FLUCTUATION OF SKIN LYMPHATIC CAPILLARY-PRESSURE IN CONTROLS AND IN PATIENTS WITH PRIMARY LYMPHEDEMA

The microlymphatic pressure was monitored by using the servo-nulling t echnique at the forefoot skin in 24 healthy volunteers (number of capi llaries studied: 97) and in 27 patients with primary lymphedema (capil lary number: 67). The lymphatic capillaries were stained by fluorescen ce microlymphography with fluorescein isothiocyanate-dextran 150 and c annulated using glass needles with a diameter between 7 and 9 mu m. Th e lymphatic capillary hypertension described recently in primary lymph edema was confirmed in this series (mean pressure of controls 6.7 +/- 3.8 and, of patients 12.8 +/- 5.9 mm Hg; p < 0.001). Two patterns of p ressure fluctuation were observed: rhythmic low-amplitude (mean value 3.7 mm Hg) waves with a frequency identical to respiration (respirator y movements of the thorax recorded simultaneously by a photo cell) and spontaneous nonrhythmic, low-frequency waves with a higher amplitude (mean value 5.5 mm Hg). The prevalence of waves synchronous with respi ration was identical in patients and controls, whereas the low-frequen cy waves exhibited a significantly (p < 0.05) higher prevalence in the patients (41.7%) than in the controls (70.4%). The hypothesis is adva nced that in primary lymphedema a considerable amount of lymphatic flu id is removed by lymphatic pathways with small calibre and high resist ance, resulting in microvascular hypertension, and that contractions o f the few preserved large proximal lymphatic collectors are enhanced. The latter mechanism could explain the increased prevalence of spontan eous microlymphatic pressure fluctuations with high amplitude and low frequency.