• Trauma & emergency surgery
• GI surgery (appendicitis, bowel obstruction, hernias, etc.)
• Hepatobiliary (gallstones, pancreatitis, liver)
• Breast & endocrine surgery
• Vascular surgery
• Perioperative care (fluids, wound healing, complications)
• A specific condition or procedure

Causes of Leg Ulcers

1. Venous ulcers - superficial incompetence, deep incompetence or obstruction (post-thrombotic); commonest cause
2. Arterial/ischaemic ulcers - peripheral arterial disease, atherosclerosis
3. Vasculitic ulcers - rheumatoid arthritis, SLE, polyarteritis nodosa
4. Traumatic ulcers
5. Neuropathic ulcers - diabetes, leprosy, tabes dorsalis
6. Neoplastic ulcers - Marjolin's ulcer (SCC from chronic venous ulcer), rodent ulcer (BCC)
7. Infective ulcers - tuberculosis, syphilis (gummatous), staphylococcal, Meleney's synergistic gangrene
8. Erythrocyanoid ulcer (Bazin's disease) - young women, poor arterial supply + cold sensitivity
9. Martorell's ulcer - hypertensive ulcer, old age, atherosclerosis, sudden obliteration of end arterioles
10. Congenital arteriovenous fistula - rare, occurs at early age
11. Blood dyscrasias - sickle cell disease, polycythaemia

Thromboangiitis Obliterans (TAO / Buerger's Disease) - 10 Marks

Definition

Incidence / Epidemiology

• Highest prevalence in Eastern European, Mediterranean, and Asian countries
• Predominantly affects young male smokers (onset < 45 years)
• Women now account for nearly 20% of cases due to increasing tobacco use
• Worldwide distribution

Aetiology

• Tobacco use is the single most important factor - cigarettes, cigars, smokeless tobacco, chewing tobacco, snuff
• Exact etiology unknown; likely involves an immune/inflammatory mechanism triggered by tobacco
• Causal relationship not fully established but smoking is essential for disease progression
• Tobacco cessation = cessation of disease activity

Pathology

• Inflammatory changes in walls of both arteries and veins (pan-arteritis / pan-phlebitis)
• Highly cellular, inflammatory thrombus in lumen - unlike the bland thrombus of atherosclerosis
• The inflammatory process involves all three layers of the vessel wall
• Leads to thrombosis and occlusion of small/medium vessels
• Results in a cellular, inflammatory thrombus with preservation of the internal elastic lamina (important distinguishing feature from atherosclerosis)
• Giant cells may be seen in the thrombus

Clinical Features

Presentation (onset < 45 years in a heavy smoker)

• Distal extremity claudication - foot arch or calf claudication (foot claudication is characteristic; distinguishes from PAD which is more calf)
• Cold sensitivity
• Raynaud's phenomenon
• Migratory superficial thrombophlebitis - tender red nodules along superficial veins

• Rest pain (most common presentation, seen in 2/3 of patients)
• Ischaemic ulceration - fingers, toes, feet
• Gangrene - typically starts at tips of toes/fingers (distal gangrene)
• At least two or more extremities always involved; 40% of cases affect all four limbs

Diagnosis

Clinical Criteria (TAO is a diagnosis of exclusion):

1. Age < 45 years at onset
2. History of tobacco use
3. Distal extremity ischaemia in two or more limbs
4. Angiographic findings suggestive of TAO
5. No other cause found

Investigations:

• Allen's test - positive in a young smoker with distal ischaemia suggests TAO (tests hand/finger circulation)
• Ankle-brachial index (ABI) + segmental pressures + arterial waveforms
• Buerger's postural test - affected limb goes white on elevation, then blue then red on dependency
• Duplex Doppler / Angiography - characteristic findings: corkscrew collaterals, segmental occlusion of small/medium vessels, no atherosclerosis, no proximal disease
• Echocardiography / CT angiography / MR angiography - rule out proximal embolic sources
• Lab tests to exclude other causes: CBC, ESR, CRP, fasting glucose, ANA, rheumatoid factor, antiphospholipid antibodies, complement, CREST/scleroderma markers, hypercoagulability screen
• Biopsy - only definitive test; rarely required; reserved for unusual presentations

Treatment

First-line and ONLY definitive treatment:

Complete and total abstinence from all tobacco in any form

• Arrests (but does not reverse) the disease
• Even one cigarette a day can perpetuate the disease

Medical:

• Prostacyclin (iloprost) and analogues - most effective medical therapy
• Aspirin
• Selective low-dose intra-arterial streptokinase
• Bosentan (dual endothelin-1 receptor antagonist)
• Serotonin blockers, sarpogrelate
• PDE5 inhibitors (sildenafil)
• Calcium channel blockers for Raynaud's component

Surgical:

• Sympathectomy (lumbar/cervical) - reduces vasospasm and rest pain
• Arterial reconstruction - only if suitable vessels exist (often not possible due to distal, diffuse disease)
• Angioplasty of individual tibial/foot obstructions
• Omental transfer - for critical ischaemia
• Kirschner wire in medullary canal of tibia
• Amputation - eventually required when gangrene is irreversible

Experimental:

• Intramuscular VEGF injections
• Autologous bone marrow stem cell transplantation
• Immunoadsorption

Key Exam Points to Remember

Chronic Lower Limb Ischaemia

CAUSES

• Atherosclerosis (commonest) - aortoiliac, femoropopliteal, tibial/crural levels
• Diabetes mellitus (accelerates atherosclerosis, preferentially affects tibial vessels)

• Thromboangiitis obliterans (Buerger's disease) - young male smokers
• Takayasu's arteritis - young women, large vessel
• Other vasculitides (SLE, RA, polyarteritis nodosa)

• Embolism (from cardiac source - AF, valvular disease)
• Trauma / iatrogenic
• Popliteal artery entrapment syndrome
• Cystic adventitial disease
• Radiation arteritis
• Hypercoagulable states

• Smoking (most important modifiable risk factor)
• Diabetes mellitus
• Hypertension
• Hyperlipidaemia
• Obesity
• Family history

PATHOPHYSIOLOGY

┌─────────────────────────────────────────────────────────────────┐
│              PATHOPHYSIOLOGY OF CHRONIC LIMB ISCHAEMIA          │
└─────────────────────────────────────────────────────────────────┘

Risk Factors (smoking, DM, HTN, hyperlipidaemia)
          │
          ▼
  Endothelial Injury
          │
          ▼
  Lipid deposition → Foam cell formation → Fatty streaks
          │
          ▼
  Fibrous plaque (atherosclerosis)
          │
          ▼
  Progressive arterial stenosis / occlusion
          │
     ┌────┴────┐
     │         │
  Gradual    Sudden
  onset      thrombosis
     │         │
     └────┬────┘
          │
          ▼
  Reduced arterial perfusion pressure distal to lesion
          │
     ┌────┴──────────────────────┐
     │                           │
  Collaterals develop         No/inadequate
  (compensate initially)      collaterals
     │                           │
     ▼                           ▼
  Claudication             Critical ischaemia
  (exercise demand          (rest pain, ulcer,
  exceeds supply)            gangrene)

• Profunda femoris artery is the main collateral around SFA occlusion
• Geniculate arteries provide collaterals around popliteal occlusion
• In chronic occlusion, collaterals can reconstitute distal vessels (e.g., SFA reconstitutes at adductor hiatus via profunda geniculate arteries)

CLINICAL FEATURES

Fontaine Classification (exam favourite)

┌───────────┬──────────┬───────────────────────────────────────────┐
│  FONTAINE │   GRADE  │        CLINICAL DESCRIPTION               │
├───────────┼──────────┼───────────────────────────────────────────┤
│  Stage I  │    0     │  Asymptomatic                             │
├───────────┼──────────┼───────────────────────────────────────────┤
│  Stage II │    1     │  Mild claudication                        │
│           │    2     │  Moderate claudication                    │
│           │    3     │  Severe claudication                      │
├───────────┼──────────┼───────────────────────────────────────────┤
│  Stage III│    4     │  Ischaemic rest pain (ABI < 0.4)          │
├───────────┼──────────┼───────────────────────────────────────────┤
│  Stage IV │    5     │  Minor tissue loss / non-healing ulcer    │
│           │    6     │  Major tissue loss / gangrene (CLTI)      │
└───────────┴──────────┴───────────────────────────────────────────┘

Stages III–VI = Chronic Limb-Threatening Ischaemia (CLTI)

Symptoms

• Cramp-like pain in muscles (calf most common; thigh/buttock in aortoiliac disease)
• Brought on by walking, NOT present on first step (unlike OA)
• Relieved by rest in standing/sitting within 5 minutes (unlike spinal stenosis which needs sitting)
• Reproducible claudication distance (varies only slightly day to day)

• Constant severe pain in forefoot / across metatarsophalangeal joint
• Worse at night (loss of gravity)
• Patient hangs foot out of bed or sleeps in a chair to get relief
• Severe, unrelenting, even with narcotics

• Painful erosions between toes / dorsum of foot / shins / malleoli
• Punched-out, non-healing
• Often triggered by minor trauma (poorly fitting shoes)

• Dry gangrene: demarcated, dry, mummified (good collaterals proximally)
• Wet gangrene: superadded infection, rapidly spreading, limb-threatening

Signs

• Muscle wasting
• Loss of hair
• Thickened nails (onychogryphosis)
• Pallor on elevation → dependent rubor ("sunset foot" sign)
• Ulceration / gangrene

• Diminished / absent pulses (femoral, popliteal, dorsalis pedis, posterior tibial)
• Cold limb
• Prolonged capillary refill (> 3 seconds; severe ischaemia > 10 seconds)

• Arterial bruit over stenotic segment

Relationship of Signs to Level of Disease

┌─────────────────────┬──────────────────────────────────────────────┐
│   LEVEL             │   CLINICAL FINDINGS                          │
├─────────────────────┼──────────────────────────────────────────────┤
│ Aortoiliac          │ Claudication: buttocks, thighs, calves       │
│ (Leriche syndrome)  │ Absent femoral + all distal pulses bilaterally│
│                     │ Impotence (in men)                           │
│                     │ Bruit over aortoiliac region                 │
├─────────────────────┼──────────────────────────────────────────────┤
│ Iliac               │ Unilateral thigh + calf claudication         │
│                     │ Unilateral absent femoral + distal pulses    │
│                     │ Bruit over iliac region                      │
├─────────────────────┼──────────────────────────────────────────────┤
│ Femoropopliteal     │ Calf claudication (unilateral)               │
│ (SFA - commonest)   │ Femoral pulse present; distal pulses absent  │
├─────────────────────┼──────────────────────────────────────────────┤
│ Distal (tibial)     │ Foot claudication                            │
│                     │ Femoral + popliteal present; ankle absent    │
└─────────────────────┴──────────────────────────────────────────────┘

INVESTIGATIONS

Flowchart

        Patient with suspected chronic lower limb ischaemia
                              │
              ┌───────────────┼────────────────┐
              ▼               ▼                ▼
        BEDSIDE           BLOOD TESTS      IMAGING
              │               │                │
     ┌────────┴──────┐   ┌────┴────┐    ┌──────┴────────┐
     │ Handheld      │   │ FBC     │    │ Duplex USS    │
     │ Doppler       │   │ Glucose │    │ (1st line)    │
     │               │   │ Lipids  │    │               │
     │ ABI (ABPI)    │   │ U&E/Cr  │    │ CTA           │
     │               │   │ Coag    │    │               │
     │ Toe pressures │   │ ECG     │    │ MRA           │
     │               │   │ Echo    │    │               │
     │ Buerger's     │   └─────────┘    │ DSA (gold     │
     │ postural test │                  │  standard,    │
     └───────────────┘                  │  pre-op)      │
                                        └───────────────┘

1. Ankle-Brachial Pressure Index (ABI / ABPI) - Most important bedside test

ABI = Highest ankle systolic pressure (DP or PT)
      ─────────────────────────────────────────
      Highest brachial systolic pressure

┌─────────────────┬──────────────────────────────────────┐
│   ABI VALUE     │   INTERPRETATION                     │
├─────────────────┼──────────────────────────────────────┤
│   0.9 – 1.4     │   Normal                             │
│   0.7 – 0.9     │   Mild PAD (claudication)            │
│   0.4 – 0.7     │   Moderate PAD                       │
│   < 0.4         │   Severe / Critical ischaemia (CLTI) │
│   > 1.4         │   Non-compressible vessels (DM/CKD)  │
└─────────────────┴──────────────────────────────────────┘

Note: Normal triphasic Doppler signal → diseased = biphasic/monophasic

2. Buerger's Postural Test (Bedside)

• Elevate limb to 45° for 2 minutes → ischaemic limb goes pale/white
• Hang limb in dependent position → goes blue (venous filling) then red (reactive hyperaemia)
• A positive test indicates significant ischaemia

3. Blood Investigations:

• FBC (anaemia, polycythaemia, thrombocytosis)
• Fasting glucose (diabetes)
• Lipid profile
• U&E / creatinine (renal function - contrast risk)
• Coagulation / thrombophilia screen (especially in young patients)
• ESR / CRP (inflammatory / vasculitic cause)
• ECG + echocardiogram (cardiac disease, embolic source - very common comorbidity)

4. Duplex Ultrasound Scan (DUS) - First-line imaging

• Non-invasive, no radiation
• Identifies stenosis/occlusion level and severity
• Measures flow velocities
• Used for planning intervention

5. CT Angiography (CTA)

• Excellent anatomical detail
• Rapid, widely available
• Risk: iodinated contrast (nephropathy especially in diabetics; avoid metformin perioperatively)

6. MR Angiography (MRA)

• No ionising radiation, no iodinated contrast
• Preferred in diabetics with calcified crural vessels
• Contraindicated with certain metallic implants / pacemakers
• Uses gadolinium (risk of nephrogenic systemic fibrosis in renal failure)

7. Digital Subtraction Angiography (DSA) - Gold standard

• Invasive (Seldinger technique, percutaneous femoral puncture)
• Best anatomical detail, allows simultaneous intervention (PTA/stenting)
• Reserved for pre-operative planning / when endovascular treatment planned

MANAGEMENT

Management Flowchart

        CONFIRMED CHRONIC LOWER LIMB ISCHAEMIA
                        │
          ┌─────────────┴────────────┐
          ▼                          ▼
    CLAUDICATION              CLTI (Rest pain /
    (Stages I-II)              Tissue loss / Gangrene)
          │                          │
          │                    URGENT referral to
          │                    vascular team
          │
    ┌─────┴──────────────┐
    ▼                    ▼
CONSERVATIVE         INTERVENTION
(majority)           (if lifestyle-limiting
                     despite conservative Rx)
    │
    ├─ Risk factor modification
    ├─ Exercise programme
    ├─ Antiplatelet (clopidogrel / aspirin)
    └─ Statin
                    │
          ┌─────────┴────────────┐
          ▼                      ▼
   ENDOVASCULAR              OPEN SURGERY
   (first-line for            (for complex /
    suitable lesions)          long occlusions)
          │                      │
   ┌──────┴──────┐        ┌──────┴──────────┐
   │ PTA         │        │ Aortobifemoral  │
   │ Stenting    │        │ bypass          │
   │ Subintimal  │        │ Femoropopliteal │
   │ angioplasty │        │ bypass (vein)   │
   └─────────────┘        │ Femorodistal    │
                          │ bypass          │
                          │ Axillofemoral   │
                          │ bypass          │
                          └─────────────────┘
                                  │
                             If unsalvageable
                                  │
                                  ▼
                            AMPUTATION

A. Conservative / Medical Management

• Stop smoking (most important - slows progression, reduces amputation risk)
• Control diabetes, hypertension, hyperlipidaemia
• Weight loss

• Supervised treadmill exercise for 30-45 min, 3x/week for 3 months
• Stimulates collateral vessel development
• Increases claudication distance significantly
• First-line for claudication (> 70% of patients improve with this alone)

• Antiplatelet: Clopidogrel 75 mg/day (preferred) OR Aspirin 75 mg/day - reduces cardiovascular events
• Statin - e.g., atorvastatin: stabilises plaques, reduces cardiac death independent of lipid levels
• Naftidrofuryl oxalate - vasodilator, modest improvement in claudication distance
• Cilostazol - PDE3 inhibitor, improves claudication (not available everywhere)
• Vasodilators (calcium blockers, etc.) - unlikely to give sustained benefit

B. Endovascular Treatment

• Balloon catheter inflated in stenosis/occlusion
• Very successful for iliac and femoropopliteal segments
• Less successful below knee (improving with newer technology)
• Complications (~5%): failure, haematoma, thrombosis, distal embolisation

• If vessel fails to stay dilated after PTA
• Metallic stent maintains vessel patency

• Guidewire passed in subintimal plane across long occlusion
• New lumen created by balloon inflation

• TASC A lesions → endovascular (preferred)
• TASC D lesions → open surgery (preferred)
• TASC B/C → individualised decision

C. Open Surgical Management

• Aortoiliac reconstruction: 90% patency at 5 years (excellent)
• Femoropopliteal vein bypass: ~60% patency at 5 years
• PTFE bypass: inferior to vein, especially below knee

D. Amputation - Last resort

• When revascularisation not possible / failed
• When limb is unsalvageable (wet gangrene, overwhelming sepsis)
• Levels: toe → ray amputation → transmetatarsal → below-knee (BKA) → above-knee (AKA)
• Poor circulation proximal to gangrene = revascularise first, then more conservative amputation level

SUMMARY DIAGRAM

┌───────────────────────────────────────────────────────────────┐
│               CHRONIC LOWER LIMB ISCHAEMIA - OVERVIEW         │
├───────────────────────────────────────────────────────────────┤
│  CAUSES: Atherosclerosis (90%) >> TAO, vasculitis, others     │
├───────────────────────────────────────────────────────────────┤
│  SPECTRUM:                                                    │
│  Asymptomatic → Claudication → Rest pain → Ulcer → Gangrene  │
│  (Fontaine I)    (II)           (III)      (IV)     (IV)     │
├───────────────────────────────────────────────────────────────┤
│  KEY TEST: ABI                                                │
│  Normal: 0.9-1.4 | Claudication: 0.7-0.9 | CLTI: <0.4       │
├───────────────────────────────────────────────────────────────┤
│  MANAGEMENT BY STAGE:                                         │
│  Stage I-II (Claudication):                                   │
│    → Exercise + Risk factor control + Antiplatelet + Statin   │
│    → Endovascular / Surgery only if lifestyle-limiting        │
│  Stage III-IV (CLTI):                                         │
│    → Urgent revascularisation (endovascular or open bypass)  │
│    → Amputation if unsalvageable                             │
└───────────────────────────────────────────────────────────────┘