Objective To observe the effect of radiofrequency ablation technology for the treatment of infected wounds in minipigs. Methods Infected wounds of full-thickness skin defects (about 6.15 cm2/wound) were prepared in 8 6-month-old minipigs (weighing, 30-35 kg) using the method of Davis et al. The 160 wounds were randomly divided into 4 groups (n=40). Infected wounds were debrided with the radiofrequency ablation technology in group A, with the electric knife in group B, and with the scalpel in group C; no treatment was done in group D as a control. The healing rate, healing time, and tissue filling rate were observed; bacterial quantitative examination and histological examination were done at 0, 2, 7, and 14 days after operation. Results All infected wounds were successfully established after 48 hours when Staphylococcus aureus dilution were inoculated. The wounds after radiofrequency ablation technology treatment were fresh and flat with slight bleeding; the healing time of group A was significantly shorter than that of groups B, C, and D (P lt; 0.05), and the healing rate of group A was significantly higher than that of groups B, C, and D at 7 and 14 days after operation (P lt; 0.05). The tissue filling rate of group A was significantly higher than that of groups B, C, and D at 2 days after operation (P lt; 0.05); the tissue filling rates of groups A, B, and C were significantly higher than that of group D at 7 and 14 days after operation (P lt; 0.05). At 0, 2, 7, and 14 days, there were significant differences in the bacterial count per gram tissue among 4 groups (P lt; 0.05), the order from low to high was groups A, B, C, and D. The histological observation showed that the surface of wound was smooth in group A at 0 day, and group A was better than the other groups in wound healing; at 2 days, some exudates were observed in 4 groups, but it was least in group A. There was inflammatory cell infiltration in various degrees in 4 groups at 7 and 14 days; it was lightest in group A with thick epithelium and dense collagen bundles, followed by groups B and C, and it was severe in group D. Conclusion The radiofrequency ablation technology can effectively remove the necrotic tissues of infected wounds, remarkably reduce the number of bacteria, improve the healing rate, and shorten the healing time of wounds.
Objective To investigate the therapeutic effectof infected incision wounds after sternotomy by using different reconstructive methods. Methods From December 1997 to December 2006, 13 patients (8 males, 5 females; age, 28-72 years averaged 52 years) with infected incision wounds after sternotomy underwent the reconstruction surgery respectivelyusing the pectoralis major muscle flaps, the medial flaps of the pectoralis major muscle, the rectus abdominis muscle flaps or the greater omentum transpositions. Among the patients, 8 were complicated by diabetes mellitus, 4 by pneumonia and heart failure, 3 by empyema, 4 by chronic insufficiency of the pulmonary function, 1 by malignant tumor, and 6 by severe obesity. Freshlysplit wounds werefound in 11 patients and chronic wounds in the other 2 patients.The size of thewounds was 10cm×5cm-22cm×10cm. Results Among the 13 patients，10 survived after operation and the other 3 died of massive hemorrhage from the anastomostic rupture of the blood vessel, pneumonia, and cancer metastasis, respectively. Of the 10 patients, 6 had their wounds healed by first intention. The follow-up for 6 months to 5 years revealed that there was no recurrencein all the survived patients. Of the 10 patients, 2 developed partial necrosisof the skins at the sutured wounds, which was healed after the skin grafting operation; 2 had an infection at the drainage area but had a healing after the dressing changes. Conclusion The smaller wounds in the upper partof the sternotomy incision should be repaired with the medial flaps of the pectoralis major muscle; the greater wounds in the upper part of the incision shouldbe repaired and reconstructed with the rectus abdominis muscle flap; the smaller wounds in the lower part of the incision should be repaired with the pectoralis major muscle flap, and if the wounds are longer, they should be repaired and reconstructed with the pectoralis major muscle flap and the rectus abdominis muscle flap; and if the wounds are huge enough with an exposure of the important internal organs, the greater omentum transposition should be used, and the residual wounds should be treated with dressing changes and even skin grafting.