New research and innovations in venous leg ulcer management
25/05/10 | Leg ulcers | Mieke Flour
This paper describes the latest research and areas of interest in the management of venous leg ulcers. Among many interesting lines of investigation are further research into the effects of different forms of compression therapy and an examination of the hypotheses put forward for the causes of delayed wound healing, These include wound infection, and how these problems may be overcome.
- Investigation into the properties of compression techniques and the effects of pressure changes on venous leg ulceration
- Identification of the risk factors for slow and non-healing leg ulcers
- Evaluation of agents used in the treatment of wound infection and biofilms
- Investigation into the use of larval therapy for debridement
- Promising research into the effects of venous surgery plus compression therapy
- Scientific research into wound healing using skin substitutes and artificial skin
A recent in-depth study of 18 different brands of therapeutic hosiery outlines the essential knowledge that can help underpin our day-to-day management of people with venous disease, including leg ulcers . This provides insight into the effect pressure has on the affected limb in both static and dynamic circumstances.
An important new development is calculating static and dynamic parameters such as pressure changes and measuring the dynamic stiffness index of medical elastic compression stockings. Previous randomised studies have shown that stockings of the same compression class have different acute effects on venous haemodynamics . The explanation for this could be the variations in stiffness of the products used.
Direct in vivo imaging techniques allow clinicians to see the effect of the various compression methods on tissues. This includes bandaging, stockings and intermittent pneumatic compression devices. This has led to new insights into the pressures needed to achieve traditional treatment goals: the reduction of oedema and improved deep or superficial vein diameters and venous flow.
Delayed wound healing
Several risk factors have been identified as correlating with the failure of venous leg ulcers to heal with compression therapy. These comprise longer ulcer duration, large surface area, fibrinous deposition present on >50% of the wound surface and an ankle brachial pressure index (ABPI) of <0.85.
An open prospective single-centre study was undertaken in order to determine possible risk factors associated with the failure of venous ulcers to heal when treated with a multilayer high compression bandaging system for 52 weeks . In total, 189 patients (101 women and 88 men with a mean age of 61 years) with venous leg ulcers (ulcer surface >5cm² with a duration of more than three months) were included. After 52 weeks of compression therapy, 24 (12.7%) venous ulcers had failed to heal. The study concluded:
- Prognostic factors for ulcers that healed without problems were a small ulceration area (<20cm²), venous ulcer duration of less than 12 months, a decrease in calf circumference of more than 3cm, and the emergence of new skin islets on >10% of the wound surface during the first 50 days of treatment.
- Indicators of slow healing were a large body mass index (BMI) >33kg/m², a short walking distance covered during the day of less than 200 metres, previous wound debridement, and ulcers with the deepest presentation (>2cm).
- A calf ankle circumference ratio of <1.3, a fixed ankle joint, and reduced ankle range of motion were the only independent parameters associated with non-healing (p<0.001).
The results of this study suggest that non-healing venous ulcers are related to the impairment of the calf muscle pump .