Transradial Percutaneous Coronary Angioplasty – Advantages over the traditional femoral (groin) approach

By Dr Paul Chiam
Published on Medical Grapevine

Coronary angioplasty and stenting has become a common and “first option” method for revascularization in patients with ischemic heart disease. Since its development in 1977, coronary angioplasty has been performed via the femoral artery in the groin.

The transfemoral technique of coronary angioplasty has become very well established. The transradial approach to performing coronary angioplasty was first reported in 1993. Over the past decade, transradial percutaneous coronary intervention (PCI) has become increasingly performed and has become the “first line” technique for many operators.

Why the need for the transradial approach to PCI

Transfemoral PCI has been the standard technique for nearly four decades and many refinements and technological advances have made it relatively easy and safe to perform. However, femoral artery cannulation carries a small but significant risk of access-site vascular complications and bleeding. Hematomas and pseudoaneurysms at the site of arterial puncture are not uncommon and can cause pain, discomfort to patients, and also increase need for further interventions and costs. Retroperitoneal haemorrhage although rare, can be potentially life-threatening. Certain patient populations are at increased risk of these bleeding events, such as the elderly and the obese. Most of the bleeding complications after transfemoral PCI are due to access site complications. Although only major bleeding has been shown to be a predictor of all-cause mortality, any form of bleeding increases morbidity, prolongs hospital stay and drives up hospital costs.

Patients also experience discomfort or even pain during manual compression when removing the groin sheath after PCI (usually 20-30 minutes manual compression of the femoral artery is required to achieve complete hemostasis), and also need a longer period of bed rest in the supine position after sheath removal (to minimize movement of the lower limb and thus prevent re-bleeding).

To improve patient comfort and to reduce access site complications, an alternative approach for PCI via the radial artery (that could reduce access site complications) became necessary.

Transradial PCI – the technique and the advantages

In brief, the radial artery is punctured just proximal to the styloid process, and via the Seldinger technique, a small calibre sheath (outer diameter approximately 2.5mm) is placed in the radial artery. A “cocktail” of drugs (heparin, verapamil and nitroglycerin) is then administered into the radial artery to reduce vasospasm. The catheter is then advanced to the coronary artery ostium under fluoroscopy and the angioplasty is performed in the usual fashion. Immediately after the procedure, the sheath is removed from the radial artery and a compressive “radial” band is applied around the wrist/ distal forearm to achieve hemostasis.

The immediate benefit to the patient is that he/she can sit up right after the procedure and even ambulate. There is no need for prolonged supine bed rest and no need for a manual groin compression. Many studies have shown that there is improved patient comfort, with patients invariably preferring the transradial approach to PCI over the transfemoral route.

The primary advantage of transradial PCI is in reducing access site complications and bleeding. Access site complications or bleeding are rare with the transradial approach because the radial artery is small and superficial, and thus easily compressible.

Patients undergoing transradial PCI also have shorter hospital stays as there are fewer access site complications. In addition, same day discharge after transradial PCI has been shown to be feasible and safe. These factors have been shown to reduce hospital costs.

Recently, several studies have demonstrated that using transradial PCI in patients presenting with a myocardial infarction resulted in a lower 1-year death rate compared to patients who had PCI performed via the transfemoral approach. Whether this reduction in mortality is solely due to reduced bleeding or a combination of factors remains to be clarified.

Transradial PCI – the drawbacks

The vast majority of catheters used in coronary angioplasty were developed for use from the transfemoral (groin) approach. Using these catheters from the transradial approach (in particular the right radial artery – the most commonly used route) requires a slightly different skill set to manipulate the catheters to engage the coronary arteries. Puncturing a much smaller artery, navigating the radial and subclavian arteries especially tortuous vessels frequently found in elderly patients, are more technically challenging and do necessitate a steeper learning curve.

Radial artery occlusion (RAO) is a potential complication, although with increasing miniaturization of the catheters, the incidence has fallen from 5% previously reported to 1-2% with current transradial angioplasty systems. Fortunately, RAO is usually clinically asymptomatic due to collateral supply to the hand via the ulnar artery. However, RAO will preclude future use of the radial artery as part of hemodialysis services or as a graft for coronary artery bypass.

Conclusion

Transradial percutaneous coronary intervention has become increasingly performed and is the technique of choice for many interventional cardiologists. When performed by experienced operators, transradial PCI offers improved patient comfort, decreases access site complications and bleeding and also reduces hospital stay and costs.