ObjectiveTo investigate the effects of intermittent irrigation of insulin solution combined with continuous drainage of vacuum sealing drainage (VSD) in chronic diabetic lower limb ulcers. MethodsBetween January 2012 and December 2014, 45 patients with diabetic lower limb ulcer were treated with VSD (group A, n=15), with VSD combining irrigation of normal saline (group B, n=15), and with VSD combining irrigation of insulin solution (group C, n=15) after debridement. There was no significant difference in gender, age, course of ulcers, area and depth of wound, glycosylated hemoglobin, and Wagner grade among 3 groups (P>0.05), and the data were comparable. The levels of fasting blood glucose, 2-hour postprandial blood glucose, and random blood glucose were determined everyday during treatment. The contents of insulin growth factor 1 (IGF-1), tumor growth factor α (TNF-α), and nitric oxide (NO) in necrotic tissue after drainage were determined. The coverage rate and thickness of granulation tissue and clearance rate of bacteria in wound were calculated, the granulation tissue in the center of the wound was harvested for pathological observation with HE staining after 6 days of treatment. The second stage operation was performed according to the condition of wounds, and the time to the second stage operation and the method of the second stage operation were recorded and the survival rate of grafted skin or flap was calculated. ResultsThe pathological staining showed that there were a few new microvessels and fibroblasts in group A after treatment;more new microvessels and fibroblasts were observed in group B;and many new microvessels and fibroblasts were found in group C. There was no significant difference in levels of fasting blood glucose, 2-hour postprandial blood glucose, and random blood glucose among 3 groups during treatment (P>0.05). The coverage rate and thickness of granulation tissue and clearance rate of bacteria in group C were significantly higher than those in groups A and B after treatment (P<0.05). The contents of IGF-1 and NO were significantly increased and TNF-α was significantly decreased in group C when compared with those in group A (P<0.05). Compared with group B, IGF-1 and NO contents were significantly increased at 3-6 days and at 2-6 days respectively, and TNF-α content was significantly decreased at 3-6 days in group C (P<0.05). The method of the second stage operation showed no significant difference among 3 groups (χ2=2.920, P=0.230), but the time to the second stage operation in group C was significantly shorter than that in groups A and B (P<0.05), and the survival rate of grafted skin or flap in group C was significantly higher than that in groups A and B (P<0.05). ConclusionThe treatment of diabetic lower limb ulcers with intermittent irrigation of insulin solution combined with continuous drainage of VSD can reduce inflammatory reaction effectively, promote development of granulation tissue, improve recovery function of tissue, increase the rate and speed of wound healing obviously, but it has no effect on blood glucose levels.