Flow characteristics of in-situ internal thoracic artery graft with competitive flow

Abstract

We report flow characteristics of an in-situ internal thoracic artery (LITA) graft with angiographically competitive flow to the left anterior descending artery (LAD), based upon intraoperative transit-time flow measurement (TTFM) during coronary artery bypass grafting with aortic valve replacement (AVR) and during re-AVR seven years later. Although intraoperative TTFM of the graft showed lower mean flow and higher pulsatility index, suggesting inadequate anastomosis, fast Fourier transform (FFT) analysis of TTFM waveforms presented gradual waning of the amplitude, as shown in patent grafts. FFT analysis of the TTFM waveforms is helpful to judge the patency of LITA to LAD, even with competitive flow.

Learning objective: The internal thoracic artery (LITA) graft to left anterior descending artery (LAD) with angiographically competitive flow shows gradual waning of the amplitude on fast Fourier transform (FFT) analysis of the transit-time flow measurement (TTFM) waveforms, although lower mean graft flow, higher pulsatility index, and higher systolic reversal flow may suggest inadequate anastomosis. FFT analysis of the TTFM waveforms is useful to judge the patency of LITA to LAD, even with competitive flow.

Keywords: Competitive flow; Fractional flow reserve; In-situ internal thoracic artery graft; Left anterior descending artery; Transit-time flow measurement.