Alterations in femoral artery hemodynamics associated with femoropopliteal bypass.
Subcritical iliac artery stenoses become critical stenoses if common femoral artery (CFA) flow rates increase sufficiently. Infrainguinal bypasses done in the presence of subcritical iliac artery stenoses may be in jeopardy on the basis of inadequate inflow if critical iliac stenoses are produced by increased CFA flow resulting from the bypasses. This study was undertaken to define the CFA hemodynamic changes seen with femoropopliteal bypass and to determine the relative effects of subcritical iliac artery stenoses on these pressure and flow changes. The iliac and femoral arteries of five canine hindlimbs were isolated for placement of a constricting microcaliper, intraarterial pressure cannula, and electromagnetic flow probe. Systemic pressure was monitored via the contralateral CFA. CFA pressure and flow were measured at incremental iliac artery stenoses with the superficial femoral artery (SFA) occluded and with the SFA patent, simulating femoropopliteal bypass. Indices of CFA pressure/systemic pressure (FAI) and percentage increases in CFA flow with open versus occluded SFAs were calculated. CFA flow rates were significantly higher with open versus occluded SFAs, with and without iliac artery stenoses present. Despite these increases in CFA flow, CFA pressure indices were unchanged when comparing open with occluded SFAs even in the presence of subcritical iliac artery stenoses. These findings suggest that femoropopliteal bypass does not result in increases in CFA flow rates sufficient enough to cause decreased graft perfusion pressures in the presence of subcritical iliac artery stenoses. Therefore, the patency of an infrainguinal bypass done in the presence of a subcritical iliac artery stenosis should not be adversely affected in the early postoperative period on the basis of inflow.
D000818:Animals; D001157:Arterial Occlusive Diseases / Q000503:physiopathology / Q000601:surgery*; D001794:Blood Pressure; D004285:Dogs; D005263:Femoral Artery / Q000503:physiopathology / Q000601:surgery*; D006439:Hemodynamics; D007083:Iliac Artery / Q000503:physiopathology / Q000601:surgery*; D011150:Popliteal Artery / Q000601:surgery*; D012039:Regional Blood Flow