This study investigated the possibility that pericapillary
fibrin deposition, found in the calf skin of patients with venous ulceration and
lipodermatosclerosis, might already be present in the dermis of the gaiter area of apparently healthy limbs before any skin changes were visible. The apparently healthy limbs of 19 consecutive patients with a healed
venous ulcer on one leg and no history of ulceration or clinical evidence of
lipodermatosclerosis in the opposite calf, were studied. Bipedal ascending phlebography and foot volume plethysmography were performed, and systemic fibrinolytic activity and
fibrinogen levels were calculated. Transcutaneous
oxygen measurements were expressed as a ratio of levels from a fixed position in the gaiter skin over a control site on the arm. Biopsies of a standard site in the gaiter skin and the thigh were assessed for the presence of
laminin,
fibrinogen and
fibronectin using immunofluorescent microscopy. The extent of pericapillary fluorescence was expressed as a ratio of the number of capillaries with deposits divided by the total number of capillaries staining with
laminin (
fibrin and
fibronectin scores). Pericapillary
fibrin deposits were observed in the dermis in 16 of the biopsies of the gaiter region (median score 0.20), and in eight of the biopsies from the thigh (median score 0.0). This difference was highly significant (P<0.01, Wilcoxon signed rank test). The transcutaneous
oxygen ratio correlated negatively with the
fibrin score (Spearman rank correlation coefficient -0.62, P<0.01), and there was a weak negative correlation between the half volume refilling time on foot volume plethysmography (an
indicator of venous reflux) and the
fibrin score (Speraman rank correlation coefficient -0.47, P<0.05). No such correlation could be shown between the
fibrin score and the indicators of calf pump function, the euglobulin clot lysis time or the plasma
fibrinogen. The presence of significant numbers of pericapillary
fibrin deposits within the dermis of the gaiter skin has been demonstrated in 84% of this cohort of 'at risk' limbs before there is any evidence of clinical
lipodermatosclerosis.