Chap 55-56 CVI General Considerations Flashcards
what conditions contribute to venous pathology?
valvular incompetence of the deep or superficial veins
perforator incompetence
venous obstruction
muscle pump dysfunction
what does normal venous pressure do with exercise?
resting venous pressure drops with exercise >50%
returns to normal but takes >20sec
What are primary and secondary cause of valve dysfunction?
preexisting weakness in vessel or leaflets
secondary to direct injury superficial phlebitis
excessive venous distention from hormonal effects or high pressure
How does high venous pressure enter the superficial system?
failure of valves located at junctions b/w deep and superficial
failure of valves in communicating perforator
What are the most common tributaries with reflux?
saphenous
small saphenous
both
What are obstructive causes of reflux?
venous thrombosis
destruction of valves from DVT
compression (May-thurner)
What is the genetic inheritance of VV?
autosomal dominant with variable penetrance
How does microangiopathy occur?
hemo changes in large veins are transmitted to microcirculation
microvalve dysfunction
What are features of microangiopathy?
elongation, dilatation, tortuosity of capillary beds
thickening of BM with increased collagen and elastic fibbers
endothelial damage
increased pericapillary edema with ‘halo’ formation
what happens to the capillary once microangiopathy has started?
increase permeability and high venous pressure
accumulation of fluid, macromolecules and extravasated red blood cells in the interstitial
fragmentation and destruction of microlymphatics (impairs drainage)
What mechanisms have been postulated for devel of microangiopathy?
fibrin cuff formation (accumulation of fluid in pericapillary sapce)
this impairs fibrinolysis, increase diffusion barrier, inhibit repair process and maintain inflame process
WBC trapping in capillaries with activation of leuks and inflammation
growth factor activation (unavailable for healing)
What are skin changes in CVI?
edema
corona phlebectatia
hyper pigmentation from hemosiderin deposition
lipodermatosclerosis with scarring and thickening of the skin
atrophie blanche
what is lipodermatosclerosis?
inflammation of the fat under the epidermis
get fat necrosis
causes tapering at ankles
What is atrophie blanche?
smooth, ivory-white plaque stippled with telangiectases and is surrounded by hyper-pigmentation
What is the character of the edema associated with CVI?
initially pitting
then brawny and resistant to pitting
What is corona phlebectatica?
fan shaped appearance of intradermal veins on the ankle (inframalleolar ankle flare)
advanced disease