Success of arterial revascularization determined by contrast ultrasound muscle perfusion imaging.

BACKGROUND

In the early postoperative evaluation of the success of arterial revascularization, ankle-brachial index (ABI) and other noninvasive tests lack reliability, especially in patients with incompressible arteries or local edema. Contrast-enhanced ultrasound (CEUS) imaging of limb muscle perfusion may be an alternative to standard tests if it detects treatment success reliably.

METHODS

We compared a simplified CEUS method with clinical staging, pulse volume recording (PVR), and ABI in patients with lifestyle-limiting peripheral arterial disease undergoing revascularization by percutaneous transluminal angioplasty (PTA) or bypass surgery. Patients underwent staging, PVR, ABI, and CEUS before, directly after, and 3 to 5 months after successful PTA (n = 20) or successful bypass grafting (n = 14). For CEUS, contrast agent was injected into an antecubital vein, and the time from beginning to peak intensity of contrast enhancement (TTP) in the calf muscle was measured.

RESULTS

Successful revascularization by both PTA and bypass was associated with a significant improvement in staging, PVR, ABI, and TTP directly after intervention and at follow-up. Median ABI increased from 0.60 to 0.85 (P = .001) after PTA and from 0.36 to 0.76 (P = .003) after bypass surgery. Median TTP decreased from 45 seconds to 24 seconds (P = .015) and from 30 seconds to 27 seconds (P = .041), respectively. McNemar analysis revealed unidirectional changes in both ABI and TTP (P = .625 after PTA and P = 1.000 after bypass surgery), and equivalence analysis showed 95% confidence intervals within clinical indifference, indicating that TTP was equivalent to standard tests in detecting successful revascularization.

CONCLUSIONS

Contrast ultrasound perfusion imaging of calf muscle after arterial revascularization may be a valuable alternative to standard noninvasive tests such as ABI or PVR to determine the success of an arterial revascularization.