External validation of a prognostic model of preoperative risk factors for failure of restorative proctocolectomy.
OBJECTIVE
The Cleveland Clinic has proposed a prognostic model of preoperative risk factors for failure of restorative proctocolectomy (RPC) with ileal pouch-anal anastomosis. The model incorporates four predictive variables: completion proctectomy, handsewn anastomosis, diabetes mellitus and Crohn's disease. The aim of the present study was to perform an external validation of this model in a new cohort of patients who had RPC.


METHODS
Validation was performed in a multicentre cohort of 747 consecutive patients who had an RPC between 1990 and 2015 in three tertiary-care facilities, using a Kaplan-Meier survival analysis and Cox regression analysis. The performance of the model was expressed using the Harrell concordance error rate. The primary outcome measure was pouch survival with maintenance of anal function.


RESULTS
During the study period, 45 (6.0%) patients experienced failure at a median interval of 31 months (interquartile range 9-82 months) from the original RPC. Multivariable analysis showed handsewn anastomosis to be the only significant independent predictor. The Harrell concordance error rate was 0.42, indicating poor performance. Anastomotic leakage and Crohn's disease of the pouch were strong postoperative predictors for pouch failure and showed a significant difference in pouch survival after 10 years (P < 0.001).


CONCLUSIONS
The poor performance of the Cleveland Clinic prognostic model makes it unsuitable for daily clinical practice. Handsewn anastomosis was associated with pouch failure in our cohort with relatively few events. A prediction model for anastomotic leakage or Crohn's disease of the pouch may be a better solution since these variables are strongly associated with pouch failure.
Department of Surgery, Academic Medical Center, Amsterdam, the Netherlands.
S
S
Sahami
Department of Surgery, Academic Medical Center, Amsterdam, the Netherlands.
S A L
SA
Bartels
Department of Surgery, University Hospitals Leuven, Leuven, Belgium.
A
A
D'Hoore
Department of Surgery, Mayo Clinic College of Medicine, Phoenix, Arizona, USA.
T
T
Young Fadok
Department of Surgery, Academic Medical Center, Amsterdam, the Netherlands.
P J
PJ
Tanis
Department of Surgery, University Hospitals Leuven, Leuven, Belgium.
A
A
de Buck van Overstraeten
Department of Surgery, University Hospitals Leuven, Leuven, Belgium.
A M
AM
Wolthuis
Department of Surgery, Academic Medical Center, Amsterdam, the Netherlands.
C J
CJ
Buskens
Department of Surgery, Academic Medical Center, Amsterdam, the Netherlands.
W A
WA
Bemelman
D011125:Adenomatous Polyposis Coli / Q000453:epidemiology / Q000601:surgery*; D000328:Adult; D000714:Anastomosis, Surgical / Q000379:methods*; D057868:Anastomotic Leak / Q000453:epidemiology*; D015331:Cohort Studies; D003093:Colitis, Ulcerative / Q000453:epidemiology / Q000601:surgery*; D039021:Colonic Pouches; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000601:surgery*; D015897:Comorbidity; D003424:Crohn Disease / Q000453:epidemiology / Q000601:surgery*; D003920:Diabetes Mellitus / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007081:Ileostomy; D053208:Kaplan-Meier Estimate; D010535:Laparoscopy; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016737:Proctocolectomy, Restorative; D011379:Prognosis; D016016:Proportional Hazards Models; D015203:Reproducibility of Results; D012307:Risk Factors; D017211:Treatment Failure
Pouch failure; external validation; handsewn anastomosis; prognostic model; restorative proctocolectomy