The aim of this study was twofold: firstly, to study the nature of any temporal variation in capillary numbers, and secondly to determine the proportion of perfused to total nutritional capillaries in normal skin. Using in vivo microscopy, the temporal behaviour of the number of visible capillaries in the skin of the dorsum of foot was observed over periods of time varying from 5 min to 55 days in 15 healthy subjects. Capillary perfusion was then studied by comparing capillary numbers before and after intravenous injection of sodium fluorescein. The mean percent difference in the number of visible capillaries over a mean period of 25.3 days was 5.5%. The percentage ratio of perfused to total capillaries was 54.2%. This study shows that there is little quantitative change in capillary numbers over periods of up to 50 days, and that under physiological conditions, about half of the nutritional capillaries of skin are not perfused.

Adult↗

PubMedDate not supplied

Repeatability of intravital capillaroscopic measurement of capillary density.

The reliability of intravital capillaroscopy for determining capillary density (CD) of skin has been questioned because it depends upon the variability of the measuring process and subjective interpretation of data as well as the intrinsic heterogeneity of capillary spacing. The aim of this study was to assess the repeatability of a standardised method for measuring CD of the skin of the dorsum of foot. In each of 30 subjects (10 controls and 20 patients with peripheral vascular disease), the foot was systematically mapped by examining 20 sites on the dorsum of foot and 2 sites on each toe, using white light (native) videomicroscopy at 40 x magnification. Off-line analysis of videoprints was then undertaken to determine CD at each site, by counting capillaries within areas of acceptable photographic quality only, having first defined the criteria for counting capillaries. The mean values were then calculated and taken to represent the CD of the foot or toes. Repeatability of the measuring equipment was first assessed by noting the presence or absence of each corresponding capillary in 2 prints, taken at intervals of hours or days (in 10 subjects) or months (in 2 patients), of an identical area of skin which was marked by a microtattoo on the first occasion. On average, 95% of corresponding capillaries were identified in both prints (from controls and patients), thus implying little intrinsic temporal variation of capillary anatomy as well as excellent repeatability of the measuring equipment. Repeatability of data analysis was assessed by the same observer reading the same 20 prints in a blinded manner on three separate occasions (intraobserver repeatability), and 2 observers reading the same 24 prints (interobserver repeatability). The mean coefficient of intraobserver variation of CD estimate was 5.6% and the interobserver correlation coefficient was 0.94. Finally, overall repeatability of the method was assessed by repeating the procedure on a subsequent occasion (mean time interval of 5 days) in 10 subjects. The rate of agreement in mean CD between the two procedures [defined as 100- (difference between the two measurements/mean of the two measurements) x 100]% ranged from 86.4 to 97.1% (mean 93.5%). Thus using the above methodological technique, native capillaroscopy can be reliably used to determine CD of the dorsum of foot in comparing patient subgroups, as well as in longitudinal studies.

Aged↗

PubMedDate not supplied

Heterogeneity of capillary density of skin over the dorsum of the foot and toes of healthy subjects.

The spatial pattern of capillaries is one of many factors important for the optimisation of oxygen and nutrient delivery in a specified region of tissue. One area of particular interest to the vascular specialist is the skin of the dorsum of the foot and toes, as these are especially prone to ulceration in patients with arterial disease. The aim of this study was therefore to establish the extent of capillary density (CD) heterogeneity in the normal skin of the dorsum of the foot and toes, since any great non-uniformity might produce regions of low perfusion, which may become vulnerable to ulceration. Using white-light (native) videomicroscopy at a magnification of x 40 in 15 healthy subjects (mean age 72 years), the dorsum of the foot and toes was systematically mapped by determining the CD at each of 25 sites on the dorsum of the foot, and at 2 sites on the distal phalanx of each toe. Off-line analysis of videoprints was then undertaken to determine CD at each site, according to a fixed protocol of measurement and data analysis. The mean value and spatial coefficient of variation of CD was then calculated for each foot. There was striking spatial heterogeneity of CD in the dorsum of the foot, some areas having low numbers of capillaries and other areas in the same foot having higher capillary numbers. This spatial heterogeneity of CD was observed in all the feet studied, and the mean coefficient of variability was 22.3%. The toes had a significantly higher mean CD (47.7/mm2) than the dorsum of the foot (33.5/mm2, p < 0.001). The finding of a significant spatial heterogeneity of CD in the foot of normal subjects has important implications in relation to function, methodology of CD measurement and the possibility that regional 'rarefaction' of CD may contribute to the pathogenesis of skin ulceration in arterial disease.

Adult↗

PubMedDate not supplied

White cell and platelet trapping in patients with chronic venous insufficiency.

The cause of venous ulceration remains unclear but recent evidence suggests that white cell trapping may play a significant role. In this study venous blood taken from the dependent leg of 15 normal subjects was compared to samples taken from a similar number of patients with deep venous insufficiency. About 25 p. cent fewer white cells and platelets left the dependent foot of the patients with venous hypertension. When the foot was elevated there was a significant washout of white cells but not platelets suggesting platelet consumption within the microcirculation of the dependent foot. In 8 of the patients these changes were reversed by external compression.

Humans↗

PubMedDate not supplied

Venous claudication. A report of 15 cases and a review of the literature.

The symptom of intermittent claudication is not invariably due to arterial disease. Exercise-related pain resulting from venous insufficiency is poorly defined, but has been described by a number of authors in the past. Fifteen patients with symptoms suggestive of venous claudication are reported. The history and clinical findings are described. The further investigation of these patients is outlined, starting with the non-invasive methods of Doppler ultrasonography and strain gauge plethysmography. Ascending phlebography was performed on all affected limbs (n. 19) and descending phlebography was performed on those shown to have a patent deep venous system. These investigations demonstrated deep venous abnormalities associated with the distinct symptom complex. Venous claudication is defined and the literature reviewed. It is hoped that a clearer understanding of the condition will result in more frequent and accurate diagnosis with subsequent benefit to the patient.

Adult↗

PubMedDate not supplied

A randomised trial of bandaging after sclerotherapy for varicose veins.

169 legs with primary varicose veins suitable for sclerotherapy were entered into the trial. At the time of injection they were randomly allocated to be bandaged for three or six weeks; patients allocated to the six-week group had their legs rebandaged after the first three week. Patients were subsequently assessed blind at three months and thereafter at yearly intervals.

Bandages↗