Predicting outcomes for infrapopliteal limb-threatening ischemia using the Society for Vascular Surgery Vascular Quality Initiative

Objective: The outcomes of open surgical or endovascular intervention for limb-threatening ischemia (LTI) involving the infrapopliteal vessels are dependent on complex anatomic, demographic, and disease factors. To assist in decision-making, we used the Vascular Quality Initiative (VQI) to derive a model using only preoperatively available factors to predict important outcomes for open or endovascular revascularization. Methods: National VQI data for the infrainguinal bypass and peripheral vascular intervention (PVI) modules were reviewed in a blinded fashion for patients who underwent intervention for LTI of the infrapopliteal vessels. Primary outcomes consisted of major adverse limb event (MALE) and amputation-free survival (AFS). Generalized linear modeling was used for the multivariate analyses, with entry of variables dependent on results of univariate analysis. Results: From January 2003 through August 2014 a total of 19,053 infrainguinal open bypass and 48,739 PVI procedures were identified, among which 5264 and 5252, respectively, represented infrapopliteal (tibial-peroneal-pedal) revascularization for LTI. From these, 3036 infrapopliteal open bypass patients and 1319 infrapopliteal PVI patients had sufficient follow-up data for study inclusion. For open surgery, the reduced generalized linear model revealed that American Society of Anesthesiologists class 4 or 5, previous major amputation, living at home, and female sex had the greatest adverse effect on MALE, and dialysis dependence, low body mass index, and lack of great saphenous vein as a conduit had the greatest negative effect on AFS. For PVI, lesion length from 10 to 15 cm, treatment of three or more arteries, and classification other than A on the Trans-Atlantic Inter-Society Consensus demonstrated the largest adverse effects on MALE, and dialysis dependence, low body mass index, and congestive heart failure most negatively affected AFS. Conclusions: This study on a cross-section of patients selected for intervention in academic and community hospitals offers a "real world" glimpse of factors predictive of outcome. The VQI can be used to derive models that predict the outcomes of open surgical bypass or PVI for LTI involving the infrapopliteal vessels.