Intravascular ultrasound scan evaluation of the obstructed vein

Purpose: The purpose of this study was the comparison of intravascular ultrasound scanning (IVUS) with transfemoral venography in the assessment of chronic iliac vein obstruction. Methods: IVUS and standard, single-plane, transfemoral venography were performed in 304 consecutive limbs during balloon dilation and stenting of an obstructed iliac venous segment. The appearance of the obstruction was described, and the degree of stenosis (maximal diameter reduction) was estimated with venography and IVUS. The stenotic area was derived with diameter calculations (πr2) and also was measured with the built-in software of the IVUS apparatus before and after dilation and stenting in 173 limbs. Preoperative hand/foot differential pressure and preoperative dorsal foot venous and intraoperative transfemoral hyperemia-induced pressure elevations after intra-arterial injection of papaverine hydrochloride were measured. Results: With IVUS, fine intraluminal and mural details were detected (eg, trabeculation, frozen valves, mural thickness, and outside compression) that were not seen with venography. The median stenosis (with diameter reduction) on venographic results was 50% (range, 0 to 100%) and on IVUS results was 80% (range, 25% to 100%). In a comparison with IVUS as the standard, venography had poor sensitivity (45%) and negative predictive value (49%) in the detection of a venous area stenosis of >70%. The actual stenotic area was more severe when measured directly with IVUS (0.31 cm2; range, 0 to 1.68 cm2) versus derived (0.36 cm2; range, 0 to 3.08 cm2; P