Surgery chapters
Arterial disorders: limb ischaemia, aneurysms and carotid disease
Chronic and acute limb ischaemia, ankle-brachial pressure index, angioplasty and bypass, amputation, abdominal aortic and peripheral aneurysms, carotid disease, Buerger's disease and Raynaud's phenomenon.
- Chronic limb ischaemia runs from intermittent claudication (calf pain on walking, relieved by rest; superficial femoral artery commonest) to critical ischaemia (rest pain, ulcers, gangrene); the key bedside test is the ABPI (normal 0.9-1.3, claudication under 0.9, rest pain under 0.5).
- Acute limb ischaemia (6 Ps; embolus from AF or MI) needs IV heparin and urgent embolectomy (Fogarty) or thrombolysis within about 6 hours; watch for compartment syndrome after reperfusion.
- Repair an AAA at 5.5 cm or if it grows fast or causes symptoms; offer carotid endarterectomy for symptomatic stenosis of 70% or more.
On this page
Overview
Most arterial disease in adults is atherosclerosis, driven by smoking, diabetes, hypertension and high cholesterol. It narrows arteries (ischaemia) or weakens them (aneurysm). Emboli from the heart cause acute limb ischaemia.
PGET has about one MCQ here. Typical themes: site of block from the symptoms, ABPI, acute limb ischaemia, AAA size thresholds, carotid surgery and Buerger's disease.
Chronic lower limb ischaemia
Features
| Stage | Features |
|---|---|
| Intermittent claudication | Cramping pain in a muscle group on walking, relieved by a short rest (minutes), recurring at a similar distance; worse uphill or fast |
| Rest pain | Burning pain in the foot at night, eased by hanging the leg down or sleeping in a chair |
| Tissue loss | Ulcers (between toes, heel, pressure points), gangrene |
- Critical limb ischaemia = rest pain and/or ulceration or gangrene: the leg is threatened and needs urgent vascular assessment.
- Signs: absent pulses, bruits, cold shiny hairless skin, thick nails, slow capillary refill.
- Buerger's test: on raising the leg the foot turns pale (angle of pallor below 20 degrees is severe); on hanging it down it becomes dusky red (dependent rubor, "sunset foot"). Venous guttering on elevation.
A critically ischaemic foot kept hanging down may look red and swollen, mimicking cellulitis. Elevate it: it goes white.
Site of disease from the symptoms
| Level of block | Claudication | Pulses |
|---|---|---|
| Aorto-iliac (both sides) | Buttocks, thighs and calves; impotence = Leriche syndrome | Both femorals absent |
| Iliac (one side) | Thigh and calf (sometimes buttock) on one side | One femoral absent |
| Femoropopliteal (superficial femoral) | Calf (the commonest pattern) | Femoral present, popliteal and foot pulses absent |
| Distal (tibial) | Calf and foot | Femoral and popliteal present, ankle pulses absent |
Pain is felt one level below the block. The superficial femoral artery (at the adductor hiatus) is the commonest site, so calf claudication is commonest.
Ankle-brachial pressure index (ABPI)
ABPI = highest ankle systolic pressure ÷ highest brachial systolic pressure (measured with a hand-held Doppler).
| ABPI | Meaning |
|---|---|
| 0.9-1.3 | Normal |
| Under 0.9 | Arterial disease (claudication range) |
| Under 0.5 | Severe disease, rest pain |
| Under 0.3 | Tissue loss imminent |
| Over 1.3 | Calcified, incompressible arteries (diabetes, CKD): falsely high, unreliable |
Ankle (dorsalis pedis) systolic 70 mmHg, brachial systolic 140 mmHg
ABPI = 70 ÷ 140 = 0.5 → severe disease (rest pain range)
- An exercise test (treadmill) can unmask disease when resting ABPI is normal: a significant fall after exercise confirms flow-limiting disease.
- Toe pressures are used in diabetics when ankle vessels are calcified.
Investigations
- Duplex ultrasound: first-line imaging of stenoses and occlusions.
- CT angiography or MR angiography: plan intervention.
- Digital subtraction angiography (DSA): gold standard, now mainly at the time of angioplasty.
- Bloods: glucose/HbA1c, lipids, renal function (before contrast), FBC.
Management of claudication
- Risk factor control: stop smoking (the single most important step), control diabetes and BP, lose weight.
- Statin for all, regardless of cholesterol; antiplatelet (clopidogrel 75 mg daily, or aspirin 75 mg daily).
- Supervised exercise programme (at least 2 hours a week for 3 months) improves walking distance.
- Cilostazol or naftidrofuryl in some patients if exercise fails.
- Intervention if lifestyle-limiting despite the above.
- Only a minority of claudicants deteriorate, and under 5% need amputation over 5 years. But claudication is a marker of coronary and cerebral disease: many die of MI or stroke.
- Beta-blockers can worsen claudication slightly but are not banned if needed.
Revascularisation
| Method | Best for |
|---|---|
| Percutaneous transluminal angioplasty (PTA) ± stent | Short stenoses or occlusions, especially iliac; low risk; endovascular first in many cases |
| Endarterectomy | Localised disease, e.g. common femoral bifurcation, carotid |
| Bypass surgery | Long occlusions. Aortobifemoral (aorto-iliac), femoropopliteal and femorodistal bypass; extra-anatomic (axillobifemoral, femorofemoral crossover) for unfit patients |
- Vein (great saphenous) is the best conduit below the inguinal ligament; prosthetic grafts (PTFE, Dacron) do well in large vessels (aorta, iliac) but worse below the knee.
The diabetic foot
- Combines neuropathy (painless ulcers at pressure points, Charcot joint), ischaemia (small and calf vessel disease) and infection.
- Neuropathic ulcers: warm foot, pulses present, ulcer under metatarsal heads. Ischaemic ulcers: cold foot, absent pulses, ulcers on toes and heels.
- Treat infection urgently (debride, drain, antibiotics), offload pressure, revascularise if ischaemic. Toe or ray amputation often heals in diabetics with local small-vessel disease.
Acute limb ischaemia
Causes
| Embolus | Thrombosis in situ |
|---|---|
| Source: atrial fibrillation (commonest), recent MI (mural thrombus), valve disease, aneurysm | Rupture of an existing atheromatous plaque; graft or stent occlusion |
| Sudden, severe; no previous claudication | Previous claudication; collaterals present, so often less severe |
| Normal pulses in the other leg | Absent pulses in the other leg too |
| Common sites: bifurcations (common femoral, popliteal, aortic saddle) | - |
Other causes: trauma, dissection, popliteal aneurysm thrombosis, intra-arterial injection of drugs (seen in drug users), compression (cervical rib in the arm).
Features: the "6 Ps"
Pain, Pallor, Pulselessness, Perishing cold, Paraesthesia, Paralysis.
Paraesthesia and paralysis (loss of sensation and movement) mean the limb is threatened and needs urgent revascularisation. Fixed, non-blanching mottling with rigid muscles means the limb is non-viable (amputation, not revascularisation).
Management
- IV unfractionated heparin bolus (5000 units) at once to stop clot spreading; analgesia; oxygen.
- Embolus: embolectomy with a Fogarty balloon catheter through a groin (common femoral) arteriotomy under local or general anaesthesia; check with on-table angiography.
- Thrombosis or less severe ischaemia: catheter-directed thrombolysis (tPA) or angioplasty/bypass. Contraindications to thrombolysis: recent stroke, bleeding tendency, recent surgery, pregnancy.
- After the operation: anticoagulate long-term and treat the source (AF).
- Time matters: muscle and nerve damage becomes irreversible after about 6 hours of complete ischaemia.
Reperfusion problems
- Compartment syndrome: swelling of reperfused muscle inside tight fascial compartments. Pain out of proportion, pain on passive stretch, tense calf; pulses may still be present. Fasciotomy of all four calf compartments.
- Reperfusion injury: hyperkalaemia, acidosis, myoglobinuria and acute kidney injury.
Palpable pulses do not exclude compartment syndrome. Diagnose on clinical grounds (pain on passive stretch) and pressure measurement; do not wait for the pulse to disappear.
Amputation
Indications: the "3 Ds": Dead (gangrene), Deadly (wet gangrene, spreading infection, toxicity), Dead loss (severe unreconstructable rest pain, useless painful limb).
| Level | Points |
|---|---|
| Toe / ray | Diabetic local gangrene with reasonable foot blood supply |
| Transmetatarsal | Forefoot gangrene |
| Syme's (ankle) | Rare in vascular disease |
| Below-knee (transtibial) | Preferred where possible: better walking with a prosthesis. Skin flap: long posterior (Burgess) |
| Through-knee | Alternative |
| Above-knee (transfemoral) | Heals more reliably; walking much harder |
- Ideal stump length: about 10-12 cm below the knee (not under 8 cm); above the knee at least 20 cm.
- Complications: infection, wound breakdown, phantom limb pain, contracture, DVT, stump neuroma.
Aneurysms
- Aneurysm = permanent dilatation of an artery to more than 1.5 times normal diameter (a 50% increase).
- True aneurysm: all three wall layers. False (pseudo) aneurysm: contained leak with only fibrous tissue wall (after femoral puncture, trauma, infection, anastomotic leak).
- Shape: fusiform (commonest) or saccular.
- Causes: atherosclerosis/degeneration (commonest), trauma, infection (mycotic), connective tissue disease (Marfan, Ehlers-Danlos), syphilis (thoracic), arteritis.
Abdominal aortic aneurysm (AAA)
- Commonest true aneurysm; mostly infrarenal. Main risk factors: male sex, age over 65, smoking, family history, hypertension.
- Usually asymptomatic: a pulsatile, expansile mass above the umbilicus, found by chance or on screening (a single ultrasound for men at 65 in the UK).
- Imaging: ultrasound for screening and surveillance; CT angiography to plan repair.
| Diameter | Plan |
|---|---|
| 3.0-5.4 cm | Ultrasound surveillance (more often as size rises); control risk factors, stop smoking |
| 5.5 cm or more | Elective repair if fit |
| Growing more than 1 cm a year, or symptomatic (tender) | Repair regardless of size |
- Rupture risk rises sharply with size: low under 5.5 cm, but very high at 7 cm.
- Repair options: open (inlay tube or bifurcated graft) or EVAR (endovascular stent graft through the femoral arteries; many infrarenal aneurysms are suitable). EVAR has lower early mortality but needs lifelong surveillance for endoleak and graft migration.
Complications of AAA repair: MI (commonest cause of death), bleeding, renal failure, ischaemic left colon (inferior mesenteric artery loss: bloody diarrhoea), distal emboli ("trash foot"), spinal ischaemia, graft infection, late aorto-enteric fistula (GI bleeding months to years later).
Ruptured AAA
- Sudden abdominal or back pain, collapse, pulsatile mass, shock; often mistaken for renal colic. Most rupture retroperitoneally (which tamponades briefly); intraperitoneal rupture is usually fatal at once.
- Management: call senior help, permissive hypotension (keep systolic pressure low, under about 100 mmHg, just enough for consciousness), cross-match 6 units, straight to theatre for open repair or EVAR. CT only if the patient is stable.
- Overall mortality, including deaths before hospital, is very high.
An elderly hypotensive man with "renal colic" and back pain has a ruptured AAA until proven otherwise.
Peripheral aneurysms
- Popliteal aneurysm: the commonest peripheral aneurysm; often bilateral and associated with AAA, so examine the other knee and the abdomen. Danger is thrombosis or distal embolism (acute limb ischaemia), not rupture. Repair those over about 2 cm or with thrombus.
- Femoral false aneurysm after catheterisation: pulsatile groin swelling; small ones treated by ultrasound-guided thrombin injection or compression; larger ones need surgical repair.
Carotid artery disease
- Atheroma at the carotid bifurcation throws off emboli to the brain and eye.
- Symptoms (anterior circulation): TIA (deficit lasting under 24 hours), stroke, amaurosis fugax (transient monocular blindness, "curtain coming down"), contralateral weakness or numbness, dysphasia.
- Investigation: carotid duplex ultrasound; CT or MR angiography to confirm.
- Carotid endarterectomy for symptomatic stenosis of 70% or more (some benefit from 50-69%), done as soon as possible (ideally within 2 weeks) of the event, plus best medical therapy (antiplatelet, statin, BP control).
- Asymptomatic stenosis: mostly medical treatment; surgery only for selected patients.
- Complications: stroke, MI, cranial nerve injury (hypoglossal: tongue deviates to the operated side; also vagus/recurrent laryngeal, marginal mandibular), neck haematoma.
Upper limb and other arterial problems
- Subclavian steal syndrome: proximal subclavian stenosis makes blood flow backwards down the vertebral artery to the arm when the arm is used, causing dizziness or syncope with arm exercise; BP differs between arms.
- Cervical rib / thoracic outlet syndrome: compression of subclavian artery (post-stenotic aneurysm, emboli, Raynaud's), vein or the lower brachial plexus (T1: wasting of small hand muscles).
- Mesenteric ischaemia: chronic causes post-prandial pain ("gut claudication") and weight loss; acute is an emergency (pain out of proportion to signs, often in AF).
- Renal artery stenosis: hypertension, renal failure.
Buerger's disease and vasospasm
Thromboangiitis obliterans (Buerger's disease)
- Inflammatory occlusion of small and medium arteries and veins (tibial, plantar, radial, digital) in young male smokers (usually under 30-40). Common in South Asia.
- Features: claudication of the foot (instep), rest pain, digital ulcers and gangrene, migratory superficial thrombophlebitis, Raynaud's; upper limbs may be involved.
- Angiography: distal occlusions with corkscrew collaterals; proximal arteries normal.
- Treatment: complete and permanent cessation of smoking (and all tobacco), which halts but does not reverse the disease. Pain relief, wound care, prostacyclin analogues; amputation of gangrenous digits. Bypass is seldom possible.
Raynaud's phenomenon
- Episodic digital vasospasm on cold or emotion: fingers turn white (spasm) → blue (cyanosis) → red (reactive hyperaemia), often painful.
| Primary (Raynaud's disease) | Secondary (Raynaud's syndrome) |
|---|---|
| Young women; benign; symmetrical; no ulcers | Older onset, asymmetrical, digital ulcers, abnormal nail-fold capillaries |
| No underlying cause | Systemic sclerosis, SLE, RA, vibrating tools ("vibration white finger"), cervical rib, beta-blockers |
- Treatment: keep warm (gloves), stop smoking, avoid triggers; nifedipine (calcium-channel blocker); treat the cause. Sympathectomy gives poor long-term results.
Giant cell (temporal) arteritis
- Over 50, headache, scalp tenderness, jaw claudication, high ESR. Start high-dose steroids at once to prevent blindness; then temporal artery biopsy (at least 2.5 cm, as lesions skip).
Expect: locating the block from the site of claudication (calf = superficial femoral; Leriche = aorto-iliac), ABPI values and falsely high readings in diabetics, rest pain eased by dependency, first-line management of claudication (stop smoking, exercise, statin, antiplatelet), the 6 Ps, embolus versus thrombosis, heparin and Fogarty embolectomy, fasciotomy for compartment syndrome, indications for amputation, AAA repair at 5.5 cm and the ruptured AAA mimicking renal colic, popliteal aneurysm with AAA, carotid endarterectomy for symptomatic 70% stenosis, Buerger's disease in young smokers and the colour sequence of Raynaud's.
Quick revision
- Calf claudication: superficial femoral artery; buttock + impotence: Leriche.
- ABPI normal 0.9-1.3; under 0.5 rest pain; over 1.3 falsely high (calcified).
- Claudication: stop smoking, exercise, statin, clopidogrel; intervene if lifestyle-limiting.
- Acute ischaemia: 6 Ps; heparin, then embolectomy or thrombolysis; fasciotomy after reperfusion.
- AAA: survey under 5.5 cm; repair at 5.5 cm, rapid growth or symptoms.
- Ruptured AAA: permissive hypotension, straight to theatre.
- Popliteal aneurysm: commonest peripheral, bilateral, thromboses rather than ruptures.
- Carotid endarterectomy: symptomatic stenosis 70% or more, within 2 weeks.
- Buerger's: young male smokers, stop all tobacco.
Written by The House Job from standard references (Bailey & Love).
FAQ
Why does a patient with rest pain hang the leg over the edge of the bed?
Gravity raises the perfusion pressure in the foot, so blood flow improves slightly and the ischaemic pain eases.
Why may ABPI be falsely normal or high in diabetes?
The calf arteries become calcified and cannot be compressed by the cuff, so the measured ankle pressure is falsely high; toe pressures are used instead.
What is the first thing to do for an acutely ischaemic leg from an embolus?
Give an intravenous heparin bolus to stop the clot extending, relieve pain and arrange urgent embolectomy.
At what size is an abdominal aortic aneurysm repaired?
At 5.5 cm or more in a fit patient, or earlier if it is tender or growing quickly.
What is the treatment of Buerger's disease?
Complete and permanent stopping of smoking and all tobacco, which halts progression; other measures only relieve symptoms.