The relationship between the number of capillaries in the skin of the venous ulcer-bearing area of the lower leg and the fall in foot vein pressure during exercise.

The changes in foot vein pressure during exercise have been measured in 30 normal legs and 109 legs with varicose veins or postphlebitic changes and correlated with the number of capillaries visible in a histological section of skin from the ulcer-bearing area. There was a significant correlation between the inability of the calf pump to reduce foot vein pressure during exercise and the number of capillaries in the skin. It is suggested that the increased number of capillaries secondary to venous hypertension during exercise may be the prime cause of the nutritional abnormalities that eventually cause a venous ulcer.