A Retrospective Analysis Of Skin And Soft Tissue Expander Placement Site Infection Related Factors And The Infection’s Clinical Treatment

BackgroundPlacement site infection, with incidence rate of about 2-7%, is a common complication of skin and soft tissue expansion and often determines the success or failure of the procedure. The infection associated factors include age, embedded layer, location, smoking, size of expander, the number of embedded expander, and the placement of internal or external valve. However, the problems associated with placement infection are scarcely studied and are mostly reported in the study of other complications. In addition, the there is currently no consensus on the infection treatment protocol and the related outcome in most of the studies are not convincing because of the relative sample sizes. ObjectiveTo determine the possible risk factors for expander-placement associated infection by a retrospective case-control study involving the cases with and without infection. MethodsA retrospective analysis on cases with infection at the skin soft tissue expander placement sites during 2003 to 2012 in Department of Plastic and Reconstructive Surgery, Xijing Hospital, was performed. A control group was included in this study. The association between the pathogenic bacteria and corresponding infections, and the appropriate treatment and the outcomes were evaluated. The epidata and spss softwares were used for data acquisition and processing. The independent sample t test, chi-square test, Fisher’s exact test were used for statistical analysis. P ≤ 0.05 was considered as statistically different. ResultsThe differences in the amount of drainage, time for drainage-tube removal, rate of expander exposure, incidence rate of hematoma, injection completion rate and expander sizes between infection and control groups were statistically significant. In contrast, there were no statistic differences in factors of age, number of expander placed, method of injection valve placement, pre-operative white blood cell count, preoperative prothrombin time, volume of blood loss during operation. Staphylococcus aureus was the most common pathogen, accounting for 86.96%. The laboratory results showed more than 80% of bacteria were sensitive to cefazolin, levofloxacin, oxacillin, and penicillin. The cure rate of infection was 100% after using topical dressing, debridement and drainage, and intravenous infusion of sensitive antibiotics. The rate of successfully completed soft tissue expansion was 90.08%. ConclusionPoor hemostasis induced increase in drainage during operation is an important risk factor for postoperative infection. The infection and expander exposure complication demonstrate close relationship with one of the factors exacerbates the other reciprocally. The incidence of infection greatly impacts expander’s injection process, often leading to the final injection volume shortage and seriously affecting the expansion outcome. The ampulla externalization, age, the number of placed expander, intraoperative blood loss, preoperative WBC count, preoperative prothrombin time have no impact on the infection rate. Staphylococcus aureus is the most common pathogen. Expander implantation site infection is mainly a local infection. The treatment should be focused on local dressing application, surgical debridement and drainage, supplemented by intravenous infusion of sensitive antibiotics. Specific treatment plan should be arranged based on the extent of infection.