Inappropriate neutrophil activation in venous disease

Factors Influencing Venous Remodeling in the Development of Varicose Veins of the Lower Limbs

One of the early symptoms of chronic venous disease (CVD) is varicose veins (VV) of the lower limbs. There are many etiological environmental factors influencing the development of chronic venous insufficiency (CVI), although genetic factors and family history of the disease play a key role. All these factors induce changes in the hemodynamic in the venous system of the lower limbs leading to blood stasis, hypoxia, inflammation, oxidative stress, proteolytic activity of matrix metalloproteinases (MMPs), changes in microcirculation and, consequently, the remodeling of the venous wall. The aim of this review is to present current knowledge on CVD, including the pathophysiology and mechanisms related to vein wall remodeling. Particular emphasis has been placed on describing the role of inflammation and oxidative stress and the involvement of extracellular hemoglobin as pathogenetic factors of VV. Additionally, active substances used in the treatment of VV were discussed.

The biological and physiological impact of the performance of wound dressings

Chronic wounds affect millions globally and are a huge financial burden. Whilst there are many wound dressings commercially available to manage these wounds, the complexity of the repair process makes it difficult to select the right dressing for the right wound at the right time. Thus, in this narrative review, we have examined reasons why wounds fail to heal, summarised the pathophysiology of the chronic wound environment and provided an evidence-based, clinically-relevant compilation of the published literature relevant to dressing design and evaluation. This has highlighted the need for a deeper understanding of wound exudates, how exudates change throughout the healing process, and how they are impacted by different dressing materials. Studies assessing biochemical and biophysical changes in exudates throughout the healing process are extremely valuable in this regard, enhancing both our understanding of the wound healing process and the ability to assess dressing performance. In addition, this knowledge allows us to replicate various wound conditions in the laboratory, and develop clinically-relevant models for testing current and new dressings, therefore providing a more comprehensive understanding of how and when they should be used. This approach makes the use of dressings more effective, thereby improving outcomes, and reducing the economic burden of chronic wounds.

Polymorphonuclear phenotypical expression of CD18, at baseline and after in vitro activation, in several clinical disorders: Revision of our case series

BACKGROUND

In relation to the different and important roles of the beta2 integrins, we have revisited the expression of polymorphonuclear leukocyte CD18 in several clinical disorders, at baseline and after in vitro activation.

SUBJECTS

we have examined subjects with type 1 diabetes mellitus, vascular atherosclerotic disease, type 2 diabetes mellitus without and with macrovascular complications, chronic renal failure on conservative treatment, essential hypertension, deep venous thrombosis, acute ischemic stroke and subjects with venous leg ulcers.

METHODS

unfractioned leukocyte suspension was prepared according to the Mikita's method, while the leukocyte were separated into mononuclear and polymorphonuclear cells with a Ficoll-Hypaque medium. Using specific monoclonal antibody, the CD18 expression was evaluated with cytofluorimetric analysis, using FACScan (Becton Dickinson) be Cellquest software; the activation in vitro with PMA was effected according to modified Yasui and Masuda methods.

RESULTS

in type 1 diabetes mellitus, at baseline CD18 is under expressed in comparison with normal control, and not changes after PMA activation were observed; in subjects with vascular atherosclerotic disease, in type 2 diabetes mellitus CD18 is over expressed at baseline but does not vary after activation; in subjects with chronic renal failure, essential hypertension and in subjects with acute ischemic stroke the CD18 up-regulate at baseline compared to normal control, and it increases further after activation; in subjects with deep venous thrombosis the CD18 expression is not different from control group at baseline, but it increases after activation; finally, in subjects with venous leg ulcers the CD18 is normally expressed at baseline, and it does not change after PMA activation.

CONCLUSIONS

in the different clinical disorders, the trend of this integrin subunit provides some specific information, useful to select the best therapeutic strategy in clinical practice.

Understanding Chronic Venous Disease: A Critical Overview of Its Pathophysiology and Medical Management

Chronic venous disease (CVD) is a multifactorial condition affecting an important percentage of the global population. It ranges from mild clinical signs, such as telangiectasias or reticular veins, to severe manifestations, such as venous ulcerations. However, varicose veins (VVs) are the most common manifestation of CVD. The explicit mechanisms of the disease are not well-understood. It seems that genetics and a plethora of environmental agents play an important role in the development and progression of CVD. The exposure to these factors leads to altered hemodynamics of the venous system, described as ambulatory venous hypertension, therefore promoting microcirculatory changes, inflammatory responses, hypoxia, venous wall remodeling, and epigenetic variations, even with important systemic implications. Thus, a proper clinical management of patients with CVD is essential to prevent potential harms of the disease, which also entails a significant loss of the quality of life in these individuals. Hence, the aim of the present review is to collect the current knowledge of CVD, including its epidemiology, etiology, and risk factors, but emphasizing the pathophysiology and medical care of these patients, including clinical manifestations, diagnosis, and treatments. Furthermore, future directions will also be covered in this work in order to provide potential fields to explore in the context of CVD.

Drug therapies and delivery mechanisms to treat perturbed skin wound healing

Acute wound healing is an orderly process of four overlapping events: haemostasis, inflammation, proliferation and remodelling. A drug delivery system with a temporal control of release could promote each of these events sequentially. However, acute wound healing normally proceeds very well in healthy individuals and there is little need to promote it. In the elderly and diabetics however, healing is often slow and wounds can become chronic and we need to promote their healing. Targeting the events of acute wound healing would not be appropriate for a chronic wound, which have stalled in the proinflammatory phase. They also have many additional problems such as poor circulation, low oxygen, high levels of leukocytes, high reactive oxygen species, high levels of proteolytic enzymes, high levels of proinflammatory cytokines, bacterial infection and high pH. The future challenge will be to tackle each of these negative factors to create a wound environment conducive to healing.

Therapeutic potential of natural compounds in inflammation and chronic venous insufficiency

The term varicose vein refers to the twisted and swollen vein visible under the skin surface which occurs most commonly in the leg. Epidemiological studies report a varying percentage of incidences from 2 to 56% in men and <1-60% in women. Venous insufficiency is most often caused by the damage to the valves and walls of the veins. The mechanism of varicose vein formation is complex. It is, however, based on hypotensive blood vessels, hypoxia, and other mechanisms associated with inflammation. This work describes mechanisms related to the formation and development of the varicose vein. It discusses risk factors, pathogenesis of chronic venous disease, markers of the epithelial and leukocyte activation, state of hypoxia and inflammation, reactive oxygen species (ROS) generation, and oxidative stress. Additionally, this paper describes substances of plant origin used in the treatment of venous insufficiency. It also considers the structure of the molecules, their properties, and their mechanisms of action, the structure-activity relationship and chemical properties of flavonoids and other substances. The flavonoids include quercetin derivatives, micronized purified flavonoid fraction (Daflon), natural pine bark extract (Pycnogenol), and others such as triterpene saponine, extracts from Ruscus aculeatus and Centella asiatica, Ginkgo biloba extract, coumarin dereivatives that are used in chronic venous insufficiency. Flavonoids are natural substances found in plants, including fruits, vegetables, flowers, and others. They are important to the circulatory system and critical to blood vessels and the blood flow. Additionally, they have antioxidant, antiinflammatory properties.

Polymorphonuclear Leukocyte Integrinsin Deep Venous Thrombosis

The polymorphonuclear leukocytes (PMN) have a role in the pathophysiology of deep venous thrombosis (DVT). We examined the phenotypical expression of PMN beta2-integrins (CD l l a, CDl l b, CD 11c) in a group of 19 subjects with leg DVT. PMN cells were incubated with fluorescent monoclonal antibodies against CD11a, CD11b, CD11c, and the evaluation was made by flow cytofluorimetry. The same integrins were determined after in vitro activation with 4-phorbol 12-myristate 13-acetate (PMA) and N-formylmethionyl-leucyl-phenylalanine (fMLP). In DVT subjects, at baseline, the phenotypical expression of CD11b was decreased and that of CD11c increased when compared with normal controls. In normal subjects PMN activation with PMA and fMLP led to a constant increase of all PMN adhesion molecules, while in DVT subjects the CDl l a did not show any change. These data might have therapeutical ap plications, especially with the aim of preventing post-thrombotic deterioration of vein function.

Leucocyte Rheology at Baseline and after Activation in Post-Phlebitic Syndrome

Objective:

To evaluate leucocyte rheology, expressed as leucocyte filtration, polymorphonuclear leucocyte (PMN) membrane fluidity and cytosolic Ca2+ concentration in subjects with post-phlebitic leg syndrome (PPS).

Methods:

In 22 subjects with PPS we determined leucocyte filtration [unfractionated, mononuclear (MN) and PMN cells], employing the St George Filtrometer, PMN membrane fluidity using the fluorescent probe 1-[4-(trimethylamino)phenyl]-6-phenyl-1,3,5-hexatriene (TMA-DPH) and PMN cytosolic Ca2+ concentration using the fluorescent probe Fura 2-AM. Subsequently we determined the same PMN parameters after in vitro activation with 4-phorbol 12-myristate 13-acetate (PMA) and N-formyl-methionyl-leucyl-phenylalanine (fMLP).

Results:

At baseline we observed a difference in the filtration parameters of unfractionated and MN cells and an increase in PMN cytosolic Ca2+ concentration. After activation, a significant variation in PMN filtration parameters was evident both in normals and in PPS subjects, although in subjects with PPS this variation, especially with PMA, was significantly greater. We found a decrease in PMN membrane fluidity and an increase in PMN cytosolic Ca2+ concentration only in subjects with PPS.

Conclusion:

These results suggest that there is a functional alteration of systemic leucocytes in PPS, in which the mechanisms are not yet clear.

Pathophysiology of Chronic Venous Insufficiency

Objective:

To review the physiological mechanisms determining venous return to the heart and the pathophysiological events culminating in chronic venous insufficiency (CVI), focusing primarily on the role of alterations in nitric oxide (NO) production by the vascular endothelium.

Background:

Congenital valve incompetence, thrombotic damage or venous outflow obstruction result in the development of chronic venous hypertension which frequently leads to ulceration. One major aetiological factor of trophic changes in the skin of patients with CVI is the phenomenon of leucocyte trapping.

Hypothesis:

It has been suggested that endothelial dysfunction, effectively resulting in a decrease in cellular levels of NO, is a key event in the initiation of enhanced adhesion molecule expression.

Data:

P-selectin, monocyte chemoattractant protein-1 and vascular cell adhesion molecule-1 expression can be enhanced by attenuating endothelial NO production. The mechanism by which NO alters the expression of genes encoding these adhesion molecules would appear to involve an interaction with transcription factors, in particular NF*** xB.

Conclusion:

Impaired endothelial NO synthesis associated with CVI may enhance the expression of adhesion molecules and chemotactic factors and lead to leucocyte adhesion and extravasation.

Immunological aspects of chronic venous disease pathogenesis

Chronic venous disease (CVD) is a very common health problem concerning up to 1/3 of the society. Although venous hypertension and valvular incompetence have been long known to be crucial for development of the illness, its exact aetiology remains unclear. Recent findings indicate that inflammatory processes may be crucial for development of incompetent valves and vein wall remodelling. One of the most interesting theories describes “leucocyte trapping” as the mechanism responsible for elevated vein wall permeability and oxidative stress in the veins. At the same time, the cytokine profile of the blood in incompetent veins has not been thoroughly examined. Popular anti-inflammatory drugs relieve some symptoms but do not have much proved effects in prevention and treatment.

We intend to summarize the existing knowledge of the immunological aspects of CVD in order to emphasize its importance for understanding the aetiology of this illness. We also wish to indicate some aspects that remain to be studied in more detail.

Neutrophil activity in chronic venous leg ulcers--a target for therapy?

Chronic venous leg ulcers (CVLUs) affect approximately 600,000 people annually in the United States and accrue yearly treatment costs of US $2.5-5 billion. As the population ages, demands on health care resources for CVLU treatments are predicted to drastically increase because the incidence of CVLUs is highest in those ≥65 years of age. Furthermore, regardless of current standards of care, healing complications and high recurrence rates prevail. Thus, it is critical that factors leading to or exacerbating CVLUs be discerned and more effective, adjuvant, evidence-based treatment strategies be utilized. Previous studies have suggested that CVLUs' pathogenesis is related to the prolonged presence of high numbers of activated neutrophils secreting proteases in the wound bed that destroy growth factors, receptors, and the extracellular matrix that are essential for healing. These events are believed to contribute to a chronically inflamed wound that fails to heal. Therefore, the purpose of this project was to review studies from the past 15 years (1996-2011) that characterized neutrophil activity in the microenvironment of human CVLUs for new evidence that could explicate the proposed relationship between excessive, sustained neutrophil activity and CVLUs. We also appraised the strength of evidence for current and potential therapeutics that target excessive neutrophil activity.

Varicose veins show enhanced chemokine expression

OBJECTIVES

Leucocyte infiltration in the wall of varicose veins has been reported previously. This study was designed to investigate the expression of pro-inflammatory cytokines and chemokines in control and in patients with varicose veins and to test the effect of treating varicose vein patients with acetylsalicylic acid (ASA) on cytokine expression prior to removal of varices.

MATERIAL AND METHODS

Sections of vein were removed during operation from both patient groups, and ribonuclease protection assays (RPAs) were performed to assess the expression of chemokines. Group I included non-varicose saphenous veins from healthy patients undergoing amputation for trauma. Varicose veins were obtained from patients with primary varicose undergoing surgical treatment who received no drug (group II) or treatment with 300 mg day(-1) of ASA for 15 days before surgery (group III).

RESULTS

Non-varicose veins constitutively expressed low levels of monocyte-chemoattractant protein (MCP-1) and interleukin (IL)-8 mRNA. Varicose veins had a distinct chemokine expression pattern, since significant up-regulation of MCP-1 and IL-8 and a marked expression of IP-10, RANTES, MIP-1alpha and MIP-1beta mRNA were detected. Removal of the endothelium did not alter this pattern. Varicose veins obtained from patients treated with ASA showed a consistent decrease in chemokine expression, although it did not reach statistical significance.

CONCLUSIONS

Varicose veins showed increased expression of several chemokines compared to control veins. A non-significant reduction of activation was observed following treatment with ASA for 15 days.

Oxidative stress in chronic venous leg ulcers

Venous leg ulcers are common and cause considerable morbidity in the population. As healing may be slow or may never be achieved, ulcers create persistent and substantial demands on clinical resources. Great efforts have been made to accelerate tissue repair in chronic venous leg ulcers with limited success. This may at least be partly due to the limited knowledge on the microenvironment of chronic wounds. In fact, the tremendous impact of the microenvironmental conditions on the outcome of wound healing has increasingly become apparent. Oxidative stress as a consequence of an imbalance in the prooxidant-antioxidant homeostasis in chronic wounds is thought to drive a deleterious sequence of events finally resulting in the nonhealing state. The majority of reactive oxygen species are most likely released by neutrophils and macrophages and to an unknown extent from resident fibroblasts and endothelial cells. As the inflammatory phase does not resolve in chronic wounds, the load of reactive oxygen species persists over a long period of time with subsequent continuous damage and perpetuation of the inflammation. In this article, we will critically discuss recent findings that support the role of oxidative stress in the pathophysiology of nonhealing chronic venous leg ulcers.

Making sense of the venous leg ulcer debate: a literature review

Venous leg ulcers cause patients much distress. Treating them is expensive, with many hidden costs. As understanding of the causes and development of this condition improves, debate over the best treatments or treatment combinations is growing.

Iron and 8-isoprostane levels in acute and chronic wounds

The purpose of this study was to determine differences in iron and iron protein (ferritin and transferrin) levels in chronic venous ulcers and acute wounds. The deleterious effect of iron in free-radical-induced tissue damage was indirectly examined by assessing 8-isoprostane levels and antioxidant status in wound fluid samples. Wound fluid samples from chronic leg ulcers in nonhealing and healing phases and wound fluid from mastectomy wounds were assayed for ferritin, transferrin, total iron, 8-isoprostane, and total antioxidant status. Immunohistochemistry and Perls' staining were performed on paired biopsies from chronic leg ulcers and on normal skin biopsies. Chronic wound fluid had significantly greater levels of ferritin (p < 0.05) and lower levels of transferrin (p < 0.001) than acute wound fluid and there was a significant reduction in the level of ferritin in healing compared to nonhealing chronic leg ulcers (p < 0.05). No significant differences were observed in the levels of total iron present in the wound fluids. Histologic staining showed consistently more ferritin and ferric iron in chronic wound tissue than in normal skin. Elevated levels of 8-isoprostane and antioxidants were observed for chronic wound fluid compared to acute wound fluid (p < 0.001). These results suggest the existence of an environment of oxidative stress in chronic wounds and the likely contribution of iron to exacerbating tissue damage and delaying healing in these wounds.

Evidence of oxidative stress in chronic venous ulcers

Reactive oxygen species have been implicated in the impaired healing of chronic leg ulcers but little direct evidence is available. We have observed a significant (p < 0.01) elevation of the allantoin : uric acid percentage ratio, a marker of oxidative stress, in wound fluid from chronic leg ulcers (median 17, range 8-860) compared to both paired plasma (median 2, range 1-8) and acute surgical wound fluid (median 4, range 3-7). However, the allantoin : uric acid percentage ratio did not differ significantly between chronic wounds that healed and those that failed to heal. Neutrophil elastase was elevated 30- to 1300-fold in chronic wound fluid compared to plasma and there was a correlation (r(2) = 0.742) between wound fluid elastase and the allantoin : uric acid percentage ratio. Total antioxidant capacity of wound fluid, as measured with a chemiluminescence assay, did not show a correlation (r(2) = 0.03) with the observed oxidative stress. These observations suggest that conditions of localized oxidative stress, possibly related to neutrophil-associated production of reactive oxygen species, are present in chronic leg ulcers. It is possible that future therapeutic strategies aimed at reducing oxidative stress, in addition to good standard care, could improve healing rates of chronic wounds.

Compression bandaging: are practitioners achieving the ideal sub-bandage pressures?

Compression bandaging is the mainstay of conservative management of patients with venous ulceration. But debate is growing over what levels of pressure to apply and how to balance this with what patients can tolerate.

Inflammation. 2: Its role in the healing of chronic wounds

Why do some wounds fail to heal in the expected time? Part two of this article on inflammation discusses the possible causes, which include recurrence of trauma, bacterial and other contamination and perhaps, above all, the ageing process.

Leukocyte rheology before and after chemotactic activation in some venous diseases

OBJECTIVE

to evaluate leukocyte rheology, polymorphonuclear leukocyte (PMN) membrane fluidity and cytosolic Ca2+ concentration in subjects with post-phlebitic leg syndrome (PPS) and acute deep-venous leg thrombosis (DVT).

SUBJECTS

twenty-two subjects with leg PPS and 14 subjects with leg DVT.

METHODS

we evaluated the leukocyte filtration (unfractionated, mononuclear cells (MN) and PMN), the PMN membrane fluidity and the PMN cytosolic Ca2+ concentration. Subsequently, we evaluated the same PMN variables after in vitro chemotactic activation with 4-phorbol 12-myristate 13-acetate (PMA) and N -formyl-methionyl-leucyl-phenylalanine (fMLP).

RESULTS

at baseline we observed a significant difference in the filtration variables of unfractionated and MN cells and in PMN cytosolic Ca2+ concentration. After activation, in normal subjects and subjects with PPS and DVT, a significant variation in PMN filtration at 5 and 15 minutes was evident. In normal subjects, no variation was present in PMN membrane fluidity or cytosolic Ca2+ concentration after activation. In subjects with PPS and DVT, we found a decrease in PMN membrane fluidity and an increase in PMN cytosolic Ca2+ concentration. After PMN activation (at 5 and 15 min) Delta% of IRFR distinguished normal subjects from subjects with PPS and DVT, while no difference was found in Delta% of membrane fluidity or cytosolic Ca2+ concentration.

CONCLUSIONS

there is a functional alteration of leukocytes in these patients whose mechanisms are not yet clear.

Proliferation and mitogenic response to PDGF-BB of fibroblasts isolated from chronic venous leg ulcers is ulcer-age dependent

Several pathophysiologic mechanisms have been proposed to explain slow-healing leg ulcers, but little is known about the growth behavior of cells in these wounds. Platelet-derived growth factor-BB applied topically to chronic wounds has shown beneficial effects, although the effects have been less pronounced than would have been expected based on studies on acute wounds. The objective of this study was to compare fibroblasts in culture obtained from chronic wounds (non-healing chronic venous leg ulcers), acute wounds and normal dermis regarding growth, mitogenic response to platelet-derived growth factor-BB and levels ofplatelet-derived growth factor alpha-receptor and beta-receptor. Fibroblasts were obtained by an explant technique and expanded in vitro using fibroblast growth medium supplemented with 10% fetal bovine serum and used for the assays at their third passage. Growth of chronic wound fibroblasts (n = 8) was significantly (p < 0.05) decreased compared with those from acute wounds (n = 10) and normal dermis (n = 5). Fibroblasts from ulcers older than 3 y grew significantly (p < 0.01) slower than those from ulcers that had been present for less than 3 y. Morphology and size of fibroblasts from the oldest chronic wounds deviated substantially from those of acute wounds and normal dermis, and resembled in vitro aged or senescent fibroblasts. Mitogenic response of chronic wound fibroblasts to human recombinant platelet-derived growth factor-BB was also reduced with ulcer age. No significant differences were found in the amount of either platelet-derived growth factor alpha-receptor or beta-receptor among the three groups. The features decreased growth related to ulcer age, altered morphology, and reduced response to platelet-derived growth factor, indicating that fibroblasts in some chronic wounds have approached or even reached the end of their lifespan (phase III). This might provide one explanation for the non-healing state and therapy resistance to topical platelet-derived growth factor-BB of some venous leg ulcers.

New approaches to the treatment of venous leg ulcers

Increased understanding of the pathology of leg ulcers has made the differences in the pathologies of leg ulcers between patients more apparent. This article examines some areas of research that are advancing our understanding of the pathology of venous leg ulcers. The impact that this information is having on the development of new therapies and the implications for nursing practice are discussed.

Postural vasoregulation and mediators of reperfusion injury in venous ulceration

PURPOSE

To test the hypothesis that ischemia and reperfusion injury may contribute to the cause or nonhealing of venous ulcers, the effects of postural change on the microcirculation of ulcers and on levels of known mediators of reperfusion injury in their venous effluent were studied.

METHODS

A standard protocol of stabilization (20 minutes), limb dependency (1 hour), and reelevation (2 hours) was used in 10 patients with venous leg ulcers as proven by clinical history, examination, ankle-brachial pressure index, and light reflective rheography. Superficial blood flow in and around ulcers was repeatedly examined with a new laser-Doppler scanning technique. Blood samples from the saphenous vein or a tributary adjacent to the ulcer before dependency and at 0, 10, 30, 60, and 120 minutes after reelevation were analyzed for tumor necrosis factor-alpha, interleukin (IL)-1RA, IL-1 beta, IL-6, platelet-activating factor, thromboxane B2, leukotriene B4, and P-selectin.

RESULTS

Scans showed a consistent pattern of high ulcer blood flow, which decreased on dependency (p < 0.05) and then returned to baseline levels on reelevation and (in 7 of 10) eventually exceeded initial values. Mediator assays showed that levels of platelet-activating factor, IL-1RA, and IL-6 were significantly higher in resting ulcer venous effluent than in systemic venous samples; the reverse was true for P-selectin. There was no statistically significant change in effluent concentration of any mediator as a function of posture, ulcer size, or healing.

CONCLUSIONS

Postural vasoregulation causes relative ischemia and reperfusion in venous leg ulcers. However, this is not associated with changes in release of mediators known to be related to reperfusion injury in internal organs.

Pathophysiology of venous leg ulceration--an update

The microcirculatory component of the pathophysiology of venous ulceration is now attracting considerable research interests, but is still far from fully elucidated. Currently, the central role is filled by the inappropriately activated white cell and its interaction with the endothelium. Interstitial oedema, pericapillary fibrin cuff and capillary microthromboses could all fit in with this hypothesis. However, there are other demonstrated changes, for instance in lymphatic drainage, intrinsic fibrinolysis and hemorheological changes which also need to be taken into account. The interaction between the microcirculatory changes is an obvious target for the systemic pharmacotherapy of venous ulceration.

Increased arterial inflow in extremities with chronic venous insufficiency: an important and unappreciated hemodynamic parameter

BACKGROUND

The purpose of this study was to evaluate and analyze arterial inflow (AI) in lower extremities of patients with symptoms of chronic venous insufficiency (CVI) and of members of a healthy control group.

METHODS

Foot mercury-in-silicon strain-gauge plethysmography was used to measure AI, venous reflux, and muscle pump efficiency in 388 extremities of 194 patients with symptoms of CVI. Severe stage III symptoms (Society for Vascular Surgery/International Society for Cardiovascular Surgery classification) were present in 84 extremities, moderate stage II symptoms were present in 81 extremities, and mild stage I symptoms were present in 158 extremities. No symptoms, stage 0, were found in 65 contralateral extremities of patients with unilateral symptoms. Identical parameters were measured in 70 extremities of 35 healthy subjects in a control group. AI in each staged group was compared with that of the control group and with that of the other groups with symptoms with the use of Kruskall-Wallis analysis of multiple variances.

RESULTS

The mean AI (+/-SD) in milliliters per 100 ml of foot tissue per minute in the extremities in the control group was 0.82 +/- 0.48. In the extremities without symptoms, contralateral to those with symptoms in patients with unilateral disease, the AI was 1.24 +/- 0.88. In extremities with mild symptoms the AI was 1.54 +/- 1.20, in extremities with moderate symptoms it was 2.88 +/- 1.70, and in extremities with severe symptoms it was 6.25 +/- 4.91. The AI was significantly increased in all extremities of patients with CVI (stages 0 to III) when compared with that of patients in the control group. Extremities with stage II and III disease had significantly higher AI than did extremities with stage 0 and stage I disease. The difference in AI between extremities with stage 0 and I disease was not statistically significant, and no significant difference in AI was seen between extremities with stage II and III disease.

CONCLUSIONS

When plethysmographic methods are used to evaluate extremities with CVI, high AI, if not considered, can overrepresent the true magnitude of reflux. High AI may indicate presence of primary anatomic arterioventricular fistulas, or it may be the consequence of inflammatory changes and secondary functional arterioventricular shunting. Increased AI in contralateral extremities with no symptoms may point to the role of high flow in the pathogenesis of CVI. Clarification of this question requires further investigation.

Ambulatory venous pressure: correlation with skin condition and role in identifying surgically correctible disease

OBJECTIVES

(1) To evaluate the full spectrum of venous skin damage with respect to ambulatory venous pressure. (2) To determine whether the ambulatory venous pressure/tourniquet test can be used to select patients for superficial venous surgery (eg. long or short saphenous stripping).

DESIGN

Prospective study.

SETTING

Vascular studies unit.

MATERIALS AND METHODS

Ambulatory venous pressure was measured in a larger sample of limbs (360) with a wide spectrum of venous disease. In addition the effect of a tourniquet placed below the knee on ambulatory venous pressure and venous refilling time was assessed in 234 limbs. This was compared with Duplex assessment of deep and superficial venous reflux at this site.

RESULTS

There was a linear trend towards more severe skin damage with increasing ambulatory venous pressure. Ulceration was associated with more severe calf muscle pump dysfunction (higher ambulatory venous pressure) than were lipodermatosclerosis, eczema or pigmentation. The tourniquet test was not able to distinguish between deep and superficial reflux as determined by Duplex scanning.

CONCLUSIONS

Ambulatory venous pressure should be used to quantify venous insufficiency and remains the reference standard test of the venous calf muscle pump. The tourniquet test should not be used to select patients for surgery since it cannot distinguish deep from superficial venous incompetence. Venous reflux is best localised using Duplex ultrasound.