Vascular Flashcards
Define acute limb ischaemia
a sudden decrease in arterial perfusion in a limb which threatens the viability of the limbs
Define Chronic limb ischaemia
Peripheral arterial disease resulting in a symptomatic reduced blood supply to the limbs
Intermittent claudication –> critical limb ischaemia
Causes of acute limb ischaemia?
Thrombus
Emboli - AF, post-MI mural thrombus, abdominal aortic aneurysm, or prosthetic heart valves
Trauma - also compartment syndrome
Causes of chronic limb ischaemia?
Atherosclerosis
Vasculitis
RFs for chronic limb ischaemia?
Smoking Diabetes mellitus Hypertension Hyperlipidaemia Increasing age Family history Obesity and physical inactivity Renal failure
6 Ps of acute limb ichaemia in order of when they usually occur?
Pain
Pallor
Pulselessness
Perishingly cold
Paraesthesia - indication for immediate revascularisation
Paralysis - indication for immediate revascularisation
Explain the Rutherford classification of acute limb ischaemia
I: Viable, No immediate threat, No sensory or motor loss, audible arterial and venous doppler
IIA: Marginally threatened, salvageable if prompt tx, minimal sensory loss, no motor deficit, inaudible arterial and audible venous doppler
IIB: Immediately threatened, salvageable if immediate revascularisation, sensory loss in toes or more with rest pain, mild/moderate motor deficit, inaudible arterial and audible venous doppler
III: Irreversible, major tissue loss + permanent damage, profound sensory loss, profound paralysis, inaudible arterial and inaudible venous doppler
Explain the Fontaine classification of chronic limb ischaemia
Stage 1: Asymptomatic
Stage 2: Intermittent claudication
Stage 3: Ischaemic rest pain
Stage 4: Ulceration/gangrene
Where is the disease in calf claudication?
Superficial femoral artery
Where is the disease in buttock claudication?
Iliac artery
Define critical limb ischaemia (3 points)
Ischaemic rest pain for >2 weeks
Ulcers or gangrene
ABPI <0.5 or ankle pressure <40mmHg
Leriche Syndrome pathophysiology and triad of symptoms?
aortoiliac occlusive disease
buttock claudication
erectile dysfunction
absent/weak distal pulses
What Buerger’s angle indicates severe ischaemia
<20 degrees
What bloods to do in acute limb ischaemia?
FBC Serum lactate: to assess level of ischaemia Thrombophilia screen Clotting profile Group and save
Gold standard ix for chronic limb ischaemia?
MRI/CT angiogram
Acute limb ischaemia Mx?
Surgical emergency (Rutherford IIB)
o High-flow oxygen
o Gain IV access
o Initiate heparin
If embolic cause, options are:
• Embolectomy via a Fogarty catheter
• Local intra-arterial thrombolysis
• Bypass surgery, if there is insufficient flow back
If thrombotic cause, options are:
• Local intra-arterial thrombolysis
• Angioplasty
• Bypass surgery
If irreversible - amputation
Long term mx of acute limb ischaemia?
Reduce cardiovascular mortality risk
Lifestyle: regular exercise, smoking cessation, weight loss
Anti-platelet agent: low-dose aspirin or clopidogrel
Chronic limb ischaemia mx?
Lifestyle: smoking cessation, regular exercise (programme), weight loss
Statin therapy: atorvastatin 80mg OD
Anti-platelet: clopidogrel 75mg OD
Optimise diabetes control
Praxilene: if not fit for surgery
Surgery: angioplasty +/- stenting or bypass graft
Complications of acute limb ischaemia tx?
Reperfusion injury - can cause compartment syndrome and AKI
Complications of chronic limb ischaemia?
Sepsis secondary to infected gangrene
Acute-on-chronic ischaemia
Amputation
Characteristics of venous eczema?
Itchy red, blistered and crusted plaques; or dry fissured and scaly plaques on one or both lower legs (commonly mistaken for cellulitis).
Atrophie blanche: star-shaped ivory-white depressed atrophic plaques with red dots within the scar (dilated capillaries) and surrounding hyperpigmentation (due to haemosiderin deposition)
Orange-brown patches of pigmentation caused by haemosiderin deposition
Lipodermatosclerosis
Characteristics of Lipodermatosclerosis?
Skin hardening (often referred to as induration) Hyperpigmentation Erythema Swelling Inverted champagne bottle appearance
Characteristics of venous ulcers?
Large, irregular border with sloping edges
Shallow depth
Often located over the medial aspect of the ankle (referred to as the gaiter region).
Associated with mild pain
Characteristics of arterial ulcers?
Small, clearly defined border, irregular edge
Dry necrotic base
Deep
Often in between toes/dorsum of feet over bony prominences
Painful
How does a saphena varix present?
Lump 2-4cm inferior-lateral to the pubic tubercle
Blue tinge
Soft to palpate
Vanishes on lying down (differentiates from inguinal hernia)
RFs for varicose veins?
Prolonged standing Obesity Pregnancy Family history Valve damage: post DVT High flow: AV fistula Venous outflow obstruction: DVT, pelvic masses (pregnancy), ascites, lymphadenopathy
Where do the great and lesser saphenous veins run?
Great saphenous vein: medial side of leg
Lesser saphenous vein: lateral side of lower leg
Complications of varicose veins?
Swelling Skin changes: haemosiderin deposition, lipodermatosclerosis Venous ulceration Thrombophlebitis Varicose eczema Bleeding (if trauma occurs)
Explain the trendelenburg test for varicose veins
Allows localisation of the sites of valvular incompetence
Leg is elevated and the veins are emptied
Tourniquet placed over the saphenofemoral junction
Pt stands and filling of the veins is observed - if remains collapsed incompetent valve is at level of SFJ
If they fill then incompetent valve is inferior
Clinical tests for varicose veins?
Tap test
Trendelenburg test
Cough impulse test (Cruveihier’s test)
Perthe’s test
What does Perthe’s test tell you?
Distinguishes between venous valvular insufficiency in the deep, perforator and superficial venous systems
Gold standard ix for varicose veins?
Duplex ultrasound
Conservative tx of varicose veins?
Education: avoid prolonged standing, weight loss, increase exercise (promotes calf muscle action)
Compression stockings
When to refer varicose veins to vascular team?
Symptomatic primary or recurrent varicose veins
Lower-limb skin changes, e.g. pigmentation/eczema, thought to be caused by chronic venous insufficiency
Superficial vein thrombosis (hard, painful veins) with suspected venous incompetence
Venous leg ulcer: a break in the skin below the knee that has not healed within 2 weeks
Invasive tx of varicose veins?
- endothermal ablation
- ultrasound-guided foam sclerotherapy
- vein ligation, stripping and avulsion
Post-op complications of varicose vein tx?
Haemorrhage
Thrombophlebitis – especially for foam/ablation treatments
DVT – especially for endovenous treatments
Disease recurrence
Nerve damage: saphenous or sural nerves
Characteristics of neuropathic ulcers?
Punched out lesion with deep sinus
Variable depth - partial thickness to severe
Under pressure points - plantar aspect of 1st/5th MTP joint
RFs for arterial ulcers?
o Coronary heart disease o History of stroke or TIA o Diabetes mellitus o Peripheral arterial disease e.g. intermittent claudication, critical limb ischaemia o Obesity and immobility
Tx of venous ulcers?
4 layer compression banding
Ix for neuropathic ulcer?
- Blood glucose
- Serum B12
- ABPI +/- duplex to assess for concurrent arterial disease
- Microbiology swab and X-ray (for osteomyelitis) if signs if infection
RFs for neuropathic ulcers?
DM B12 deficiency Alcohol Charcot Marie Tooth Concurrent peripheral vascular disease
What is wet gangrene?
necrosis with superimposed infection
What is dry gangrene?
necrosis in absence of infection
What is gas gangrene?
subset of necrotising myositis caused by spore-forming Clostridial species
What is necrotising fasciitis?
a life-threatening infection of deep fascia causing necrosis of subcutaneous tissue
RFs for gangrene?
o Diabetes o Peripheral vascular disease o Leg ulcers o Malignancy o Immunosuppression o Steroid use o Puncture/surgical wounds o Trauma
Indications for amputation?
Peripheral vascular disease: most common reason for lower limb amputation
Trauma: most common reason for upper extremity amputation
Infection
Malignancy
Congenital abnormalities
Complications of amputation?
Intra-operative:
Haemorrhage
Anaesthetic risks: damage to teeth/throat/larynx, reaction to medications, nausea and vomiting, cardiovascular and respiratory complications
Early: Pain: patient usually has an epidural post-op and a perineural nerve catheter inserted to give LA directly into the nerves for major amputations Bleeding Infection Scarring Blood clots
Late:
Phantom limb: neuropathic analgesics, e.g. pregabalin/amitriptyline, can help
Reintervention: if poor healing, may require more proximal amputation
Contractures: adjacent joint contractures, prevent with early aggressive mobilisation
Post-amputation neuroma: prevent with proper nerve handling at time of procedure - tx = targeted muscle reinnervation
Bone overgrowth
Types of upper limb amputations?
Transcarpal: transect finger flexor/extensor tendons
Wrist disarticulation
Transradial: middle third of forearm
Transhumeral
Shoulder disarticulation: retain humeral head to maintain shoulder contour
Types of knee amputation?
Transfemoral: usually cut 10-15cm above knee joint to allow for prosthetic fitting
Through-knee
Below-knee: 12-15 cm below knee
Types of ankle/foot amputation?
Syme: ankle disarticulation, patent tibialis posterior artery required, usually for forefoot gangrene in diabetes
Pirogoff: hindfoot amputation, removal of forefoot and talus followed by calcaneotibial arthrodesis
Chopart/Boyd: hindfoot amputation, partial foot amputation through the talonavicular and calcaneocuboid joints, primary complication: equinus deformity
Lisfranc: midfoot, equinovarus deformity common
Transmetatarsal
Great toe: preserve 1cm at base of proximal phalanx
UK AAA screening?
Abdominal US scan for all men at age 65 < 3cm: discharge 3.1 – 4.4cm: annual ultrasound 4.5 – 5.4cm: 3 monthly ultrasound > 5.5cm: treat
RFs for AAA?
o Severe atherosclerotic damage to aortic wall o Smoking o Hypertension o Hyperlipidaemia o Family history o Male gender o Increasing age
Types of AAA repair?
Surgical open repair: involves midline laparotomy/long transverse incision, exposing + clamping the aorta proximally and iliac arteries distally, before segment is removed and replaced with a prosthetic graft
Endovascular repair (EVAR): involves introducing a stent-graft system via femoral arteries and fixing the stent across the aneurysm
Pros of EVAR?
Avoids open abdominal surgery
Quicker recovery
Avoids aortic-cross clamping
Reduced mortality in first 4 years of follow-up
Cons of EVAR?
Follow-up with USS/CT scans essential to monitor the endograft
Higher rates of failure and reintervention
Complication: endovascular leaking when an incomplete seal forms around the aneurysm resulting in blood leaking around the graft - can cause aneurysm to expand and rupture
Complications of AAA repair?
Failure of repair
Infection
Haemorrhage
Complications of arterial surgery: bleeding, thrombosis, embolism, graft infection, MI, AV fistula formation
Complications of aortic surgery: gut ischaemia, renal failure, respiratory distress, trauma to ureters or anterior spinal arteries leading to paraplegia, aorto-enteric fistulae
Stanford classification of aortic dissection?
Type A: tear in ascending aorta (70%) - cardiothoracic surgeons
Type B: tear in descending aorta distal to left subclavian artery (30%) - vascular surgeons
RFs for aortic dissection?
HTN
Male
Connective tissue disorders: Marfan’s, Ehlers-Danlos
Cardiac: acute atherosclerosis with dilation
Trauma
Iatrogenic: aortic manipulation in cardiac surgery
Congenital cardiac abnormalities: bicuspid aortic valve, coarctation of the aorta
Inflammation: Takayasu’s
Acute mx of aortic dissection?
- Beta-blocker + opioid analgesia
Type A: cardiothoracic surgical removal of ascending aorta
Type B: TEVAR
Complications of aortic dissection?
Backward tear: aortic incompetence/regurgitation, inferior MI
Forward tear: unequal arm pulses/BP, stroke, renal failure
Aortic rupture
Aortic regurgitation
Myocardial ischaemia, secondary to coronary artery dissection
Cardiac tamponade
Stroke or paraplegia, secondary to cerebral artery or spinal artery involvement
Complications of carotid endarterectomy?
o Bleeding
o Stroke as a result of surgery itself
o Damage to recurrent laryngeal nerve
o Damage to hypoglossal nerve
Contents of thoracic outlet?
brachial plexus
subclavian artery
subclavian vein
Causes of thoracic outlet syndrome?
hyperextension injuries
repetitive stress injuries
external compression
anatomical abnormalities e.g. cervical rib
Risk scoring of subclavian steal syndrome?
Pre-Subclavian Steal – demonstrating purely a reduced anterograde vertebral flow
Intermittent Alternating Flow – antegrade flow occurs in the diastolic phase and retrograde flow occurs in the systolic phase
Advanced Disease – there is a permanent retrograde flow
What is subclavian steal syndrome?
During exercise, a proximal stenosing lesion of the subclavian artery causes reversal of blood flow in the ipsilateral vertebral artery to meet the demands of the arm - this causes syncope/neurological deficits
Ix and Mx for subclavian steal?
Ix: Duplex USS
Mx: percutaneous angioplasty ± stenting or bypass - optimise CV RFs
Special cast for diabetic foot ulcers?
Total contact casting - takes the weight off
