Venous disease Flashcards
What are the three components to the venous system in the legs?
deep venous system - main route for blood to return from the legs to the heart via the IVC
-mirror major arteries
superficial venous system - collateral route for venous return via Great Saphenous Vein (runs from ankle to groin on medial aspect- joins the deep system at the saphenofemoral junction in the groin) and Small saphenous vein (runs from the ankle to the knee in the posterior aspect of the calf where it joins the deep system in the popliteal vein)
What vein is used as a conduit in bypass operations?
Great saphenous veins
What do perforator veins do?
provide additional channels connecting the superficial and deep systems at various levels
How does cross section of a vein compare to an artery?
diameter of vein much thinner - allowing veins to be easily compressed
tunica externa (connective tissue) is thickest layer in vein whereas muscular tunica media is much thinner compared to artery
What percentage of total circulating blood volume do veins store?
60 %
What are the normal function of veins?
return deoxygenated blood to the heart
capacitance vessels - low resistance and elasticity
thermoregulation - dilation of superficial veins
What muscle in legs help venous return?
calf muscle pumps
What is chronic venous insufficiency?
describes abnormalities in the venous circulation in which blood return to heart is significantly compromised
What provokes chronic venous insufficiency?
provoked by factors which increase the pressure in the venous system and / or cause damage to the valves.
Results in changes in wall including inflammatory infiltration and reduced elastin content- which alters integrity.
Progressive enlargement of veins causes the valves to become leaky and blood to reflux with gravity.
As cycle continues with progressive venous dilatation, venous hypertension and valve dysfunction- superficial veins become prominent and are known as varicose veins.
Deposition of red blood cells under the skin and inflammation and fibrosis within the subcutaneous fat- can culminate in skin breakdown- resulting in venous ulceration.
What are the risk factors for venous disease?
genetics
increasing age
female - especially multiparous
High BMI
sedentary lifestyle - esp prolonged standing
previous damage to veins- DVT, trauma
What are the symptoms of chronic venous insufficiency?
dull aching heaviness in limbs (relieved by elevation)
itching, skin changes and ulceration - venous eczema
significant venous bleeding
Signs of venous disease on examination?
reticular veins
varicose veins
haemosiderin deposition (RBC forced into skin)
lipodermatosclerosis (inflammation in subcutaneous fat)
ulceration
What is the classification for this?
CEAP classification
- clinical manifestation
-etiology
-anatomy
-pathophysiology
How are ulcers classified?
Arterial
-symptoms suggestive of Peripheral Arterial Disease
-exertional, reproducible leg pain
-nocturnal rest pain
risk factors: smoking, diabetes, hypertension
weak / absent pulses and monophasic/ absent doppler signals
WORSE WITH ELEVATION
Venous
Symptoms suggestive of CVI (chronic venous insuffiency)
-Leg ache/ heaviness
-venous skin changes
risk factors: female> , high BMI, standing occupation , genetics
palpable pulses and triphasic doppler signals
BETTER WITH ELEVATION
OR Mixed arteriovenous aetiology
Describe arterial ulcers?
well circumcised
pale centre- lack of blood supply
‘punched out’
deep
little granulation tissue
toes, foot or lateral malleolus
Describe venous ulcers?
less painful
shallow
more exudate
found more around the medial malleolus
base more red than arterial
evidence of granulation
more slough- by product of inflammatory phase of wound healing (fibrin , leukocytes, micro-organisms and proteinaceous material)
What is the main imaging modality for CVI?
venous duplex ultrasound- dynamic assessment which can demonstrate reflux through incompetent valves and map out the particular venous sections which are affected
blood tests such as Hb are useful if concern about significant venous bleed from varicose vein
wcc- if concern regarding infection in ulcer
Management for patients with suspected venous leg ulcers?
referral for a vascular ultrasound if ulcer hasn’t healed in a few weeks
referral to dermatology or rheumatology may be appropriate
How can we type treatment?
conservative management-
Keep active(activate calp pump), elevate legs (reduce effects of gravity when legs are down) , emollients
treat any infection
compression stockings or bandaging (reduce pooling of blood in superficial veins and help venous return)
endovenous intervention-
endovenous ablation (to damage intima of vein and induced pro coagulopathic state and vein walls stick together and prevent reflux of blood into segment of vein)
- performed under local anaesthetic (tumescence and local anaesthetic)
-laser
-thermal
-foam
Risks of endovenous ablation
DVT (blood thinner, compression stockings and patients to walk daily to reduce risk)
bleeding/ bruising
skin changes/ numbness
recurrence
When is open surgery performed?
patients who have had recurrent varicose veins after endovenous treatment and unsuitable for it
What is open surgery?
tying off segments of vein affected by reflux . Done at junction in groin.
Superficial varicose veins lower down in the leg can be treated with phlebectomies - making small incisions under local anaesthetic and inserting a small hook through these and pull out sections of superificial vein . Pressure is used to stop venous bleeding.
Future directions for CVD?
engineer replacement valves for veins
early diagnosis
target public health campaigns to explain ways public can prevent
What is deep vein thrombosis?
clot formation in any of the deep veins - popliteal or femoral .
Potential for piece of clot to break off and travel to lungs via pulmonary arteries.
Risk factors for DVT?
Venous stasis
-surgery or prolonged immobility
Hypercoagulability
-blood stickier
endothelial injury
-smoking
-trauma
History and examination of DVT?
acute painful, hot ,red, swollen leg
pain worse on mobilising and having leg down
may be provoked or unprovoked
What is the wide differential diagnosis for patients presenting with painful, swollen legs?
cellulitis
heart failure
trauma
compartment syndrome
What do we use to predict likelihood of DVT?
Modified Well’s score
Investigation of DVT?
low probability- D- dimer blood test- measures protein fragment when clot breaks down (not specific for DVT)
high probability- venous duplex ultrasound
Medical management of DVT?
anticoagulation
compression stockings
if unprovoked, investigate possible cause
-thrombophilia screen
-consider for cancer based on other signs and symptoms
What is treatment for large proximal DVTS? (ileo femoral)
catheter directed thrombolysis or thromboectomy
What are the rare presentations of acute, massive proximal lower limb DVT?
phlegmasia alba dolens (white leg)
-total occlusion of deep venous outflow
-patent superficial venous system
phlegmasia cerulea dolens (blue leg)
-occlusion of deep and superficial venous outflow
-precursor to venous gangrene
-increased risk of limb loss and death
