How is percutaneous coronary intervention (PCI) performed?

Updated: Nov 27, 2019
  • Author: George A Stouffer, III, MD; Chief Editor: Karlheinz Peter, MD, PhD  more...
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Answer

The patient is prepared as described earlier (see Patient Preparation).

For transradial catheterization, an arteriotomy is made approximately 2 cm proximal to the radial styloid process so as to avoid the distal bifurcation and diminutive vessels. While palpation is being done, the radial artery is punctured with a micropuncture needle, and a hydrophilic sheath is placed by means of the modified Seldinger technique.

Once the sheath is in place, an intra-arterial vasodilator is given (nicardipine 500 µg or verapamil 5 mg), with half the dose administered at the beginning of the procedure and the other half at the end. Intravenous (IV) heparin dramatically reduces the risk of radial artery occlusion and is therefore often used in transradial catheterization (usual dose, 50 units/kg; maximum total dose, 5000 units).

For transfemoral catheterization, the arteriotomy site is the common femoral artery, above its bifurcation into the deep femoral artery (profunda femoris) and the superficial femoral artery and below the inferior epigastric artery. Because the skin crease can sometimes be misleading, a combination of various other anatomic landmarks may be used, such as bony landmarks (aiming 2 cm below the center of the inguinal ligament) and the point of maximal palpable impulse.

Fluoroscopy is often used to mark the femoral head, and the target zone for the arteriotomy is the middle of the femoral head. A micropuncture (21-gauge) or 18-gauge needle is used to puncture the femoral artery, and a sheath is placed with the modified Seldinger technique. Sheath size varies according to the preference of the operator; in general, it is in the range of 4-6 French.

Once access is obtained, catheters are advanced over a 0.035-in. J-tip guide wire into the ascending aorta. Various different catheter shapes are available; the choice depends on the operator’s preference and the patient’s anatomy. Selective coronary angiography is performed in different views (at least two orthogonal views for each segment of the coronary) using hand or power injections of iohexol.

Guide catheters have the same external diameter as diagnostic catheters but a larger lumen and are used for PCI. Once the catheter has engaged the coronary ostium and diagnostic angiograms have been obtained, weight-based IV anticoagulant (unfractionated heparin [UFH], bivalirudin, or low-molecular-weight heparin [LMWH]) therapy may be administered. If the patient is not on long-term dual antiplatelet therapy (DAPT), a loading dose of a P2Y12 inhibitor is also given. As noted above, all patients should have been pretreated with aspirin.

A 0.014-in. guide wire is then advanced into the coronary artery across the stenotic lesion. All balloon catheters and other devices will be tracked over this wire. In some cases, direct stenting of the lesion can be done; however, in most cases, vessel preparation with either predilation with a semicompliant balloon or an atherectomy device is performed. The balloon is then withdrawn, and a stent of appropriate length and diameter is advanced over the coronary guide wire, positioned across the lesion, and deployed.

Depending on the angiographic appearance of the stent, postdilation of the stent may or may not be performed with a noncompliant balloon. An intravascular imaging tool, such as intravascular ultrasonography (IVUS) or optical coherence tomography (OCT) (see Anatomic and Physiologic Assessment), can be used for further delineation and assessment of the anatomy including plaque burden, vessel size, and stent deployment.

After the PCI result is deemed adequate, the coronary wire is removed and final angiograms are taken.


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