A review of microvascular measurements in wound healing.

The microcirculatory evaluation in patients affected by arteriopathic or venous ulcers is usually carried out using laser Doppler flowmetry, transcutaneous oxygen (transcutaneous pressure of oxygen, TcPO(2)), and carbon dioxide (transcutaneous pressure of carbon dioxide, TcPCO(2)) measurements and capillaroscopy. These techniques provide significant pathophysiologic and prognostic information. TcPO(2) and TcPCO(2) diagnose and classify the extent of arterial disease in the leg ulcers caused by arterial disease; the prognostic value is recognized, though doubts about its prognostic potential exist in the case of leg ulcer. Laser Doppler flowmetry is able to identify the first functional impairment in the early stages of the arterial disease and in the complicated venous insufficiency. Capillaroscopy gives us morphological and quantitative parameters of the capillary bed that is damaged in arteriopathic and venous ulcers; nevertheless, it does not provide us with definite prognostic indexes. Combining the 3 methods may contribute to yield objective measures in the clinical management of lower extremity ulcers.

Calcium channel blockers blunt postural cutaneous vasoconstriction in hypertensive patients.

The aim of this work was to test whether calcium channel blockers interfere with skin vasoconstrictor reflexes that minimize postural increases in capillary pressure and avoid fluid extravasation and eventually subcutaneous edema. Studies were conducted in 23 untreated mild to moderate essential hypertensives; drugs, either calcium channel blockers or not, were given for 2 weeks according to a crossover, sequence-randomized design. Skin blood flow was measured by laser Doppler flowmetry in two skin areas: (1) the dorsum of the foot, where arteriovenous anastomoses are poorly represented, and (2) the plantar surface of the great toe, where those anastomoses are predominant. Determinations were obtained both with the foot at heart level and with it placed passively 50 cm below the heart level; percent flow changes from the horizontal to the dependent position were the measure of postural vasoconstriction. Two dihydropyridine derivatives, amlodipine (10 mg UID) and nifedipine (60 mg UID), and verapamil (240 mg BID), a chemically unrelated compound, diminished to similar extents the postural fall in skin blood flow at the dorsum of the foot. Blockade of alpha1-adrenergic and AT-1 subtype angiotensin II receptors by doxazosin (4 mg UID) and losartan (50 mg UID), respectively, exerted no effect. Postural skin blood flow responses at the plantar surface of the great toe were unmodified during the pharmacological trials. Thus, calcium channel blockers of different chemical origins antagonized postural skin vasoconstriction at the dorsum of the foot. The data indicate altered postural capillary blood flow regulation, since arteriovenous anastomoses are anatomically absent at this site; the effect was independent of either alpha1-adrenoceptor or angiotensin II receptor antagonism. Interference with skin postural vasoconstrictor mechanisms may result in net filtration of fluid to the extravascular compartment. This mechanism might explain the as yet unknown pathogenesis of ankle edema during treatment with calcium antagonists.

Pulse wave velocity. A new calculation method.

BACKGROUND: The increase in aortic Pulse Wave Velocity (PWV) is considered a surrogate marker of vascular disease; it can be non-invasively assessed by means of an indirect method calculating the time that the pulse wave takes to travel a definite distance along the vasculature; the distance/time ratio corresponds to the velocity measure. The presentation of a new calculation method is the aim of the present study. METHODS: A duplex scanner at the common carotid artery, the abdominal aorta at the prebifurcation site and the femoral common artery levels, was performed on 127 out-patients with risk factors, 38 of which were affected by clinical vascular disease, and on 50 healthy subjects (control group). The spectral analysis from these three sites was registered simultaneously with an ECG trace and the interval between the R wave apex and the spectral complex systolic foot was measured. The Transit Time (TT) was calculated by the difference between the values obtained from the proximal and distal measurement sites and PWV dividing the distance between them by the TT (PWV = Distance/TT); statistical significance and intra and inter observer variation coefficient, expressed as mean +/- standard deviation, were calculated by the analysis of variance and Turkey test, the correlation with the major risk factors and the intima-media thickness by the multivariate analysis. RESULTS: The PWV is increased in the patients group compared to control group (p < 0.001). Multivariate analysis shows a positive correlation with age, hypercholesterolemia, arterial hypertension, diabetes mellitus, intima-media thickness and arterial disease, no correlation was found with the smoking habit. The "patients" group shows an increased PWV in those with atherosclerotic plaques and/or clinical vascular disease compared to non atherosclerotic patients with risk factors (p < 0.001); the intra and inter observer variation coefficient ranged between 4.87 +/- 1.82% and 8.06 +/- 3.16% respectively. CONCLUSIONS: The proposed PWV measurement method is simple, quick, reproducible and repeatable, it can separate healthy subjects from patients with risk factors, atherosclerotic plaques and clinical vascular disease. Due to the strong correlation with age, normal values in different age groups are necessary before the PWV can be used as a marker of vascular disease.

Quantification of venous reflux by means of some duplex scanner and light reflection rheography parameters and its correlation with chronic venous insufficiency symptoms.

BACKGROUND: The quantification of venous reflux is rarely made but it is valuable for studying the natural history of CVI, its prognostic implications and the therapy effectiveness. We have evaluated some parameters of chronic venous insufficiency, caused by valvular incompetence, by means of duplex scanner and light reflection rheography searching for a better correlation with the clinical stages of vein disease. METHODS: We have examined 107 patients (35 males, 72 females; aged 22-78, mean 61.5 +/- 14.3) with long saphenous insufficiency in different clinical stages and measured the venous reflux, the reflux duration, the reflux grade, the vein diameter near the saphenofemoral junction with the duplex scanner and the refilling time with the light reflection rheography. The reproducibility of the studied techniques has been determined by examining 20 legs four times each in the same day or on different days. Statistical analysis of the data was performed by means of the variance analysis followed by the Waller-Duncan test. RESULTS: The venous reflux, the venous diameter and the refilling time can easily range between mild and severe insufficiency: reflux is 6.3 +/- 2.5 ml/sec at stage I; 27.5 +/- 10.1 at stage III; venous diameter is 6.04 +/- 1.4 at stage I; 10.6 +/- 2.2 at stage III; refilling time is 23.6 +/- 9.6 at stage I; 5.4 +/- 2.4 at stage III. The reflux time and reflux grade are unable to separate the various CVI stages. CONCLUSIONS: The measurement of venous reflux, venous diameter and refilling time is simple, quick, reproducible; these indices are able to differentiate mild from severe CVI but unable to separate patients at the second stage of the venous disease from those at the third stage and then ineffective in the ulcer risk assessment but the reflux is highly predictable. The ulcer risk is practically absent for reflux < 12 ml/sec; highly probable for reflux > 15 ml/sec (20/46 cases; 43.4%).

[Recurrence of varicose veins after treatment. Multicenter study by the Italian Doppler Club, Clinical and Technological Society]. / La comparsa di varici dopo loro trattamento. Studio multicentrico del Doppler Club Italiano Società di Clinica e Tecnologia.

BACKGROUND: The first results of a multicentric study dealing with recurrent varicose veins after surgery are presented. The aims of the study are: identifying the type of varicose vein, specifying the most frequent complaints (esthetical or functional), locating the causes of recurrence, establishing the causes and the most frequent seat of recurrence, clarifying whether it is enough to call recurrent all the varicose veins which appear after surgery or whether it is necessary to distinguish various typologies. METHODS: 194 patients (139 women and 55 men) aged 51.6 average (range 28-87), have been studied up to now with duplex and color scanner following a precise protocol which consisted of three stages: before treatment, within 2 months from treatment and after recurrence of varicose veins or venous insufficiency symptoms. RESULTS: Recurrent varicose veins represented 65.7%, residual ones 14.3%, new ones 2.5%. It has not been possible to identify the type of varicose vein in 8.3% of cases. Stripping of the great saphenous veins was carried out in 88% of cases, short stripping in 4.1%, stripping of the short saphenous veins in 6.9%. Recurrent varicose veins were due to technical error in 78.7% of cases, to diagnostic error in 9.2%, to unidentifiable causes in 12% of cases. CONCLUSIONS: Data relating to the prospective study of the research will be published in subsequent papers.