From the Guidelines
After a carotid stent placement, the first follow-up carotid ultrasound is recommended within the first month post-procedure, as stated in the 2024 ESC guidelines for the management of peripheral arterial and aortic diseases 1. This recommendation is based on the latest and highest quality evidence available. The surveillance schedule allows for early detection of potential complications such as in-stent restenosis, stent migration, or thrombosis. Some key points to consider when performing the follow-up carotid ultrasound include:
- Assessment of the stented segment with color and spectral Doppler to evaluate for flow abnormalities
- Velocity measurements to detect restenosis
- Examination of the distal and proximal vessel segments to ensure adequate flow throughout the carotid artery The one-month scan serves as a new baseline for comparison with future studies and helps identify any immediate post-procedural issues. Subsequent scans may be performed at 6 months, 12 months, and then annually thereafter to monitor for the development of restenosis, which can occur due to neointimal hyperplasia or atherosclerotic progression, as discussed in the 2025 clinical consensus statement of the ESC Council on Stroke and the ESC Working Group on Aorta and Peripheral Vascular Diseases 1. Some clinicians may adjust this schedule based on individual patient risk factors, with more frequent monitoring for patients with multiple comorbidities or complex stent placements. It is essential to note that the risk of restenosis is similar with carotid revascularization using the endovascular route or open surgery, and optimal technical quality of the procedure and its final luminal result minimize the risk of thrombosis and restenosis, as indicated in the 2025 clinical consensus statement 1. Principal clinical risk factors for restenosis include diabetes, dyslipidaemia, female gender, chronic kidney disease, and smoking, as mentioned in the 2025 clinical consensus statement 1. In patients who develop restenosis after carotid stent placement, the management strategy should be individualized, taking into account the severity of restenosis, symptoms, and overall clinical condition, as discussed in the 2011 ASA/ACCF/AHA/AANN/AANS/ACR/ASNR/CNS/SAIP/SCAI/SIR/SNIS/SVM/SVS guideline on the management of patients with extracranial carotid and vertebral artery disease 1.
From the Research
Carotid Ultrasound After Carotid Stent
- The timing of carotid ultrasound after carotid stent placement is crucial for monitoring the patency of the stent and detecting potential complications such as in-stent restenosis.
- According to a study published in 2021 2, a surveillance regimen of baseline carotid ultrasound at ≤30 days after the procedure, followed by assessment at 6 and 12 months, and yearly thereafter appears to be a safe and effective protocol.
- The study found that peak systolic velocity (PSV), end diastolic velocity (EDV), and the internal carotid artery (ICA)/common carotid artery (CCA) PSV ratio were useful parameters for detecting in-stent restenosis.
- Five patients (5.2%) in the study exhibited velocities indicative of ≥80% in-stent restenosis at 12 months after the procedure, highlighting the importance of regular follow-up ultrasound examinations.
Parameters for Detecting In-Stent Restenosis
- The study 2 found that a PSV >340 cm/sec and ICA/CCA ratio >4.15 is consistent with an 80-99% restenosis after transcarotid artery revascularization (TCAR).
- These parameters can be used to identify patients with clinically significant restenosis who may require repeat intervention.
- Regular carotid ultrasound examinations can help detect in-stent restenosis early, allowing for timely intervention and reducing the risk of adverse neurological outcomes.
Antiplatelet Therapy and Carotid Ultrasound
- Antiplatelet therapy is commonly used in patients undergoing carotid stent placement to reduce the risk of thrombotic complications.
- Studies have shown that dual antiplatelet therapy (DAPT) with aspirin and clopidogrel is effective in reducing the risk of ischemic events after carotid stent placement 3, 4, 5, 6.
- However, the optimal duration of DAPT after carotid stent placement is still controversial, and further studies are needed to determine the best approach.
- Carotid ultrasound can be used to monitor the effectiveness of antiplatelet therapy and detect potential complications such as in-stent restenosis.