Less than 25% of patients with retrograde vertebral artery flow on carotid duplex ultrasonography scan demonstrated a corresponding reversal of flow in the basilar artery. The vast majority of patients do not develop flow reversal in the basilar artery. Provocative maneuvers to increase collateral flow to the arm ipsilateral to retrograde vertebral artery flow did not appear to alter basilar artery flow velocity or direction of flow. Transcranial Doppler ultrasonography is indicated in patients with retrograde vertebral artery flow to document basilar artery flow, especially prior to intervention in patients with symptoms suggestive of posterior cerebral circulation insufficiency.
Introduction —Segmental femoropopliteal duplex scanning in conjunction with ankle plethysmographic waveforms and ankle/brachial indices (ABI) was evaluated as an alternative to traditional physiologic testing for the initial vascular laboratory evaluation of patients with lower extremity peripheral arterial disease (PAD). To assess the potential of this evaluation, patients with PAD were evaluated in the vascular laboratory with (1) pulse volume recording and segmental pressures (SPVR) and (2) femoropopliteal duplex imaging with pulsed Doppler waveform analysis and bilateral ankle plethysmographic waveforms and ABI (SDuplex). Methods. —SPVR and SDuplex data were prospectively obtained from 39 patients and 72 limbs. Separate technologists performed the physiologic and duplex examinations independently. Angiograms performed within 90 days were used as the gold standard for evaluating results from both procedures. Results from both examinations were interpreted for severe (>50% diameter reduction) inflow and superior femoral artery (SFA) disease. A McNemar test was performed on the SPVR and SDuplex paired data, and direct (hands-on) examination time was calculated for both procedures. Results. —Angiograms were available for 20 of 72 (28%) of the limbs evaluated and demonstrated no significant differences between both methods for evaluating inflow (femoral or above) disease, yet SDuplex was superior to SPVR for evaluating SFA disease. McNemar test data also suggested that SDuplex was superior to SPVR in diagnosing severe disease at the SFA level. The average time for SPVR examination performance was 28 minutes and 31 minutes for SDuplex with ABI and ankle waveforms. Conclusions. —SDuplex was superior to SPVR for evaluating SFA disease. No noteworthy differences in direct (hands-on) examination times for both procedures suggest the additional benefit of enhanced reimbursement. With superior SFA accuracy, more site-specific information, and greater reimbursement potential, SDuplex should be considered an alternative to the traditional physiologic examination for evaluating patients with lower extremity PAD.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.