Transradial Revascularization of a Chronic Total Left Anterior Descending Artery Occlusion

The advantages of the radial approach include fewer access-related bleeding complications, improved patient comfort with early ambulation and shorter hospital stays, as well as reduced procedure cost.

A 41-year-old male with a past medical history of diabetes mellitus, obesity, and dyslipidemia presented with gradually progressing exertional angina for 6 to 8 months. His nuclear stress test revealed reversible defects in the mid and basal anteroseptal wall, lateral apex, anterior apex, and true apex, which were all of moderate intensity. Coronary angiography revealed multi-vessel disease, including a very long proximal left anterior descending (LAD) chronic total occlusion (CTO) (Figure 1) and a dominant right coronary artery (RCA) with multiple sequential severe stenosis. Right-to-left collateral flow from the septal perforators filled the distal LAD partially. Resting left ventricular systolic function was preserved without any significant wall motion abnormality. The patient had poor targets for surgical revascularization of the LAD; therefore, a percutaneous coronary intervention (PCI) was planned.

A 6-French (Fr) extra backup (EBU) 3.5 guide catheter (Medtronic) was used to engage the left main via a 6 Fr Glide sheath (Terumo) in the right radial artery. A 5 Fr JR4 diagnostic catheter was used via left radial access to perform contralateral injection of the RCA and collaterals to the LAD (Figure 2). Prowater (Abbott Vascular) and Confianza (Abbott Vascular) wires were unsuccessful in crossing the entire length of occlusion (Figure 3). A Choice PT2 (Boston Scientific) moderate support wire successfully crossed the distal occlusion. An over-the-wire Apex (Boston Scientific) 1.5mm x 8mm balloon was used to confirm intraluminal position and to predilate the occluded segments. Multiple overlapping Promus (Boston Scientific) drug-eluting stents were deployed to the diseased vessel and post-dilated at high pressure (Figure 4) with an excellent angiographic result (Figure 5). The sheath was promptly removed and a hemostatic wristband was applied for 2 hours. The patient was discharged the next morning on aspirin and prasugrel, along with other medicines.

Discussion

In the United States, the transradial access rate for cardiac catheterization has increased from 1% in 2007 to nearly 11% in 2011. The advantages of the radial approach include fewer access-related bleeding complications, improved patient comfort with early ambulation and shorter hospital stays, as well as reduced procedure cost. These advantages translate to a mortality benefit in higher risk interventional procedures.¹

Successful revascularization of CTOs in patients with viable myocardium may reduce symptoms of angina, decrease the need for bypass surgery, and provide a long-term survival benefit of up to ten additional years.² Feasibility and safety of the transradial approach is reported in a few single-center experiences. In these limited data, transradial revascularization of CTO lesions has produced similar rates of success and lower access site-related complications without increased procedural time or contrast use in comparison to the transfemoral approach.^3-5 However, the application of the radial approach for percutaneous treatment of CTOs is infrequent in the U.S., and its feasibility has been questioned. At our center, we prefer the use of radial access for CTO revascularization, unless we are limited due to a very small or diseased radial artery, extreme brachiocephalic tortuosity or when the radial artery is used for arterio-venous shunts or bypass grafts. As seen in this case report, a very difficult, long CTO can be treated successfully via the radial approach.

The following tips may be helpful for use of the radial approach for the treatment of a CTO:

• Avoid ad hoc PCI of a CTO. Always confirm viability and plan the procedure.
• Ultrasound measurement of the radial artery with S/L NTG can be helpful to determine the sheath and guide size that can be used without increasing the incidence of spasm or asymptomatic radial artery occlusion.
• One can use a 6 Fr system if radial artery size is < 2.2 mm and a 7 Fr system if the diameter > 2.2 mm. 
• Another option is to consider using a sheathless guide system (limited availability in the U.S.). A 7 Fr guide has the same outer diameter (2.31 mm) as a 5 Fr sheath (2.28 mm).
• Active placement of the guide catheter to obtain maximum support is extremely important. We generally use an EBU curve for the left and a MAC 3.0 (Medtronic) or Amplatz left curve for the RCA.
• Other options to obtain or enhance greater guide support include: 
• Use of a GuideLiner catheter (Vascular Solutions); 
• Anchor balloon technique in a side branch; or 
• Very careful, deep selective intubation of the guide catheter.
• Use of a long CTO wire (operator’s choice) with an over-the-wire balloon or crossing catheter is recommended for further support and for distal injection when needed.
• Dual access and visualization of collaterals is helpful when available.
• Use of the right radial approach and keeping the wrist position very close to the side of the groin will reduce radiation exposure.

The authors can be contacted via Dr. Kintur Sanghvi at SanghviK@Deborah.org.

References

1. Vorobcsuk A, Kónyi A, Aradi D, et al. Transradial versus transfemoral percutaneous coronary intervention in acute myocardial infarction Systematic overview and meta-analysis. Am Heart J 2009; 158(5): 814-821.
2. Suero J, Marso S, Jones P, Laster S, et al. Procedural outcomes and long-term survival among patients undergoing percutaneous coronary intervention of a chronic total occlusion in native coronary arteries: a 20-year experience. J Am Coll Cardiol 2001; 38: 409-414.
3. Yang C, Guo G, Chen S, Yip H, et al. Feasibility and safety of a transradial approach in intervention for chronic total occlusion of coronary arteries: a single center experience. Chang Gung Med J 2010 Nov-Dec; 33(6): 639-645.
4. Wu C, Fang H, Cheng C, Hussein H, et al. The safety and feasibility of bilateral radial approach in chronic total occlusion percutaneous coronary intervention. Int Heart J 2011; 52: 131-138.
5. Yutaka T, Takeshita S, Akasaka T, Matsumi J, et al. Comparison of transradial versus transfemoral approach for coronary angioplasty of chronic total occlusions. J Am Coll Cardiol 2012; 59: E190.