Vascular Surgery Flashcards
ANEURYSMS Pathophysiology
• Abnormal dilatation of blood vessel; might be associated with structural abnormalities or
hypertensive disease, tobacco smoking and family history (but not diabetes)
• 9x more common in males; Increasing prevalence in age
• True Aneurysm – Contains all three always of the arterial wall; Can either be Fusiform or Saccular in shape; Mostly due to arteriosclerosis but can also be infective causes (Mycotic Aneurysms) or structural defects (Marfan’s, Ehlers-Danlos)
• False Aneurysm – Often only lined by T. Adventitia or surround connective tissues; Usually secondary to penetrating trauma or iatrogenic injury
• Common Anatomical Sites – Thoracic, Abdominal, Peripheral (Iliac, Femoral, Popliteal, Visceral, Carotid, Subclavian) and Cerebral Berry Aneurysms
o Crawford Classification I – IV for Thoracoabdominal Aneurysms
o 95% of Abdominal Aortas are Infra-
renal; 15% extend to involve origins of
Common Iliac arteries, may be associated with other peripheral
o 5-10% are inflammatory, affecting the
retroperitoneum connective tissues
Risk factors for Vascular Disease in general
• Hypertension and Smoking
• Hypercholesterolemia and Diabetes Mellitus
o NB: Diabetes not a risk factor for Aneurysms –? Remodelling of the vascular wall
• Sedentary Lifestyle, Overweight or Obesity
• Family History of Heart disease and Ethnic background
ABDOMINAL AORTIC ANEURYSM
• Defined as dilation more than 3cm or 1.5× diameter of adjacent Inferior Vena Cava
• Typically, patients >55yrs, Risk of rupture increases with diameter (>5.5cm dilatation)
• Presents as sudden/severe onset Epigastric/Back/Loin pain, Rapid onset hypotension, pain,
sweating ± Pulsatile abdominal mass
• Repair can be through Open Aortic Surgery or Endovascular Aortic Repair (EVAR)
Ruptured AAA
• Resuscitation – Transfer to theatre immediately, IV access and catheterisation, allow for
permissive hypotension to avoid risk of rupture
o Cross-match 10 units of blood, order FFP and platelets
o High-flow oxygen via Non-rebreather mask, IV Morphine
• Preoperative principles – Straight to theatre, induction only after patient is prepared and
draped and surgical team is ready, Central + Arterial line sited if stable, Antibiotic prophylaxis
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• Proximal clamping before full fluid expansion with blood, distal outflow controlled and
Aneurysm sac is opened allowing for graft placement
• Sequential reperfusion with volume expansion to minimize post-declamping shock
• Blood products may be required to correct coagulopathy
Potential Complications of Aneurysms and EVAR
• Death (up to 50% of operated cases), Myocardial Infarction, Stroke
• Renal Failure, Gut Ischaemia/Infarction, Limb Embolisation
• Abdominal/Thoracic Compartment Syndrome
• Local Wound Complications, Access Artery Injury, Contrast Nephropathy
• Ischaemic Complications – Colonic
Ischaemia, Cord Ischaemia (very
rarely), Renal Artery Occlusion, Early
and Late Limb Occlusion
• Infective Complications – Can result in
Generalised Sepsis and Death
• Endoleak – Type I (Distal or Proximal to
Graft), Type II (Retrograde tributary
flow), Type III (Inadequate Sealing of Overlapping Graft Joints, or Rupture of Graft Fabric),
Type IV (Porosity of Graft) and Type V (Expansion of Aneurysm without Obvious Endoleak)
RENAL ARTERY STENOSIS
• Narrowing of the Renal Arteries due to Atherosclerosis (90%) or Fibromuscular Dysplasia
o Leads to reduced delivery to Kidneys leading to false idea of hypotension, causing
activation of Renin-Angiotensin-Aldosterone System causing 2O Hypertension
o Complications include that of Hypertension and Chronic Renal Failure
o Fibromuscular Dysplasia – Non-atherosclerotic, Non-inflammatory process with
genetic preposition; most common cause in young ± females
• Long term structural changes – Fibrosis, Thickening of Bowman’s Capsule and Tubulosclerosis,
Tubular and Glomerular Atrophy/Tuft = ↓↓GFR
• Presentation – Mostly asymptomatic; Hypertension that is refractory to treatment
o Might present with acute Pulmonary Oedema due to sudden ↓↓GFR
• ACE-Inhibitors Inhibit the RAA System, which can potentially lead to Renal Hypoperfusion
(Loss of Renal Efferent Arteriole Vasoconstriction by Angiotensin II)
Management of Renal Artery Stenosis
• Investigations – Doppler Ultrasound,
Subtraction Angiography, CTA, MRA
o Captopril Challenge Test – Raised
Renin in response to Captopril
• Treatment – Medical optimisation (Diuretics
and BP control), Renal Artery Angioplasty ±
Stenting (Also for Fibromuscular Dysplasia),
Nephrectomy as last resort
VARICOSE VEINS
• Valvular incompetence leading to backflow causing Tortious, Dilated segments of veins
o Thread veins (Intradermal; flare, starburst or broken appearance)
o Reticular veins (1-2mm diameter veins)
o Truncal (Long and Short Saphenous veins)
• Congenital, Primary idiopathic, Acquired causes (Pelvic masses e.g. Pregnancy, Tumour, Pelvic
Venous Abnormalities e.g. Previous DVT)
• Presents with Pain, Ache and Itching, Swelling and Oedema; Tends to be worse at end of day,
hot weather or premenstruation
• Complications – Varicose Eczema, Phlebitis, Lipodermatosclerosis, Ulceration or Bleeding
• RF – Older age and Female, Pregnancy, Family History, Obesity, Sedentary, Trauma
VARICOSE VEINS Treatment
• Referral to Vascular service if Symptomatic, Lower Limb
changes due to Chronic Venous Insufficiency, Superficial
Vein Thrombosis, Venous Ulcer
• Investigations – Colour Duplex Doppler
• Interventional Treatment with Confirmed Varicose Veins
and Truncal Reflux
• Medical Management – Microsclerotherapy (Fine
injection of detergent based sclerosing drugs), Laser
Sclerotherapy, TED stockings
• Surgical Management – Stab avulsions,
Saphenofemoral/popliteal disconnection, Endovenous
laser therapy (EVLT), Radiofrequency Ablation, Subfascial
Endoscopic Perforator Ligation
CHRONIC LIMB ISCHAEMIA
• Upper Limb less frequent than Lower Limb
• Upper Limb – Associated with previous trauma/radiotherapy, Atherosclerosis, Buerger’s
disease (Associated with smoking), Subclavian Steal Syndrome (Stenosis of Subclavian artery
proximal to Vertebral artery origin leading to Retrograde Vertebral flow), Takayasu’s Arteritis
(Intimal fibrosis and vascular narrowing), Thoracic Outlet Syndrome
o Weakness, Cramping, Exercise-related pain, Digital Ischaemia/Gangrene
o Roo’s Test, Adson’s Test, Allen’s Test, Tinel’s Test
o Treatment based on cause; Excision of first rib (For Thoracic Outlet Syndrome),
Cervical Sympathectomy (Deinnervation of Second and Third Thoracic Ganglia, used
for Palmar Hyperhidrosis, Buerger’s disease, etc)
• Lower Limb – Fountain Classification: I (Asymptomatic), II (Intermittent Claudication), III (Pain
at rest), IV (Ulceration/Gangrene); Grade III and IV = Critical Ischaemia
Intermittent Claudication
• Muscular pain worsened with increasing level of exercise by relieved on rest
• Differential Diagnosis – Spinal Stenosis, Osteoarthritis, Nerve Root Entrapment, Popliteal
artery entrapment (rare cause)
• Diagnosis – Clinical; Post-exercise fall in ABPI; Imaging not diagnostic but useful for
intervention planning; Abdominal Ultrasound if AAA suspected
• Treatment – Lifestyle changes (Smoking cessation, Statin, Exercise, BP control, Diabetic
control, Antiplatelet therapy), Endovascular (Percutaneous Angioplasty with Stenting;
Typically used for Aortoiliac and superior femoral but not distal due to high risk of occlusion
• Surgical Management – Aortobifermoral Graft, Femorofemoral Crossover Bypass Graft,
Common Femoral Endarterectomy, Femoropoliteal Bypass, Femorodistal Bypass (reserved for
Critical Limb Ischaemia)
o Amputation – Severe Critical Limb Ischaemia where flow cannot be restored;
Amputation is only option to reduce severe pain or risk of infection, and Improve QOL
ACUTE LIMB ISCHAEMIA
• Sudden decrease in limb perfusion leading to potential threat to viability; Acute Thrombosis
with pre-existing Atherosclerosis (60% of cases); Embolisation (30% of cases)
• Pain, Pallor, Pulselessness, Paraesthesia, Paralysis, Perishingly cold
• Limb loss in 40%; Severe Ischaemia lead to irreversible tissue damage within 6 hours
ACUTE LIMB ISCHAEMIA Emergency Management
• High flow O2, Fluid resuscitation, Blood for
FBC, U&E, Troponin, Clotting, Glucose, G+S,
Request CXR and ECG (Looking for e.g. AF),
Opiate Analgesia
• Heparinisation by IV with APTT monitoring; 2
to 2.5× normal range
• Management – Amputation (if non-salvageable), Complications (e.g.
Hyperkalaemia, Acidosis, Acute Renal Failure,
Cardiac Arrest), Thrombolysis, Angioplasty,
Arterial surgery
GANGRENE
Ischaemic Tissue Necrosis with Desiccation (Dry) or Putrefaction (Wet), Caused by
Thrombosis, Embolisation or External Compression
o Chronic Limb Ischaemia associated with Dry Gangrene
Necrotising Fasciitis
Deep infection spreading across the fascial plane within subcutaneous
tissue with relative sparing of underlying muscle
o Majority infections by skin commensals – S. aureus, S. epidermidis
o Fournier Gangrene – Peroneal Necrotising Fasciitis associated with Diabetes
