Upper extremity arteriovenous fistulas induce modest hemodynamic effect on the in situ internal thoracic artery

The left internal thoracic artery is the ideal conduit for coronary artery revascularization due to superior patency compared with venous grafts. The hemodynamic effects of an arterio-venous fistula on the native in situ internal thoracic artery and the potential for coronary flow steal after revascularization with the internal thoracic artery, are not well-characterized.

Fifteen chronic hemodialysis patients with functioning left upper extremity arterio-venous fistulas were evaluated with the use of transthoracic color Doppler analysis. Flow characteristics of the left and right internal thoracic arteries at baseline, with arterio-venous fistula occluded, and during hemodialysis were recorded. Peak systolic and diastolic velocities for the right and left internal thoracic arteries were calculated for each fistula state (occluded, open, and on-dialysis). One-way analysis of variance was used to compare the different means.

Mean flow velocity calculations failed to identify any statistically significant differences between the ipsilateral and contralateral internal thoracic artery in any fistula state. In addition, mean internal thoracic flow velocities were similar between the different fistula states.

Changes in arteriovenous fistula flow state did not significantly alter Doppler flow hemodynamics of either the ipsilateral or contralateral in-situ internal thoracic artery. Further studies of the possible effects on internal thoracic arteries used as pedicled coronary grafts may be required.