peripheral vascular disease Flashcards
lower limb venous flow
low pressure system
requires ‘pump’
needs valves to prevent backflow
what happens if the valves stop working in the lower limb venous system
blood travels from high pressure (deep veins) to low pressure (superficial veins) > chronic venous insufficiency
chronic venous insufficiency
reflux between deep and superficial systems
causes increase in hydrostatic pressure in superficial system > venous hypertension > inflammatory response including leucocyte activation and abnormal healing response > vein wall fibrosis
varicose veins
valves connecting deep and superficial systems become incompetent
leads to venous dilation
investigation for varicose veins
duplex
and clinical examination
management for varicose veins
conservative: graduate compression stockings
endovenous/surgical: foam sclerotherapy, endothermal ablation, open surgery
3 clinical entities of limb ischaemia
acute limb ischaemia
acute on chronic limb ischaemia
chronic limb threatening limb ischaemia
acute limb ischaemia is due to
embolism
thrombus
trauma
laterogenic
how does embolism cause acute limb ischaemia
cardiac- usually context of AF (formed in left atria) or MI (left ventricle)
sometimes paradoxical embolus
non-cardiac- atheroembolism (diseased aorta, AA) or aortic mural thrombus
paradoxical embolus
clot from deep venous system passes through patent foramen ovale into arterial system
how does thrombus cause acute limb ischemia
hypercoagulable states
chronic atherosclerotic stenosis
investigation for acute and chronic limb ischaemia
measure severity by ABI
duplex US and doppler
ECG- MI arrhythmia
CT angiography-
management of limb ischaemia
medical: dependent of extent, IV heparin, IV fluids surgical: mild- moderate: thrombolysis if embolus: embolectomy bypass (acute-on-chronic) compartment syndrome: fasciotomies
management of chronic limb ischaemia
exercised program anti-platelet and statin (clopidogrel) (Naftidrofuryl oxalate as vasodilator) surgical: not generally recommended - percutaneous transluminal angioplasty - bypass
acute on chronic limb ischaemia
acute occlusion on background of underlying disease
same initial management as Acute limb ischaemia
urgent arterial imaging required