Tissue fluid pressure and flow in the subcutaneous tissue in lymphedema – hints for manual and pneumatic compression therapy

In obstructive lymphedema of lower limbs tissue fluid pressures in the subcutaneous tissue was 2.5±3.0 mmHg (range-1 to +10 mmHg) and did not differ from those measured in normal subjects. During manual massage the applied force generated pressures ranging from 60 to 120 mmHg. Pneumatic compression generated tissue fluid pressures depending on sleeve inflation pressures, however, they were on the average 20% lower than in the inflated chambers. The high pressure gradient across skin and subcutis could be explained by skin rigidity (fibrosis), low hydraulic conductivity of subcutis and dissipation of the applied force in subcutis to the proximal noncompressed regions. Strain gauge put around the limb provided data on girth changes during compression and allowed to calculate the approximate volume of the proximally displaced fluid. It showed that tissue fluid flow occurred during manual compression only during pressing of tissues to stop immediately after its cessation. In contrast, pneumatic sequential compression produced unidirectional flow toward groin without backflow. The total proximally displaced volume from ankle to groin was up to 100ml/cycle.