Angiogenesis, lymphatics and oedema Flashcards
(23 cards)
Examples of pathological neovascularisation:
Tumour, retinopathies Psoriasis, RA Plaque progression Restenosis Endometreosis Vascular malformations
What mechanical factor drives arteriogenesis?
Flow shear stress
Definition of erythema?
Redness of skin or mucus membranes in superficial capillaries
Angiogenic promoters:
VEGF, FGFs, angiopoietins (relative concentration dependent)
Angiogenic inhibitors:
Angiopoietins Angiostatin Troponin I Integrins beta3 IL-12
What happens at the level of the inguinal ligament?
The external iliac becomes the common femoral artery
What is the autonomic response to necrosis?
Vasodilation of surrounding capillaries causing mummification and surrounding erythema
Definition of claudication?
Cramping pain in the leg induced by exercise due to obstruction of arteries
What can follow claudication?
Rest pain then gangrene
Sign that leg oedema is caused by heart failure?
Bilateral (both legs) with raised JVP
Sign that leg oedema is caused by a DVT?
Only present in one leg
Other causes of leg oedema?
Dependancy/immobility Pregnancy - central veins compressed Low plasma proteins Chronic venous insufficiency Lymphatic insufficiency Chronic renal failure
Differences between transudate and exudate?
Transudate contains little protein and comes as a result of increased hydrostatic pressure/decreased colloid pressure as liver synthesises less protein
Exudate contains cells, proteins and is inflammatory in nature from a leaky epithelium - readily clots due to fibrinogen
Syndromic causes of primary lymphoedema?
Turner’s
Noonan’s
Prader-Willi’s
Overgrowth, vascular or cutaneous cause of primary lymphoedema?
Klippel-Trenaunay
Congenital cause of primary lymphoedema?
Milroy’s - VEGFR3 mutation - onset is typically <1 year old, is present at birth and is bilateral
Late onset cause of primary lymphoedema?
Lymphoedema distichiasis (FOXG2 mutation) Late onset >1 year old Typical presentation is a teenager with double rows of eyelashes
Causes of secondary lymphoedema:
RT (axillary)
Surgery (groin LN resection)
Cellulitis (destroys lymphatics)
Filariasis (helminths parasite that destroys lymphatics)
Management of oedema?
Treat cause Elevation Compression Massage Skin care Liposuction
Danger of compression in oedema?
Can cause ulcers
Must check pedal pulses, cap refill and ankle-brachial pressure index to see occlusions or duplex of the leg to observe disease distribution
Why can you not perform ankle-brachial pressure index on diabetics?
Because their vessels are stenosed and calcified so their vessels can’t be compressed and their pressure indices will be falsely high
What is the Charles procedure?
Removing all tissue down to the fascia and skin grafting legs
What is the Homann’s procedure?
Keeping skin flaps, debulking and suturing
