Negative Pressure Wound Therapy Versus Conventional Dressing in Treatment of Diabetic Foot Wound

Abstract

Background: Foot wounds in people with diabetes mellitus are a common and serious global health issue. Negative pressure wound therapy can be used to treat these wounds and a clear and current overview of current evidence is required to facilitate decision-making regarding its use. Aim of the Work: To compare the efficacy of negative pressure wound therapy with that of a control group using conventional moist wound dressings, in healing of diabetic foot ulcers, in terms of 1) Change in size of wound. 2) Rate of granulation tissue formation as percentage of ulcer surface area. 3) Period of hospital stay. 4) Cost of both modalities of treatment. And 5) Complications after treatment. Study Design: Prospective Randomized Controlled Trial. Place: This study was conducted in the vascular surgery department at Al-Azhar university hospitals. Methodology: The study included 50 patients randomized into two groups (25 patient for VAC therapy & 25 patient for conventional dressing) suffering from diabetic foot wounds. Results: In our study, 6 of 25 (24%) in the Conventional treatment group were females whereas 19 of 25 (76%) in the Conventional treatment group were males. 3 of 25 (12%) in the NPWT group were females and 22 of 25 (88%) were males. In the Conventional treatment group, 21 of 25 (84%) were above 60 years of age. 20 of 25 (80%) in the NPWT group were above 60 years of age. Wound bed showed signs of healing by granulation tissue formation in 19 among 25 patients (76%) compared to Conventional treatment, 7 showed granulation among 25 patients (28%) one week after initiation of treatment. (P=0.001). Granulation of the wounds was > 50% in 20 of the 25 patients underwent NPWT whereas only 3 of the 25 in the Conventional treatment had shown > 50% granulation. There was a highly statistically significant difference between average Granulation as % of ulcer area and it is significantly high in vacuum dressing. It was 51.92 ± 21.03 in Conventional treatment compared with 78.68 ± 18.12 in NPWT group (p- value < 0.05). Wound size was measured at initial presentation and then after treatment. Before treatment, the mean surface area of wounds in the NPWT group was 40.44 cm2, the Conventional treatment 38.52cm2. After wound management, mean surface area of the diabetic wounds was 36.08 ± 2.56 cm2 in the NPWT group and 37.63 ± 2.86 cm2 in the Conventional treatment. This represents a statistically significant difference (P=0.05). At the end of our study the incidence of secondary higher amputation in NPWT group was 5/25 (20%), the Conventional treatment 6/25 (24%). There was no significant difference between both groups (P=0.13). There is a statistically significant difference between average graft take-up and it is higher in vacuum dressing. It was 80.78 ± 14.54 in NPWT and 59.58±19.25 in control group. (P-value = 0.035). Daily mean cost in conventional dressing group was 67.43 ± 5.3 EP compared to 95.7 ± 10.2 EP in VAC group. A difference which is statistically different. Also, at the end of the study, total mean cost in conventional dressing group was 1976 ± 123 EP compared to 2275 ± 154 EP in VAC group. There was a difference in the total cost finally. Period of hospital stay till the wound was fully granulated and ready for skin grafting was 22.87 ± 7.62 in NPWT compared to 32.53 ± 10.17 in the conventional group. There is a highly statistically significant difference between average duration of hospital stay and it is reduced significantly in vacuum dressing. (p-value= 0.02). Conclusion: The rate of granulation tissue formation, wound surface area, overall graft survival was better in NPWT group as compared to conventional dressing group. Overall hospital stay and amputation rate were less in the NPWT group. Thus, NPWT can be considered as a superior option in the management of diabetic foot wounds. Cost of VAC therapy was higher than conventional dressing.