title: Body surface area:  a new predictor factor for conversion and prolonged operative time in laparoscopic colorectal surgery.
abstract: BACKGROUND
  Body surface area is a measurement of body size used in clinical settings. Its impact on laparoscopic colorectal surgery has not been previously studied.
  
  
  OBJECTIVE
  The aim of this study was to assess the impact of body surface area on the conversion rate and laparoscopic operative time.
  
  
  METHODS
  This study was conducted as a retrospective analysis of prospectively collected data.
  
  
  METHODS
  This study was conducted at a single tertiary care institution.
  
  
  METHODS
  Nine hundred sixteen consecutive patients operated on between January 2004 and August 2011 were identified from a prospective database.
  
  
  METHODS
  Conversion rate and laparoscopic operative time were analyzed related to age, sex, obesity, disease location (colon vs rectum), type of disease (neoplastic vs nonneoplastic), history of previous surgery, and body surface area; body surface area was calculated by the Mosteller formula. Body surface area was analyzed by the use of median and quartile cutoff values (1.6, 1.8, and 2.0). Multivariate models were adjusted for different confounders. Interaction between body surface area and BMI was ruled out.
  
  
  RESULTS
  The conversion rate was 10%. Conversion rates for quartiles 1, 2, 3, and 4 were 4.4%, 8.3%, 12.7%, and 14.8%, p = 0.001. Patients with body surface area ≥ 1.8 had a higher conversion rate than those with body surface area <1.8 (13.9% vs 5.3%, OR: 2.35 (95% CI: 1.45-3.86; p = 0.0001)). Multivariate analysis showed that body surface area ≥ 1.8 was associated with conversion (OR: 2, 95% CI: 1.1-3.7, p = 0.02) and a longer operative time after adjusting for sex, age, obesity, disease location (rectum vs colon), and type of laparoscopic approach.
  
  
  CONCLUSIONS
  This was a single-institution retrospective study.
  
  
  CONCLUSIONS
  Body surface area is a predictor for conversion and longer laparoscopic operative time. It should be considered when informing patients, selecting cases in the early learning curve, and assessing standard of care.
authors.affiliation: Section of Colorectal Surgery, Service of General Surgery, Hospital Italiano of Buenos Aires, Buenos Aires, Argentina. carlos.vaccaro@hospitalitaliano.org.ar
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Vaccaro
authors.forename: Hernan
authors.initials: H
authors.lastname: Vaccarezza
authors.forename: Gustavo L
authors.initials: GL
authors.lastname: Rossi
authors.forename: Ricardo
authors.initials: R
authors.lastname: Mentz
authors.forename: Victor M
authors.initials: VM
authors.lastname: Im
authors.forename: Guillermo Ojea
authors.initials: GO
authors.lastname: Quintana
authors.forename: Nadia
authors.initials: N
authors.lastname: Peralta
authors.forename: Enrique R
authors.initials: ER
authors.lastname: Soriano
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D001830:Body Surface Area; D003108:Colonic Diseases / Q000601:surgery; D016001:Confidence Intervals; D061887:Conversion to Open Surgery / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D010535:Laparoscopy / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D061646:Operative Time; D012372:ROC Curve; D012002:Rectal Diseases / Q000601:surgery; D012189:Retrospective Studies; D055815:Young Adult