Venous Disease Flashcards
vein structure?
adventitia media intima intima lined with endothelial cells layer of smooth muscle cells (thinner than in arteries)
are veins pulsatile?
no
vein physiology?
thin walled
non pulsatile
elastic and collapsable
carries 65% of circulating volume
venous flow = cardiac output, how is this?
cardiac output depends on venous return to the heart so venous flow = cardiac output
do veins have tone?
yes
some but not loads or as much as arteries
valves more responsible for preventing backflow
what is vis-a-front?
suction effect of diastole in the heart and low CVP creating a pressure gradient
pulls blood forward in veins
what is vis-a-tergo?
pressure from behind pushing blood through veins
pressure gradient between capillary pressure (20-25) and venous pressure (0)
what else encourages venous flow?
muscle pump in lower limb
thoracic pump (intra-abdominal pressure decreases in expiration which increases flow)
5% also drains via lymphatics
common venous problems?
varicose veins
venous ulcers
DVT
chronic venous insufficiency
what are varicose veins?
dilated, tortuous, superficial veins
can expand to 3-4mm (defined as dilated)
types of varicose veins?
idiopathic
obstructive (DVT, pregnancy, pelvic mass)
congenital (klippel trenauney syndrome)
venous drainage in legs?
blood drains from foot into deep veins at saphenofemoral junction and saphenopopiliteal junction
what is klippel trenauney syndrome?
rare congenital disorder characterised by a triad of cutaneous capillary malformation (port wine stain), lymphatic anomalies and abnormal veins in association with variable overgrowth of bone and soft tissues
investuigation of varicose veins?
doppler (look for venous insuficiency, reflux(blood backflow))
conservative management of varicose?
compression lifestyle (elevate legs, don't stand for too long etc)