title: Healing by primary versus secondary intention after surgical treatment for pilonidal sinus.
abstract: BACKGROUND
  Pilonidal sinus arises in the hair follicles in the buttock cleft at the bottom of the backbone. The estimated incidence is 26 per 100,000, people, affecting men twice as often as women. The mean age of presentation is 21 years (men) and 19 years (women) respectively.Pilonidal sinus results in chronic discharging wounds that cause pain and impact upon quality of life and social function. These sinuses may become infected and present as acute abscesses. Management of these abscesses is uncontroversial and revolves around incision and drainage, however, the mode of surgical management of the chronic discharging sinus is debatable. Surgical strategies traditionally centre on excision of the sinus tracts followed by primary closure and healing by primary intention or leaving the wound open to heal by secondary intention. There is uncertainty as to whether open or closed surgical management is more effective.
  
  
  OBJECTIVE
  To determine the relative effects of open compared with closed surgical treatment for pilonidal sinus on the outcomes of time to healing, infection and recurrence rate.
  
  
  METHODS
  We sought relevant trials from the Wounds Group Specialised Register (Searched 13/6/07); The Cochrane Central Register of Controlled Trials (CENTRAL) (2007, Issue 2); Ovid MEDLINE (1950 - May Week 5 200& ); Ovid EMBASE (1980 - 2007 Week 23); Ovid CINAHL (1982 - June Week 2 2007). We checked the bibliographies of review and primary articles for relevant studies and contacted authors of all included studies.
  
  
  METHODS
  All randomised controlled trials (RCTs) evaluating open with closed surgical treatment for pilonidal sinus. Exclusion criteria were: non-RCTs; children aged younger than 14 years and studies of pilonidal abscess.
  
  
  METHODS
  Screening of eligible studies, data extraction and methodological quality assessment of trials were conducted independently by two review authors. Data from eligible studies were recorded using data extraction forms and any disagreements were referred to a third review author. Results were presented using mean differences for continuous outcomes and relative risk with 95% confidence intervals for dichotomous outcomes.
  
  
  RESULTS
  Eighteen studies were included (1573 patients). Twelve RCTs compared open healing with primary closure, 10 of which used midline closure and 2 trials used off-midline closure. Six studies compared midline and off-midline closure. Open compared with closed techniques: Evidence suggested more rapid healing after primary closure although there was no difference in the infection rate after wound closure. Recurrence was less likely to occur after open healing (RR 0.42; 95% CI 0.26 to 0.66) suggesting a 58% lower risk of recurrence after open wound healing compared with primary closure. Patients returned to work earlier after primary closure (WMD 10.48 days 95% CI 5.75 to 15.21 days). There was no difference between the two groups for other complications and length of stay. There were few useable data on cost, patient satisfaction and pain. Closed midline compared with closed off-midline: there was good evidence of slower healing, higher rates of infection (RR 4.70; 95% CI 1.93 to 11.45), higher rates of recurrence (Peto OR 4.95; 95% CI 2.18 to 11.24) and other complications (RR 8.94; 95% CI 2.10 to 38.02) after midline primary closure compared with off-midline closure techniques.
  
  
  CONCLUSIONS
  No clear benefit was shown for surgical management by primary closure or open healing by secondary intention. A clear benefit was shown for off-midline closure rather than midline closure after pilonidal sinus surgery. Off-midline closure should be the standard management when primary closure is the desired surgical option.
authors.forename: I
authors.initials: I
authors.lastname: McCallum
authors.forename: P M
authors.initials: PM
authors.lastname: King
authors.forename: J
authors.initials: J
authors.lastname: Bruce
mesh_terms: D006801:Humans; D010864:Pilonidal Sinus / Q000601:surgery*; D016032:Randomized Controlled Trials as Topic; D014945:Wound Healing