What procedure was performed involving a 4.5 x 16 mm Express stent?

The procedure involving a 4.5 x 16 mm Express stent is associated with the primary stenting of the right coronary artery. This type of stent is designed to be placed within a coronary artery to maintain vessel patency after balloon angioplasty, allowing for improved blood flow to the heart muscle by supporting the artery walls and preventing restenosis.

Stenting is a minimally invasive procedure often utilized in cases of coronary artery disease where significant blockages are present. The choice of the size of the stent, such as the 4.5 x 16 mm size mentioned, indicates a specific vessel diameter and lesion length that need support within the vascular system, in this case, the right coronary artery. The right coronary artery is one of the major coronary arteries supplying blood to the heart, and its obstruction can significantly affect heart function.

In the context of the other options, while procedures like valve insertion, bypass grafts, and angioplasty can involve stents, they do not typically utilize a stent like the Express stent specifically for the indication noted in this scenario. The correct choice reflects a targeted intervention for coronary artery issues, making it the appropriate answer.