Millimeter-Scale "Optical Biopsy" Targets Stroke Culprit: OCT Technology Reopens a Blocked Carotid Artery

Dr. Gai Yanting's team uses OCT imaging to plan precise carotid stent placement at Shanghai Donglei Brain Hospital.

A Close Call: His Carotid Artery Was 90% Blocked

Zhang Jianguo (a pseudonym), a 63-year-old man, first learned he had carotid stenosis during a routine physical exam a year earlier. At the time, he had no symptoms and assumed it could wait. But during the first half of 2025, he began experiencing repeated dizziness and intermittent numbness in his hands and feet — warning signs that his brain was not getting enough blood.

He came to Shanghai Donglei Brain Hospital for further evaluation. After detailed testing, Dr. Gai Yanting's team made an alarming finding: the stenosis in his left internal carotid artery had reached 90%, severely limiting blood supply to the brain and placing him at very high risk of ischemic stroke.

What Is OCT? A "Microscope" Finer Than a Human Hair

Optical coherence tomography (OCT) is an ultra-high-resolution intravascular imaging technology. Using near-infrared light, it produces cross-sectional images of the vessel wall at a resolution of about 10 microns — close to the diameter of a human hair.

"It's like installing a microscope inside the blood vessel," Dr. Gai explained. "We can see cholesterol crystals, tiny cracks, and the fibrous cap of the plaque with remarkable clarity."

Compared with conventional angiography alone, OCT offers three decisive advantages in neurovascular intervention:

Millimeter Precision: A Targeted Strike on the Blockage

The biggest challenge of the procedure was navigating the tortuous carotid pathway and positioning the imaging probe exactly at the stenosis. "Even a millimeter-level deviation can lead to inaccurate images or affect the treatment decision," Dr. Gai noted.

With OCT guidance, the team mapped the lesion in detail and then deployed a carotid stent matched precisely to Zhang Jianguo's vessel. The stent expanded against the plaque, reopened the artery, and restored normal blood flow to the brain.

⚠️ When Is Intervention Recommended?

Carotid plaque is not only a disease of the elderly. Long-term smoking, hypertension, elevated blood sugar, a high-fat diet, and lack of exercise are all major risk factors. According to Dr. Gai, the following patients should be actively evaluated for treatment:

• Symptomatic patients with carotid stenosis ≥50% (symptoms include transient ischemic attack, dizziness, limb weakness, or slurred speech)
• Asymptomatic patients with stenosis ≥70% on non-invasive imaging, or ≥60% on angiography
• Patients with unstable plaque, such as ulcerated or mixed plaques

After the Procedure: Lifelong Vascular Protection

Successful surgery is only the first step. Long-term management is essential to keep the artery open and prevent recurrence. Dr. Gai's team provided Zhang Jianguo with a comprehensive postoperative plan:

• Medications: take antiplatelet and lipid-lowering drugs as prescribed; control blood pressure and blood glucose strictly.
• Lifestyle: quit smoking and limit alcohol; engage in moderate aerobic exercise and avoid strenuous activity.
• Diet: low-sodium diet (daily sodium intake <1500 mg), low-fat diet (reduce fried foods, animal organs, and cream; increase fish, nuts, vegetables, and fruit), rich in dietary fiber.
• Monitoring: keep blood pressure, lipids, and blood glucose within target ranges; get adequate sleep; attend scheduled follow-up visits.

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