title: A Multicenter Predictive Score for Amputation-Free Survival for Patients Operated on with an Heparin-Bonded ePTFE Graft for Critical Limb Ischemia.
abstract: To retrospectively create a predictive score for estimating amputation-free survival (AFS) in patients with critical limb ischemia (CLI) operated on with the use of a heparin-bonded expanded polytetrafluoroethylene (ePTFE) bypass graft (Hb-ePTFE).
  
  
  
  Over a 13-year period, ending in March 2015, a Hb-ePTFE graft was implanted in 683 patients undergoing below-knee revascularization for CLI in seven Italian vascular hospitals. Data concerning these interventions were retrospectively collected in a multicenter registry with a dedicated database. Univariate and multivariable analyses with Kaplan-Meier estimates were used to identify potential significant predictors of AFS at 5 years, and then a predictive risk score was constructed. A qualitative assessment of the Kaplan-Meier survival estimates for each integer score was performed, and subgroups of risk were stratified on the basis of the primary end point.
  
  
  
  Overall, estimated 5-year AFS rate was 48.3 % (SE 0.024). At multivariate analysis, older age, coronary artery disease, end-stage renal disease, tissue loss and poor runoff score were predictors of AFS. The integer score ranged from 0 to 11; Kaplan-Meier analysis for AFS in each score group identified three subgroups with significant differences at 5 years: low-risk subgroup (scores from 0 to 2, 67.7 %), medium-risk subgroup (scores 3 and 4, 49.2 %, p < 0.001 in comparison with low-risk subgroup) and high-risk subgroup (scores from 5 to 11, 25.2 %, p < 0.001 in comparison with either low-risk subgroup or medium-risk subgroup).
  
  
  
  A category of low-risk patients with CLI treated with the indexed graft does exist, thus suggesting a primary role for Hb-ePTFE in such patients. A prospective validation of such a score is necessary.
authors.affiliation: Vascular Surgery, Department of Cardiothoracic and Vascular Surgery, Careggi University Teaching Hospital, University of Florence School of Medicine, Largo Brambilla, 3, 50134, Florence, Italy. dorigow@unifi.it.
authors.forename: Walter
authors.identifier: 0000-0003-3814-5961
authors.initials: W
authors.lastname: Dorigo
authors.affiliation: Vascular Surgery, Department of Surgery and Morphological Sciences, Circolo University Teaching Hospital, University of Insubria School of Medicine, Varese, Italy.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Piffaretti
authors.affiliation: Vascular Surgery, Department of Cardiothoracic Surgery, University of Bari, Bari, Italy.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Pulli
authors.affiliation: Vascular Surgery, Department of Surgery and Morphological Sciences, Circolo University Teaching Hospital, University of Insubria School of Medicine, Varese, Italy.
authors.forename: Patrizio
authors.initials: P
authors.lastname: Castelli
authors.affiliation: Vascular Surgery, Department of Cardiothoracic and Vascular Surgery, Careggi University Teaching Hospital, University of Florence School of Medicine, Largo Brambilla, 3, 50134, Florence, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Pratesi
mesh_terms: D000367:Age Factors; D000368:Aged; D000671:Amputation, Surgical; D000925:Anticoagulants / Q000008:administration & dosage; D001807:Blood Vessel Prosthesis; D020099:Coated Materials, Biocompatible; D003324:Coronary Artery Disease / Q000150:complications; D005260:Female; D006493:Heparin / Q000008:administration & dosage*; D006801:Humans; D007511:Ischemia / Q000601:surgery*; D007676:Kidney Failure, Chronic / Q000150:complications; D035002:Lower Extremity / Q000098:blood supply; D008297:Male; D015999:Multivariate Analysis; D011138:Polytetrafluoroethylene; D012189:Retrospective Studies; D018570:Risk Assessment
chemical_list: D000925:Anticoagulants; D020099:Coated Materials, Biocompatible; D011138:Polytetrafluoroethylene; D006493:Heparin