An Artificial Neural Network Stratifies the Risks of Reintervention and Mortality after Endovascular Aneurysm Repair; a Retrospective Observational study

PLoS One. 2015 Jul 15;10(7):e0129024. doi: 10.1371/journal.pone.0129024. eCollection 2015.

Abstract

Background: Lifelong surveillance after endovascular repair (EVAR) of abdominal aortic aneurysms (AAA) is considered mandatory to detect potentially life-threatening endograft complications. A minority of patients require reintervention but cannot be predictively identified by existing methods. This study aimed to improve the prediction of endograft complications and mortality, through the application of machine-learning techniques.

Methods: Patients undergoing EVAR at 2 centres were studied from 2004-2010. Pre-operative aneurysm morphology was quantified and endograft complications were recorded up to 5 years following surgery. An artificial neural networks (ANN) approach was used to predict whether patients would be at low- or high-risk of endograft complications (aortic/limb) or mortality. Centre 1 data were used for training and centre 2 data for validation. ANN performance was assessed by Kaplan-Meier analysis to compare the incidence of aortic complications, limb complications, and mortality; in patients predicted to be low-risk, versus those predicted to be high-risk.

Results: 761 patients aged 75 +/- 7 years underwent EVAR. Mean follow-up was 36+/- 20 months. An ANN was created from morphological features including angulation/length/areas/diameters/volume/tortuosity of the aneurysm neck/sac/iliac segments. ANN models predicted endograft complications and mortality with excellent discrimination between a low-risk and high-risk group. In external validation, the 5-year rates of freedom from aortic complications, limb complications and mortality were 95.9% vs 67.9%; 99.3% vs 92.0%; and 87.9% vs 79.3% respectively (p<0.001).

Conclusion: This study presents ANN models that stratify the 5-year risk of endograft complications or mortality using routinely available pre-operative data.

Publication types

  • Observational Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aortic Aneurysm, Abdominal / mortality*
  • Aortic Aneurysm, Abdominal / surgery*
  • Endovascular Procedures / adverse effects*
  • Female
  • Humans
  • Male
  • Neural Networks, Computer*
  • Postoperative Complications / etiology
  • Retreatment
  • Retrospective Studies
  • Risk Assessment