1 Introduction
Coronary heart disease (CHD) is one of the most common cardiovascular diseases in clinical practice. Coronary angiography (CAG) and percutaneous coronary intervention (PCI) are the main diagnostic and therapeutic methods for CHD. Transfemoral access is the earliest access site proposed for both CAG and PCI (1). Transfemoral access is easily accessible even in hypotensive patients but, on the other hand, it may lead to a high incidence of complications (e.g., arteriovenous fistula and pseudoaneurysm) and the postoperative immobilization time is long. Therefore, the application of transradial access (TRA) for CAG and PCI was first reported in 1993 by Kiemeneij et al. (2). To date, the TRA has become the preferred method for CAG and PCI (3). However, the TRA-associated complications are noteworthy, such as radial artery occlusion (RAO). Although some preventive strategies have been recently adopted for RAO, the incidence of RAO is still as high as 3.7%(4). Therefore, Kiemeneij et al. (5)reported the use of dTRA for CAG and PCI for the first time in 2017.
To date, randomized controlled clinical trials and meta-analyses have shown that CAG and PCI using dTRA can significantly reduce the incidence of RAO (6-8). Will the dTRA become the preferred method for CAG and PCI in the future? The puncture success rate of the dTRA is lower than that of the TRA (6, 7). The diameter of the distal radial artery is smaller than that of the radial artery, which is one of the most important reasons affecting the puncture success rate. At present, there are very few studies about the diameter of the distal radial artery.