Stenting: Function, Problems, and Procedure

Uses for Stents  Peripheral artery disease (PAD)  Renal vascular hypertension  Hemodialysis access maintenance  Coronary artery disease (CAD)  Carotid artery disease  Aneurysms

History  Percutaneous Interventional cardiology introduced in  Stenting first performed in the mid 1980’s. FDA approved it in  70-90% of balloon angioplasty procedures now use a stent.  Currently 1,500,000 stenting procedures performed annually.

Stent Types  Components- stainless steel with different designs.  Designs  Drug-eluting stents stents  Sizes

Drug-eluting Stents  Sirolimus –Immunosuppressive agent used for solid organ transplant. –Coated with 140mcg/cm^2. –Releases over days.  Paclitaxel –Chemotherapeutic drug used to treat patients with ovarian or breast cancer. –Coated with 3mcg/cm^2. –Released over at least a ten day period.

Procedure Procedure  Sterile Table.  Clean entry site- femoral or brachial artery.  Cut into skin.  Catheterization, with use of a guide wire.  Inject contrast to visualize vessels.  Balloon angioplasty.  Stent attached to deflated balloon and takent to site.

Restenosis  Reclosure of the artery  Bare metal stents rate is around 20-30%  Drug-eluting stents rate is around 9%  Usually recurrence time  Most vulnerable- those with diabetes, long stents (35mm+), or in small arteries  Why it occurs

Post Procedure  Pressure and dress Femoral artery  Take proscribed medications  Limit activities- lift no more than 10 pounds  Other restrictions depending on extent of heart disease.  Get exercise- 3-4 days a week for around 30 mins. Walking is best.  No MRI’s for at least six months.

Contraindicators and Complications  Contraindicators –Size of the artery –Where the blockage is located –Other Blockages –Condition of the heart –Allergies  Complications –Blood clots –Tearing the artery –Abrupt vessel closure –Excessive bleeding through femoral artery –Heart attack or sudden cardiac death –Stroke

Plaque Classifications  Homogeneous –Usually white –Smooth outer surface –Consistent texture throughout  Heterogeneous –Yellowish color –Rough edges –Inconsistent texture –More likely to rupture and have blood clots  Stenting –After six months will grow thin layer of cells –Now classified as homogeneous