Vascular surgery Flashcards
Definition of aortic dissecion
The entry of blood through an intimal tear in the thoracic aorta into an intima-media space creating a false lumen that extends ante- or retrograde
Risk factors for aortic dissection
Hypertension and old age!!
Connective tissue disorders (Marfan’s)
Structural abnormalities (e.g. bicuspid aortic valve or coarctation - aortic root dilatation)
Turner syndrome
Pregnancy
Classifications of aortic dissection
DeBakey classifications:
Type I: involves both ascending and descending aorta (Stanford A)
Type II: involves ascending aorta only (Stanford A)
Type III: involves descending aorta only (Stanford B)
Stanford classification of aortic dissection
Stanford A = proximal to subclavian artery
IS AN EMERGENCY - as can become proximal leading to regurgitation, ST elevation and haemodynamic compromise
Which is more common, aortic dissection or ruptured abdominal aneurysm
Aortic dissection is twice as common as ruptured abdominal aneursym
Clinical features of aortic dissection
Tearing chest pain radiating to back
Often associated with episode of collapse
Symptoms of CHF, dysphagia, haemoptysis, haematemesis
+/- evidence of occlusion of aortic branches (paraplegia, acute limb ischaemia, CVA, inferior MI, acute renal failure)
Hypertension in 90%
R/L BP discordance
Red. or absent peripheral pulses
Soft early diastolic murmur (aortic regurgitation)
Imaging in aortic dissection
CXR: - widened mediastinum - double aortic contour - Irregular aortic contour - inward displacement of atherosclerotic calcification Echo: confirms diagnosis Post-contrast CT: - intimal flap - double lumen - dilatation of aorta
Management of aortic dissection
IMMEDIATE MANAGEMENT OF HTN
Type A - usually require surgical intervention (unless evolving CVA or established renal failure)
Type B - may be managed nonsurgically
- fastidious BP control
- surg if evidence of aortic expansion
Definition of abdominal aortic aneurysm
An increase in aortic diameter by over 50% (usually regarded as diameter greater than 3cm)
Risk factors for development of abdominal aortic aneurysm
HTN Peripheral vascular disease Family history Connective tissue disorders Arteritis Smoking Hypercholesterolaemia
Risk factors for rupture of pre-existing abdominal aortic aneurysm
Large size
HTN
COPD
Female gender
Risk of AAA rupture at 5 years by size
5-6cm: 25%
6-7cm: 35%
Over 7cm: 75%
Clinical presentation of stable AAA
75% asymptomatic Epigastric or back pain Malaise and weight loss Possible blue, painful toes (thromboemboli) Wide AA pulse (3cm)
Clinical presentation of ruptured AAA
Sudden onset abdominal, flank or back pain (+/- radiation groin, back, legs) Syncope N+V Rapid palpitations Light-headedness Tachycardia Palpable pulsatile abdominal mass Hypotension Shock
Investigations of choice in AAA
USS: preferred for monitoring small aneurysms
CT angiogram:
- Draped aorta sign (sign of contained rupture)
- high attenuation crescent sign - sign of impending rupture (fresh blood insinuating into mural thrombus before penetrating wall)
- retroperitoneal haematoma
Indications for surgical repair of AAA
Rupture
Symptomatic aneurysm
Rapid expansion
Asymptomatic larger than 5.5cm
Conservative management of AAA before surgery is indicated
Management of Hypertension!
Definition of intermittent claudication
Intermittent, reproducible calf or thigh pain precipitated by exercise and relieved by rest, due to ischaemia of the lower limbs in the setting of peripheral arterial disease
Clinical features of intermittent claudication
Calf or thigh pain
- precipitated by exercise
- relieved by rest
- occurs after predictable distance
- “cramp” or “tightness”
- Exact location varies according to vessels involved
Buttock and hip = aortoiliac disease
Thigh = common femoral artery or aortoiliac
Calf = superficial or popliteal femoral artery
Management of intermittent claudication
Risk factor reduction
Anti-platelet medications (aspirin)
Surgical revascularisation
- aorto-iliofemoral reconstruction or bypass
- Angioplasty +/- stenting
indications for revascularisation;
- Refractory rest pain or claudiction limiting lifestyle
- Non-healing ulcers or gangrene
Definition of critical limb ischaemia
Persistently recurring ischaemic rest pain requiring regular adequate analgesia for more than two weeks OR tissue loss (ulceration or gangrene) of the foot or toes with an ankle pressure of less than 50mmHg or toe pressures less than 30mmHg
Cause of critical limb ischaemia
Atherosclerosis
Same mechanism as intermittent claudication but greater obstruction
Clinical features of critical limb ischaemia
Ischaemic pain at rest
- cramp/tightness
- increase when foot elevated (e.g. lying down in bed)
- relieved with dependency (putting put lower)
+/- ulceration or gangrene
Absent foot pulses
ABI less than 0.4
Management of critical limb ischaemia
Automatic indication for revascularisation (percutaneous angioplasty or bypass surgery)
Risk factor modification
Definition of acute limb ischaemia
A medical emergency caused by sudden arterial occlusion in a limb with inadequate collateral supply
Epidemiology of acute limb ischaemia
Rare
Mortality as high as 75%
Infrequent in those with established peripheral arterial disease due to inc. collateral circulation
VERY UNCOMMON in upper limb
Causes of acute limb ischaemia
Embolism (LA, mural thrombus, prosthetic/disease heart vlaves, aneurysm or atheromatous stenosis, tumour, foreign body)
Thrombosis
Trauma
Dissecting aneurysm
Clinical features of acute limb ischaemia
6 Ps: - Pain - paraesthesia - pallor - pulselessness - paralysis - perishing with cold \+ fixed staining/mottling (late sign) \+/- objective sensory loss (late sign!)
how to differentiate embolic v thrombotic limb ischaemia
Embolism:
- more rapid onset of symptoms
- potential source of embolus (e.g. known AF)
Thrombus:
- Pre-existing chronic arterial disease and comorbidities
- reduced pedal pulses in contralateral leg
- Foreign implants in peripheral artery (e.g. stent etc.)`
Management of acute limb ischaemia
Heparin + analgesia
treatment of associated cardiac disease
Embolic disease: embolectomy or intra-arterial thrombolysis
thrombotic disease:
Intra-arterial thrombolysis/angioplasty or bypass surgery
Clinical features of chronic mesenteric ischaemia
Recurrent acute episodes of abdominal pain: - dull, crampy - postprandial (within 1h) - epigastric - inc. severity after high fat meals - pain subsides over 2h Weight loss due to food aversion Nausea, vomiting and early satiety
Diagnosing mesenteric ischaemia
CT and MR angiography
Duple ultrasound can detect high-grade stenoses
most common cause of peripheral leg ulcers
Venous leg disease
Clinical features of venous hypertension
Perimalleolar oedema Pigmentation (haemosiderin staining) lipodermatosclerosis (skin hard and woody) Eczema ulceration
management of venous ulcers
manage venous HTN:
- DVT prophylaxis (antiplatelets, compression therapy)
- refer to leg ulcer clinic
- wound debridement
- pain management (e.g. topical lignocaine)
- Elevation (red. oedema to inc. healing)
- exercise (inc. movement of blood)
Skin and ulcer hygiene
- regular washing, Cadexomer iodine
Management of comorbidities
Definition of varicose veins
Manifestation of superficial venous insufficiency characterised by bulging (over 3mm diameter) tortuous superficial veins, usually in the lower limb)
Definition of reticular veins
“feeder veins”, blush subderma veins 1-3mm in diameter that give rise to telangiectasia
Definition of telangiectasias
“spider veins”, very small (less than 1mm diameter) thread veins found commonly in clusters on the surface of the skin
distribution of varicose veins
Long saphenous vein:
- anteromedial distribution
Small saphenous vein:
posterior distribution
Indications for surgery of varicose veins
Mostly for cosmetics or minor symptoms
Absolute indications:
- lipodermatosclerosis leading to venous ulceration
- recurrent superficial thrombophlebitis
- bleeding from ruptured varix
Conservative treatment of varicose veins
Aerobic exercise Elevation Flex ankles frequently during prolonged durations of sitting Weight control Graduated compression stockings
Invasive therapies for varicose veins
Open surgery: LSV stripping
Radiofrequency ablation
Endovascular laser ablation
Sclerotherapy
Management of DVT
Prevent PE:
- anticoagulation - initially with LMWH (unless in setting of CKD)
- oral anticoagulation for at least 3-6m
Surgical thrombolectomy or thrombolysis is an option
Definition of superficial thrombophlebitis
Pain, tenderness, induration and erythema along the course of a superficial vein due to inflammation and/or thrombosis and less commonly, infection of the vein. Generally benign and self-limiting but can be complicated by DVT and PE
Management of superficial thrombophlebitis
Symptom alleviation Prevention of thrombus propagation For less extensive phelbitis (less than 5cm) - elevation - warm or cool compresses - NSAIDs More extensive (over 5cm or in saphenofemoral/saphenopopliteal junction) - anticoagulation with heparin
Grading of carotid stenosis
Mild: less than 50%
moderate: 50-70% stenosis
Severe: 70-99%
clinical features of carotid stenosis
Focal neurological deficit in the carotid artery distribution
- amaurosis fugax
- contralateral weakness or numbness of a limb or face
- dysarthria or aphasia
Indications for carotid endarterectomy
Symptomatic and 70-99% stenosis (clear benefit)
Symptomatic and 50-69% stenosis (possible benefit)
Asymptomatic MALES with over 70% stenosis
Wet v Dry gangrene
Wet gangrene = infectious (i.e. necrotising fasciitis)
Dry gangrene = ischaemic
Management of dry gangrene
IV heparin
If threatened non-viable extremity with LE over 2y:
Surgical revascularisation +/- amputation
Threatened non-viable less than 2y LE - PCI +/- amputation
Viable extremity: thrombolytic therapy
Location of arterial v venous ulcers
Arterial: soles of feet, heels and toes
venous: inner part of ankles (medial malleoli)
Borders of arterial v venous ulcers
Venous: poorly defined
Arterial: well-defined, punched out
ABPI indicative of arterial disease
Less than 0.9
