title: Development and validation of a risk stratification score for ventral incisional hernia after abdominal surgery: hernia expectation rates in intra-abdominal surgery (the HERNIA Project).
abstract: BACKGROUND
  Ventral incisional hernias (VIH) develop in up to 20% of patients after abdominal surgery. No widely applicable preoperative risk-assessment tool exists. We aimed to develop and validate a risk-assessment tool to predict VIH after abdominal surgery.
  
  
  METHODS
  A prospective study of all patients undergoing abdominal surgery was conducted at a single institution from 2008 to 2010. Variables were defined in accordance with the National Surgical Quality Improvement Project, and VIH was determined through clinical and radiographic evaluation. A multivariate Cox proportional hazard model was built from a development cohort (2008 to 2009) to identify predictors of VIH. The HERNIAscore was created by converting the hazards ratios (HR) to points. The predictive accuracy was assessed on the validation cohort (2010) using a receiver operator characteristic curve and calculating the area under the curve (AUC).
  
  
  RESULTS
  Of 625 patients followed for a median of 41 months (range 0.3 to 64 months), 93 (13.9%) developed a VIH. The training cohort (n = 428, VIH = 70, 16.4%) identified 4 independent predictors: laparotomy (HR 4.77, 95% CI 2.61 to 8.70) or hand-assisted laparoscopy (HAL, HR 4.00, 95% CI 2.08 to 7.70), COPD (HR 2.35; 95% CI 1.44 to 3.83), and BMI ≥ 25 kg/m(2) (HR1.74; 95% CI 1.04 to 2.91). Factors that were not predictive included age, sex, American Society of Anesthesiologists (ASA) score, albumin, immunosuppression, previous surgery, and suture material or technique. The predictive score had an AUC = 0.77 (95% CI 0.68 to 0.86) using the validation cohort (n = 197, VIH = 23, 11.6%). Using the HERNIAscore: HERNIAscore = 4(∗)Laparotomy+3(∗)HAL+1(∗)COPD+1(∗) BMI ≥ 25, 3 classes stratified the risk of VIH: class I (0 to 3 points),5.2%; class II (4 to 5 points),19.6%; and class III (6 points), 55.0%.
  
  
  CONCLUSIONS
  The HERNIAscore accurately identifies patients at increased risk for VIH. Although external validation is needed, this provides a starting point to counsel patients and guide clinical decisions. Increasing the use of laparoscopy, weight-loss programs, community smoking prevention programs, and incisional reinforcement may help reduce rates of VIH.
authors.affiliation: Department of Surgery, University of Texas Health Science Center, Houston, TX.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Goodenough
authors.affiliation: Department of Surgery, University of Texas Health Science Center, Houston, TX.
authors.forename: Tien C
authors.initials: TC
authors.lastname: Ko
authors.affiliation: Department of Surgery, University of Texas Health Science Center, Houston, TX.
authors.forename: Lillian S
authors.initials: LS
authors.lastname: Kao
authors.affiliation: Department of Surgery, University of Texas Health Science Center, Houston, TX.
authors.forename: Mylan T
authors.initials: MT
authors.lastname: Nguyen
authors.affiliation: Department of Surgery, University of Texas Health Science Center, Houston, TX.
authors.forename: Julie L
authors.initials: JL
authors.lastname: Holihan
authors.affiliation: Department of Surgery, University of Texas Health Science Center, Houston, TX.
authors.forename: Zeinab
authors.initials: Z
authors.lastname: Alawadi
authors.affiliation: Department of Surgery, University of Texas Health Science Center, Houston, TX.
authors.forename: Duyen H
authors.initials: DH
authors.lastname: Nguyen
authors.affiliation: Department of Surgery, University of Texas Health Science Center, Houston, TX.
authors.forename: Juan R
authors.initials: JR
authors.lastname: Flores
authors.affiliation: Department of Surgery, Baylor College of Medicine, Houston, TX.
authors.forename: Nestor T
authors.initials: NT
authors.lastname: Arita
authors.affiliation: Department of Surgery, University of Kentucky, Lexington, KY.
authors.forename: J Scott
authors.initials: JS
authors.lastname: Roth
authors.affiliation: Department of Surgery, University of Texas Health Science Center, Houston, TX. Electronic address: mkliang@yahoo.com.
authors.forename: Mike K
authors.initials: MK
authors.lastname: Liang
mesh_terms: D000005:Abdomen / Q000601:surgery*; D003661:Decision Support Techniques; D005260:Female; D005500:Follow-Up Studies; D058733:Hand-Assisted Laparoscopy / Q000009:adverse effects*; D006555:Hernia, Ventral / Q000453:epidemiology* / Q000209:etiology / Q000601:surgery; D059685:Herniorrhaphy / Q000379:methods*; D006801:Humans; D015994:Incidence; D007813:Laparotomy / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D013529:Surgical Wound Dehiscence / Q000150:complications* / Q000453:epidemiology; D013997:Time Factors; D014481:United States / Q000453:epidemiology