title: Perirenal fat surface area as a risk factor for morbidity after elective colorectal surgery.
abstract: BACKGROUND
  Visceral obesity appears to be an emerging parameter affecting postoperative outcome after abdominal surgery. However, total visceral fat remains time consuming to calculate, and there is still a lack of data about its value as an independent risk factor in colorectal surgery.
  
  
  OBJECTIVE
  The aim of this study was to validate the simple measurement of perirenal fat surface as a surrogate of visceral obesity, and to test the value of perirenal fat surface as a risk factor for morbidity in colorectal surgery and to compare it with the predictive value of other obesity parameters such as BMI and waist-hip ratio.
  
  
  METHODS
  This is a prospective observational cohort study.
  
  
  METHODS
  The study was conducted at a tertiary university hospital.
  
  
  METHODS
  Two hundred twenty-four consecutive patients (130 male) undergoing elective colorectal surgery with a mean age of 65.2 years (SD, ±12.9) were identified.
  
  
  METHODS
  Elective colorectal resections were performed.
  
  
  METHODS
  We assessed complications as the primary outcome measure. Secondary outcome measures were the conversion rates, duration of operation, and length of hospital stay.
  
  
  RESULTS
  Perirenal fat surface was validated as a surrogate of visceral fat and a strong correlation between the 2 was confirmed (Spearman correlation coefficient ρ = 0.96). The overall postoperative complication rate was 22.8% (51/224) with 14.7% moderate complications (grade I and II) and 7.6% severe complications (grade III-IV), with a mortality rate of 0.5%. Multivariate analysis confirmed perirenal fat surface as an independent risk factor for postoperative complications (OR, 3.87; 95% CI, 1.73-8.64; p = 0.001), whereas BMI and waist-hip ratio were not statistically associated with postoperative complications (OR, 1.16; 95% CI, 0.51-2.66; p = 0.72).
  
  
  CONCLUSIONS
  This study was limited by its sample size.
  
  
  CONCLUSIONS
  Perirenal fat surface is an excellent and easy-to-reproduce indicator of visceral fat volume. Furthermore, perirenal fat surface is an independent risk factor for postoperative outcome in colorectal surgery that appears to be of higher predictive value than BMI and waist-hip ratio.
authors.affiliation: 1Clinic for Visceral and Transplantation Surgery, Department of Surgery, University Hospital of Geneva, Geneva, Switzerland 2CRC and Division of Clinical Epidemiology, Department of Community Health and Medicine, University of Geneva, University Hospital of Geneva, Geneva, Switzerland.
authors.forename: Minoa
authors.initials: M
authors.lastname: Jung
authors.forename: Francesco
authors.initials: F
authors.lastname: Volonté
authors.forename: Nicolas C
authors.initials: NC
authors.lastname: Buchs
authors.forename: Angèle
authors.initials: A
authors.lastname: Gayet-Ageron
authors.forename: François
authors.initials: F
authors.lastname: Pugin
authors.forename: Pascal
authors.initials: P
authors.lastname: Gervaz
authors.forename: Frederic
authors.initials: F
authors.lastname: Ris
authors.forename: Philippe
authors.initials: P
authors.lastname: Morel
mesh_terms: D000368:Aged; D015992:Body Mass Index; D015331:Cohort Studies; D003108:Colonic Diseases / Q000601:surgery*; D017558:Elective Surgical Procedures; D005260:Female; D006801:Humans; D050152:Intra-Abdominal Fat; D010535:Laparoscopy; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D061646:Operative Time; D011183:Postoperative Complications; D011237:Predictive Value of Tests; D012002:Rectal Diseases / Q000601:surgery*; D015203:Reproducibility of Results; D012307:Risk Factors; D049629:Waist-Hip Ratio