To explore the clinical effect of vacuum sealing drainage (VSD) combined with autologous skin grafting under oxygen supply in the treatment of refractory diabetic foot ulcer.

A total of 100 patients with refractory diabetic foot ulcers who were admitted to People′s Hospital of Xinjiang Uygur Autonomous Region from March 2018 to March 2020 were selected as the research objects. According to the random number table method, they were divided into observation group and control group, with 50 patients in each group. Patients in the observation group were given anti-infection, dressing change, blood glucose control, and symptomatic supportive treatment, and debridement was given as scheduled after the improvement of relevant examinations. After debridement, the Vacuseal material was cut according to the size of the patient′s wound and then attached to the wound. An opening was made at a distance of 3 cm from the normal skin of the wound, and a drainage tube was drawn out. The attached material was sutured intermittently with the edge of the wound. The biological semipermeable membrane was tightly attached to the entire skin wound of the patient. After the attachment was completed, the drainage tube was connected to the central negative pressure device to maintain continuous negative pressure suction. The negative pressure suction pressure value was maintained at about 40 kPa, and the daily negative pressure suction time was about 6 h. VSD oxygen supply was performed in the order of pure oxygen first and then ozone every day, the oxygen flow rate of pure oxygen was 5 L/min for 1 h/d and the oxygen flow rate of ozone was 10 mL/min, 30 min/d. The wound surface of the patient was evaluated when the dressing was changed every day. When the wound surface had less secretions, the granulation tissue was bright and ruddy, the texture was firm without edema, and there was no inflammation, and the blood glucose control reached the standard, autologous skin grafting was performed. After the operation, the patients were required to rest in bed absolutely, and the affected limb was elevated and immobilized. The first dressing change was performed 4 d after the operation, and then the dressing change was performed according to the growth of the grafted skin on the wound surface, with an interval of 2 to 3 d. Insulin was used to control blood glucose during treatment. The patients in the control group were not given oxygen and ozone treatment, and the rest of the treatments were the same as those in the observation group. The clinical efficacy of the two groups at 1 week after the end of treatment; the wound pruritus score, granulation tissue morphology score, and visual analogue scale (VAS) score before and 1 week after the end of treatment; the amputation rate and skin graft survival rate and healing time of skin grafting at 1 month after the end of treatment and the changes of matrix metalloproteinase (MMP)-2 and MMP-9 levels 1 week after the end of treatment were compared. Data were compared with t test and chi-square test.

One week after the end of treatment, the total effective rate of treatment in the observation group was 98.00% (49/50), which was significantly higher than that in the control group [82.00% (41/50)], and the difference was statistically significant (χ²=7.111, P<0.05). The wound pruritus score, granulation tissue morphology score and VAS score of the observation group before treatment were (2.18±0.34), (2.10±0.29), (5.49±0.87) points, respectively, and 1 week after the end of treatment were (1.03±0.26), (1.07±0.18), (2.43±0.41) points; the wound pruritus score, granulation tissue morphology score and VAS score of the control group before treatment were (2.21±0.39), (2.13±0.32), (5.53±0.98) points, respectively, 1 week after the end of treatment, the scores were (1.64±0.31), (1.58±0.23), (3.39±0.53) points, respectively. There were significant differences in the scores of each index between the two groups before treatment and 1 week after the end of treatment, the differences were statistically significant (P<0.05). And the wound pruritus score, granulation tissue morphology score and VAS score of the observation group were significantly lower than those of the control group 1 week after the end of treatment, and the differences were statistically significant (t=10.661, 12.348, 10.131; P<0.05). There was no statistically significant difference in the amputation rate between the two groups (P>0.05). The survival rate of skin grafting in the observation group was 98.00% (49/50), which was significantly higher than that in the control group [84.00% (42/50)], and the difference was statistically significant (χ²=4.396, P=0.039). The recovery time of skin grafting in the observation group was (14.73±1.42) d, which was shorter than that in the control group [(18.32±1.81) d], and the difference was statistically significant (t=11.034, P<0.05). The expression levels of MMP-2 and MMP-9 in the observation group were 285.34±28.19 and 363.29±20.81 before treatment, and 167.49±21.08 and 241.38±17.84 1 week after the end of treatment, respectively; the expression levels of MMP-2 and MMP-9 in the control group were 279.81±29.35 and 359.89±24.31 before treatment, and 213.53±34.26 and 283.53±22.19 1 week after the end of treatment, respectively, there were statistically significant differences in the expression levels of MMP-2 and MMP-9 between the two groups before treatment and 1 week after the end of treatment (P<0.05), and the expressions level of MMP-2 and MMP-9 in the observation group 1 week after the end of treatment were lower than that of the control group, and the differences were statistically significant (t=8.093, 10.468; P<0.05).

Under oxygen supply, VSD combined with autologous skin grafting has a good effect on refractory diabetic foot ulcer, and can improve the survival rate of skin grafting, shorten the healing time of skin grafting, and reduce the expression levels of serum MMP-2 and MMP-9.