The role of compression therapy in the treatment of venous leg ulcers

Epidemiological data regarding venous leg ulcers, specifically low healing rates and frequent recurrences (occurring in 20–70% of the cases), seems surprising regarding recent progress in the management of this complication. The aim of this review is to present the current state of knowledge on venous leg ulcer management, especially compression therapy. Treatment of venous ulcers should be comprehensive and wellorganized, based on modern standards and up-to-date, and should involve elaborated treatment strategies. A thorough diagnostic process followed by adequate treatment may result in marked improvement of the outcomes, with up to 67% healing rate at 12 weeks and up to 81% within 24 weeks. Continuation of therapeutic activities after the ulceration has been healed is reflected by a marked decrease in the recurrence rates, down to 16% whenever the patient is actively involved in the therapeutic process. Furthermore, early diagnosis and appropriate causal treatment may prevent progression of the illness.


Introduction
Crural venous ulcers constitute a serious health, social and economic problem.A multicenter study on the epidemiology of venous diseases carried out in Poland demonstrated that 1.26% of patients suffer from venous ulceration and another more than 2% have recovered from this condition. 1Approximately 80% of lower extremity ulceration cases are a consequence of chronic venous insufficiency (CVI). 2,3Healing of venous ulcers is complex and lasts from a few weeks to several years.Treatment should include multidirectional and interdisciplinary activities aimed at decreasing/reduction of venous hypertension. 4,5Compression therapy is the gold standard in the treatment of crural venous ulcers, as it reduces vein diameter and stimulates venous drainage. 6,7In line with current recommendations, continuation of causal treatment and sustaining physiological blood pressure values are recommended after the ulcers have healed completely. 3,7Conservative treatment, without compression therapy and venous hypertension control, is associated with high risk for recurrent ulceration. 8,9][12] Improper venous outflow results from a dysfunction of 1 or, more often, a few causative mechanisms of venous circulation: valve efficiency, vein patency, vessel wall tension, and muscle pump performance. 13,14Valve insufficiency causes the blood to recede in a peripheral direction after a momentary movement upwards during muscle performance.This takes place during the diastolic phase, when valve closure is the only mechanism preventing the blood from flowing backwards.The presence of non-adapted valves is the cause of primary deep vein failure.On the other hand, past thrombotic process is most frequently responsible for the secondary damage of valves. 4,15nother potential cause of disorders in venous outflow is the closure of deep vein lumen, which results in a complete and/or partial obstruction in the deep venous system.The only way of venous return are superficial veins that become dilated and overloaded due to an enhanced perfusion.Venous dilation may result in valve insufficiency, development of varicose veins in the superficial system and reverse flow in perforating veins.At the same time, deep vein thrombosis results in recanalization which leads to the damage and dysfunction of the vascular wall and valves. 15The changes of the vascular wall lead to dilation of the vein, which, as a result, causes valve cusps to move away from each other.This results in venous reflux and venous hypertension, and eventually leads to varicose vein development. 13isorders in venous blood outflow may be also associated with muscle pump dysfunction.The most likely reason of the latter is muscle atrophy (for example, due to arthritis or physical inactivity), which reduces the compression force necessary to overcome gravity, stimulate the flow and prevent long-term blood retention. 16e occurrence of 1 and often a few of the dysfunctions leads to reflux and retention of blood in 1, 2 or 3 venous systems and, as a consequence, to the pathological increase in hydrostatic pressure to more than 90 mm Hg, i.e., socalled venous hypertension.This is particularly evident in the area of the distal perforating veins that connect these 2 systems.As a result, the most severe skin lesions develop in the area of the medial malleolus. 14,17

Clinical manifestation of chronic venous insufficiency
Clinical manifestation, along with the degree of development of chronic venous disorders (CVD), more advanced changes in the form of CVI and ulceration, is presented by CEAP classification (C -clinical, E -etiology, A -anatomic, P -pathophysiologic).The clinical picture of CVI comprises the occurrence of varicose veins, edema, atrophic skin lesions, and subjective afflictions such as pain, muscle cramps, paresthesia, and itchiness, in the advanced form of venous ulcers.It depends on the kind of pathology occurring in the venous system, the pace of the changes, hemodynamic disorders, duration of the illness, and also on subjective sensations reported by the patient. 18 varicose vein is defined as a vein which has changed its shape, course or elongation.In the initial stage, only cosmetic effects are visible in the form of telangiectasia -the dilation of intradermal veins to 1 mm, and in reticular veins -as an intradermal dilations to 4 mm, which can be a sign of the early stage of venous insufficiency.These effects can occur individually or create clusters in the form of "a sprawling shrub".9][20] Larger varicose veins emerge most frequently (90%) from inflows or trunks of the great saphenous vein; cases of varicose veins of small saphenous vein are less visible (5%). 18,19dema occurs in about 50% of patients with CVI.It is a clinical sign of an increased volume of extravascular extracellular fluid, the presence of which can be confirmed if, after pressing the skin with a thumb for 10 s, an imprint is visible. 21In the initial phase, edema recedes after a nights' sleep, but increases during daytime proportionately to physical exertion and the time spent in a sitting or standing position or under the influence of high temperature. 22After a couple of years, protrusions appear in the area of the edema. 22Atrophic skin lesions are, apart from edema and developing varicose veins, the earliest signs of venous hypertension.The characteristic area where they occur is located above the ankles, most frequently on the shin medial surface. 4,23,24The clinical picture of these lesions is diverse: from skin discoloration and inflammation to hard-to-heal ulcers.The 1 st symptom of skin lesions is intensified hemosiderosis. 3,18,24Color changes, the so-called skin lesions, are accompanied by changes in the thickness of the skin and subcutaneous tissue.The skin becomes thin, less elastic, hard, and dry.Such skin condition on the shins is defined as lipodermatosclerosis. 18,24 In the case of regular skin discolorations, areas of microcirculatory vessel atrophy can occur, called Milian's white atrophy (atrophie blanche), which are characterized by the presence of white, very delicate and thin skin with visible peripheral vessels. 3In the next stage, fibrosis causes accretion of the fibrous ring above the ankles, and the skin becomes more vulnerable to infections and local allergic reactions. 2,18n about 1% of the patients, ulceration appears within the area of the skin lesions.It can emerge due to superficial, deep and perforating vein insufficiency, any 2 or all of them simultaneously. 3,18,25Similarly to skin lesions, ulceration is most frequently located in the area of the medial malleolus, i.e., in the area which is the most vulnerable to the influence of venous hypertension. 3,26Ulceration can emerge as a result of, e.g., injury, skin irritation or scratching of the skin due to itchiness.
The clinical symptoms of CVI are diverse and to a large extent depend on the subjective attitude of the patient, stage of disease development, environmental and cultural conditions, as well as the patient's personality, and her/his psychosocial needs.Among the reported symptoms, there are: discomfort caused by the cosmetic defect, sensation of heaviness and/or fullness, and distension of lower limbs (especially in a sitting position).Skin itchiness, prickling, paresthesia, a burning sensation and muscle cramps are also reported by the patients.In the advanced form of the disease, symptoms are even more acute and, additionally, severe pain occurs, especially in the case of venous ulceration. 2,4,18,27[29][30]

Venous ulcers: Clinical aspects
Venous ulceration is the most frequent cause of chronic wounds located within the lower limbs.Active and healed ulcerations occur in 0.3 up to ca. 3% of the adult population.Ulcers occur twice as often in women (especially in their 40s) as in men, who are affected by the problem 10 years later, on average.The highest morbidity occurs between the age of 50 and 80. 1 According to the CEAP classification, venous ulceration is defined as a deficiency of full-thickness skin, usually in the area of the ankles, which has no tendency of idiopathic healing and is maintained by venous disorders. 31It is most frequently (74%) located in the area of the medial malleolus, but it can also occupy other surfaces. 4The small, shallow wound can reach even enormous size, encircling the entire shin.Ulceration is usually of oval shape with a flat bottom covered with necrotic tissue, fibrin clusters and, if there is an infection, also with pus. 2,4If a proper healing process takes place, the ulceration has flat irregular edges, and in wounds which have been present for years, a thick, shaft-shaped edge may be present. 2,32The skin surrounding the ulceration also looks different, as it gets thicker and dry. 33enous ulceration treatment, apart from invasive treatment which is introduced with patients with no contraindications to a surgical procedure, includes numerous elements of conservative therapy.5][36] It requires undertaking actions connected with compression therapy, i.e., limitation of the influence of venous hypertension, limitation of the processes of inflammation and wound infections, as well as many comprehensive actions, such as venous system diagnostics (Duplex scan, ankle-brachial index), causative therapy -compression therapy, topical treatment, physiotherapeutic procedures (sequential pneumatic massage/manual massage -edema reduction), physical activity, prophylaxis, limb care and hygiene, educating the patient, using analgesic, phlebotropic and rheologically active drugs, weight reduction, supplementing of deficiencies, and high-protein diet. 4,36,37

Compression therapy in the treatment of venous leg ulcers
Compression therapy is the gold standard in the treatment of venous ulcers.It involves application of gradual, external and layer pressure with the highest pressure in the area of ankle and the lowest pressure under the knee, using special bandages or ready-to-use layered compression bandage systems.Proper systematic application of compression therapy reverses the pathological changes of the venous system, i.e., "venous hypertension", which are the cause of ulceration, and improves ulceration healing conditions. 3,7,36,38The narrowing of the vessel lumen leads to a decrease of the volume of venous blood in a limb and speeds up its flow.It also reduces the painfulness of ulceration and edema.There is also an improvement in the activity of the calf's muscle pump, condition of the skin and subcutaneous tissue. 39,40Among the methods used in compression therapy in venous ulceration treatments, we can distinguish: short-stretch bandages, elastic bandages, compression stockings and other knitwear products, as well as devices generating dynamic compression/ intermittent pneumatic compression. 3,4The most suitable compression material in the treatment of active ulceration are short-stretch bandages put on in a 2-or multi-layer system. 7,41However, in the case of small-area ulceration, ready-to-use compression products are the most suitable solution.The opinion of experts on the matter of compression therapy is unequivocal and says that in venous ulceration treatment, the recommended pressure in the ankle area is 40 mm Hg and 17-20 mm Hg under the knee. 3,7,36ffective and safe compression therapy depends on the correct application, which involves the proper theoretical and practical preparation of specialist nurses.Compression therapy should not be performed by unqualified people.

Local treatment of venous leg ulcers
Venous ulcer care involves optimization of the microenvironment of the wound's background and includes only actions reflecting the physiological course of healing.The TIME strategy to a great extent contributes to the stimulation of natural healing mechanisms and includes the following elements of ulceration debridement: T -tissue debridement, I -infection and inflammation control, M -moisture balance, and E -epidermization stimulation. 3,73][44] There are various methods of ulceration debridement, e.g., surgical, enzymatic, autolytic, mechanical, the use of biosurgical methods, negative pressure, and ultrasound. 3,7,44

Preventing recurrence of venous leg ulcers
The healing of the ulceration does not mean the pathology in the venous circulation system is cured.The main risk factor of ulceration recurrence is the continuous influence of venous hypertension, which is most frequently caused by CVI and post-thrombotic syndrome.Recurrence risk factors are most often divided into local and general. 5,10,40ocal factors include: 1. no compression therapy after the healing of the ulceration -insufficient knowledge and neglect on the part of medical staff; 2. lack of cooperation of the patient during the compression therapy, e.g., a low level of knowledge and motivation of the patient, confidence in the ineffectiveness of compression in the prevention of recurrence, treating the healing as a complete recovery, confidence about other causes of recurrence, difficulties in putting on and the inconvenience connected with wearing compression stockings, and lack of cooperation on the part of the patient's family/caregiver; 3. lack of systematic application of compression therapy; 4. decrease in tolerability of compression therapy (improper degree of compression), and 5. orthopedic disorders: numbness of ankle joint, improperly fitted shoes, etc.
5][46][47] After the healing of ulceration, the monitoring of the patient and the constant maintenance of low pressure values are required.That is why compression therapy is recommended after the healing of ulceration. 48Educating the patients and their family is an important part of the therapy and prophylaxis.It is the kind of action that aims at changing the role of the patient from a passive task performer to a partner, who will consciously and actively take part in the healing process.Customized and systematic education enables the patient to understand the core of the problem, which is a condition for good cooperation between the patients and the therapeutic team.[51]

Conclusions
Compression therapy is the gold standard in the treatment of venous ulcers and results in the highest healing rates.It involves employing external and layered pressure, using special bandages, ready-to-use layered compression bandage systems, and, in the case of small ulceration which does not weep, compression stockings. 3,7,36,52,53A systematic literature review shows that every form of properly employed compression favorably influences the process of venous ulceration healing, and it is difficult to determine which method is the most effective. 25,34,54In the research carried out by Szewczyk among 112 people suffering from venous ulcers, the healing dynamics of ulceration treated with 2-and 4-layer compression system was comparable. 4 In another study conducted in an ulceration treatment clinic on a group of 46 patients with venous ulcers, the authors demonstrated a similar effectiveness of the 2and 4-layer system as well as compression stockings. 55n yet another study, a group of 134 patients with wounds of venous etiology was randomly divided into 2 groups. 41n one group, individually selected compression stockings were used, and in the other group, short-stretch bandages were applied to compare their effectiveness.In the group where stocking were used, the rate of healing and the time of healing were higher.On the other hand, another study, which included 200 patients with ulceration of venous etiology, compared the effectiveness of 4-layer compression therapy and elastic bandages. 56The final analysis demonstrated that 4-layer compression was more effective.Customized compression and pressure degree significantly improve the conditions existing in venous circulation and microcirculation, if applied constantly.
In the majority of cases of venous ulcers, conservative treatment in line with the standards brings good results if the care is based on systematic interdisciplinary actions.If the care is occasional, the ulceration lasts longer and the rate of recurrence is high.The most important predictors include the duration of ulceration and its initial area.It has been proved that ulcerations characterized by short duration (<6 months) and small initial area (<5 cm 2 ) have the highest (95%) chance of healing within a period shorter than 24 weeks.It takes much more time for developed and extensive ulcers to heal. 4,32,57,58he care of a patient with CVI does not end with the healing of the ulceration.In order to maintain skin continuity, actions are required to be undertaken by both the patient and the therapeutic team.No or insufficient participation of one of the parties may lead to another ulceration.Epidemiological studies show high rates of recurrence which are about 26-70%. 12,32,57,58According to the study data, about 26% of ulcers recur within the 1 st 12 months after the therapy is over. 26egularly controlled and constantly monitored patients can significantly extend the period of remission, or even avoid ulceration recurrence. 59It is thought in the scientific community that the most effective method of prevention is the continuation of compression therapy.][62] To summarize, systematic application of properly customized compression therapy in the form of special bandages or ready-to-use compression products remains the gold standard in the conservative treatment of venous leg ulcers.Compression therapy is recommended in order to prevent recurrence as well as emergence of recurring ulceration in the case of a healed ulceration. 3,7