Peripheral vascular disease and arterial injuries

Peripheral Vascular Disease (PVD)

• Definition: Disorders that alter the natural flow of blood through the arteries and veins of the peripheral circulation.

• Prevalence: Affects legs more than arms; common in individuals aged 60-80 years.

• Comorbidity: Some patients exhibit both arterial and venous diseases.

Review of Lower Limb Anatomy

• Arterial Circulation:

  • External iliac artery

  • Femoral artery

  • Popliteal artery

  • Anterior tibial artery

  • Posterior tibial artery

  • Peroneal artery

  • Dorsalis pedis artery

• Venous Circulation:

  • Femoral vein

  • Great saphenous vein

  • Small saphenous vein

  • Anterior tibial vein

  • Posterior tibial vein

  • Peroneal vein

  • Dorsal venous arch

  • Plantar arch

Physiological Effects of Diminished Blood Flow

• Tissue Integrity: Tissues can suffer from ischemia if oxygen and nutrient supply falls short.

• Consequences: Chronic lack of blood flow can lead to tissue death.

Factors Influencing Ischemia Effects

1. Type of artery: Arteries like the subclavian have good collateral circulation, while the popliteal artery has poor collateral circulation.

2. Rate of artery occlusion: Sudden occlusions lead to acute ischemia; gradual occlusions may allow for collateral adaptations.

3. Condition of collateral vessels: Healthy collateral vessels can mitigate ischemia effects, while thrombosed vessels worsen outcomes.

4. Patient's overall condition: Comorbidities like myocardial insufficiency or severe anemia increase vulnerability.

Changes in Ischemia

• Acute Occlusion: Leads to rapid and severe tissue ischemia.

• Gradual Occlusion: Allows the body to adapt, decreasing risk of sudden tissue death.

Compartment Syndrome**

• Description: A condition arising when swollen compartments impede blood flow; pressure changes can be detrimental.

Arterial Injuries

• Mechanisms of Injury:

  • Blunt trauma (direct)

  • Penetrating trauma (high/low energy)

  • Iatrogenic causes

  • Intra-arterial drug injection

• Types of Vascular Injuries:

  1. Arterial division:

     • Complete transection presents ischemia without hemorrhage.

     • Partial tears usually lead to bleeding.

  2. Arterial contusion and thrombosis: Most common in closed injuries.

  3. Arterial spasm: Needs arterial exploration for accurate diagnosis.

Consequences of Vascular Injury

• Complications:

  • Blood loss

  • Ischemia

  • Compartment syndrome

  • Tissue necrosis

  • Risk of amputation and mortality.

Urgency of Intervention

• Protocol: Rapid resuscitation, evaluation, and urgent surgical treatment are crucial.

Diagnostic Techniques

• Examination:

  • Physical assessment

  • Doppler pressure assessment (Ankle-Brachial Index)

  • Duplex scanning

  • Arteriogram

  • Surgical exploration

• Importance: A careful physical examination and a high suspicion index are key to timely diagnosis.

Clinical Assessment Features

History

• Mechanism of injury

• Volume and location of blood loss

General Examination

• Vital signs: assess magnitude of blood loss and check for additional injuries.

Local Examination

• Hard Signs:

  • External arterial bleeding

  • Loss of distal pulses

  • Classic ischemia signs (six Ps).

  • Pulsating/expanding hematoma.

  • Palpable thrill or audible bruit.

• Soft Signs:

  • Non-expanding hematoma

  • Proximity of wounds to major arteries

  • Adjacent nerve injury

  • Previous hemorrhage history.

Diagnostic Tools

• Doppler Ultrasound: Determines arterial supply presence and flow adequacy.

• Duplex Scanning: Noninvasive, reliable for detecting arterial and venous injuries, AV fistulas, pseudoaneurysms.

Operative Angiography**

• Used intraoperatively for rapid assessment of injury sites.

Immediate Treatment Protocol**

• Control bleeding and replace volume; address fractures/dislocations; consider heparin and antibiotic therapy.

Surgical Exploration and Treatment**

1. Arterial Repair:

• Address transverse/longitudinal tears or transections.

• Manage contusions or spasms.

2. Local Heparin: For clot management.

3. Venous Management: Repair veins before arteries.

4. Skin Coverage: Essential for open injuries.

5. Fasciotomy: Considered in compartment syndrome.

6. Fracture Fixation: Prioritize stable structures.

Intra-Arterial Drug Injection**

Clinical Presentation**:

• Burning sensation

• Severe pain, blanching

• Swelling, coldness, or cyanosis

• Normal pulse may mask critical damage

• Risk of digital gangrene.

Treatment**:

• Administer heparin and dexamethasone.

• Utilize low molecular weight dextran to reduce platelet aggregation.

• Provide analgesia, elevation, early exercise, and consider fasciotomy.