title: Incidence and risk factors of incisional hernia formation following abdominal organ transplantation.
abstract: BACKGROUND
  Hernia formation is common following abdominal operations, and transplant patients are at increased risk due to postoperative immunosuppression. The purpose of this study was to estimate the incidence of incisional hernia formation following primary abdominal solid organ transplantation and identify clinical risk factors for hernia formation.
  
  
  METHODS
  We performed a single-institution retrospective review of a prospectively collected database to evaluate all patients who underwent primary liver, kidney, or pancreas transplantation between 2000 and 2011. The primary outcome was hernia formation at the transplant incision. Univariate and multivariate Cox proportional hazards models were used to identify risk factors for incisional hernia formation.
  
  
  RESULTS
  A total of 3,460 transplants were performed during the study period: 2,247 kidney only, 718 liver only, and 495 pancreas or simultaneous pancreas and kidney (pancreas group). The overall incisional hernia rate was 7.5 %. The Kaplan-Meier rates of hernia formation at 1, 5, and 10 years were 2.5, 4.9, and 7.0 % for kidney; 4.5, 13.6, and 19.0 % for liver; and 2.5, 12.7, and 21.8 % for the pancreas groups. On univariate analysis, surgical site infection (SSI), body mass index (BMI) >25, delayed graft function, and withholding a calcineurin inhibitor or mycophenolate mofetil (MMF) were associated with hernia formation in the kidney group. SSI and BMI >25 were associated with hernia formation in the liver group. In the pancreas group, SSI, cyclosporine, and withholding MMF were all associated with hernia formation. On multivariate analysis, SSI was strongly associated with hernia formation in all groups. Hazard ratio: kidney = 24.71 (13.00-46.97); liver = 12.0 (6.40-22.52); pancreas = 12.95 (2.78-60.29).
  
  
  CONCLUSIONS
  Incisional hernias are common following abdominal organ transplant with nearly one in five patients developing an incisional hernia 5 years after liver or pancreas transplantation. Strategies focusing on prevention and early treatment of SSI may help to decrease the risk of incisional hernia formation following abdominal organ transplantation.
authors.affiliation: University of Wisconsin Hospital and Clinics, 600 Highland Avenue, K4/748 CSC, Madison, WI, 53792, USA.
authors.forename: Carter T
authors.initials: CT
authors.lastname: Smith
authors.forename: Micah G
authors.initials: MG
authors.lastname: Katz
authors.forename: David
authors.initials: D
authors.lastname: Foley
authors.forename: Bridget
authors.initials: B
authors.lastname: Welch
authors.forename: Glen E
authors.initials: GE
authors.lastname: Leverson
authors.forename: Luke M
authors.initials: LM
authors.lastname: Funk
authors.forename: Jacob A
authors.initials: JA
authors.lastname: Greenberg
mesh_terms: D005260:Female; D005500:Follow-Up Studies; D046449:Hernia, Abdominal / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D015994:Incidence; D016030:Kidney Transplantation / Q000009:adverse effects; D016031:Liver Transplantation / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D016377:Organ Transplantation / Q000009:adverse effects*; D016035:Pancreas Transplantation / Q000009:adverse effects; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D014922:Wisconsin / Q000453:epidemiology