title: Incidence of and risk factors for incisional hernia after abdominal surgery.
abstract: BACKGROUND
  Few larger studies have estimated the incidence of incisional hernia (IH) after abdominal surgery.
  
  
  METHODS
  Patients who had abdominal surgery between November 2009 and February 2011 were included in the study. The incidence rate and risk factors for IH were monitored for at least 180  days.
  
  
  RESULTS
  A total of 4305 consecutive patients were registered. Of these, 378 were excluded because of failure to complete follow-up and 3927 patients were analysed. IH was diagnosed in 318 patients. The estimated incidence rates for IH were 5·2 per cent at 12  months and 10·3 per cent at 24 months. In multivariable analysis, wound classification III and IV (hazard ratio (HR) 2·26, 95 per cent confidence interval 1·52 to 3·35), body mass index of 25 kg/m(2) or higher (HR 1·76, 1·35 to 2·30), midline incision (HR 1·74, 1·28 to 2·38), incisional surgical-site infection (I-SSI) (HR 1·68, 1·24 to 2·28), preoperative chemotherapy (HR 1·61, 1·08 to 2·37), blood transfusion (HR 1·46, 1·04 to 2·05), increasing age by 10-year interval (HR 1·30, 1·16 to 1·45), female sex (HR 1·26, 1·01 to 1·59) and thickness of subcutaneous tissue for every 1-cm increase (HR 1·18, 1·03 to 1·35) were identified as independent risk factors. Compared with superficial I-SSI, deep I-SSI was more strongly associated with the development of IH.
  
  
  CONCLUSIONS
  Although there are several risk factors for IH, reducing I-SSI is an important step in the prevention of IH.
  
  
  BACKGROUND
  UMIN000004723 (University Hospital Medical Information Network, http://www.umin.ac.jp/ctr/index.htm).
authors.affiliation: Divisions of Surgical Oncology, Nagoya University Graduate School of Medicine, Nagoya, Japan; Divisions of Surgical Infection, Department of Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Itatsu
authors.forename: Y
authors.initials: Y
authors.lastname: Yokoyama
authors.forename: G
authors.initials: G
authors.lastname: Sugawara
authors.forename: H
authors.initials: H
authors.lastname: Kubota
authors.forename: Y
authors.initials: Y
authors.lastname: Tojima
authors.forename: Y
authors.initials: Y
authors.lastname: Kurumiya
authors.forename: H
authors.initials: H
authors.lastname: Kono
authors.forename: H
authors.initials: H
authors.lastname: Yamamoto
authors.forename: M
authors.initials: M
authors.lastname: Ando
authors.forename: M
authors.initials: M
authors.lastname: Nagino
mesh_terms: D000005:Abdomen / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006555:Hernia, Ventral / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D015994:Incidence; D007431:Intraoperative Complications / Q000209:etiology; D008297:Male; D008875:Middle Aged; D061646:Operative Time; D011183:Postoperative Complications / Q000209:etiology*; D011446:Prospective Studies; D012307:Risk Factors; D013530:Surgical Wound Infection / Q000209:etiology; D055815:Young Adult