A comparative study to evaluate the effect of limited access dressing (LAD) on burn wound healing.

Biochemical and histopathological analyses are commonly used objective parameters in research and clinical fields to assess the healing status of burn wounds. In this study, the effect of newer intermittent negative-pressure wound therapy in combination with moist environment [limited access dressing (LAD)] on burn wound healing is studied. Various biochemical parameters like hydroxyproline, hexosamine and total protein, and antioxidants like reduced glutathione (GSH), glutathione peroxidase (GPx) and oxidative biomarker malondialdhyde (MDA) were measured in the granulation tissue. Histopathologically, necrotic tissue, amount of inflammatory infiltrate, angiogenesis and extracellular matrix deposition (ECM) were studied to determine wound healing. A total of 55 patients were divided into two groups as follows: LAD group (n = 28) and conventional dressing group (n = 27). Patients treated with LAD have shown significant increase in the mean levels of (±SD) hydroxyproline (75·2 ± 26·30 versus 27·8 ± 15·5; P = 0·010), hexosamine (9·0 ± 1·99 versus 8·0 ± 1·18; P = 0·038), total protein (15·6 ± 8·23 versus 10·26 ± 4·94; P = 0·003), GSH (7·40 ± 1·91 versus 5·1 ± 1·28; P = 0·037), GPx (112·6 ± 46·4 versus 92 ± 32·4; P = 0·016), and decrease in MDA (6·5 ± 2·24 versus 1 0·6 ± 3·8; P = 0·002). Histopathologically, between LAD and conventional dressing groups, there was a significant difference after 10 days of treatment (mean±SE) in necrotic tissue of (LAD versus conventional dressing groups = 10 ± 1·8 versus 11·9 ± 2·6; P = 0·033), inflammatory cells (8·4 ± 1·9 versus 13 ± 3·46; P = 0·021), new blood vessels (12·5 ± 2·87 versus 9·4 ± 1·7; P = 0·047), ECM deposit (12·9 ± 2·41 versus 9·68 ± 1·3; P = 0·018) and showed comparatively fewer inflammatory cells, increased and well-organised extracellular matrix deposit, more angiogenesis in LAD group as compared with that in conventional dressing group. To conclude, LAD exerts its beneficial effects on wound healing by reducing oxidative stress, decreasing necrotic tissue and amount of inflammatory infiltrate, and increasing ECM deposition and angiogenesis.

Effects of limited access dressing in chronic wounds: A biochemical and histological study.

BACKGROUND: Negative pressure wound therapy has emerged as an attractive treatment modality for the management and healing of chronic ulcers. Though numerous clinical studies are available, there is a lack of biochemical and histological studies evaluating the healing of chronic wounds. MATERIALS AND METHODS: In the present study, a total 60 patients were divided into two groups: Limited access dressing (LAD) group (n = 30) and conventional dressing group (n = 30). Various biochemical parameters such as hydroxyproline, total protein and antioxidants such as reduced glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT) and oxidative biomarker malondialdhyde (MDA) are measured in the granulation tissue. Histologically amount of inflammatory infiltrate, angiogenesis, and collagen deposition are studied to assess wound healing. RESULTS: Patients treated with LAD have shown significant increase in the mean (±standard deviation) hydroxyproline (77.3 ± 30.1 vs. 32.3 ± 16.18; P = 0.026), total protein (13.89 ± 9.0 vs. 8.9 ± 4.59; P = 0.004), GSH (7.4 ± 1.91 vs. 5.1 ± 1.28; P = 0.039), GPx (122.3 ± 59.3 vs. 88.7 ± 34.11; P = 0.030), CAT (1.80 ± 1.14 vs. 0.9 ± 0.71; P = 0.002) and decrease in MDA (13.4 ± 5.5 vs. 8.6 ± 3.8; P = 0.004). Histological study showed comparatively fewer inflammatory cells, increased and well organised collagen bundles, and more angiogenesis in the LAD group when compared with that with conventional dressing after 10 days of treatment. CONCLUSION: In the present study, we have found beneficial effect of newer intermittent negative pressure therapy in combination with moist environment (LAD) on chronic wound healing by increasing collagen deposition and angiogenesis; and reducing oxidative stress and inflammatory infiltrate.

Effect of limited access dressing on hydroxyproline and enzymatic antioxidant status in nonhealing chronic ulcers.

BACKGROUND: Healing ability of nonhealing chronic ulcers can be assessed by estimating hydroxyproline, total protein and enzymatic antioxidants such as glutathione peroxidase (GPx), glutathione S-transferase (GST) in the granulation tissue. MATERIALS AND METHOD: A total of 34 patients were analysed from two groups: Limited access dressing (LAD) group (n = 17) and conventional dressing group (n = 17). RESULTS: Patients treated with LAD that exerts combination of intermittent negative pressure and moist wound-healing had shown a significant increase in the hydroxyproline (P = 0.026), total protein (P = 0.004), GPx level (P = 0.030) and GST level (P = 0.045). CONCLUSION: Patients treated with LAD indicated significantly better anabolic effect on wound-healing compared to that of patients treated with conventional dressing.