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Arterial Disorders

Features of Chronic Arterial Stenosis or Occlusion in the Leg

Intermittent Claudication

  • Definition: Pain caused by anaerobic muscle metabolism, typically cramp-like.
  • Characteristics:
    • Triggered by walking, not present at rest.
    • Relieved by rest (both standing and sitting), within 5 minutes.
    • Claudication distance (distance a patient can walk before stopping) decreases with increased activity or poor health (e.g., anemia, cardiorespiratory disease).
    • Pain location: Generally, one anatomical level below the arterial disease.
      • Most common artery affected: Superficial femoral artery (70% of cases), resulting in posterior calf pain.
      • Aortoiliac disease: Causes thigh or buttock claudication.
      • Leriche’s syndrome: Buttock claudication with sexual impotence due to arterial insufficiency.

Rest Pain

  • Occurs when disease progresses: Claudication distance decreases, and perfusion to the leg is severely compromised.
  • Worse at night, especially when the foot is elevated.
    • Pain is relieved by hanging the foot out of bed or sleeping in a chair.
    • Even bedclothes can exacerbate the pain.

Ulceration and Gangrene

  • Ulceration: Painful erosions between toes or non-healing ulcers on the dorsum of the feet, shins, or around the malleoli.
  • Gangrene: Blackened, mummified tissue, often complicated by superadded infection, leading to wet gangrene.
  • Chronic Limb-Threatening Ischemia (CLTI): Includes ischemic rest pain, ulceration, or gangrene. Urgent vascular assessment is required to prevent major amputation.

Colour, Temperature, Sensation, and Movement

  • Chronic ischemia: Limb equilibrates with environmental temperature, may feel warm under bedclothes.
  • No paralysis or sensory loss typically.
  • Dependent rubor or sunset foot sign: Red/purple discoloration when the limb is dependent. Elevation of the limb reveals pallor.
  • Capillary refill time: Normally 2-3 seconds but may be prolonged to 10 seconds in severe ischemia.

Arterial Pulses

  • Examination: Femoral, popliteal, posterior tibial, dorsalis pedis, and abdominal aorta (for aneurysms).
  • Pulse findings:
    • Diminished or absent pulses distal to occlusion.
    • Collateral circulation may make distal pulses palpable.
    • Popliteal aneurysm: Suspected if the popliteal pulse is prominent and the popliteal fossa loses its natural concavity.
    • Exercise test: Claudication causes the pulse to disappear with vasodilation.
    • Arterial bruit: Indicates turbulent flow due to stenosis, though often absent in tight stenoses.

Summary of Key Features:

  • Intermittent claudication
  • Rest pain
  • Ulceration and gangrene
  • Dependent rubor (sunset foot sign)
  • Diminished or absent arterial pulsation
  • Slow capillary refill
  • Arterial bruit

Relationship of Findings to Disease Site

  • Anatomical level of stenosis can often be determined based on symptoms and clinical signs.

Investigation of Arterial Occlusive Disease

General Investigation

  • Purpose:
    • Confirm the presence and severity of Peripheral Arterial Disease (PAD).
    • Identify the anatomical location of the disease.
    • Assess patient suitability for intervention.
  • Multisystem Atherosclerosis:
    • PAD suggests possible disease in other arteries, including:
      • Coronary arteries (50% of patients).
      • Cerebral arteries (25–50% of patients).
    • Common comorbidities:
      • Chronic obstructive pulmonary disease (COPD).
      • Malignancy.
  • Blood Tests:
    • Full blood count: Check for anemia.
    • Blood glucose: Screen for diabetes.
    • Lipid profile: Assess cholesterol and triglyceride levels.
    • Serum urea and electrolytes: Evaluate kidney function.
  • Additional Assessments:
    • Electrocardiogram (ECG): Detect coronary ischemia, left ventricular hypertrophy, arrhythmias.
    • Echocardiogram or Exercise Testing: Further cardiac evaluation.
    • Pulmonary Function Test: For patients with severe lung disease.
    • Arterial Blood Gases: Assess respiratory function.

Doppler Ultrasound Blood Flow Detection

  • Hand-held Doppler Probe:
    • Uses continuous-wave ultrasound to detect blood flow via the Doppler shift.
    • Converts frequency changes into an audio signal.
  • Assessment of Blood Flow:
    • Signal Quality:
      • Normal artery: Triphasic signal.
      • Diseased artery: Biphasic or monophasic signal.
    • Limitations:
      • Presence of a Doppler signal indicates blood flow but not sufficiency for limb viability.
  • Ankle–Brachial Pressure Index (ABI):
    • Calculation: Ratio of ankle systolic pressure to the highest brachial systolic pressure.
    • Normal ABI: 0.9–1.4.
    • ABI < 0.9: Indicates hemodynamically significant arterial lesion.
    • ABI < 0.4: Suggests Chronic Limb-Threatening Ischemia (CLTI).
    • Exercise Testing: A drop in ABI >20% after exercise indicates flow-limiting arterial disease.
    • Limitations: ABI may be falsely elevated (>1.4) due to arterial wall calcification, especially in diabetic patients.
  • Toe–Brachial Pressure Index (TBI):
    • Usage: More reliable in patients with arterial calcification.
    • TBI < 0.6: Suggests significant arterial disease.
    • Note: Limitations exist in diabetic patients with toe amputations or gangrene.

Duplex Doppler Ultrasound (DUS)

  • Technique:
    • Combines B-mode ultrasound imaging with Doppler flow analysis.
    • Colour Coding: Visualizes blood flow direction and velocity.
  • Advantages:
    • Non-invasive, cost-effective, and safe.
    • Accurate in experienced hands.
  • Limitations:
    • Aortoiliac Segment: Difficult to image due to bowel gas or obesity.
    • Calcified Vessels: May hinder assessment.
    • Operator Dependency: Accuracy relies on technician expertise.

Digital Subtraction Percutaneous Angiography (DSA)

  • Procedure:
    • Injection of radio-opaque dye into the arterial system.
    • Access via percutaneous femoral artery puncture using the Seldinger technique.
    • Digital Imaging: Background structures are subtracted for clarity.
  • Advantages:
    • Provides dynamic flow information.
    • Can be combined with endovascular interventions.
  • Complications:
    • Bleeding, hematoma, false aneurysm, thrombosis, arterial dissection, distal embolization.
    • Renal Dysfunction: Due to contrast agents.
    • Allergic Reactions: To contrast media.
  • Usage:
    • Reserved for patients likely to require interventional procedures.

Computed Tomography Angiography (CTA) and Magnetic Resonance Angiography (MRA)

  • CTA:
    • Advantages:
      • Minimally invasive alternative to DSA.
      • Excellent for visualizing arterial anatomy with 3D reconstruction.
    • Concerns:
      • Ionizing Radiation exposure.
      • Use of iodinated contrast may cause contrast-induced nephropathy.
      • Caution in patients with renal dysfunction and diabetes.
  • MRA:
    • Advantages:
      • Non-invasive, no ionizing radiation.
      • Avoids iodinated contrast; uses gadolinium instead.
      • Better at differentiating between contrast and calcification.
    • Limitations:
      • Contraindicated in patients with claustrophobia or certain metal implants (e.g., pacemakers).
      • Gadolinium Risk: Potential for nephrogenic systemic fibrosis in renal impairment.
      • Image quality may be affected by arterial stents.

Management of Arterial Stenosis or Occlusion

General Considerations

  • Prognosis:
    • Only 25% of patients with intermittent claudication worsen over their lifetime.
    • Less than 5% require amputation within 5 years.
    • ABI < 0.50: Increased risk of deterioration and limb loss.
  • Cardiovascular Risks:
    • Claudication indicates possible silent coronary artery disease.
    • ABI Decrease: A drop of 0.1 below 0.9 increases relative risk of major cardiovascular events by 10%.
    • Mortality:
      • Annual major cardiovascular event risk is >5%.
      • 50% mortality within 10 years due to myocardial infarction or stroke.
  • Risk Factors:
    • Smoking, diabetes mellitus (DM), hypertension, hyperlipidemia.
  • Management Goals:
    1. Prevent cardiovascular morbidity through risk factor modification.
    2. Relieve symptoms and improve quality of life.

Non-Surgical Management

  • Exercise Program:
    • Structured exercise: At least 2 hours per week for 3 months.
    • Improves claudication distance and reduces cardiovascular risk.
  • Smoking Cessation:
    • Essential for slowing disease progression and improving symptoms.
  • Diabetes Management:
    • Strict glycemic control.
    • Weight loss for obese patients.

Pharmacotherapy

  • Antihypertensives:
    • Control blood pressure.
    • Note: Beta-blockers may worsen claudication symptoms.
  • Statins:
    • HMG-CoA reductase inhibitors.
    • Prescribed even with normal lipid profiles.
    • Benefits:
      • Stabilize atherosclerotic plaques.
      • Reduce cardiac mortality.
  • Antiplatelet Agents:
    • Clopidogrel 75 mg daily is preferred.
    • Aspirin 75 mg daily as an alternative.
  • Other Medications:
    • Vasodilators: Generally not effective for PAD.
    • Smoking Cessation Aids: Medications to support quitting smoking.

Transluminal Angioplasty and Stenting

  • Percutaneous Transluminal Angioplasty (PTA):
    • Procedure:
      • Balloon catheter inserted through a percutaneous femoral artery puncture.
      • Balloon inflated within the stenosed or occluded segment.
      • Angiogram confirms successful dilatation.
    • Indications:
      • Patients with claudication, rest pain, or tissue necrosis.
    • Techniques:
      • Subintimal Angioplasty: For long occlusions; creates a new lumen by inflating the balloon in the arterial wall.
  • Complications:
    • Failure, hematoma, bleeding, thrombosis, distal embolization.
    • May affect future surgical options.
  • Stenting:
    • Used when arteries exhibit elastic recoil after angioplasty.
    • Metallic stents deployed to maintain vessel patency.

Arterial Reconstructive Surgery

  • Indications:
    • Patients unsuitable for angioplasty or with extensive disease.
  • Procedures:
    • Aortoiliac Disease:
      • Aortobifemoral bypass graft using a Dacron graft.
      • Alternative: Axillofemoral bypass if the abdomen cannot be entered.
    • Infrainguinal Disease:
      • Femoral–popliteal bypass.
      • Femoral–distal bypass for disease extending below the knee.
      • Conduits:
        • Saphenous vein graft: Preferred due to better patency.
        • Synthetic grafts (PTFE): Used when vein is unsuitable.
  • Outcomes:
    • Aortoiliac Reconstruction:
      • 90% patency at 5 years.
    • Femoral–popliteal Bypass:
      • Immediate success: >90%.
      • 5-year patency: ~60% with vein grafts.
      • PTFE grafts: Lower success rates.
    • Femoral–distal Bypass:
      • Higher risk of early graft failure and limb loss.
      • Used primarily for limb salvage.
  • Complications:
    • Graft failure, infection, bleeding, thrombosis.
    • Risk of limb loss if graft fails.

This concise summary highlights the key concepts and methodologies related to the investigation and management of chronic arterial stenosis or occlusion in the leg, focusing on the most common and preferred approaches.

Other Sites of Atheromatous Occlusive Disease

Carotid Stenosis

  • Location: Carotid bifurcation in the neck.
  • Symptoms:
    • Transient Ischemic Attacks (TIAs): Mini-strokes causing recurrent, short-lived symptoms.
    • Unilateral motor/sensory loss: Affects arm, leg, or face.
    • Transient blindness (amaurosis fugax): Caused by platelet thrombi embolizing into the cerebral circulation.
    • Speech impairment (dysphasia): Seen with involvement of the dominant hemisphere.
  • Significance: TIAs are warning signs of impending major stroke.
  • Assessment: Duplex scan to detect stenosis.
  • Treatment:
    • Carotid Endarterectomy for stenosis >50%.
    • Procedure:
      • Clamping of vessels.
      • Arteriotomy in the common carotid artery extending into the internal carotid artery.
      • Removal of occlusive disease (endarterectomy).
      • Closure of the arteriotomy, often with a patch.
      • A temporary shunt may be used to maintain cerebral blood flow during surgery.

Summary Box: Indications for Carotid Endarterectomy in Symptomatic Patients

  • Carotid stenosis ≥ 50% and:
    • Ipsilateral amaurosis fugax or monocular blindness.
    • Contralateral facial paralysis or paraesthesia.
    • Arm/leg paralysis or paraesthesia.
    • Hemianopia.
    • Dysphasia (if dominant hemisphere involved).
    • Sensory or visual inattention/neglect.

Subclavian Artery Stenosis

  • Symptoms:
    • Claudication in the arm.
    • Digital ischemia from distal embolization.
  • Associated Conditions:
    • Subclavian Steal Syndrome:
      • Reversed flow in the vertebral artery during arm exercise leads to syncope and cerebral ischemia.
    • Associated with neck pathology (e.g., cervical rib).
  • Treatment:
    • Angioplasty or surgical bypass.
    • Removal of associated pathology, such as cervical rib, during arterial repair.

Mesenteric Artery Occlusive Disease

  • Symptoms:
    • Postprandial pain (intestinal angina).
    • Weight loss.
  • Pathophysiology: At least two of the three enteric vessels (coeliac axis, superior mesenteric artery, inferior mesenteric artery) must be occluded to produce symptoms.
  • Treatment:
    • PTA, endarterectomy, or bypass.
    • Exclude other intestinal disorders before treatment.

Renal Artery Stenosis

  • Symptoms:
    • Hypertension.
    • Renal failure in advanced cases.
  • Treatment:
    • PTA or surgery can improve renal blood flow.
    • Mainstay of treatment involves medications for controlling hypertension and diabetes.

Acute Arterial Occlusion

Overview

  • Definition: Sudden blockage of an artery, usually caused by an embolus.
  • Causes:
    • Embolus: Most common cause; obstruction from an object (often a thrombus) carried from another site.
    • Thrombosis: Occurs on an atherosclerotic plaque; less dramatic due to existing collateral circulation.

Embolic Occlusion

  • Definition: An embolus lodges in a vessel, obstructing blood flow.
  • Common Sources:
    • Left atrium in atrial fibrillation.
    • Left ventricular mural thrombus after myocardial infarction.
    • Vegetations on heart valves in infective endocarditis.
    • Thrombi in aneurysms or on atherosclerotic plaques.
  • Affected Organs and Symptoms:
    • Arm and Leg:
      • Five Ps of Acute Limb Ischaemia (ALI):
        • Pain
        • Pallor
        • Paraesthesia
        • Paralysis
        • Pulselessness
      • Note: Differentiate from thrombosis on atheroma; collateral circulation affects management.
    • Brain:
      • Transient Ischaemic Attack (TIA) or stroke due to occlusion of the middle cerebral artery or its branches.
    • Retina:
      • Amaurosis fugax: Fleeting blindness from a small thrombus entering the central retinal artery.
      • Permanent blindness if obstruction persists.
    • Mesenteric Vessels:
      • Gangrene and perforation of the intestine.

Acute Limb Ischaemia (ALI)

  • Definition: An emergency requiring rapid assessment and surgical intervention.
  • Common Causes:
    • Embolic arterial occlusion.
    • Trauma.
    • Less Common Causes:
      • Thrombosed popliteal artery aneurysm.
      • Popliteal artery entrapment.
  • Clinical Features:
    • Sudden onset of severe pain or numbness in the limb.
    • No prior history of claudication.
    • Skin Changes:
      • Initially cold and pale.
      • Progresses to mottled appearance:
        • Non-fixed (blanching to pressure).
        • Fixed (non-blanching), indicating skin death.
    • Neurological Deterioration:
      • From paraesthesia to complete loss of sensory and motor function.
      • Results in an insensate and paralysed limb (poor prognosis).
    • Muscle Symptoms:
      • Weakness and pain.
      • Rhabdomyolysis: Pain due to ischaemic muscle injury.
    • Pulses:
      • Absent distally.
      • Femoral pulse may be palpable and forceful.
    • Doppler Assessment:
      • Faint monophasic signals or no signals in pedal vessels.
    • Venous Assessment:
      • Check flow in great saphenous vein (GSV) and popliteal vein.
      • Concurrent venous thrombosis indicates poor prognosis.

  • Classification (Rutherford Categories):

    • Class I: Viable limb.
    • Class IIa: Marginally threatened.
    • Class IIb: Immediately threatened.
    • Class III: Irreversible damage.

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  • Investigations:

    • ECG: Detect myocardial infarction or atrial fibrillation.
    • Creatinine kinase: Assess for rhabdomyolysis.
    • Renal function tests: Check for myoglobinuria and acute kidney injury.
    • Imaging: Duplex ultrasound (DUS) or computed tomography angiography (CTA) if it doesn't delay treatment.

Treatment

  • Immediate Management:
    • Heparin Administration:
      • 5000 units IV to prevent thrombus extension.
    • Pain Relief:
      • Essential due to severe, constant pain.
  • Definitive Treatments:
    • Embolectomy:
      • Procedure:
        • Performed under local or general anaesthesia.
        • Expose the affected artery (usually femoral).
        • Use a Fogarty balloon catheter:
          • Inserted proximally and distally.
          • Balloon inflated and withdrawn to remove embolus and clot.
        • Repeat until normal blood flow is restored.
        • Intraoperative angiogram may confirm restoration of flow.
      • Postoperative Care:
        • Continue heparin therapy.
        • Transition to long-term anticoagulation with warfarin.
    • Thrombolysis:
      • Indication: When immediate surgery isn't essential.
      • Procedure:
        • Perform arteriography to locate occlusion.
        • Insert a catheter into the occluded vessel.
        • Infuse tissue plasminogen activator.
        • Monitor progress with regular arteriograms.
      • Outcome:
        • Successful lysis typically within 24 hours.
        • Abandon if no progress over time.
      • Contraindications:
        • Recent stroke.
        • Bleeding diathesis.
        • Pregnancy.
        • Poor results in patients over 80 years.
  • Compartment Syndrome:
    • Cause: Swelling of muscles within confined fascial compartments after revascularisation.
    • Symptoms:
      • Severe pain disproportionate to clinical findings.
      • Numbness/paraesthesia in nerve distributions.
      • Tense compartments; pain on passive muscle movement.
      • Pulses may still be present.
    • Treatment:
      • Urgent fasciotomy to relieve pressure.
      • Commonly performed in the calf (anterior tibial compartment).
      • May also affect thigh, arm, or foot.
      • Prophylactic fasciotomies may be advisable after prolonged ischaemia.

Acute Mesenteric Ischaemia

  • Causes:
    • Thrombotic occlusion due to atherosclerosis.
    • Embolic occlusion from cardiac sources.
  • Clinical Features:
    • Sudden, severe abdominal pain.
    • Bowel emptying: Vomiting and diarrhoea.
    • Possible cardiac source of emboli.
  • Diagnosis:
    • Often made during laparotomy when widespread infarction is found.
    • Late diagnosis leads to high mortality.
  • Treatment:
    • Resection of necrotic bowel.
    • Embolectomy of the superior mesenteric artery.
    • Bypass surgery if necessary.
    • Second-look laparotomy after 24 hours to assess bowel viability.

Other Forms of Embolism

  • Infective Emboli:
    • Composed of bacteria or infected clots.
    • May cause:
      • Mycotic aneurysms.
      • Septicaemia.
      • Infected infarcts.
  • Parasitic Emboli:
    • From ova of parasites like Taenia echinococcus and Filaria sanguinis hominis.
    • Occur in certain regions.
  • Tumour Emboli:
    • Rare cases from hypernephroma or cardiac myxoma.
  • Fat Embolism:
    • Follows major bone fractures.
    • Usually causes venous emboli to the lungs.
    • Leads to acute respiratory distress syndrome (ARDS).

Air Embolism

  • Causes:
    • Air entering venous circulation:
      • Accidental injection.
      • Surgery (head, neck) or trauma (cut throat).
      • Fallopian tube insufflation or illegal abortion.
  • Effects:
    • Air reaches the right side of the heart.
    • Forms an airlock in the pulmonary artery.
    • Causes acute right heart failure.
  • Treatment:
    • Position patient in head-down (Trendelenburg) position.
    • Place patient on the left side to trap air in the apex of the ventricle.
    • In severe cases, aspirate air from the heart via a needle below the left costal margin.

Therapeutic Embolisation

  • Purpose:
    • Arrest haemorrhage from:
      • Gastrointestinal tract.
      • Urinary tract.
      • Gynaecological sites.
      • Respiratory tract.
    • Treat arteriovenous malformations by blocking arterial supply.
    • Control growth of unresectable tumours.
  • Technique:
    • Requires selective catheterisation using the Seldinger technique.
    • Embolic Materials:
      • Gelfoam sponge.
      • Plastic microspheres.
      • Other suitable agents.

This summary covers the essential concepts of acute arterial occlusion, including causes, clinical features, treatments, and associated complications. It focuses on the most common and preferred methodologies for diagnosis and management, ensuring clarity and conciseness for effective revision.

Aneurysm

General

  • Definition: A localized dilation of an artery with a ≥50% increase in diameter; less than 50% is termed ectatic.
  • Types:
    • True Aneurysm: Involves all three layers of the arterial wall (intima, media, adventitia).
    • False Aneurysm: Wall consists of a single layer of fibrous tissue.
  • Classification:
    • By Wall:
      • True
      • False
    • By Morphology:
      • Fusiform: Spindle-shaped dilation involving the entire circumference of the artery.
      • Saccular: Pouch-like outpouching on one side of the artery.
    • By Aetiology:
      • Atheromatous: Due to atherosclerosis (most common).
      • Mycotic: Caused by bacterial infection (misnomer as "mycotic" suggests fungal origin).
      • Traumatic
      • Collagen Disease

Clinical Features

  • Asymptomatic Presentation:
    • Most aneurysms are asymptomatic when identified, often during routine health checks or investigations for other conditions.
  • Symptomatic Aneurysms:
    • Risk Increases with aneurysm size (twice the normal vessel diameter).
    • Symptoms relate to the affected vessel and surrounding tissues due to:
      • Compression of adjacent structures.
      • Thrombosis within the aneurysm.
      • Rupture of the aneurysm.
      • Emboli release causing distal ischemia.
  • Physical Examination:
    • Expansile Pulsation: A palpable, pulsating mass.
    • Differential Diagnosis:
      • Transmitted pulsation from adjacent masses, cysts, or abscesses.
      • Tortuous or ectatic arteries mimicking an aneurysm.

Abdominal Aortic Aneurysm (AAA)

General

  • Prevalence:
    • Most common large-vessel aneurysm.
    • Found in 2% of autopsies.
    • 95% have associated atheromatous degeneration.
    • 95% occur below the renal arteries (infrarenal).
  • Asymptomatic AAA:
    • Repair Consideration:
      • Indicated when aneurysm diameter is >55 mm (measured anteroposteriorly via ultrasound).
      • Risk of Rupture:
        • <55 mm: ≤1% annual risk.
        • 55–60 mm: 5–10% annual risk.
        • ≥70 mm: ~25% annual risk.
    • Surveillance:
      • Regular ultrasound monitoring for aneurysms <55 mm.

Investigations

  • Laboratory Tests:
    • Full Blood Count
    • Electrolytes
    • Liver Function Tests
    • Coagulation Profile
    • Blood Lipid Estimation
    • Blood Cross-Matching before surgery.
  • Cardiopulmonary Assessment:
    • Electrocardiogram (ECG)
    • Chest Radiographs
    • Anaesthetic Assessment may include:
      • Echocardiogram
      • Cardiopulmonary Exercise Testing
      • Spirometry
  • Imaging:
    • Computed Tomography (CT) Scan:
      • Preferred for assessing aneurysm morphology.
      • Allows 3D reconstruction.
      • Essential for planning endovascular repair.
    • Duplex Ultrasound Scan (DUS):
      • Initial assessment of lower limb pulses and arterial occlusive disease.
    • Note: Digital Subtraction Angiography (DSA) is not ideal for size assessment due to intraluminal thrombus giving a false appearance.

Choice of Operation: Open vs. Endovascular Repair

  • Guidelines:
    • NICE (UK):
      • Recommends open surgical repair unless contraindicated.
      • EVAR for high-risk patients or those with a hostile abdomen.
    • European Society for Vascular Surgery:
      • Recommends EVAR as the first-line treatment.
      • Open repair for patients with long life expectancy.
  • Decision Factors:
    • Patient Health and comorbidities.
    • Aneurysm Morphology.
    • Resource Availability and expertise.
    • Patient Preference after informed discussion.

Open Aneurysm Repair

Procedure

  • Anaesthesia: General.
  • Incision: Midline or supraumbilical transverse.
  • Exposure:
    • Small bowel moved to the right.
    • Posterior peritoneum overlying the aorta opened.
    • Aneurysm Neck identified just below the renal arteries.
  • Clamping:
    • Above the aneurysm (below renal arteries).
    • Below the aneurysm (common iliac arteries).
  • Heparinization: 3000–5000 units administered before clamping.
  • Aneurysm Sac:
    • Opened longitudinally.
    • Back-bleeding controlled with sutures (lumbar and mesenteric vessels).
  • Graft Placement:
    • Aortic Prosthesis (Dacron or PTFE) sutured end-to-end inside the sac using non-absorbable suture.
  • Closure:
    • Aneurysm sac closed around the graft to prevent adhesion to the bowel.
    • Abdomen closed.

Endovascular Aneurysm Repair (EVAR)

Overview

  • Minimally Invasive: Access via femoral arteries.
  • Suitability:
    • 75% of infrarenal aneurysms are suitable.
    • Unsuitable if:
      • Short, flared, or angulated neck.
      • Difficult iliac artery access due to narrowing or tortuosity.
  • Procedure:
    • Access: Both femoral arteries exposed (general or local anaesthesia).
    • Guidewires and Catheters: Used to navigate across the aneurysm.
    • Angiogram: Performed to locate renal arteries.
    • Stent-Graft Deployment:
      • Components:
        • Main Body and Two Limbs (or two-piece systems).
      • Materials: Dacron or PTFE with metallic stents.
      • Anchoring:
        • Hooks or Barbs engage the aortic wall.
        • Infrarenal Fixation: Fabric deployed below renal arteries.
        • Suprarenal Fixation: Bare metal stents extend above renal arteries.
      • Moulding Balloon may be used to ensure proper seal.
  • Outcome:
    • Success Depends on achieving a good seal to prevent endoleak.
  • Follow-Up:
    • Lifelong Surveillance with duplex ultrasound or CT scans.
    • Monitor for:
      • Endoleaks
      • Graft Migration
      • Component Separation
      • Metal Strut Fracture

Ruptured Abdominal Aortic Aneurysm

Presentation

  • Rupture Sites:
    • Anterior Rupture: Into peritoneal cavity (20%); high pre-hospital mortality.
    • Posterolateral Rupture: Into retroperitoneal space (80%); may allow time for intervention.
  • Symptoms:
    • Severe Abdominal and/or Back Pain
    • Hypotension
    • Pulsatile Abdominal Mass
  • Diagnosis:
    • CT Scan: Confirms rupture and assesses EVAR suitability.
    • Ultrasound: May detect aneurysm but not rupture.
  • Management:
    • Emergency Surgery is imperative.
    • Resuscitation:
      • Venous Access: For fluids; avoid excessive fluid resuscitation.
      • Blood Pressure: Maintain systolic <100 mmHg.
      • Cross-Match Blood
      • Urinary Catheter and Arterial Line insertion.
    • Surgery:
      • Open Repair: Rapid abdominal entry; clamps applied promptly.
      • EVAR: Preferred if anatomically suitable; can be done under local anaesthesia.
      • Aortic Occlusion Balloon: May be used for temporary control.

Summary: Management Steps

  1. Early Diagnosis: Recognize symptoms promptly.
  2. Immediate Resuscitation:
    • Oxygen therapy.
    • Intravenous fluid replacement.
    • Central venous access.
  3. Blood Pressure Management: Keep systolic pressure below 100 mmHg.
  4. Preparation for Surgery:
    • Insert urinary catheter.
    • Cross-match blood.
    • Transfer rapidly to the operating room.

Symptomatic Abdominal Aortic Aneurysm

Presentation

  • Pain:
    • Abdominal and/or Back Pain without rupture.
    • Thigh and Groin Pain due to nerve compression.
  • Other Symptoms:
    • Gastrointestinal: Pressure effects causing symptoms.
    • Urinary and Venous Symptoms: Due to compression.
    • Inflammation: In approximately 3% of aneurysms.
    • Distal Embolization: Leading to ischemic symptoms.
  • Management:
    • Surgical Repair is usually indicated.
    • Urgency: Surgery should be performed promptly.
    • Risk: Higher operative mortality compared to elective repair.

Postoperative Complications

After Open Repair

  • Cardiac Complications:
    • Ischemia
    • Myocardial Infarction
  • Respiratory Complications:
    • Atelectasis
    • Lower Lobe Consolidation
  • Colonic Ischemia:
    • Occurs in ~10%; usually self-resolving.
  • Acute Kidney Injury:
    • Risk increases with pre-existing renal impairment or significant blood loss.
  • Neurological Complications:
    • Sexual Dysfunction
    • Spinal Cord Ischemia
  • Aortoduodenal Fistula:
    • Rare but serious; suspect with postoperative haematemesis or melaena.
  • Prosthetic Graft Infection:
    • May require graft removal and replacement with:
      • Autologous Deep Vein Graft (e.g., superficial femoral vein).
      • Axillobifemoral Bypass.

After EVAR

  • Fewer Systemic Complications: Less cardiac, respiratory, renal, and neurological issues.
  • Unique Complications:
    • Endoleak (Types I–V)
    • Graft Migration
    • Metal Strut Fracture
    • Graft Limb Occlusion
  • Management:
    • Lifelong Surveillance:
      • Regular imaging with duplex or CT scans.
      • Monitor for endoleaks and graft integrity.
    • Secondary Interventions:
      • Required in 10–20% of patients.
      • May involve:
        • Repeat Ballooning
        • Proximal Cuff or Distal Limb Extension
        • Component Reconnection

Classification of Endoleaks Following EVAR

  • Type I:
    • Definition: Ineffective seal at the proximal (Ia) or distal (Ib) ends of the stent-graft.
    • Result: Persistent filling of the aneurysm sac.
  • Type II:
    • Definition: Retrograde flow from aortic collaterals (e.g., inferior mesenteric artery, lumbar arteries).
    • Result: Persistent filling of the aneurysm sac.
  • Type III:
    • Definition:
      • IIIa: Component disconnection.
      • IIIb: Stent fabric tear.
    • Result: Structural failure leading to aneurysm sac filling.
  • Type IV:
    • Definition: Stent-graft fabric porosity.
    • Result: Persistent filling of the aneurysm sac.
  • Type V (Endotension):
    • Definition: Persistent aneurysm sac expansion without evidence of Types I–IV endoleak.

These concise revision notes cover the core concepts of aneurysms, focusing on abdominal aortic aneurysm, their clinical features, investigations, management options, and postoperative complications, with emphasis on the most common and preferred methodologies.

Peripheral Aneurysm

Popliteal Aneurysm

  • Prevalence:
    • Accounts for 70% of all peripheral aneurysms.
    • Typically diagnosed in men in their seventh decade.
    • 50% are bilateral.
    • One-third are associated with an abdominal aortic aneurysm.
  • Clinical Presentation:
    • May present as a swelling behind the knee.
    • Symptoms due to complications:
      • Severe ischaemia following thrombosis.
      • Distal ischaemia resulting from emboli.
  • Diagnosis:
    • Confirmed with Duplex Ultrasound Scan (DUS).
    • Assessment of distal vessels with CT, MRA, or DSA if foot pulses are diminished or absent.
  • Management:
    • Asymptomatic Aneurysms:
      • >20 mm in diameter should be considered for elective repair to prevent complications.
      • Some surgeons recommend repair for smaller aneurysms if the sac contains thrombus due to increased risk of distal embolisation.
    • Symptomatic Aneurysms:
      • All symptomatic aneurysms should be considered for repair, including those with single crural vessel embolisation.
  • Surgical Techniques:
    • Exclusion Bypass:
      • Medial approach to the above- and below-knee popliteal arteries.
      • Ligation of the aneurysm.
      • Restoration of flow using a saphenous vein bypass graft.
      • Preferred due to familiarity with anatomy similar to femoropopliteal bypass.
    • Inlay Graft Repair:
      • Posterior approach.
      • Allows ligation of feeding geniculate branches.
      • Enables aneurysmectomy in cases of neurovascular compression.
      • Limited exposure; suitable when aneurysm is confined to the popliteal fossa.
  • Acute Presentation:
    • Usually presents with a thrombosed aneurysm and an ischaemic foot.
    • Rupture is very rare.
    • Thrombosis occurs due to chronic embolisation leading to occluded run-off vessels.
    • Surgical success is often limited due to diseased outflow vessels.
    • Embolectomy and intra-arterial thrombolysis may be attempted.
    • High limb loss rate (~50%).

Femoral Aneurysm

  • True Femoral Aneurysm:
    • Uncommon.
    • Complications occur in <3% of cases.
    • Conservative treatment generally indicated.
    • Important to check for aneurysms elsewhere; over half have associated abdominal or popliteal aneurysms.
    • Large aneurysms should be repaired.
  • False Femoral Aneurysm:
    • Occurs in 2% of patients after arterial surgery at the site.
    • Management:
      • Local repair with reanastomosis under antibiotic cover.
      • If infection is the cause, may require excision of the infected graft and insertion of a bypass around the infected area.
      • High failure rate; limb loss may be unavoidable.
    • Thrombin Injection:
      • For aneurysms ≤3 cm, thrombin injection under ultrasonography guidance can avoid surgery.
    • Surgical Repair:
      • Aneurysms >3 cm usually require open surgical repair with suturing of the puncture site.

Iliac Aneurysm

  • Occurrence:
    • Usually occurs in conjunction with an aortic aneurysm.
    • Rarely occurs in isolation; difficult to diagnose clinically.
    • About 50% present already ruptured.
  • Management:
    • Open surgery typically involves an inlay graft.
    • Some may be suitable for endovascular repair.

Arteriovenous Fistula

Definition

  • A communication between an artery and a vein.
  • Can be congenital or result from trauma.
  • Also created surgically for haemodialysis access.

Effects

  • Structural Effects:
    • Veins become dilated, tortuous, and thick-walled (arterialised).
  • Physiological Effects:
    • If large, can cause an increase in cardiac output.
    • May lead to cardiac failure.

Clinical Features

  • Pulsatile swelling if superficial.
  • Thrill felt on palpation.
  • Continuous bruit ("machinery murmur") on auscultation.
  • Dilated veins may be visible.
  • Compression of the proximal artery reduces swelling, thrill, and bruit.

Diagnosis

  • Duplex scan and/or angiography.
  • Shows rapid venous filling.

Management

  • Often complex.
  • Embolisation is commonly used.
  • Surgical excision:
    • Used for severe deformity or recurrent haemorrhage.
    • Collaboration with a plastic surgeon recommended.
  • Ligation of Feeding Artery:
    • Usually ineffective.
    • May prevent future embolisation treatments.

Arteritis and Vasospastic Conditions

Thromboangiitis Obliterans (Buerger's Disease)

  • Characteristics:
    • Occlusive disease of small and medium-sized limb arteries.
    • Thrombophlebitis of superficial or deep veins.
    • Raynaud's syndrome.
  • Epidemiology:
    • Occurs in young male smokers.
  • Pathology:
    • Inflammatory changes in arterial and venous walls leading to thrombosis.
  • Treatment:
    • Total abstinence from smoking arrests the disease.
    • Established occlusions treated similarly to atherosclerotic disease.
    • Amputations may eventually be required.

Other Forms of Arteritis

  • Associated with:
    • Connective tissue disorders (e.g., rheumatoid arthritis, systemic lupus erythematosus, polyarteritis nodosa).
  • Temporal Arteritis:
    • Local infiltration with inflammatory and giant cells.
    • Leads to arterial occlusion.
    • Symptoms:
      • Ischaemic headache.
      • Tender, palpable, pulseless arteries in the scalp.
      • Irreversible blindness if the ophthalmic artery is occluded.
    • Management:
      • Immediate steroid therapy to prevent vision loss.
      • Temporal artery biopsy may be performed but should not delay treatment.
  • Takayasu's Disease:
    • An arteritis that obstructs major arteries, especially those off the aortic arch.
    • Typically has a relentless course.

Cystic Myxomatous Degeneration

  • Definition:
    • Accumulation of clear jelly-like material in the outer layers of an artery.
    • Commonly affects the popliteal artery.
  • Clinical Features:
    • Narrows the vessel, causing claudication.
  • Diagnosis:
    • Duplex scan is the investigation of choice.
  • Treatment:
    • Decompression by removing the myxomatous material.
    • Excision of the diseased artery with interposition vein graft repair if necessary.

Raynaud's Disease and Raynaud's Syndrome

Raynaud's Disease

  • Definition:
    • An idiopathic condition with abnormal arteriolar response to cold.
  • Epidemiology:
    • Usually affects young women.
  • Clinical Features:
    • Affects the hands more than the feet.
    • Characteristic Sequence:
      1. Blanching (white) due to arteriolar constriction.
      2. Dusky cyanosis (blue) as capillaries fill with deoxygenated blood.
      3. Red engorgement as oxygenated blood returns.
    • May be accompanied by pain and inability to perform fine movements.
    • Superficial necrosis is very uncommon.
  • Treatment:
    • Protection from cold.
    • Avoidance of pulp and nail bed infection.
    • Calcium antagonists (e.g., nifedipine) may help.
    • Electrically heated gloves can be useful.
    • Sympathectomy is generally ineffective or short-lived.

Raynaud's Syndrome

  • Definition:
    • Similar features to Raynaud's disease but secondary to other conditions.
  • Associated Conditions:
    • Collagen diseases (e.g., systemic lupus erythematosus, rheumatoid arthritis).
    • Use of vibrating tools (occupational hazard).
  • Clinical Features:
    • Similar to Raynaud's disease but may be more aggressive.
    • Known as "vibration white finger" when due to vibrating tools.
  • Treatment:
    • Directed at the underlying condition.
    • Conservative measures similar to Raynaud's disease.
    • Sympathectomy is not recommended.
    • Medications:
      • Nifedipine.
      • Steroids.
      • Vasospastic antagonists.
    • Avoidance of vibrating tools.

Acrocyanosis

  • Definition:
    • Persistent mottled cyanosis of the fingers and/or toes.
  • Clinical Features:
    • Painless and not episodic.
    • May be accompanied by paraesthesia and chilblains.
  • Epidemiology:
    • Tends to affect young women.
  • Differentiation:
    • Distinguished from Raynaud's disease by lack of episodic attacks and pain.

Sympathectomy

  • Procedure:
    • Endoscopic transthoracic sympathectomy is now used as a minimally invasive treatment for palmar and axillary hyperhidrosis.
  • Historical Use:
    • Open cervical sympathectomy was previously used for vasospastic disorders.
    • Found to be unsuccessful and is now obsolete.
  • Lumbar Sympathectomy:
    • Used in the past to treat lower limb ischaemia.
    • Also considered obsolete today.

This concise revision summarizes the core concepts related to peripheral aneurysms, arteriovenous fistulae, and arteritis/vasospastic conditions, focusing on the most common presentations and preferred management approaches, as outlined in the provided context.