an arterial disease
What is the cause behind burger’s disease?
toxic spasm caused by SMOKING in a middle aged man
What is affected in Burger’s disease?
Neuro vascular bundle (small & medium arteries, veins, & nerves)
What is the pathology of thromboangitis obliterans?
- spasm of vasa-vasorum affect arteries & veins in different patches of lengths (segmental)
- thrombosis occurs in acute stage
- aggregation of peripheral nerve vessels & micro abscesses
Chronic phase -> hypercellularity & frequent recanalization of vessel lumen
End stage —> organized thrombus & blood vessel fibrosis
fibrosis & round cell infiltration in the adventitia with perivascular fibrosis which welds artery & vein & nerve is characteristically seen in which disease?
Burger’s disease
What is the most common site affected by Burger’s?
bilateral but ASYMMETRICAL
small & medium sized arteries
POSTERIOR TIBIAL & POPLITEAL ARTERIES
What is the general clinical picture of chronic ischemia?
- claudication pain (early)
- rest pain (late except in Burger’s)
- impotence (Le riche syndrome)
- ischemic chest pain
- post-cibal angina due to mesenteric ischemia
GENERAL EXAMINATION
- calcification & cord-like radial artery
- hypertension
- murmurs
- aneurysm
What are the findings on inspection of patient presenting with chronic ischemia?
INSPECTION
color changes
- (Burger’s angle): PALLOR with leg elevation then REACTIVE HYPEREMIA with hanging leg below bed
- Rubor (stagnation of blood)
venous filling
trophic changes
- muscle wasting
- thin scaly dry skin
- hair fall
- brittle nails
- ulcerations over pressure areas
gangrene
ischemic ulcer
What will be felt upon palpation of patient presenting with chronic ischemia?
- weak or absent pulse
- decreased capillary flow
- temperature (cold limb)
- motor power (muscle wasting)
- sensations (paresis)
What is heard on auscultation of ischemic limb?
ARTERIAL BRUIT
systolic murmur at site of narrowing
What are the general investigations that could be used in case of chronic ischemia?
- Laboratory
- plain x-ray (calcification of blood vessels)
- ECG & echocardiography
What are the general investigations that could be used in case of chronic ischemia?
- Laboratory
- plain x-ray (calcification of blood vessels)
- ECG & echocardiography
What is the doppler & duplex US used for?
- detection of narrowing & occlusion
- ANKLE BRACHIAL INDEX
1 : 1.3 –> normal
less than 0.9 –> claudication
less than 0.5 –> rest pain
less than 0.3 –> impending gangrene
Which method of investigation detects the presence of distal run-off?
Conventional angiography
What will be shown during investigation of Burger’s disease using angiography?
- no distal run-off
- segmental obliteration of arteries
- tree-root or spider legs collateral circulation seen in chronic cases
- corckscrew appearance due to recanalization of arteries (in small arteries)
What will be seen on angiography in atherosclerosis?
- distal run-off
- proximal large arteries affected
What is the the diagnostic investigation for Burger’s disease?
BIOPSY
inflammatory changes in the walls of arteries & veins leading to thrombosis & micro abscesses
What is the diagnostic criteria of critical limb ischemia?
1- rest pain
2- resistant ulcer
3- gangrene
4- ABI less than 0.3
angiography & surgical intervention should be done
chronic obstruction at aorto-bi-iliac level will lead to?
Leriche syndrome
What is the diagnostic criteria for Leriche syndrome?
- bilateral claudication pain reaching glutei
- bilateral absent femoral pulse
- erectile dysfunction
What non-operative treatment is usually done for chronic limb ischemia?
General Measures
- reduce risk factors
- stop smoking
- control DM & hypertension
- lipid control
Exercise Rehabilitation
- increase flow through collaterals
- daily walking & stop before claudication pain
Foot Care
Pharmacotherapy
- Vasodilators
- Anti-platelets
- Anticoagulants (if there’s thrombosis)
- Vitamin A & E
What are the indications for operative treatment?
- Critical limb ischemia
- claudication interfering with life & job
- rest pain
- ischemic ulcer resistant to medical treatment
How should the type of surgical procedure be chosen?
according to distal run-off
GOOD DISTAL RUN-OFF: reconstructive procedures
long distance run-off –> OPEN
endovascular
NO DISTAL RUN-OFF: non-reconstructive procedures
sympathectomy
amputation
What are the types of reconstructive procedures?
OPEN SURGERY
- by-pass surgery (grafting)
-anatomical
-extra-anatomical
types of grafts
- biological: from saphenous vein
- extra-anatomical: PTFE (teflon)
ENDOVASCULAR
- balloon angioplasty: isolated short segment stenosis or graft stenosis with symptoms
- intravascular stents: stent inserted after balloon to prevent elastic recoil
What are the types of non-reconstructive surgery?
SYMPATHECTOMY
- recurrence within 5 years
- has vasodilator effect on collaterals
- could lead to denervation hypersensitivity -> recurrence
- has little value in claudicating patient
AMPUTATION
- for gangrene
- failure of sympathectomy
What are the differences between atherosclerosis & Burger’s?
ATHEROSCLEROSIS BURGER’S
- caused by age, gender, hyperlipidemia - SMOKING
- subintimal atheromatous plaque - all 3 layers of medium sized arteries & veins & nerves
- old age - middle age
- progressive - fluctuant
- proximal (large arteries) - distal (smaller arteries)
- symmetrical - asymmetrical
- rest pain comes later - earlier rest pain
- IHD, stroke - DVT & neuropathy
- distal run off - no distal run-off
- conservative or constructive - conservative or non-constructive
What is the difference between claudication & rest pain?
CLAUDICATION REST
- PAD - Critical limb ischemia
- anaerobic metabolism of muscle (lactic acid) - ischemic neuritis
- at site of obstruction - foot
- crampy - severe bursting
- due to walking & exercise - due to warming & elevation
- relieved by rest - by exposure & dependency
- use duplex - use angiography
- medical first - immediate intervention
What is the sequence of Raynaud’s disease?
1- blanching (pallor)
2- dusky cyanosis
3- red engorgement
accompanied by pain
What is the cause of Raynaud’s disease?
vasoconstriction of small arteries in response to sympathetic overactivity or exposure to cold
What is the clinical picture of Raynaud’s disease?
- occurs in young women (20-40)
- affects upper extremity more than lower
- peripheral pulses are normal
- bilateral & symmetrical
How should Raynaud’s disease be managed?
CONSERVATIVE
- avoid exposure to cold, emotional stress, & smoking
- electrically heated gloves in winter
- avoidance of pulp & nail beed infection
PHARMA
- calcium antagonists (nifedipine)
- guanethidine: block peripheral a & B adrenergic activity
- nitroglycerine
SURGICAL
- sympathectomy
only if severe disabling recurrent attacks or there is an ischemic ulcer resistant to healing
What is the difference between Raynaud’s disease & syndrome?
DISEASE SYNDROME
- young age - any age
- females - both
- exposure to cold or stress - Burger’s disease
- only upper limb - can affect lower limb
- bilateral & symmetrical - unilateral or bilateral & asymmetrical
- present radial pulse - may be absent
- no complications - can lead to complications
- conservative management - target management at underlying cause
What is acrocyanosis?
vasospastic disease in response to cold like Raynaud’s but the difference is:
- painless
- not paroxysmal
- marked cyanosis
- affects upper & lower limb
What is the cause of frost bite & what does it lead to?
- due to exposure to severe coldness
- causes damage of vessel walls (not only spasm)
- complicates into blister formation & gangrene
TREAT by urgent warming by immersion of affect part in warm water
When is amputation indicated?
when limb is:
DEAD (gangrene)
DEADLY (sarcoma, gas gangrene, crush syndrome)
DEAD LOSS (mangled limb, severe rest pain, massive lymphedema)
What is the most important difference between lower limb & upper limb amputations?
LOWER LIMB: respect levels of amputation
- below knee
- above knee
UPPER LIMB: preserve as much as you can of the limb
What are the early complications of amputation?
- infection, hemorrhage, ..
- ischemia of flap
- wound dehiscence
What are the late complications of amputation?
- skin: ulcerations & adherent scar
- excess muscle that prevents proper use of prosthesis
- progressive ischemia of stump
- phantom limb or stump neuroma
- stiffness of joint above stump
- osteomyelitis, projecting bone
