Clinical efficacy of a silver-releasing foam dressing in venous leg ulcer healing: a randomised controlled trial

Abstract

Biatain and Biatain-Ag are two identical wound dressings except the fact that Biatain-Ag releases silver. In the present multinational double-blinded randomised controlled trial the effect of the two dressings were compared for treatment of venous leg ulcers. A total of 181 patients were treated for 6 weeks with either Biatain or Biatain-Ag followed by 4 weeks treatment with Biatain. Biatain-Ag showed superior performance in relative wound area reduction after 6 weeks treatment and the estimated treatment difference increased after 10 weeks indicating that the effect of silver continues at least for 4 weeks after treatment. A subgroup of the patients differed significantly from the others with respect to parameters associated with a poor healing prognosis; patients were older, had significant history of venous thrombosis, larger ulcers with longer duration and more often recurrent. For this subgroup of patients Biatain-Ag showed significant (P < 0·05) better performance in terms of relative ulcer area reduction and healing rate. In conclusion, this study suggests the superior performance of Biatain-Ag compared with the non silver-releasing dressing Biatain in particular for patients having ulcers associated with a poor healing prognosis.

Keywords: Delayed healing; Randomised double-blinded clinical trial; Silver foam dressing; Venous leg ulcers; Wound area regression.

Figure 1

Flowchart of subject disposition. Asterisk indicates a total of 182 subjects who were randomised in the study; however, one patient was in systematic antibiotic treatment (shown after code breaking, Biatain‐Ag group) and was erroneously enrolled, hence the intention to treat (ITT) analysis set comprised 181 subjects.

Figure 2

Mean relative reduction in ulcer area over time. Asterisk indicates that the relative reduction at 4 weeks was only adjusted for effect of baseline and treatment.

Figure 3

Differences in distribution of baseline characteristics (France versus all others) given as 95% CI. The figure illustrates, for each dichotomous characteristic (such as ‘deep venous aetiology’ or ‘age above 80’), the difference between the percentages of French and ‘all other’ subjects with that is ‘age above 80’. The difference can, in principle be anything between −100% and 100%. The difference is equipped with a 95% confidence bar, centred at the observed difference. If the bar is monochrome, red or blue, one group (France or ‘all others’) has a larger prevalence than the other. A red bar shows that a given characteristic is significantly more frequent in France, whereas a blue marks that a given characteristic is statistically more frequent in the group of ‘all others’. The mixed coloured bar indicates that the difference between the groups is non significant.