title: Wound drains after incisional hernia repair.
abstract: BACKGROUND
  Incisional hernias are caused by the failure of the wall of the abdomen to close after abdominal surgery, leaving a hole through which the viscera protrude. Incisional hernias are repaired by further surgery. Surgical drains are frequently inserted during hernia repair with the aim of facilitating fluid drainage and preventing complications. Traditional teaching has recommended the use of drains after incisional hernia repair other than for laparoscopic ventral hernia repair. More than 50% of open mesh repairs of ventral hernias have drains inserted. However, there is uncertainty as to whether drains are associated with benefits or harm to the patient.
  
  
  OBJECTIVE
  To determine the effects on wound infection and other outcomes, of inserting a wound drain during surgery to repair incisional hernias, and, if possible, to determine the comparative effects of different types of wound drain after incisional hernia repair.
  
  
  METHODS
  For this third update we searched the Cochrane Wounds Group Specialised Register (Searched September 8, 2011), the Cochrane Central Register of Controlled Trials (CENTRAL), The Cochrane Library Issue 8, 2011, Ovid MEDLINE (2010 to September 2011), Ovid EMBASE (2007 to September 2011), and EBSCO CINAHL (2010 to September 2011).
  
  
  METHODS
  We considered all randomised trials performed in adult patients who underwent incisional hernia repair and that compared using a drain with no drain. We also considered trials that compared different types of drain.
  
  
  METHODS
  We extracted data on the characteristics of the trial, methodological quality of the trials, outcomes (e.g. infection and other wound complications) from each trial. For each outcome, we calculated the risk ratio (RR) with 95% confidence intervals (CI) and based on intention-to-treat analysis.
  
  
  RESULTS
  No new trials were identified by the updated searches. Only one trial was eligible for inclusion in the review with a total of 24 patients randomised to an electrified drain (12 patients) compared with a corrugated drain (12 patients). There were no statistically significant differences between the groups for wound infection or in the length of stay in hospital.
  
  
  CONCLUSIONS
  There is insufficient evidence to determine whether wound drains after incisional hernia repair are associated with better or worse outcomes than no drains.
authors.affiliation: Department of Surgery, Royal Free Campus, UCL Medical School, London, UK. kurinchi2k@hotmail.com.
authors.forename: Kurinchi Selvan
authors.initials: KS
authors.lastname: Gurusamy
authors.forename: Victoria B
authors.initials: VB
authors.lastname: Allen
authors.forename: Kumarakrishnan
authors.initials: K
authors.lastname: Samraj
mesh_terms: D004322:Drainage / Q000009:adverse effects* / Q000295:instrumentation; D006555:Hernia, Ventral / Q000601:surgery*; D006801:Humans; D011183:Postoperative Complications / Q000601:surgery*; D016032:Randomized Controlled Trials as Topic; D012086:Reoperation; D013526:Surgical Mesh; D013530:Surgical Wound Infection / Q000517:prevention & control; D014945:Wound Healing