title: Prognostic modeling of preoperative risk factors of pouch failure.
abstract: BACKGROUND
  The prospect of pouch failure needs to be considered when evaluating the management strategy for patients who may be candidates for an ileo anal pouch. An ability to predict the likelihood and timing of failure preoperatively may influence surgical decision making.
  
  
  OBJECTIVE
  The aim of this study was to define a preoperative prognostic model for ileoanal pouch failure.
  
  
  METHODS
  A novel random forest methodology was used to evaluate the prognostic significance of 21 preoperative potential risk factors for pouch failure. A forest of 3000 random survival trees was grown to estimate pouch failure for each patient and to identify important risk factors that maximize survival prediction.
  
  
  METHODS
  This study took place at a tertiary referral department at a major academic medical center.
  
  
  METHODS
  Patients undergoing an ileoanal pouch at this institution between 1983 and 2008 were included.
  
  
  METHODS
  The primary outcome measured was pouch survival.
  
  
  RESULTS
  Between 1983 and 2008, 3754 patients underwent ileoanal pouch. Type of resection (total proctocolectomy vs completion proctectomy), type of anastomosis (stapled vs mucosectomy), patient diagnosis (mucosal ulcerative colitis and others vs Crohn's disease) and diagnosis of diabetes had the strongest effect on pouch survival. Predicted survival was worse for completion proctectomy (HR, 1.44; 95% CI, 1.08-1.93), Crohn's disease (HR, 2.37; 95% CI, 1.48-3.79), handsewn anastomosis (HR, 1.72; 95% CI, 1.23-2.42), and diabetes (HR, 2.31; 95% CI, 1.25-4.24). Pouch survival was worse for the oldest group of patients.
  
  
  CONCLUSIONS
  This study was limited by its retrospective nature.
  
  
  CONCLUSIONS
  Random forest techniques applied to a large number of patients undergoing the ileoanal pouch identify factors associated with pouch failure. Attention directed at these factors may improve outcomes for these patients.
authors.affiliation: Department of Colorectal Surgery, Cleveland Clinic Foundation, Cleveland, OH, USA. manilie@ccf.org
authors.forename: E
authors.initials: E
authors.lastname: Manilich
authors.forename: F H
authors.initials: FH
authors.lastname: Remzi
authors.forename: V W
authors.initials: VW
authors.lastname: Fazio
authors.forename: J M
authors.initials: JM
authors.lastname: Church
authors.forename: R P
authors.initials: RP
authors.lastname: Kiran
mesh_terms: D000328:Adult; D000714:Anastomosis, Surgical; D003108:Colonic Diseases / Q000601:surgery*; D039021:Colonic Pouches; D003657:Decision Making; D003663:Decision Trees; D005260:Female; D006801:Humans; D010535:Laparoscopy; D008297:Male; D011237:Predictive Value of Tests; D016737:Proctocolectomy, Restorative; D011379:Prognosis; D016016:Proportional Hazards Models; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D015996:Survival Rate; D017211:Treatment Failure