Atherectomy

Atherectomy

Fig.1.19.

Definition

Atherectomy is a procedure to open blocked arteries or vein grafts by using a device on the end of a catheter to cut or shave away atherosclerotic plaque blocking the flow of blood.

(Fig 1.19.)
In this digitized ultrasound of a blood vessel, C is the catheter, D is the dissection, and F is the artherosclerotic flap.



Purpose

Atherectomy is performed on the coronary arteries to restore the flow of oxygen-rich blood to the heart, to relieve chest pain, and to prevent heart attacks. It may be done on patients with chest pain who have not responded to other medical therapy and on some individuals who are candidates for balloon angioplasty or coronary artery bypass graft surgery. It is sometimes performed to remove plaque that has built up after a coronary artery bypass graft surgery. Artherectomy may also be performed on the carotid arteries leading to the brain or on certain vertebral arteries.



Description

Atherectomy uses a catheter inserted into the artery that has at its tip either a rotating device that reams out the artery, a device that shaves the plaque away, or a laser that vaporizes the plaque. At the beginning of the procedure, medications are administered to control blood pressure, dilate the coronary arteries, and prevent blood clots. The patient is awake but sedated. The catheter is inserted into an artery in the groin, leg, or arm, and threaded through the blood vessels into the blocked artery. The cutting head or laser is positioned against the plaque and activated, and the plaque is ground up and suctioned out or vaporized.

In some patients, artherectomy can be an alternative to coronary bypass surgery. It is significantly less painful, less costly, and has a much shorter recovery time than bypass surgery. The location(s), degree of blockage, and general health status of the individual are all factors in deciding whether artherectomy is the most appropriate procedure.

The types of atherectomy are directional, rotational, transluminal extraction and laser artherectomy extraction. Directional atherectomy was the first type approved, but is no longer commonly used; it scrapes plaque into an opening in one side of the catheter. Rotational atherectomy uses a high-speed rotating shaver to grind up plaque. Transluminal extraction uses a device that cuts plaque off vessel walls and vacuums it into a bottle. It is used to clear bypass grafts. Laser artherectomy uses a laser to break up and vaporize the plaque. In some patients, a balloon angioplasty may be done and a stent inserted after successful artherectomy.

Performed in a cardiac catheterization lab, atherectomy can be used instead of, or along with, balloon angioplasty. Atherectomy is successful about 95% of the time; however, plaque forms again in 20-30% of patients.

Precautions

Atherectomy should not be performed when the plaque is located where blood vessels divide into branches, when plaque is angular or inside an angle of a blood vessel, on patients with weak vessel walls, on ulcerated or calcium-hardened lesions, or on blockages through which a guide wire will not pass. Laser artherectomy has less successful outcomes in individuals with diabetes or renal failure, and usually is not the procedure of choice for these patients.

Preparation

The day before atherectomy, the patient takes medication to prevent blood clots and may be asked to bathe and shampoo with an antiseptic skin cleaner.

Aftercare

After the procedure, the patient spends several days in the hospital's cardiac monitoring area. For at least 20 minutes, pressure is applied to a dressing on the insertion site. For the first hour, an electrocardiogram (ECG) and close monitoring are conducted; vital signs are checked every 15 minutes. Pain medication is then administered. The puncture site is checked once an hour or more. For most of the first 24 hours, the patient remains in bed.

Risks

Chest pain is the most common complication of atherectomy. Other common complications are injury to the blood vessel lining, plaque that re-forms, the development of blood clots, and bleeding at the site of catheter insertion. More serious but less frequent complications are blood vessel holes, blood vessel wall tears, or reduced blood flow through the artery.