title: Are wound ring protectors effective in reducing surgical site infection post appendectomy? A systematic review and meta-analysis.
abstract: BACKGROUND
  Surgical site infection (SSI) is one of the main causes of postoperative morbidity and mortality. Appendectomy for acute appendicitis is one of the most commonly performed surgical interventions worldwide. The use of ring retractors to protect the wound edge from contaminated intra-abdominal contents may be an effective method to reduce SSI.
  
  
  OBJECTIVE
  The aim of this systematic review and meta-analysis is to determine whether the use of wound ring retractors reduces SSI rates after open appendectomy.
  
  
  METHODS
  A systematic review of randomized controlled trials (RCTs) and meta-analysis of ring retractors was undertaken using the PRISMA guidelines. PubMed, Cochrane RCTs Central Register, CINAHL, and ISRCTN registry were searched for eligible studies. Only studies in which open appendectomy was undertaken were included. The Cochrane Collaboration's RevMan 5.3 was used for analysis. A subgroup analysis by degree of appendiceal inflammation was performed.
  
  
  RESULTS
  Four RCTs inclusive of 939 patients met eligibility requirements. One trial used single ring while three used double ring protectors. Differences in the definition of SSI, skin preparation, and type and duration of prophylactic antibiotic were found between the 4 studies. The use of ring retractors show some evidence of SSI reduction risk ratio 0.44 [95 % CI (0.21, 0.90)]. On sub-analysis, ring retractor was more effective in more severe degrees of appendiceal inflammation i.e., the contaminated group.
  
  
  CONCLUSIONS
  Our review suggests some benefit in using ring retractors to reduce SSI post appendectomy; however the small number and variable quality of the studies suggest the need for more RCTs to confirm these results.
authors.affiliation: Department of Surgery, Lambe Institute for Translational Research, National University of Ireland, Galway, Ireland. Khalidmd20@gmail.com.
authors.forename: K
authors.initials: K
authors.lastname: Ahmed
authors.affiliation: Department of Surgery, Lambe Institute for Translational Research, National University of Ireland, Galway, Ireland. Tara_conn@hotmail.com.
authors.forename: T M
authors.initials: TM
authors.lastname: Connelly
authors.affiliation: Department of Vascular Surgery, University Hospital Limerick, Limerick, Ireland. khalid@live.ie.
authors.forename: K
authors.initials: K
authors.lastname: Bashar
authors.affiliation: Department of Surgery, Lambe Institute for Translational Research, National University of Ireland, Galway, Ireland. STEWARTREDMOND.WALSH@NUIGALWAY.IE.
authors.forename: S R
authors.initials: SR
authors.lastname: Walsh
mesh_terms: D001062:Appendectomy / Q000379:methods*; D001064:Appendicitis / Q000601:surgery*; D006801:Humans; D013530:Surgical Wound Infection / Q000517:prevention & control*
keywords: Ring protector; Surgical site infections; Surgical wound protector