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