Advertisement

WIfI: Highlighting Hotspots of Limb Loss?

Open ArchivePublished:May 17, 2019DOI:https://doi.org/10.1016/j.ejvs.2019.04.019
      The past three decades have established that limb loss is a multifactorial process. Alongside this growing appreciation, tools have been developed to aid clinicians in stratifying patients into high and low risk groups. The Society for Vascular Surgery Wound, Ischaemia and foot Infection (WIfI) classification was born out of the recognition that existing classification systems had deficiencies in the description of at least one domain.
      • Mills J.L.
      • Sr
      • Conte M.S.
      • Armstrong D.G.
      • Pomposelli F.B.
      • Schanzer A.
      • Sidawy A.N.
      • et al.
      The society for vascular Surgery lower extremity threatened limb classification system: risk stratification based on wound, ischemia, and foot infection (WIfI).
      For example the Rutherford classification provides a granular description of the effects of tissue ischaemia, but fails to account for the role of foot infection in limb loss.
      • Hardman R.L.
      • Jazaeri O.
      • Yi J.
      • Smith M.
      • Gupta R.
      Overview of classification systems in peripheral artery disease.
      Conversely, the University of Texas classification system incorporates elements of all three factors, but lacks granularity as it dichotomises both infection and ischaemia into either present or absent.
      • Karthikesalingam A.
      • Holt P.J.E.
      • Moxey P.
      • Jones K.G.
      • Thompson M.M.
      • Hinchliffe R.J.
      A systematic review of scoring systems for diabetic foot ulcers.
      A classification system is prognostically useful if it successfully divides patients into low, intermediate, and high risk groups. In a study published in this edition of the Journal, van Reijen et al.
      • van Reijen N.S.
      • Ponchant K.
      • Ubbink D.T.
      • Koelemay M.J.W.
      The prognostic value of the WIfI Classification in patients with chronic limb threatening ischemia: a systematic review and meta-analysis.
      have for the first time provided us with high quality evidence that the WIfI score does successfully group patients into risk categories. In this systematic review, the authors identified 12 studies incorporating 2669 patients from centres in Japan, Europe, and the United States, showing that there is a clear difference in limb salvage and amputation free survival between patients classified as high or low risk (clinical stages 4 and 1 respectively) according to WIfI. The differences in outcomes between patients in intermediate groups were less impressive.
      The main limitation of the study (highlighted by the fact that the GRADE level of evidence was either low or very low for all outcomes) is that there was no adjustment for either patient treatment modality or comorbidity. Significant heterogeneity was evident, both within and between included studies, with patients treated conservatively, endovascularly, or surgically all analysed together. It is entirely possible, therefore, that the lack of any significant difference in outcomes between patients in clinical stages 2 and 3 is simply a reflection of successful revascularisation of stage 3 patients.
      This study has highlighted two important messages. Firstly, we can have confidence that the WIfI score provides an appropriate method for stratifying patients into high and low risk groups. Furthermore, it has highlighted the fact that to properly validate a classification system in patients with chronic limb threatening ischaemia, we must also be able to quantify the risks and benefits of attempted revascularisation.

      References

        • Mills J.L.
        • Sr
        • Conte M.S.
        • Armstrong D.G.
        • Pomposelli F.B.
        • Schanzer A.
        • Sidawy A.N.
        • et al.
        The society for vascular Surgery lower extremity threatened limb classification system: risk stratification based on wound, ischemia, and foot infection (WIfI).
        J Vasc Surg. 2014; 59 (220–34.e1-2)
        • Hardman R.L.
        • Jazaeri O.
        • Yi J.
        • Smith M.
        • Gupta R.
        Overview of classification systems in peripheral artery disease.
        Semin Intervent Radiol. 2014; 31: 378-388
        • Karthikesalingam A.
        • Holt P.J.E.
        • Moxey P.
        • Jones K.G.
        • Thompson M.M.
        • Hinchliffe R.J.
        A systematic review of scoring systems for diabetic foot ulcers.
        Diabet Med. 2010; 27: 544-549
        • van Reijen N.S.
        • Ponchant K.
        • Ubbink D.T.
        • Koelemay M.J.W.
        The prognostic value of the WIfI Classification in patients with chronic limb threatening ischemia: a systematic review and meta-analysis.
        Eur J Vasc Endovasc Surg. 2019; 58: 362-371

      Linked Article

      Comments

      Commenting Guidelines

      To submit a comment for a journal article, please use the space above and note the following:

      • We will review submitted comments as soon as possible, striving for within two business days.
      • This forum is intended for constructive dialogue. Comments that are commercial or promotional in nature, pertain to specific medical cases, are not relevant to the article for which they have been submitted, or are otherwise inappropriate will not be posted.
      • We require that commenters identify themselves with names and affiliations.
      • Comments must be in compliance with our Terms & Conditions.
      • Comments are not peer-reviewed.