The mechanisms of venous stasis in post-phlebitic syndromes.

Venous stasis in post-phlebitic syndromes may be caused by several physiopathological processes. Phlebography and functional investigations (Doppler, occlusive rheoplethysmography) enables us to make a fairly precise analysis of the causal factors: --The obstruction of a large venous collector defines the obstructive syndromes. The size of the stasis depends on the functional value of the substitutional channels; distinction may be made between compensated obstructive syndromes (with efficient substitutional circulation) and poorly or non-compensated obstructive syndromes. --Orthostatic reflux in devalvulated deep veins constitutes another factor of stasis. Distinction to be made between minor reflux, and major reflux with massive reflux in the great trunks and associated insufficiency of the tibial communicators. --Post-phlebitic superficial venous insufficiency is often observed. Its physiopathology is basically no different to that of primary varices, the functioning of the tibial communicators is often perturbed. --The restrictive syndrome, result of functional investigations, corresponds to a reduction of the venous distensibility whose effects are superadded to those of the syndromes described above.