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FOUR-LAYER COMPARED WITH UNNA’S BOOT IN VENOUS LEG ULCER MANAGEMENT

BACK TO THE FUTURE - EWMA DUBLIN 17-19 May 2001

 

C. Allegra *, P. Bonadeo **, S. Gasbarro ***, R. Polignano **** with collaboratio of A. Andriessen and S. Rowan *****

*Dipartimento di Angiologia A.S.L S. Giovanni-Adolorata, Rome, **Ambulatorio Chirurgia Vasculare, Mangiagalli Hospital, Milan, *** Rep. Di Chirurgia Vasculare, S. Anna Hospital, Ferrara,**** Camerata Hospital, Firenze, Italy, *****S&N Wound Management GBU, Malden, Netherlands and S&N International.

SUMMARY The purpose of this RCT was to compare the performance of a 4-layer system* and Unna’s boot* in the management of venous leg ulcers in an in- and out-patient setting, looking at healing rates, handling properties, patient comfort. N=91 patients were, 49 received ulcer management with 4-layer and 42 with the control. Upon entry to the study patients were assessed using a standard procedure, which included the measurement of ankle brachial indices. For each patient, the observation period was 24 weeks. Data from the validated questionnaires was entered into a database. The area of ulceration was determined from tracing of ulcer margins. Larger reduction in ulcer area was demonstrated in the study vs. control group The 4- layer bandage system was shown to be clinically effective and was well tolerated by the patients.

INTRODUCTION It is recognised that the single most important factor in treating venous leg ulcers is the application of effective compression. A venous ulcer will fail or be slow to heal without the application of sustained graduated compression. Many of the bandages traditionally used to treat patients are ineffective due to lack of technique and practice by persons applying the bandage. Multi-layer systems composed of short stretch and cohesive medium stretch bandages represent a good compromise between elastic and inelastic bandage systems, it was demonstrated that these bandages show moderate pressure loss over time and large pressure decrease on lying down.(1) During ambulation the leg cannot expand under a firm short stretch bandage, therefore, short stretch bandages generate a larger pressure amplitude during exercise, (2,3) which makes them particularly useful in patients who ambulate. The main disadvantage of short stretch bandages is that they tend to become loose after a few hours of wear time and tend to slip down the leg.(4,5). During the last 15 years several investigators have recognized that non adherent elastic short stretch bandage systems lose 50% of their initial interface pressure within the first few hours of wear.(6, 7,4,8) This lead to the development of the 4-layer bandage (9) that is widely used in community clinics in the United Kingdom. (9,5,10,11,13)

PROFORE* four-layer high compression bandaging system was developed to apply sustained graduated compression. The bandage regime applies 40 mmHg pressure at the ankle, graduated to 17 mmHg at the knee, leading to optimum conditions for healing (9). The pressure is maintained until the bandages are removed, generally a week later.(5) The four layer bandage system has been clinically shown to achieve an 80% healing rate for venous ulcers over a 12 week period (5) providing the most effective venous ulcer treatment. The purpose of this study is to compare the performance of PROFORE and the short stretch bandage technique (Viscopaste/Tensoplast) in the management of compression therapy of venous leg ulcer patients in an in- and out-patient setting.

MATERIALS UNDER EVALUATION

PROFORE, four-layer bandage system:

-Non-adherent wound contact layer, 9.5cm x 9.5cm -Profore layer no1, natural padding 10cm x 2.7m. (un-stretched) -Profore layer no.2, crepe bandage 10cm x 4.5m (stretched) -Profore layer no.3, elastic compression bandage 10cm x 6m (stretched) -Profore layer no.4, cohesive bandage 10cm x 3m (un-stretched)

Viscopaste bandage in combination with Tensoplast. The wound is covered with gauze.

CONDITIONS AND OBJECTIVES

The purpose of this study is to compare the performance of Profore, four-layer bandage system with the current treatment regime (Viscopaste/Tensoplast/gauze), in the management of venous leg ulcers requiring compression therapy. This was a comparative randomised parallel group clinical evaluation, looking at performance of both systems, healing rates, handling properties and patient comfort.

4 Centers in Italy (Rome, Ferrara, Milano, Firenze) participated in the study. In-patients and/or out-patients at the trial centres were recruited to the study. The clinical Investigator sought the permission of the relevant consultant for their patients to be included in the study. Patients were assessed using a standard procedure, which included the measurement of ankle brachial pressure indices (ABPI) to determine whether the patient is suffering from significant peripheral arterial disease.

INCLUSION CRITERIA Age: at least 18 years of age. Sex: Males, Females - provided they are not pregnant. Diagnosis: Venous leg ulceration, or leg ulcers of mixed aetiology suitable for compression therapy. Administrative: The patient is able to understand the clinical evaluation and is willing to consent to the study.

EXCLUSION CRITERIA Patients with significant arterial disease (APBI < 0.8). Patients with other causes to their ulceration, such as, Rheumatoid vasculitis, Diabetic foot ulceration, Malignant ulceration. Patients who had participated in this trial previously and who healed or were withdrawn. Patients who were unable to understand the aims and objectives of the trial. Patients with clinically infected ulcers, where frequent dressing changes are required. These patients may be included in the study after the infection is resolved. Patients with ulcers >10cm².

Before being admitted to the clinical evaluation, the patient consented to participate, after the nature, scope and possible consequences of the study had been explained in an understandable form.

METHOD AND NATURE OF THE CLINICAL EVALUATION

Patients were questioned on their previous medical and social history. Assessments were made to determine the main cause of ulceration. Patients were told of the trial and given an evaluation sheet. Patients with bilateral ulceration were randomised to one treatment only. The reference limb was taken as the one with the largest total area of ulceration. Randomisation took place following consent and eligibility check. The patient's ankle circumference was measured at the initial assessment and, one week later ( in order to account for reduction in oedema). If the ankle circumference was < 18 cm extra padding was applied (Layer no. 1).

For the Viscopaste and Tensoplast was applied, the wound was covered with sterile gauze.

Bandaging for the trial dressing and the control dressing took place weekly unless the patient required it more regularly. At each follow up the ulcer was cleansed with NaCL 0.9%. Bandaging then took place using the randomised treatment. The time to healing of the reference limb was recorded up to a maximum of 24 weeks. At each follow up assessment progress of healing was recorded. When healed the patients were prescribed Class II compression stockings and returned to the regular follow up clinics. The total area of ulceration on each leg and the area of the largest ulcer on each leg were measured at week 0, at the time of withdrawal and at weeks 4,8 and 12 if they had not healed. The areas were determined from tracing of ulcers margins. For assessment of local wound conditions the classification model of the DWCS was used. The model is based on optical parameters of wounds. Wounds can be classified on the basis of three colours: black wounds - necrotic tissue yellow wounds - sloughy tissue red wounds - granulating tissue The percentage of colour present was indicated on the ulcer tracings at weeks 0, 6,12 and 24.

In addition to time to healing, assessments was made on patient comfort and the level of pain that each patient suffered, at weeks 6 and 12 and also the week the limb heals or the patient is withdrawn. Handling properties of the bandaging system was recorded at the application and before the removal of the bandages. All patients experiencing adverse incidents were monitored until symptoms subside or until there was a satisfactory explanation for the changes observed. For each individual patient, the clinical evaluation observation period was 24 weeks.

To ensure broadly comparable patient groups patients were stratified into one of 2 groups upon entry into the clinical evaluation. The area of each patient's ulceration was determined before the randomisation schedule was consulted.

ANALYSIS

Ulcer areas

The total of ulcerated area data, as determined on the ulcer tracings, was summarised at weeks 4, 8 and 12. Healed ulcers were given a value of 0. The change in ulcer area data between weeks 0 and 24 was summarised. For assessment of local wound conditions the percentage of colour present, as determined on the ulcer tracings, was summarised at weeks 0, 6,12 and 24.

Patient comfort assessment

Changes in the following aspects from baseline were analysed at both weeks 6 and 12: Sleep, mobility, ability to attend work, or daily tasks, appetite, mood, comfort of the dressing, level of pain suffered in relation with the ulceration.

Handling properties of the dressing/bandaging regime

The aspects were analysed.

Following application of the bandages: - ease of application of the bandaging system - appearance of the bandages after application

Weekly assessment before removing the bandages: - perfectly in place - partly slipping, bandages still functional - extensive slipping, bandages not functional

The number of patients withdrawn, not healed were listed in full. Patients who interrupted the trial treatment for longer than 2 weeks, either consecutively or in total, were withdrawn from the study.

The clinical evaluation was performed in accordance with the guidelines of the Declaration of Helsinki and Ethics committee approval was obtained.

Method of analysis

Data from the completed and validated questionnaires were entered into a program written in Microsoft Excel. A randomization code was used to define and allocate the patients to the trial - and control treatment. Summary baseline statistics were compiled to help evaluate the validity of statistical assumptions. Discrete variables (e.g. gender) were analyzed using a first descriptive analysis and a mANOVA test. To evaluate the effect on wound healing (i.e. percent change in area) a repeated measure analysis of variance was used, in which the effect of ulcers in the trial group vs. ulcers in the control group, time (days 0 through the end of study) and their interaction were assessed.

RESULTS

Patients were recruited to the study from 4 centres in Italy from September 98 till December 00. Recruitment of patients to the study was stopped when 91 patients were included in the evaluation. One of the centres had a change in the organisation and was unable to recruit the agreed number of patients, one centre recruited less patients than anticipated. N=49 ulcers,were allocated to the PROFORE group and N=42 were treated with the current treatment regime, Viscopaste/Tensoplast/gauze.

Of the 49 ulcers included in the study group, N=43 ulcers were legible for evaluation. 6 Ulcers were excluded from the analysis of which 3 patients were lost to follow up, 2 patient was withdrawn at their own request and 1 patient died before the study treatment was completed. Of the 42 ulcers included in the control group, N= 30 were legible for evaluation. 12 patients were withdrawn of which 4 patients on their own request, 4 patients were lost to follow up and 4 patients were withdrawn for other reasons related to the ulcer treatment.

Ulcers healed Of the 43 ulcers included in the study group 79% had healed at 24 weeks. Of the 30 ulcers included in the control group 68% had healed at 24 weeks.

Evolution in Ulcer size In the study group the mean initial length of the ulcers was 4cm (Std ± 2.1), the mean width measured 2.4 cm (Std ±1.4). Upon initial assessment the mean ulcer area of the ulcers in the study group measured 10 cm². In the control group the mean initial length was 3.3 cm. (Std ± 2.1), the mean width was 2 cm (Std ±1.4). Upon initial assessment the mean ulcer area in the control group measured 6.6 cm² In the study group at the end of the study the mean ulcer length was reduced to 0.8cm (Std ± 1.5), the width measured 0.5 cm (Std ±1) and the mean ulcer area had reduced to 0.4 cm². In the control group at the end of the study the mean length was 1.3 cm. (Std ± 2.5), the width measured 0.8 cm (Std ± 1.6) and the mean ulcer area had reduced to1 cm².

Evolution in Stage of the ulcer In the study group upon initial assessment the stage of the ulcer (mean % total ulcer area) was 6.2 % black tissue, 34.4% yellow tissue, 57.5 % granulation tissue. In the control group the stage of the ulcer (mean % total ulcer area) upon initial measured 10 % black tissue, 36 % yellow tissue, 64% granulation tissue. In the study group at the end of the study the evolution in ulcer stage was, 0 % black tissue, 14 % yellow tissue, 86 % granulation tissue. In the control group the evolution in ulcer stage at the end of the study was 0 % black tissue , 19 % yellow tissue, 47% granulation tissue.

According to the analysis techniques of the variance we could suggest that the differences of the variables in the two groups were due to their random nature rather than to their provenance from two different populations (mANOVA test). Thus in order to demonstrate the different efficacy of the two treatments, the test was conducted on the following variables: time of treatment (T) and variations in the area of the wound (DA), pain (DDam), comfort (DCf), and the percentage of the different tissues on the ulcer bed (DTs). The test yielded a negative result, meaning that the efficacy of the treatment is statistically different in the two groups, and according to the previous descriptive analysis this treatment proved to be the four layer system.

In order to spot the importance of the time factor on the patient’s healing process, a chart showing the healing index (DA), defined as the variation of the wound area ( 1 in case of complete healing, between 0 and 1 in case of partial healing, and less than 0 in case of worsening). This factor was reported for each patient in the two groups as a function of the healing time. From these data, it is possible to see that: a)the percentage of patients completely healed (A=1) is greater for the PROFORE group; b)the time required for complete healing does not appear to be distrìbuted in a different way in the two groups;

*Profore, Viscopaste and Tensoplast are products of Smith & Nephew Ltd

REFERENCES

1. Jürg Hafner, MD; Ioannis Botonakis, MD; Günter Burg, MD, A Comparison of Multi-layer Bandage Systems During Rest, Exercise, and Over 2 Days of Wear Time. Arch Dermatol/vol. 136 July 2000

2. Partsch H. Compression therapy of the legs. J Dermatol Surg Oncol.1991;17: 799-805.

3. Veraart JCJM, Daamen E, Neumann HAM. Short stretch versus elastic bandages: effect of time and walking. Phlebologie.1997;26:19-24.

4. Raj TB, Goddard M, Makin GS. How long do compression bandages maintain their pressure during ambulatory treatment of varicose veins? Br J Surg.1980; 67:122-124.

5. Blair SD, Wright DDI, Backhouse CM, et al. Sustained compression and healing of chronic venous ulcers. BMJ.1988;297:1159-1161.

6. Partsch H. Compression therapy in venous ulcers. In: Hafner J, Ramelet AA, Schmeller W, Brunner U, eds. Management of Leg Ulcers.Basel, Switzerland: S Karger AG; 1999;27:130-140. Burg G, series ed. Current Problems in Dermatology.

7. Callam MJ, Haiart D, Farouk M, et al. Effect of time and posture on pressure profiles obtained by three different types of compression. Phlebology.1991;6:79-84.

8. Neumann HAM. Commentary on inelastic and elastic leg compression. Derma-tol Surg.1999;25:699-700.

9. Moffatt CJ, Franks PJ, Oldroyd M, et al. Community clinics for leg ulcers and impact on healing. BMJ.1992; 305:1389-1392.

10. Duby T, Hoffman D, Cameron J, et al. A randomized trial in the treatment of venous leg ulcers comparing short stretch bandages, four-layer bandage system, and a long stretch-paste bandage system. Wounds.1993;5:276-279.

11. Thomson B, Hooper P, Powell R, Warin AP. Four-layer bandaging and healing rates of venous leg ulcers. J Wound Care.1996;5:213-216.

12. Scriven JM, Taylor LE, Wood AJ, et al. A prospective randomised trial of four-layer versus short stretch compression bandages for the treatment of venous leg ulcers. Ann R Coll Surg Engl.1998;80:215-220.

13. Simon DA, Freak L, Kinsella A, et al. Community leg ulcer clinics: a comparative study in two health authorities. BMJ.1996;312:1648-1651.

0 withdrawn 0 worse, 1 no response to treatment, 2 patients own request, 3 lost to follow-up, 4 dead, 5 other 1 adverse reaction 2 completed at 24 weeks 3 healed