Peripheral arterial embolization: Doppler ultrasound scan diagnosis

Abstract

Use of intraoperative monitoring with transcranial Doppler scanning during carotid endarterectomy has enabled identification of embolus signals in the ultrasound spectrum. Extension of this technique to preoperative screening has enabled identification of actively embolizing lesions and correlation with neurologic deficits. We report embolus signals in the peripheral circulation before operation, which aided diagnosis and decision to operate. The patient had been transferred from another institution after multiple revascularization procedures, including posterior tibial artery thrombectomy. Angiography performed on arrival at our institution confirmed an open bypass graft, although a small indentation was noted at the site of the previous posterior tibial artery thrombectomy. Runoff was intact to the plantar arch where there was attenuation of that vessel and occlusion of most digital branches. Duplex monitoring revealed no embolic signals in the graft or in the posterior tibial artery proximal to the previous arteriotomy. Distal to this site, embolic signals were detected. At the time of operation, a large platelet thrombus was identified at the site of the previous arteriotomy, and platelet thrombus was obtained from the plantar artery. It is concluded that Doppler ultrasound scanning enables detection of peripheral embolization and the identification and location of lesions with such embolic activity. Diagnostic accuracy may be improved when there is clinical suspicion of embolization, enabling better patient selection for surgical procedures. This report provides the first clinicopathologic characterization of the emboli detected.