What Is a Vascular Stent?

Vascular stent refers to the placement of an internal stent in the diseased segment based on the expansion and formation of a luminal balloon to support the vessels in the stenosed and occluded segment, reduce the elastic retraction and reshaping of the vessel, and maintain smooth blood flow in the lumen. Some internal stents also have the effect of preventing restenosis. It is mainly divided into coronary stent, cerebrovascular stent, renal artery stent and aortic stent.

Chinese name: Stent
Material: Metal tantalum, medical stainless steel and nickel-titanium alloy, etc.

Disadvantage: Easy to cause thrombosis, high restenosis rate
Way of unfolding: Self-expanding and balloon-expandable

What is a vascular stent

Classification of vascular stents

(1) Vascular stent is divided into metal tantalum, medical stainless steel and nickel-titanium alloy according to the material. The metal stent has achieved remarkable results after clinical treatment, but it is easy to cause thrombosis, high restenosis rate, and damage to the vessel wall. In response to the above deficiencies, covered stent and biomaterial stent have been developed. The ideal metal vascular stent should be consistent with the repair time of vascular function. Magnesium-based alloys and iron-based alloys can be degraded, and have good vascular support, which can effectively reduce stent restenosis.

(2) Vascular stents can be divided into two types: self-expanding and balloon-expanding according to the way they are deployed in blood vessels. The former, such as a Z-shaped stent and a mesh-shaped stent, can expand by themselves in blood vessels. The latter is inelastic by itself and relies on the balloon to expand to a certain diameter to attach to the blood vessel.

(3) Vascular stent can be divided into bare type, coated type and covered type according to the surface treatment. The bare type is only for polishing; the coating type is coated with heparin, titanium oxide and other substances on the metal surface; the film type is coated with a degradable or non-degradable polymer film on the surface of the metal stent.

(4) Vascular stent can be divided into simple supporting stent and therapeutic stent according to the function. The therapeutic stent includes a stent or a radioactive stent that is coated with a drug on the surface of the stent or uses a film outside the stent to carry a therapeutic substance.

Coronary stent

Coronary stent is implanted into the stenosed area of the vessel through a traditional balloon dilatation catheter to prevent restenosis after percutaneous coronary angioplasty.

Indications for vascular stent coronary intervention

(1) Most patients with asymptomatic myocardial ischemia or mild angina pectoris, patients with significant ischemia confirmed by treadmill exercise test or 24-hour ambulatory electrocardiogram monitoring, in order to reduce the risk of serious or fatal cardiac events, should consider the choice of coronary stent Surgery.

(2) Angina pectoris: moderate to severe stable angina pectoris or unstable angina pectoris, the response to the drug is not ideal, most patients have single or multiple coronary lesions. Coronary code modulation stent surgery is usually suitable, and the success rate is high, and the postoperative angina relief is obvious.

(3) Myocardial infarction: Acute myocardial infarction is caused by the sudden stop of myocardial blood flow. The most common cause is the occurrence of atherosclerosis in the main coronary arteries-thrombus occlusion. Coronary stent surgery is an effective method to restore coronary blood flow and significantly reduce myocardial infarction mortality.

Vascular stent coronary stent can tube for several years

Coronary stent implantation is already one of the most effective methods for treating coronary heart disease, so patients will ask: "How many years can the stent be managed?"

The clinical efficacy of stent in treating coronary heart disease is obvious to all, but it also has disadvantages. In the stent, restenosis can occur within 6 to 8 months after implantation, that is, re-occlusion. In the early years of metal stents, the incidence of restenosis was about 20% (15% to 40%); now the incidence of restenosis in the era of drug stents has dropped to about 9%. If the coronary angiography is re-examined six months after the operation, there is no in-stent restenosis, and in general, restenosis will rarely occur in the future.

So will it never become narrow again? The answer is no. A patient who had been implanted with a stent for 9 years had in-stent restenosis. The cause of this situation may not be entirely due to the stent itself. If the patient after the stent implantation fails to adhere to the medication, does not change the unhealthy lifestyle, the blood pressure, blood lipid, and blood sugar are not controlled optimally, the original normal blood vessels may produce new ones. It is not difficult to understand the pathological changes and restenosis of the stent. Therefore, the occurrence of restenosis can be caused by many factors.

Vascular stent renal artery stent

Renal artery stent is a balloon dilatation catheter through traditional balloon angioplasty, which is implanted into the renal artery stenosis area to prevent restenosis.

Cerebral stent

Intravascular stents can be used to expand cerebral blood vessels to treat cerebral ischemia. Cerebral vascular stents are an effective method to treat ischemic stroke. Ischemic stroke, half have intracranial and external cranial artery stenosis.

Aortic stent

The aorta (including the aorta, abdominal aorta, etc.) is locally weakened due to pathological factors, and then expands and bulges outward. It only looks like a "tumor", and is not a tumor in the usual sense, so it is a kind of Benign disease. The most common causes are hypertension and arteriosclerosis. Other causes include trauma, infection, and may be congenital. The application of minimally invasive interventional therapy can effectively treat this condition.