LAUSR

Objectives: In treating critical limb ischemia (CLI), bypass grafting to tibial or paramalleolar arteries plays pivotal role. Though the graft flow (GF) differs significantly among patients, the factors associated with GF are not well studied. Herein, we assessed the factors and developed the predictive equation of GF in tibial or paramalleolar bypass grafting. Methods: CLI patients treated in our institution from January 2012 to November 2016, with bypass to tibial or paramalleolar arteries, were enrolled. In the 137 bypass grafts, 43 grafts were excluded in which postoperative ultrasound imaging within 1 month detected flow-limiting abnormalities. A total of 94 normal grafts were finally enrolled and randomly allotted to two groups: development data set for GF equation (74 grafts) and equation validation data set (20 grafts). Multivariate analysis with stepwise selection was performed to assess and detect factors associated with GF and to obtain GF predictive equation. Analyzed variables were sex, age, runoff, hemodialysis (HD), diabetes mellitus (DM), graft quality (GQ), hypertension, dyslipidemia, smoking history, inflow site, body mass index, cerebrovascular disease, ischemic cardiac disease, and foot infection. Runoff was evaluated with intraoperative angiography, and graded according to Rutherford runoff scoring system; then, the runoff score was classified into three groups: good, fair, or poor. The estimated equation was validated by Bland-Altman method and Student t-test. Actual GF was measured intraoperatively with transit time flowmeter.