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Wounds can be caused by different mechanisms and have a significant morbidity and mortality. Negative pressure wound therapy (NPWT) is one of the most successful treatment modalities for wound healing. We have been using both foam and gauze-based NPWT. During application of NPWT, we noticed that the patient's pain was of varying intensity depending on the filler used. The aim of our work was to compare the level of pain and feedback before, during the treatment and at the dressing change after treatment with NPWT with two different fillers. For this study, we compared a pool of 13 gauze-treated patients with a pool of 18 foam-treated patients regarding the level of pain and feedback before, during the treatment and at the dressing change after treatment with NPWT. They were all post-traumatic patients with loss of tissue up to the muscular band. The patients were asked to respond to a questionnaire interviewed by the same physician to assess the level of pain using VNS (verbal numerical scale). We observed similar difference of means before and during the treatment with NPWT with gauze and foam. Regarding the pain at the dressing change, the mean of the scores for the foam was 6·5 while for the gauze was 4·15. In this case, we noticed the most significant difference between means from the scores given: 2·35 which was a statistically significant difference between the two groups (P = 0·046). The finding of this study confirms less pain at the dressing change after treatment with gauze-based NPWT. In our opinion, this finding is related to the more adhesive property of the foam probably because of the ingrowth of the granulation tissue in the micropores present on the foam. Considering this statement, we recommend the foam for neuropathic and paraplegic patients and the gauze for patients with bone and tendon exposition wounds, patients that do not tolerate NPWT with foam and low compliant patient particularly paediatric and old-age patients. We remind that the performance of this study was not sponsored by any company., (© 2011 The Authors. © 2011 Blackwell Publishing Ltd and Medicalhelplines.com Inc.)

Negative pressure wound therapy (NPWT) is becoming routine for the preparation of wounds prior to grafting for wound closure. We have been using both foam- and gauze-based NPWT to prepare wounds for closure prior to skin grafting and have obtained similar proportions of closed wounds; 7/7 for wounds treated with gauze-based NPWT and 11/11 for wounds treated with foam-based NPWT. In our follow-up consultations we observed that skin grafts on the foam-treated patients were less pliable than those on the gauze-treated patients. To assess what the mechanism of this effect might be, we compared the specific details of the treatments of both 11 foam and 7 gauze patients, including depth, location, patients' age and co-morbidity; biopsies of granulation and scar tissue were taken and stained with haematoxylin-eosin and by Masson's trichrome staining and conducted ultrasound analysis of the closed wounds, to see if there were features which explained those effects. All foam patients were treated at -125 mm Hg for an average of 25·9 days before skin grafts were applied. All gauze patients were treated at -80 mm Hg for an average of 24·7 days before skin grafts were applied. Biopsies of granulation tissue prior to skin grafting from five foam and four gauze-based NPWT patients did not reveal any obvious histological differences between the treatments. Ultrasound analysis of the skin-grafted wounds showed an average depth of scar tissue of 18 mm in the wound beds of the foam-treated wounds and 7 mm in the gauze-treated ones. Biopsies taken on the scar tissue after treatment with the gauze showed a minor tissue thickness and disorganisation and less sclerotic components. The findings of this preliminary analysis suggest that foam-based NPWT may induce a thicker layer of scar tissue beneath skin grafts than gauze-based NPWT which might explain a reduced pliability of the reconstructed bed. At present it is unclear which mechanism might be responsible for the difference in pressure (-125 versus -80 mm Hg), either the length of the time taken to reconstruct the wound bed or the intrinsic nature of the foam or gauze on the tissue surface. Prospective studies are necessary to investigate whether these preliminary observations are confirmed and to investigate what the mechanism might be., (© 2011 The Authors. © 2011 Blackwell Publishing Ltd and Medicalhelplines.com Inc.)