13.02.28 Lymphoedema

Swelling differential

    • Fluid

    • Overgrowth

    • Tumour

    • Shrinkage of t'other side

Fluid flow

    • Net pressure is OUT OF capillaries over their entire length

      • => There is no venous reabsorption of fluid

      • => Lymphatics do it all

    • NB this is not what used to be taught

Lymphatic failure

    • Filtration oedema

      • Lymphatics still functional, just overloaded

      • e.g. In acute heart failure

      • Pits easily as fluid is still flowing fine

    • Lymphoedema

      • Damage to lymphatics

      • e.g. From sustained filtration oedema

      • Pits at early stages

      • Non-pitting later on

Lymphoedema stages

    • Stage 0 (latent):

      • Vessel damage but transport capacity is still sufficient for the amount of lymph being removed

      • Lymphedema not present

    • Stage 1 (spontaneously reversible)

      • Tissue is still at the "nonpitting" stage

      • Usually upon waking in the morning, the limb or affected area is normal or almost normal in size

    • Stage 2 (spontaneously irreversible)

      • The tissue now has a spongy consistency and is considered "pitting"

      • Fibrosis found in stage 2 lymphedema marks the beginning of the hardening of the limbs and increasing size

    • Stage 3 (lymphostatic elephantiasis)

      • Swelling is irreversible and usually the limb(s) or affected area is very large

      • The tissue is hard (fibrotic) and unresponsive

Milroy's disease

    • VEGFR-3 mutation => Spontaneous oedema

Distinguishing features of lymphoedema (vs filtration oedema)

    • Only slightly helped by elevation

    • Diuretics don't help

    • >1 attack of cellulitis

      • Due to reduced immune cell trafficking

    • Exercise helps

    • Pitting

    • Skin thickening/hyperkeratosis

Notes

    • Lymphatics

      • Small collecting ducts

      • Large draining ducts, with valves + smooth muscle

    • Don't confuse lipodermatosclerosis with cellulitis

      • Requires elevation and compression, not antibiotics

    • CCBs block lymphatic smooth muscle pumping and can cause lymphoedema

    • Plexiform neurofibroma

      • Brown spots + swollen leg