Mastering Vascular Topics for MSRA: A Structured Clinical Review
- examiner mla
- Jul 18
- 4 min read
Updated: Jul 18
Vascular pathology is a high-yield theme in the MSRA Clinical Problem Solving paper. Many cases revolve around leg pain, ulcers, limb changes, or systemic vascular emergencies — and examiners love asking about safe compression use, ABPI interpretation, and recognising red flags.
This review will break down the most tested vascular conditions, their clinical features, investigations, and appropriate first-line management, all mapped to UK practice and MSRA standards.
✅ 1. Ankle–Brachial Pressure Index (ABPI)
📌 What is ABPI?
A non-invasive bedside test comparing systolic pressure at the ankle with that in the arm.
Used to detect peripheral arterial disease (PAD) and assess suitability for compression therapy.
🔍 How to Interpret ABPI:
ABPI | Interpretation | Action |
< 0.5 | Critical ischaemia | Urgent vascular referral |
0.5 – 0.8 | Moderate arterial disease | Compression contraindicated |
0.8 – 1.3 | Normal | Safe for compression |
> 1.3 | Calcified/incompressible arteries | Use toe pressures or imaging |
🔑 Key Point: Never initiate compression therapy (e.g. for venous ulcers) without checking ABPI first.
✅ 2. Peripheral Arterial Disease (PAD)
📌 Definition
PAD is caused by atherosclerosis in peripheral arteries, commonly affecting the lower limbs. It progresses from intermittent claudication to critical limb ischaemia and sometimes acute limb ischaemia.
🧠 Spectrum of PAD
Stage | Features | ABPI |
Intermittent Claudication | Cramping calf pain after walking, relieved by rest | < 0.9 |
Critical Limb Ischaemia | Rest pain (esp. at night), ulcers, gangrene, dependency rubor | < 0.5 |
Acute Limb Ischaemia | Sudden onset, 6 P’s: Pain, Pallor, Pulseless, Paraesthesia, Paralysis, Perishingly cold | Often immeasurable |
⚙️ Management of PAD
Lifestyle: Smoking cessation, exercise (supervised ≥ 3 months)
Medical therapy:
Statin: Atorvastatin 80 mg
Antiplatelet: Clopidogrel 75 mg OD
Revascularisation if medical therapy fails:
Angioplasty ± stenting
Bypass graft
Naftidrofuryl oxalate: If exercise fails and surgery is not suitable
✅ 3. Venous Ulcers vs Arterial Ulcers
📍 Venous Ulcers
Location: Medial lower leg (gaiter area)
Cause: Chronic venous insufficiency → venous hypertension
Appearance: Sloping edges, granulating base, often weeping
Surrounding skin: Hyperpigmentation, lipodermatosclerosis, varicosities
Pain: Mild to moderate, better with elevation
ABPI: > 0.8 → safe for compression
📍 Arterial Ulcers
Location: Toes, heels, lateral malleolus
Cause: Ischaemia due to PAD
Appearance: Punched-out, dry, pale or necrotic
Surrounding skin: Cold, shiny, hairless
Pain: Severe, worse at night or on elevation
ABPI: < 0.8 → compression contraindicated
🎯 Ulcer Management
Venous Ulcer: Mainstay is compression therapy (e.g. 4-layer bandaging), only if ABPI > 0.8
Arterial Ulcer: Requires vascular referral, no compression
✅ 4. Acute Limb Ischaemia (ALI)
📌 Definition
Sudden loss of limb perfusion due to embolism or thrombosis. Can lead to permanent damage within hours.
🚨 6 Ps of ALI
Pain (severe, sudden)
Pallor
Pulselessness
Paraesthesia
Paralysis
Perishingly cold
🏥 Management
Urgent vascular referral
Heparin anticoagulation
Thrombo-embolectomy or thrombolysis
ALI is a surgical emergency — imaging should not delay referral unless requested by vascular team.
✅ 5. Abdominal Aortic Aneurysm (AAA)
📌 Definition
A localised dilation of the abdominal aorta ≥3.0 cm.
🧬 Risk Factors
Male ≥ 65 years
Smoking (strongest risk factor)
Hypertension
Family history
📏 Size-Based Classification
Diameter | Classification | Management |
3.0–4.4 cm | Small | Annual ultrasound |
4.5–5.4 cm | Medium | 3-monthly ultrasound |
≥ 5.5 cm | Large | Elective repair (EVAR/open) |
🚨 Ruptured AAA
Triad: Hypotension + abdominal/back pain + pulsatile mass
Immediate action: Resuscitate, activate major haemorrhage protocol, urgent surgery
Avoid aggressive fluid bolus → permissive hypotension
✅ 6. EVAR (Endovascular Aneurysm Repair)
⚙️ What is EVAR?
Minimally invasive stent-graft insertion via femoral arteries
Used for AAA repair, particularly in high-risk surgical patients
✅ Benefits
Lower peri-op mortality
Shorter recovery
No general anaesthesia required
⚠️ Drawbacks
Requires lifelong imaging (risk of endoleak)
Not suitable for all anatomies
✅ 7. Carotid Artery Stenosis
📌 Presentation
TIA or stroke symptoms: Amaurosis fugax, contralateral weakness, dysphasia
Carotid bruit may be present
🧪 Investigations
First-line: Duplex ultrasound
For surgical planning: CT or MR angiography
✂️ Management
Stenosis (NASCET) | Symptomatic? | Action |
≥ 70% | Yes | Carotid endarterectomy within 2 weeks |
< 50% | No | Best medical therapy |
✅ 8. Varicose Veins
📌 Presentation
Visible dilated veins
Aching/heaviness worse after standing
Leg swelling
Itching, eczema, skin pigmentation in advanced cases
🧪 Investigation
First-line: Duplex ultrasound – confirms reflux, maps venous system
🩺 Management
Stage | Management |
Mild | Leg elevation, compression stockings |
Symptomatic/severe | Endothermal ablation (first-line) |
If unsuitable → foam sclerotherapy/surgery |
🔍 ABPI not needed unless ulcer is present or compression is planned.
🚩 9. Red Flag Scenarios in Vascular Medicine
Scenario | Red Flag Diagnosis | Immediate Action |
Collapsed elderly man + back pain + hypotension | Ruptured AAA | Resuscitate → Theatre |
Sudden limb pain + pulselessness | Acute Limb Ischaemia | Urgent vascular referral |
ABPI > 1.3 in diabetic with claudication | Calcified vessels | Use toe pressures/imaging |
Bilateral leg oedema + cancer history | IVC obstruction | Urgent imaging & referral |
📌 Summary Table: Compression Safety Based on ABPI
ABPI | Can You Compress? |
< 0.5 | ❌ Never |
0.5–0.8 | ❌ No |
0.8–1.3 | ✅ Yes |
> 1.3 | ❌ No – investigate further |
🧠 Final Clinical Tips for MSRA Vascular Topics
Always check ABPI before compression
Recognise ulcer types based on location + skin signs
Know when CEA is indicated: symptomatic + ≥70% (NASCET), within 2 weeks
In acute limb symptoms, think 6 Ps and act fast
Don’t delay surgery in a ruptured AAA
Know EVAR vs open repair pros/cons
Duplex is first-line for varicose veins and carotid stenosis
📚 References
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