SECTION 1: ANEURYSMS & ABDOMINAL AORTIC ANEURYSM 1. Classify aneurysms Definition An aneurysm is a localized abnormal dilatation of an artery involving all three layers of the vessel wall. Classification A. According to wall involvement 1. True aneurysm * All three layers of vessel wall are involved * Types: * Fusiform aneurysm * Saccular aneurysm 2. False aneurysm (pseudoaneurysm) * Disruption of vessel wall with blood collection contained by surrounding tissues * Example: traumatic pseudoaneurysm ⸻ B. According to shape 1. Fusiform aneurysm * Symmetrical dilatation involving entire circumference 2. Saccular aneurysm * Outpouching from one side of artery ⸻ C. According to etiology 1. Degenerative * Atherosclerotic aneurysm * Abdominal aortic aneurysm 2. Congenital * Berry aneurysm 3. Traumatic 4. Mycotic * Infective aneurysm 5. Inflammatory * Vasculitis-related 6. Dissecting aneurysm ⸻ Abdominal Aortic Aneurysm (AAA) Definition Permanent localized dilatation of abdominal aorta >3 cm diameter. Most common site: * Infrarenal abdominal aorta ⸻ Clinical Features of AAA 1. Asymptomatic Most common presentation. Detected incidentally on: * Ultrasound * CT scan ⸻ 2. Symptomatic aneurysm A. Abdominal pain * Dull, constant pain * Epigastric/periumbilical/back pain B. Pulsatile abdominal mass * Expansile pulsation * Usually above umbilicus C. Pressure symptoms Ureter compression → Hydronephrosis Duodenal compression → Vomiting Vertebral erosion → Back pain ⸻ 3. Complications Rupture Features: * Sudden severe abdominal/back pain * Hypotension * Shock * Pulsatile mass Embolism * Limb ischemia * Blue toe syndrome Thrombosis * Acute limb ischemia Aortoenteric fistula * Massive GI bleeding ⸻ Investigations 1. Ultrasound abdomen * Screening investigation * Measures aneurysm size 2. CT angiography Gold standard for: * Anatomy * Surgical planning 3. Plain X-ray * Curvilinear calcification 4. Angiography Used when intervention planned. ⸻ Management of AAA A. Conservative For small aneurysm: <5 cm: * Regular ultrasound follow-up * Control risk factors: * Stop smoking * Control BP * Statins ⸻ B. Surgical management Indications * Diameter >5.5 cm * Expansion >1 cm/year * Symptomatic aneurysm * Ruptured aneurysm ⸻ 1. Open repair Procedure: * Midline laparotomy * Aortic clamping * Replace aneurysm with synthetic graft ⸻ 2. Endovascular aneurysm repair (EVAR) * Stent graft placed through femoral artery * Less morbidity * Preferred in high-risk patients ⸻ SECTION 2: CRITICAL LIMB ISCHEMIA (CLI) Definition Critical limb ischemia is chronic arterial insufficiency causing rest pain, ulceration or gangrene due to inadequate blood supply. Criteria: * Rest pain >2 weeks * Ankle pressure <50 mmHg * Toe pressure <30 mmHg ⸻ Clinical Features 1. Rest pain * Severe pain in foot/toes * Worse at night * Relieved by dangling leg ⸻ 2. Ulcer Features: * Painful * Deep punched-out ulcer * Usually toes/pressure points ⸻ 3. Gangrene * Dry gangrene of toes * May become infected ⸻ 4. Signs of chronic ischemia 6 Ps: * Pain * Pallor * Pulselessness * Paraesthesia * Paralysis * Perishing cold ⸻ Investigations of CLI 1. Ankle brachial pressure index (ABPI) Normal: 1.0–1.3 CLI: <0.5 ⸻ 2. Duplex ultrasound * Site of stenosis * Blood flow assessment ⸻ 3. CT angiography Maps arterial lesions. ⸻ 4. Digital subtraction angiography Gold standard before intervention. ⸻ Management of CLI 1. Medical management * Stop smoking * Control diabetes * Antiplatelet drugs: * Aspirin * Clopidogrel * Statins * Exercise therapy * Wound care ⸻ 2. Revascularization A. Endovascular * Angioplasty * Stenting * Atherectomy ⸻ B. Surgical bypass Principles: Create alternate pathway around obstruction. ⸻ Bypass procedures of lower limb 1. Aorto-bifemoral bypass Indication: * Aortoiliac disease Graft: * Dacron graft ⸻ 2. Femoro-popliteal bypass Indication: * Superficial femoral artery disease Graft: * Great saphenous vein preferred ⸻ 3. Femoro-distal bypass Indication: * Below knee disease ⸻ 4. Popliteal-tibial bypass For distal ischemia. ⸻ SECTION 3: GANGRENE Definition Gangrene is death of tissue due to loss of blood supply with secondary bacterial infection. ⸻ Types 1. Dry gangrene Cause: * Chronic ischemia Features: * Black shrivelled tissue * Clear line of demarcation ⸻ 2. Wet gangrene Cause: * Infection + ischemia Features: * Swelling * Foul smell * Rapid spread ⸻ 3. Gas gangrene Cause: * Clostridium infection ⸻ Etiology * Atherosclerosis * Diabetes mellitus * Thromboangiitis obliterans * Trauma * Embolism * Frostbite ⸻ Clinical Features * Pain * Colour change * Cold limb * Loss of pulse * Sensory loss * Ulceration ⸻ Investigations * Doppler study * CT angiography * Blood sugar * Culture and sensitivity * X-ray (gas) ⸻ Management General * Treat cause * Antibiotics * Control diabetes * Analgesia ⸻ Surgical Dry gangrene: * Wait for demarcation * Amputation Wet gangrene: * Emergency debridement * Antibiotics * Amputation if required creat a doc of this text