title: Evaluation of risk prediction models, V-POSSUM and GAS, in patients with acute abdominal aortic rupture treated with EVAR or an open procedure.
abstract: BACKGROUND
  In this time of outcome measurements predictive models are needed for correction of comorbidity, in order to perform audits on the outcome of patients. The aim of this study was to evaluate the use of risk-predicting scoring methods in the treatment of RAAA with emergency endovascular aneurysm repair (eEVAR) and open repair in order to analyze outcomes.
  
  
  METHODS
  Two hundred and six consecutive patients underwent open repair or eEVAR for RAAA. Patients data were compared with preoperative risk assessments according to the V-POSSUM and the Glasgow Aneurysm Score (GAS).
  
  
  RESULTS
  The 30-day mortality rate was 45/206 (22%) in the whole cohort, 41/179 (23%) (95% Confidence Interval [CI] 17-30) after open repair and 4/27 (15%, 95% CI 6-32) after eEVAR. The patient population did not significantly change over time, according to age, gender, V-POSSUM and GAS, neither did the 30-day mortality. The GAS appeared to be a reasonable predictor of postoperative outcome for both open and endovascular RAAA repair, with an area under the curve (AUC) of 0.73 (SD 0.04; 95% CI 0.65-0.80; P<0.001). The V-POSSUM predicted mortality was somewhat less accurate: AUC 0.69 (SD 0.05; 95% CI 0.60-0.77; P<0.001). The only pre-operative variables independently predicting 30-day mortality were age (P=0.006) and lowest pre-operative systolic blood pressure (P=0.032).
  
  
  CONCLUSIONS
  Preoperative risk assessment with either V-POSSUM or GAS does not identify patients with fatal outcome at the individual level. However, these risk models may be useful as a relative estimate, in surgical audit or for inter- and intra-hospital comparisons.
authors.affiliation: Department of Surgery, Onze Lieve Vrouwe Gasthuis, Amsterdam, The Netherlands - martenkapma@hotmail.com.
authors.forename: Marten
authors.initials: M
authors.lastname: Kapma
authors.affiliation: Department of Surgery, Onze Lieve Vrouwe Gasthuis, Amsterdam, The Netherlands.
authors.forename: Olivier
authors.initials: O
authors.lastname: Kahmann
authors.affiliation: Department of Intensive Care, Onze Lieve Vrouwe Gasthuis, Amsterdam, The Netherlands.
authors.forename: Ilse
authors.initials: I
authors.lastname: van Stijn
authors.affiliation: Department of Surgery (Division of Vascular Surgery), University Medical Center Groningen University of Groningen, Groningen, The Netherlands.
authors.forename: Clark J
authors.initials: CJ
authors.lastname: Zeebregts
authors.affiliation: Department of Surgery, Onze Lieve Vrouwe Gasthuis, Amsterdam, The Netherlands.
authors.forename: Anco
authors.initials: A
authors.lastname: Vahl
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D001019:Aortic Rupture / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D001027:Aortography / Q000379:methods; D019540:Area Under Curve; D001794:Blood Pressure; D000072226:Computed Tomography Angiography; D003661:Decision Support Techniques; D057510:Endovascular Procedures / Q000009:adverse effects / Q000401:mortality; D005260:Female; D006801:Humans; D008297:Male; D018579:Patient Selection; D011237:Predictive Value of Tests; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013599:Systole; D013997:Time Factors; D016896:Treatment Outcome; D014656:Vascular Surgical Procedures / Q000009:adverse effects / Q000401:mortality