4.4 Carotid Endarterectomy and Stent Follow-up

Identify the reconstruction before interpreting the velocity

Carotid endarterectomy (CEA) removes atherosclerotic plaque through an arteriotomy; closure may be primary or use a patch. Carotid artery stenting (CAS) supports the lumen with an endovascular scaffold. Both change the anatomy being examined. The purpose of postoperative duplex is to document patency, detect restenosis or complications, and compare the result with a useful baseline. Applying a native ICA table without recognizing the reconstruction can produce a false stenosis diagnosis.

Read the operative history and prior report. Record the date, side, type of procedure, symptoms, and any interval neurologic events. New weakness, speech disturbance, or monocular visual loss requires urgent clinical assessment rather than completion of a routine surveillance appointment at an unhurried pace. A sonographer should communicate the symptoms and findings through the emergency or critical-result pathway.

Acquisition checklist

1. Examine the accessible common carotid artery proximal to the repair.
2. Trace the complete endarterectomy site or stent, including both ends.
3. Evaluate the external carotid origin and the accessible distal native ICA.
4. Obtain grayscale and color images in more than one plane.
5. Record representative spectral samples proximal to, within, and distal to a suspected lesion.
6. Compare measured velocities, lumen appearance, and distal waveforms with the baseline study.

Keep angle correction at or below 60 degrees and parallel to the actual flow stream. In a curved reconstruction, a cursor parallel to the outer wall may fail to follow the jet. Record the highest reproducible representative velocity rather than an isolated spike created by movement or a single irregular cardiac beat. Describe shadowing or an inaccessible distal endpoint explicitly.

Endarterectomy appearances and recurrent narrowing

A patch can create a wider lumen and a transition back to the smaller native ICA. Flow separation within an enlarged segment and acceleration at a geometric transition are possible. Confirm whether apparent narrowing is a true reduction in lumen or an expected change in caliber. Evaluate the proximal and distal endpoints for a flap, focal residual lesion, kink, or dissection.

Neointimal hyperplasia is an important cause of earlier recurrent stenosis. It may appear smoother and more homogeneous than typical irregular atherosclerotic plaque. Later recurrent disease can reflect renewed atherosclerosis. Timing helps the differential but does not establish tissue histology from grayscale alone. The report should describe the finding rather than assert a specific microscopic diagnosis without adequate evidence.

A focal color jet with visible narrowing, increased velocity relative to an appropriate adjacent segment, and disturbed distal flow is more persuasive than a high PSV alone. Use the laboratory's validated criteria for postoperative CEA, including its treatment of patch closure. Native ICA criteria and published postoperative thresholds must not be blended into a new unvalidated table.

Stent surveillance

Identify the proximal stent edge, body, distal edge, and adjacent native artery. Depending on the device and insonation window, stent struts may be visible as bright linear echoes. A patent stent can have velocities different from those of a native artery because wall compliance and geometry have changed. Record visible intraluminal narrowing and look for focal acceleration or a new interval rise from baseline.

Several published stent criteria use higher PSV thresholds than native-vessel criteria, but a single universal numeric threshold does not apply to every reconstruction. A report should identify which validated criteria were used. Trends are most meaningful when acquisition methods are comparable. A change in angle, sample position, equipment, or cardiac state can imitate disease progression.

Complications and urgency

Thrombosis may present as absent optimized flow and intraluminal material, sometimes accompanied by a proximal high-resistance waveform. Dissection may show an intimal flap and separate channels. Pseudoaneurysm is an extraluminal communicating sac; color swirling alone is insufficient, and spectral sampling of the communicating neck helps characterize flow. A postoperative neck hematoma can threaten the airway even without an arterial flow channel. Breathing difficulty or rapidly increasing swelling demands immediate clinical escalation.

Cerebral hyperperfusion syndrome is a clinical complication after revascularization. Severe headache, seizures, or neurologic deterioration require urgent evaluation. Extracranial duplex findings alone cannot diagnose or exclude it. Document symptoms without assuming every postoperative headache represents benign recovery or every high flow state represents restenosis.

Worked postoperative case

A patient has a baseline stent PSV of 210 cm/s with a broad, well-filled lumen. Six months later, PSV is 255 cm/s, but the angle has changed from 45 to 60 degrees and no definite narrowing is visible. Repeat standardized acquisition and review EDV, ratios, distal flow, and baseline images. The velocity increase alone does not prove severe restenosis. Now change the case: a new focal jet of 380 cm/s appears at visible narrowing with disturbed flow beyond it. That combination is substantially more concerning and needs grading with the applicable validated postoperative criteria and timely physician review.

The correct endpoint is a documented, interpretable study: reconstruction type, accessible extent, patency, lesion location, objective measurements, interval changes, limitations, and communication of urgent findings. The interpreting physician integrates these data with symptoms and other imaging to decide management.

IAC Vascular Testing standards, August 2026 — checked October 18, 2026. See its requirements for intervention-specific protocols, validated criteria, and preliminary/urgent reporting.