title: Thread-dragging therapy in treatment of a rat model of infected subcutaneous fistula.
abstract: OBJECTIVE
  This study was to develop an experimental rat model of subcutaneous fistula induced by bacteria infection and treat it with thread-dragging therapy.
  
  
  METHODS
  A spring-gauze was surgically implanted into 24 male Sprague-Dawley rats' dorsal muscles, respectively, then mixed Staphylococcus aureus and Escherichia coli were injected into the spring-gauze. After 45 d, all the spring-gauzes were removed from the rats under anesthesia. X-ray and ultrasound were performed to assess the fistula tract. Each rat was examined by a fistula probe and four rats were randomly selected for histological assessment. The residual rats were randomly divided into two groups. Group A was treated with thread-dragging therapy, and group B was treated with fistulotomy. The healing time and body weight of the two groups were compared.
  
  
  RESULTS
  On the 45th day of the spring-gauze implantation, imaging assessment proved a tract with two openings in all rats and histological results proved that lumen and surrounding granulation tissue with epithelium were similar to the features of fistula in human beings. The mean healing time of rats in group A was shorter than that of the rats in group B (P<0.01). The body weight of rats in group A was heavier than that of the rats in group B on the 7th and 14th day after surgery, respectively (P<0.05).
  
  
  CONCLUSIONS
  A rat model of subcutaneous fistula induced by mixed Staphylococcus aureus and Escherichia coli infection was successfully established. Traditional Chinese medicine thread-dragging therapy is less invasive and safer than fistulotomy.
authors.affiliation: Department of Anorectal Surgery, Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.forename: Jin-gen
authors.initials: JG
authors.lastname: Lu
authors.forename: Hao-qiang
authors.initials: HQ
authors.lastname: Yin
authors.forename: Yong-qing
authors.initials: YQ
authors.lastname: Cao
mesh_terms: D000818:Animals; D005402:Fistula / Q000382:microbiology / Q000628:therapy*; D008297:Male; D008516:Medicine, Chinese Traditional / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013203:Staphylococcal Infections / Q000628:therapy*; D040521:Subcutaneous Tissue; D016896:Treatment Outcome