Vascular Flashcards
What is the definition of an aneurysm?
> 150% dilatation of its original diameter.
True aneurysms involve all layers
Pseudo-aneurysms are collections of blood around a vessel wall - haemtoma in the adventitia
Where are the common sites to have aneurysms?
Aorta (infra renal), iliac, femorl, popliteal
What is the definition of a AAA?
> 3cm across.
How are unruptured AAA treated?
Treat any HTN
Monitor aneurysm size
Elective surgery/ stenting - >5.5cm or growing by >0.5cm/6months
What are the causes of aneurysms?
Due to degeneration of the arterial media - particularly a reduction in elastin.
Contributing factors:
Elastin degradation due to increased levels of metalloproteinases
Flow dynamics
Hypertension
Atherosclerosis
Collagen defects
Genetic
Smoking
Infections and inflammation can play a part also (Takayasu’s aortitis, and syphilis)
What is the indication for a carotid endarterectomy?
Stensosis >70%.
Should be performed within 2 weeks of first presentation
What are the risks of carotid endarterectomy?
Neck haematoma 5% Cervical and cranial nerve injury 7% (hypoglossal, vagus, recurrent laryngeal, marginal mandibular and transverse cervical nerves) Stroke 2% MI False aneurysm Infection of prosthetic patch Death 1%
Which artery is normally affected in acute mesenteric ischemia?
Superior mesenteric artery:
supplies the small bowel and up to the splenic flexure of the large bowel
What is the classic triad of acute mesenteric ischemia?
Acute severe abdo pain, no abdominal signs, rapid hypovolaemia.
What causes acute mesenteric ischemia?
Arterial: thrombotic, embolic
Non occlusive (in renal failure or low CO)
Venous
Other: trauma, vasculitis, radiotherapy, strangulation
What causes chronic colonic ischemia?
Low flow in the inferior mesenteric artery
What are the causes of Raynaud’s?
SLE Systemic sclerosis RA Cold Aggluntins Polycythaemia Oral contraceptives B blockers Occupational - vibrating tools Cervical rib
Describe the colour changes seen in Raynaud’s.
White - digital artery spasm causes blanching
Blue - accumulation of deoxygenated blood
Red - reactive hyperaemia
What are the signs of acute limb ischemia?
Pale Pulseless Painful Paralysed Paraesthetic Perishingly cold
If fixed mottling occurs this implies irreversibility
What are the causes of acute limb ischemia?
Thromobis in situ
Emboli - AF, atrial myxoma, underlying malignancy
Aneurysmal disease
Trauma
What is the management of acute limb ischemia?
Give heparin and resuscitate with IV fluids
Angiography
Either local thrombolysis or embolectomy
What is thoracic outlet syndrome?
A collection of symptoms relating to arterial, nerve and venous compression as they exit the chest.
Compression occurs normally in the area betwee the clavicle, the first rib and the scalenus anterior muscle.
What are the symptoms and signs of thoracic outlet syndrome?
Neurological - sensory and motor deficit in the distribution of C8/T1, exacerbated by movement, worse at night
Arterial - claudication or rest pain. distal arterial disease may be due to emboli from an are of dilatation or frank aneurysm.
Venous - venous hypertension
What is the hallmark symptoms of chronic limb ischemia?
Intermittent claudication - pain in the leg that gets better at rest, is worse on an incline. Seems to occur at a fix distance.
What symptoms would make you think a limb is critically ischemic?
Pain at rest, ulceration and gangrene.
What ankle brachial pressure index values suggest disease?
Normal >1
Claudication =0.9-0.6
Rest pain = 0.3 - 0.6
Impending gangrene <0.3
NB: calcified vessels are not compressible so will give a falsely high reading - DM, severe atheroscerlosis
What examintion can be used to assess limb ischemia?
Burger’s test:
lifting the leg to an angle of 20 degrees and it going pale indicated critical ischemia
What is the management of chronic limb ischemia?
Mainstay is reducing risk factors:
Stop smoking, statins, antiplatelets, BP control, good diabetes control
Angioplasty, and bypass surgery can be carried out
Amputation is used for relief of intractable pain, and releif of sepsis
What is an ulcer?
An ulcer is a dissolution of an epithelial surface.
What are the causes of ulcers?
Venous disease Arterial disease (small and large vessel disease) Neuropathy (diabetes, neuropathic) Lymphodema Vasculitis Malignancy Infection (TB, syphilis) Trauma Pyoderma gangrenosum Drugs
Describe how the site of an ulcer gives you an idea of its cause:
Above the medial malleolus - venous
Toes - arterial
Sacrum, greater trochanter, heel - pressure
What does the edge of an ulcer tell you about it?
Eroded = active and spreading Shelved/ slopping = healing Punched out = ischemic or syphilis Rolled/ everted = malignant Undermined = TB
When bypassing an artery in the leg what is the preferred graft?
Autologous vein - usually the long saphenus vein unless it has been used for previous surgery, or is smal in calibre, then other veins can be used (arms or short saphenous)
What are the complications of bypass surgey?
Early:
Haemorrhage, graft thrombosis, compartment syndrome, DVT/PE, CVR complications
Late: Graft stenosis/ occlusion Delayed wound healing Graft sepsis Anastomatic false aneurysms Limb loss
What is the differential diagnosis for a swollen leg?
Unilateral: Long standing venous disease Acute DVT Lymphodema (primary or secondary) Extrinsic pressure (pregnancy, tumour, retroperitoneal fibrosis) Klippel - Trenaunay syndrome Lipoedema Disuse / hysterical oedmea
Bilateral:
Heart, renal, liver failure
Hypoproteinaemia,
Hereditary angioedema
What are the causes of primary and seconday lymphodema?
Primary: isolated or familial
Secondary: surgical excision/ radiotherapy of local lymph nodes, tumour, trauma, filiraisis,
What is the pathological basis of varicose veins?
They are dilated tortuous veins.
Primary are most common, ?due to weakness within the vein that allows it to stretch and therefore render the valve incompetent.
Secondary veins can be caused by:
obstruction to venous flow (prengnany, fibroids, abdominal lymphadenopthy, pelvic cancer etc)
valve destruction (DVT)
high flow and pressure (AV fistulae)
What is the route of the long saphenous vein?
Drains the medial aspect of the leg and anterior aspect of thigh.
What is the route of the short saphenous vein?
Drains the posterior aspect of the calf
What are the signs that suggest there has been chronic venous incompetency?
Odema, eczema over the venous area, haemosiderin skin staining, lipodermatosclerosis (hard skin from subcutaneous fibrosis caused by chronic inflammation and fat necrosis.
What is the trendelenburg’s test?
Tests the competence of the saphenofemoral junction.
Lie patient down and raise leg to empty the vein, place two fingers on the SFJ (5cm below the femoral pulse). Ask the patient to stand and if the varicosities are controlled they will not refill, release fingers to confirm they re fill - demonstrating SF incompetence.
What is a saphena varix?
The dilatation of the saphenous vein at its confluence with the femoral vein.
It transmits a cough impulse and may be mistaken for a hernia
How do you treat varicose veins?
Treat any underlying cause Education - avoid long periods of standing up, wear support stockings, lose weight, walk regularly. Injection sclerotherapy Laser coagulation Surgery
What is an aortic dissection?
It is when there is a tear in the aortic media and blood runs through it tearing it further.
It presents with tearing chest pain and as the disection unfolds the branches of the aorta become occluded resulting in hemiplegia (carotid), acute limb ischemia (subclavian) or paraplegia (spinal arteries)
What is the difference between type A and type B dissections?
Type A involve the ascending aorta, irrespective of site of tear
Type B do not involve the ascending aorta
What is the difference between wet and dry gangrene?
Wet gangrene is tissue death + infection
Dry gangrene is just tissue death
