Stenting is a medical procedure where a small, flexible tube (stent) is inserted into a blood vessel to keep it open. Stents are often used in conjunction with other procedures like angioplasty to treat narrowed or blocked arteries, thereby improving blood flow. Here's an overview of stenting, including techniques and indications:
Techniques:
Balloon-Expandable Stents:
The stent is mounted on a balloon catheter which is then inflated at the site of the blockage. The stent expands to the size of the balloon, securing it against the artery walls.
Often used in areas where precise sizing is crucial, like coronary arteries or renal arteries.
Self-Expanding Stents:
Made from materials that naturally expand once released from a constraining sheath. They conform better to the vessel's shape, which makes them suitable for tortuous or dynamic arteries like those in the carotid or peripheral systems.
Commonly used in peripheral artery disease (PAD) treatments.
Drug-Eluting Stents (DES):
Coated with medications that slowly release to prevent the growth of scar tissue or re-narrowing (restenosis) of the artery.
Predominantly used in coronary artery disease but also for other vascular applications.
Covered or Stent-Grafts:
Stents covered with a fabric or biological material that prevents blood from leaking through the vessel wall, used in treating aneurysms or perforations.
Bioabsorbable Stents:
Made from materials that eventually dissolve, leaving behind a healed vessel. These are newer and aimed at reducing long-term complications like thrombosis.
Procedure Steps:
Access: A small incision is made, often in the groin or arm, to access the vascular system.
Guidewire and Catheter: A guidewire is threaded through the vessel to the blockage, followed by a catheter.
Angioplasty: If necessary, balloon angioplasty is performed to open the vessel.
Stent Placement: The stent is deployed at the site of the lesion.
Confirmation: Fluoroscopy or angiography confirms the stent's placement and patency of the vessel.
Closure: The access site is closed, sometimes with a closure device or manual pressure.
Indications:
Coronary Artery Disease (CAD):
To treat angina or prevent heart attacks by opening narrowed coronary arteries.
Especially useful post-myocardial infarction (MI) to maintain coronary blood flow.
Peripheral Artery Disease (PAD):
To improve blood flow in legs, thereby alleviating claudication or preventing limb ischemia.
Carotid Artery Stenosis:
For stroke prevention, particularly in high-risk surgical candidates.
Renal Artery Stenosis:
To treat hypertension or renal dysfunction due to reduced blood flow to the kidneys.
Aneurysms:
Stent-grafts are used to exclude aneurysms from the blood flow, reducing the risk of rupture.
Venous Disorders:
Including iliac vein compression (May-Thurner Syndrome) or to manage complications from deep vein thrombosis.
Biliary and Ureteral Strictures:
To maintain patency in non-vascular applications like the bile ducts or ureters.
Considerations:
Antithrombotic Therapy: Patients typically receive antiplatelet drugs like aspirin and clopidogrel to prevent stent thrombosis, especially with DES.
Restenosis and Thrombosis: Long-term outcomes vary, with some patients experiencing restenosis or stent thrombosis, which might require further intervention.
Patient Selection: Stenting isn't suitable for everyone; factors like vessel size, lesion characteristics, and patient health play a role in choosing this treatment.
Stenting has revolutionized the management of vascular diseases by offering a less invasive alternative to open surgery, with generally favorable outcomes when appropriately indicated. However, the choice to stent must be weighed against potential complications and the need for lifelong medication management in some cases.