Vascular Surgery Flashcards
Give some examples of risk factors for peripheral vascular disease.
- smoking (x9): increased fibrinogen & platelet adhesion, atherogenic, reduced HDL, increased lipids
- diabetes mellitus (x4)
- hypertension (x3)
- hyperlipidaemia
- FHx
- cerebrovascular disease
Describe claudication and its cause.
Pain in the muscles of the lower limb elicited by walking/exercise (increase gravitational pressure than upper limb).
Most frequently in calf muscles (below adductor canal).
Pain caused by buildup of lactate, K+, and substance P due to anaerobic metabolism.
Give some examples of non-vascular differentials for claudication.
- spinal stenosis
- lower limb arthritis
- musucloligamentous strain
Where are the most common locations for atheroma in the vasculature of the lower limb?
Superficial femoral artery (80%)
Aorto-iliac arteries (15%)
Calf arteries (5%)
What is Buerger’s disease?
Thromboangiitis obliterans.
Idiopatic inflammation and segmental thrombosis of the small and medium sized arteries (and sometimes veins) of the upper and lower limbs; leading to arterial ischaemia and superficial thrombophlebitis.
Leads to gangrene and ulceration.
Occurs in young male smokers.
Give some examples of the vascular differentials for claudiction.
Calf claudication (80%) Calf, thigh, and buttock claudication (18%) Leriche syndrome (2%)
What is Leriche syndrome?
Iliac artery occlusion causing bilateral buttock claudication and erectile dysfunction.
Describe the vasculature of the lower limbs.
Aorta —> Common iliac artery —> External iliac artery —> Common femoral artery —> Superficial & Deep femoral arteries
Superficial femoral artery —> Popliteal artery —> Tibio-peroneal trunk —> Anterior tibial artery, Fibular artery, and posterior tibial artery
Contrast the prevalence and symptoms of occlusion of different arteries in the lower limbs.
Iliac occclusion —> hip/buttock pain
Aortoiliac occlusion —> Leriche syndrome —> bilateral buttock pain
Superficial femoral occlusion —> most common
Tibial occlusion —> esp. in diabetics
What is the risk of claudicants’ symptoms progressing? How does this compare for smokers?
80% of claudicants have no progression of symptoms over 5yrs.
After 5yrs, 11% of claudicants who continue to smoke undergo amputation as compared to 0% for those who stop smoking.
Amputation rate over 5yrs quadrupled in diabetics.
What questions should be asked in the history of claudication?
- where do they experience cramp?
- when did it start?
- relieved by rest? (if not, other causes more likely)
- what distance can they walk before pain?
- how much does it interfere with lifestyle?
- presence of risk factors
- PMHx
What examinations should be made in the history of claudication?
Inspection: colour (cold but pink - anaerobic metabolites cause maximum dilatation), skin condition
Palpation: temp. (compare legs), capillary refill, peripheral pulses (femoral, popliteal, pos. tibial), palpate for aneurysms (inc. abdominal)
Auscultation: bruits; heart & carotid auscultation
What investigations should be performed in the history of claudication?
Bloods: FBC (anaemia aggravates peripheral vascular disease/angina, therefore correcting may reduce pain), BM (?diabetes), serum lipids (CVD risk)
ABPI & treadmill testing
Arterial duplex scan
What does ABPI stand for? How is it performed?
Ankle/brachial pressure index.
Normal >1.1
Arterial disease
How is treadmill testing in the context of peripheral vascular disease performed?
Measure ABPI before and after treadmill exercise.
Fall in ABPI indicates peripheral vascular disease.
What is an arterial duplex scan?
US + doppler
Visualises velocity and flow.
50% narrowing doubles velocity, 75% narrowing triples velocity
Describe the management of claudication caused by peripheral vascular disease.
CONSERVATIVE (e.g. 200m-300m walking distance)
- stop smoking
- aspirin 75mg OR clopidogrel 75mg unless contraindicated
- statins (benefit independent of initial cholesterol or degree of reduction)
- exercise rehab (improves walking technique, optimises collateral circulation, improves capillary perfusion)
INVASIVE (NON-SURGICAL):
- percutaneous transluminal angioplasty
INVASIVE (SURGICAL): failed angioplasty, significant risk of amputation
- surgical bypass (reverse vein graft by reversing valves and use tunnel to insert)
Define critical limb ischaemia.
(Nocturnal) rest pain + ulceration/gangrene of leg
What are the S&S of critical limb ischaemia?
Pain in foot at night (due to reduced gravitational pressure) relieved by dangling foot off bed (increases gravitational pressure to relieve oedema).
What are the examinations to be performaed in suspected critical limb ischaemia?
- pulse status
- temperature
- skin colour: “sunset foot” - foot is paradoxically red
- Buerger’s test - raise foot to 45 degrees (pallor rapidly develops) and then place foot over side of bed (cyanosis may develop)
What is the managament of critical limb ischaemia?
- exercise
- optimise medical management
- angioplasty/bypass to salvage leg (req. adequate blood supply above and below site of occlusion)
- amputation (if in severe pain or revascularisation not possible)
Give some examples of traumatic causes of vascular emergencies.
Penetrating wounds (gunshot, stab, IVDU)
Blunt trauma (joint displacement, fracture, contusion) - particularly shoulder dislocation (axillary artery), supracondylar humeral fractures in children (brachial artery), high tibial "bumper" fractures (popliteal artery), knee dislocation (popliteal artery),
Invasive procedures (arteriography, cardiac catheterisation, balloon angioplasty)
What are the examinations made in vascular trauma?
- Hx of bleeding at scene
- proximity of penetrating wound or blunt trauma to major artery
- diminished unilateral pulse
- small non-palpable haematoma
- neurogenic deficit
Urgent assessment by vascular surgeon:
- external arterial bleeding
- rapidly expanding haematoma
- palpable thrill, audible bruit
- obvious acute limb ischaemia not corrected by reduction or realignment
- serial examination duplex scan & arteriography (prevent unnecessary op., document presence of surgical lesion, localise vascular injury to plan surgical approach)
What is the management of vascular trauma?
- fluid restriction: adequate IV access (place in uninjured extremity to avoid leaking fluid directly into potential tamponade/venous injury), preserve saphenous/cephalic veins (may be req. for repair)
- surgical exploration and repair (prevent limb ischaemia; control life-threatening haemorrhage; prioritise head, chest, and abdo.; amputation may be req.)
Chest:
- management of tension pnuemothorax/tamponade
- arch of aorta/thoracic aortic junction tear: stent graft
What organs are typically damaged in deceleration injuries?
Organs not fixed which keep moving and tear
- kidneys
- transverse colon
- arch of aorta/thoracic aortic junction (90% die before hospital)
Give some examples of causes and symptoms of retroperitoneal bleeds. How are they managed?
Causes:
- pelvic fracture/surgery
- spontaneous (warfarin)
- angiogram/angioplasty
S&S:
- blood tracks upwards —> distension
- hypotension or anaemia following femoral artery catheterisation
- lower back pain
- iliac fossa mass/tenderness (often no associated haematoma at puncture site)
Confirm with ugent CT, treat with urgent surgical repair or radiological intervention
Define acute lower limb ischaemia.
Previously stable limb (contrast to critical/chronic limb ischaemia) with a sudden deterioration in arterial supply, reulting in rest pain/other features of severe ischaemia, of less than 2wks duration.
Usually no Hx of peripheral vascular disease - caused by sudden interruption to blood supply e.g.
- dissection
- trauma
- external compression
- embolism
Contrast the causes of thromboses and embolisms.
Thrombosis:
- atherosclerosis
- popliteal aneurysm
- graft closure
- thrombotic conditions
Embolism (sudden onset, known source, normal pulses in other limbs):
- AF
- mural thrombosis
- vegetations
- proximal aneurysms
- atherosclerotic plaque
