Objective   To investigate the impact of negative pressure wound treatment (NPWT) on the wound and its circum and explore the possible mechanism by which NPWT promotes the growth of chronic wound blood vessels.    Methods   Totally 12 patients with chronic wounds were subjected in our hospital

and then randomly divided into experimental and control group. The experimental group were treated with NPWT whereas the control group were treated with the traditional method

namely conventional dressing with normal saline dressing. Full-thickness skin samples on the verge of the wound were collected respectively in 1 d before the treatment and 1

2 and 7 d after the treatment respectively. The mRNA expression of the hypoxia inducible factor-1α (HIF-1α) were detected by reverse transcription polymerase chain reaction (RT-PCR). The protein expressions of HIF-1α and VEGF were detected by immunohistochemical method (IHC).    Results   The mRNA expression of HIF-1α was significantly more in the experimental group than in the control group (P0.05)

so did the protein expression (P0.05). There was more VEGF in the experimental group than in the control group

with significant difference (P0.05). Meanwhile

the expression of VEGF and the expression of HIF-1α was positively correlated (r=0.854

P0.01).    Conclusion   NPWT upregulates the expression of HIF-1α

then increases the expression of VEGF to promote wound blood vessel growth and consequently wound healing.