[Tissue engineering: possibilities and perspectives]

Successful tissue engineering requires intensive co-oporation between clinicians, biologists (cell culture, gene therapy), chemical engineers (biomaterials) and industrial partners. In case of wound healing tissue engineered constructs have already been applied successfully in burns and chronic wounds. In order to improve carrier and matrix function biomaterials still have to be optimized. The potential of such constructs might even be enhanced by gene therapeutical methods. The complex mammalian organism has to be considered as the gold standard and the model for perfect tissue engineering. The problem of vascularization of complex organs yet has to be solved. In general it seems to be more promising to substitute deficient components in vivo and to rely on modulating influences within the host organism rather than to create complex organs ex vivo.

The SIGN guideline on the care of chronic leg ulcers: an aid to improving practice

Implementation of national guidelines and local protocols can help practitioners to ensure their practice is evidence-based. This article describes how the implementation of the SIGN guideline on the care of chronic leg ulcers will help to address any deficiencies in practice.

Influence of a specialized leg ulcer service on management and outcome

BACKGROUND

The organization of leg ulcer care is poorly defined in the community. This study assessed the overall influence of a specialized community service on management and outcome of chronic leg ulcers, irrespective of aetiology.

METHODS

Assessment and outcome of ulcers were compared in patient samples (n = 200) from East and West Gloucestershire, before and after the introduction of specialized clinics into East Gloucestershire. In clinics, vascular disease was routinely assessed by duplex scanning and determination of the ankle : brachial pressure index.

RESULTS

There was no coordinated community structure for the care of patients with leg ulcers before the service was introduced, and 74 and 67 per cent of limbs in East and West Gloucestershire respectively had aetiology undiagnosed. After introduction of the clinics, the 12-week healing rate increased from 12 to 22 per cent in East Gloucestershire (P = 0. 05) and to 47 per cent in the specialized East Gloucestershire clinics (P < 0.001). The 12-month recurrence rate decreased from 50 to 41 per cent in East Gloucestershire and to 17 per cent in the East clinics (P < 0.001). The West Gloucestershire control showed no significant changes.

CONCLUSION

A specialized leg ulcer service with defined protocols provides an improved management structure for treating patients with leg ulcers in the community. Accurate diagnosis of chronic leg ulcers and improved outcome may be achieved within this specialized service.

Quality of life and leg ulcers: will NHS reform address patient need?

The present Government has made much of its commitment to gaining patients' views on the health services they receive. Qualitative studies of patients with leg ulcers have highlighted the fact that patients feel healthcare professionals do not always empathize with their plight and sometimes appear to lack the skills to help them. Quality of life in chronic wound care has, thus far, eluded definition but strenuous efforts are being made to quantify the impact that issues such as pain, isolation and frustration can have on leg ulcer patients. If healthcare professionals are able to demonstrate empathy with patients they may be able to maximize the cooperation needed for the management of ulcers. By reflecting on gaps in their knowledge and becoming more assertive in their demands for appropriate training, nurses can improve the outlook for patients' quality of life.

An economic assessment of Apligraf (Graftskin) for the treatment of hard-to-heal venous leg ulcers

Several recent advances in wound care may offer promise for the treatment of hard-to-heal venous leg ulcers. One such treatment is Apligraf (Graftskin), a bilayered, living human skin construct. To assess the economic impact of Graftskin, a model was constructed to compare the annual medical costs and cost-effectiveness of treating hard-to-heal venous leg ulcers with Graftskin vs. compression therapy using Unna's boot. A semi-Markov model was used to describe the pattern of ulcer treatment, healing, and recurrence among patients with venous leg ulcers. Patients received 1 of 2 treatment regimens, Graftskin or Unna's boot, and were followed in the model for a 12-month period. The analysis was done from the perspective of a commercial health plan; therefore, only direct medical costs were included. Health care resource use included the primary therapeutic intervention, additional compression dressings, physician office visits, home health visits, laboratory tests and procedures, management of adverse events, and hospitalizations. The model estimated the annual medical cost of managing patients with hard-to-heal venous leg ulcers to be $20,041 for those treated with Graftskin and $27,493 for those treated with Unna's boot. In addition, treatment with Graftskin led to approximately 3 more months in the healed state per person per year than did treatment with Unna's boot. Because patients treated with Graftskin experienced improved healing compared with those treated with compression therapy using Unna's boot, they required fewer months of treatment for unhealed ulcers. As a result, the use of Graftskin for treating hard-to-heal venous leg ulcers resulted in lower overall treatment costs.

Leg ulcers [bibliography]

This report reflects the best data available at the time the report was prepared, but caution should be exercised in interpreting the data; the results of future studies may require alteration of the conclusions or recommendations set forth in this report.

Hydroxyurea-induced leg ulcers

Hydroxyurea is an analogue of urea that inhibits DNA synthesis. It inhibits ribonucleotide reductase, the enzyme which converts ribonucleotide diphosphates to their deoxyribonucleotide forms. This causes selective killing of cells in the S phase of the cell cycle. Hydroxyurea is well absorbed orally, has a plasma half-life of 4 hours and is mostly excreted in the urine. It is used to treat chronic myeloid leukaemia, polycythemia vera, thrombocythaemia, sickle cell anaemia and at lower doses psoriasis. It is generally well-tolerated. The most frequently encountered sideeffects are nausea, vomiting and diarrhoea. The most serious side-effect, myelosuppression, is usually rapidly reversed on cessation of the drug.

Undertaking leg ulcer research in primary care

Evidence-based practice has become a by-word in leg ulcer care, but the picture is far from complete. More research is needed. Carrying out the research to ensure quality care in a primary care setting brings practical difficulties and raises issues which must be resolved, as a research team from Birmingham University shows.

The assessment and management of leg ulcers in rheumatoid arthritis

Patients with rheumatoid arthritis appear to be at increased risk of developing chronic leg ulcers. This review identifies the factors that predispose these patients to leg ulceration and highlights how this problem can be managed and the risk of recurrence reduced.

Comparison of the healing rates and complications of three four-layer bandage regimens

This randomised controlled study compares the healing rates, complications and patient and staff acceptability of three four-layer bandage regimens for leg ulcers. A total of 149 patients were recruited into the study, of whom 50 received the original Charing Cross system (CX4L), 50 a modified Charing Cross system (Parema) and 49 a commercially available kit, Robinson Ultra Four (Robinson). No significant difference was found in the healing rates of the three systems. Overall 12 weeks' healing was 65%, while the 20-week healing rates for the individual systems were 87% (CX4L), 84% (Parema) and 83% (Robinson). Analysis of known risk factors for delayed healing showed that no bandaging system had an advantage over the others. Staff familiarity resulted in an initial preference for the CX4L but there was no bandage preference by the end of the study. The data suggest that none of the systems has an advantage over the others and that cost savings can be made by pursuing a competitive pricing policy.

Recombinant human GM-CSF in the treatment of poorly healing wounds

Although most wounds heal rapidly, impaired or delayed tissue repair represents a major clinical challenge. Current therapy is directed at providing a wound with the most favorable environment in which to heal, rather than aiming to increase the rate of healing pharmacologically. Recent studies have suggested that a number of drugs may act specifically to increase healing rates. In vivo studies have demonstrated that recombinant human granulocyte-macrophage colony-stimulating factor facilitates wound contraction, causes local recruitment of inflammatory cells, and induces keratinocyte proliferation. It also activates mononuclear phagocytes, promotes migration of epithelial cells, and further regulates cytokine production. In 2 recent placebo-controlled studies involving venous leg ulceration, subcutaneous perilesional injections of recombinant human granulocyte-macrophage colony-stimulating factor were found to be significantly better than placebo in the time to complete wound healing. In other studies, recombinant human granulocyte-macrophage colony-stimulating factor was administered topically to wounds. Several case reports have also demonstrated the use of recombinant human granulocyte-macrophage colony-stimulating factor for postsurgical wounds, chronic leg ulcers of sickle cell anemia patients, and refractory pyoderma gangrenosum. Despite proper attention to wound care, some wounds fail to heal in an appropriate fashion and may become chronic. Studies of wound physiology as well as experimental and clinical evidence suggest that recombinant human granulocyte-macrophage colony-stimulating factor may promote healing of these lesions.

Instruction of compression therapy by means of interface pressure measurement

BACKGROUND

Compression therapy of the leg is the cornerstone in the conservative treatment of venous ulcers. The application of compression bandages, however, is largely a matter of personal experience.

OBJECTIVE

To evaluate the interface pressure under compression bandages and to improve the technique.

METHODS

Six courses on wound healing with 24-28 participants as well as individual training at our hospital were provided. Interface pressure at the distal medial calf was measured using a simple, but accurate pressure sensor that was built for this purpose (accuracy: +/-3 mm Hg).

RESULTS

During the wound healing courses, the absolute difference from the target pressure of 35-45 mmHg improved from 8.4 mm Hg (95% CI 0.0-34.1) to 3.5 mm Hg (95% CI 0.0-14.0) (P = .0001). After four sessions, interface pressures greater than 60 mmHg were avoided. During individual training, even nurses with everyday experience in compression therapy improved their accuracy.

CONCLUSION

There is a need for objective measurement of interface pressure in the teaching of compression therapy with bandages. The principles can be taught during a few exercises. However, repeated practice over a longer period of time is necessary to reach a certain accuracy.

Chronic leg ulcers in Sweden: a survey of wound management

The aim of this study was to survey management of leg ulcers by staff in Swedish primary healthcare (PHC) and home care services (HCS) run by the municipalities (n = 933), with emphasis on wound care and education. A questionnaire was completed by 933 staff (78% response rate). Diagnostic investigation and documentation in specific wound records was performed by 46.6% of respondents in PHC and 12.8% in HCS, most commonly by nurses in PHC compared to nurse auxiliaries (NAs) in the HCS. Topical treatment was most commonly chosen by nurses (82.1%). Nurse auxiliaries in PHC had greatest access to structured wound management programmes (40.0% compared with 30.1% in HCS, p < 0.05). Instruction courses, mainly organised by pharmaceutical companies (43.2%), were the most common form of education (20.4%) identified. The most time-consuming wound dressings and the highest number of patients treated at home and by NAs were found in the municipalities. For topical treatment 29 products were identified. Nurses in both PHC and the HCS used a wider range of products, e.g. hydrocolloids and absorptive dressings, than NAs in nursing homes, who used dry gauze/protective dressings and wet saline gauze to a greater extent. Substantial differences in qualifications, wound management experience and resource utilisation were found between staff in PHC and the HCS.

A comparison of topical honey and phenytoin in the treatment of chronic leg ulcers

In view of the reports that phenytoin and honey are useful in the healing of wounds, a comparison of their topical use in the treatment of chronic leg ulcers was carried out. Fifty cases of chronic leg ulceration were studied, each for a period of four weeks. They were assigned into three groups for honey, phenytoin/honey mixture, and phenytoin topical treatment. Overall mean duration of the ulcers was 56.5 months while the mean(s.d.) size was 3339 (5193) mm2. Mean percent reduction in size in the group treated with honey, 27.0 (36.9), was not significantly different (H = 0.26; 2 df; p = 0.88) from that of the mixture group, which was 25.9 (46.4), and from that of the phenytoin group which was 35.5 (53.2). This percent reduction in size was significantly greater, (H = 7.69; 2 df; P = 0.02), during the first week in the phenytoin group than in the other groups. Four of the cases progressed to complete healing at the end of four weeks with phenytoin. Pain score difference (using a graduation scale from 0 to 10) at the end of the four week treatment, was, 1.8 (1.7) in honey group, 2.0 (1.3) in mixture group and 3.6 (2.4) in phenytoin group. This difference was not significant, (H = 3.09; 2 df; P = 0.21). Our study suggests that phenytoin may be superior to honey as a topical agent in the treatment of chronic ulcers.

Pulse oximetry: a new tool to assess patients with leg ulcers

The objective of the study was to investigate pulse oximetry as a guide to assessing patients with leg ulcers before treatment. Graduated elastic compression is the treatment of choice for uncomplicated venous leg ulcers, but is contra-indicated in patients with significant arterial disease. The standard assessment of arterial insufficiency by Doppler ultrasound ankle branchial pressure index (ABPI) has shortcomings which prompted this investigation of pulse oximetry as a possible additional, or alternative, method of assessment of patients with leg ulcers, prior to treatment with compression. The study, carried out on a population of patients attending hospital leg ulcer clinics, was designed to evaluate pulse oximetry assessment in the selection and monitoring of patients with venous leg ulceration leading to a prospective controlled study of ulcer healing in groups of patients with reduced and normal ABPI, selected for compression therapy by pulse oximetry criteria. Outcome measurement required follow-up of patients selected for compression therapy by pulse oximetry to record time to healing and rate of healing of leg ulcers. Results from the study show a fair correlation between the toe-finger oximetry index (TFOI) and Doppler ABPI. There is no difference between ulcer healing in patients with reduced and normal ABPI selected for treatment on the basis of pulse oximetry maximum compression pressure (MCP). In conclusion, pulse oximetry is an aid to the selection of patients who will benefit from compression therapy, but would be excluded on the basis of Doppler ABPI.

Stimulation of fibroblast growth in vitro by intermittent radiant warming

A number of clinical studies have suggested that radiant heat improves the healing of selected acute and chronic wounds. The purpose of this study was to investigate in vitro the effect of intermittent radiant heating on the growth of human skin fibroblasts using a radiant heat-producing dressing with a designated temperature of 38 degrees C. In initial experiments cells were seeded in six well-plates, maintained in culture at 33-34 degrees C, and warmed daily for three cycles of 1 hour with 1.5 hour intervals. Changes in cell growth and metabolism were determined in sets of triplicate wells by cell counts and a colorimetric assay before and after one week's treatment. After eight days the number of cells in the radiant heat-treated group was 30% higher and the metabolic activity 47%- 90% higher than in the control group. In quiescent fibroblasts which had been maintained for four weeks in low-serum medium, the warming regime completely prevented the decrease in cell number observed in control cells. Our findings suggest that the stimulation of cell proliferation induced by intermittent heating in vitro may indicate a possible mechanism contributing to in vivo effects.

Alginate dressings in surgery and wound management: Part 2

This second in a three-part series looks at the use of seaweed-derived dressings in specific types of wounds

The development of a national guideline on the management of leg ulcers

This paper describes the development of an evidence-linked clinical guideline for the management of uncomplicated venous leg ulcers. Guidelines are developed to provide recommendations for clinical practice which are based on summaries of good quality research evidence. The aim of the guideline discussed in this article is to direct primary health care practitioners to the most effective method of assessment and treatment of venous leg ulcers and to discourage practices that do not have convincing or sufficient evidence of effectiveness. The three most important steps to the development of a valid clinical guideline are: basing recommendations on the best available evidence; explicit linkage between guideline recommendations and quality of evidence; and the involvement of a multidisciplinary group. The steps are discussed in relation to the development of the guideline alongside an introductory presentation on the role guidelines can play in improving practice. Issues arising from guideline development such as valid ways of obtaining patient input and lack of evidence are also discussed.