Development of a Scoring System for the Prediction of Early Graft Failure after Peripheral Arterial Bypass Surgery.

Background: An occluded lower limb arterial bypass is associated with poor prognosis for the limb. Currently, no risk assessment method to estimate the risk of early graft failure exists. Aim of this study was to investigate the effect of various potential factors on early graft failure of infrainguinal bypass surgery and to develop a risk-scoring model to predict it.

Methods: A prospective observational clinical study was performed. One hundred infrainguinal bypass procedures (60 autologous and 40 synthetic grafts), throughout a 3-year period were included. Nearly, 84 patients suffered by chronic limb ischemia, whereas 16 by acute limb ischemia or popliteal aneurysm disease. Various possible factors including demographic data, atherosclerosis predisposing factors, and technical details of the procedure were examined as possible causes of early graft failure. Using a combination of univariable and multivariable analysis techniques, the most significant factors were extracted, and a simple predicting risk-scoring system of early graft failure was calculated.

Results: The overall early graft failure rate was 14%. The factors related to it at a statistically significant level, 0.05, were the female gender, a bypass performed after a previous ipsilateral lower limb angioplasty, a redo procedure on the same limb, and a distal anastomosis at an inframalleolar level (pedal bypass). After internal validation, the FARP-predicting scoring system was formed as following: Female gender 1 point (F), bypass after a previous Angioplasty 1 point (A), Redo bypass 1 point (R), and Pedal bypass 2 points (P). An overall score equal or greater than 2, provided an early graft failure prediction with sensitivity of 100%, specificity 86%, positive predictive value 54%, and negative predictive value of 100% (area under the receiver operator characteristic curve: 0.959).

Conclusions: FARP is a simple scoring system for predicting early graft failure after an infrainguinal bypass procedure. Further external validation in larger populations is needed.