The prevalence of diabetes mellitus (DM) is increasing all over the world. Diabetic foot ulcer (DFU) is one of the major recognized complications. A large prospective cohort study found that the annual incidence of ulceration for DM patients and amputation for DFU patients were 8.1 and 5.1%, respectively. The annual mortality of the patients with DFU were even higher compared with DM patients.(2) The pathophysiology of DFU is complex.(3) Because of its complexity and high prevalence, it constitutes a large medical and economic problem. Up to now, there is no superior proven practice in treating DFU. The recent evidence showed that negative pressure wound therapy (NPWT) is one of the common methods to treat DFU including Hong Kong. In our systematic review of the latest 10 years publications, the result showed that most of the evidence suggested NPWT was effective in treating DFU but the evidence was still unclear. Hence, there is a need to conduct a study to assess the efficacy of NPWT in the local settings.
The objectives of this prospective observational study were: (1) to explore the effectiveness of NPWT; (2) to identify any risk factors in affecting DFU healing in using NPWT; (3) to make recommendations on the daily clinical practice. The study design is an open labeled 2-group design including conventional group (usual care) and NPWT group. This study conducted in 7 orthopaedic departments. The inclusion criteria were history of DM, age 18 or above, ulcer located at the foot, infection under control and the Saint Elain Wound Score System between 12-23. The exclusion criteria were high bleeding tendency, tumor patient, known auto-immune disease and un-cooperated patient. Each patient was followed 12 weeks.
Total 125 patients recruited, 62 in NPWT and 63 in control group. The basic demographics were comparable between groups. The results showed that the ulcers size, volume and severity were significantly higher in NPWT groups. The key findings showed that proportion of wound healing and healing rate was significantly higher in NPWT group than in conventional group. In the risk factor analysis, the regression model (adjusted R2=0.715) showed the larger wound size (below 50 cm2) and use of adjunctive methods afterwards were more beneficial for using NPWT in DFU healing. The adjunctive methods included skin graft, direct suture and other progressive wound closure method. This implies that larger wound size with the help of adjunctive method after NPWT application, the wound healing in DFU is enhanced.
