THE IMPACT OF KNEE-JOINT FLEXION ON INFRAINGUINAL VASCULAR GRAFTS - AN ANGIOGRAPHIC STUDY

Objectives: To characterise the morphologic behaviour of infrainguinal grafts during flexion of the knee. Design: A prospective angiographic study. Materials and methods: In 64 infrainguinal bypass grafts, intr avenous digital subtraction angiography was performed within the first postoperative week. Frontal and lateral projection angiograms with th e knee joint extended and with a 80-90 degrees flexion were taken. The distal anastomosis of the bypass was performed below-knee in 49 cases (18 in situ veins, 8 reserved veins with an anatomic course, 2 revers ed veins with an extra-anatomic course, 4 composite grafts, 15 synthet ic grafts with an anatomic course (14 polytetrafluoroethylene (ePTFE), 1 polyurethane), and two synthetic grafts with an extra-anatomic cour se. Fifteen ePTFE prostheses were implanted in the above-knee position . Results: Out of 64 cases a total of 16 grafts showed stenotic kinkin g during flexion; two of the 18 in situ vein grafts, four anatomic sit e, eight of the 15 synthetic grafts crossing the knee, 0 of the two ex tra-anatomic ePTFE grafts, and one of the 15 cases of above-knee femor opopliteal ePTFE grafts. Conclusions: Stenotic kinking due to knee fle xion can affect all kinds of bypass grafts including vein grafts place d anatomically and above-knee prostheses.