5 French Transradial Rotational Atherectomy

Question: Do you always do transradial PCI through a 6 Fr sheath or can you go smaller,
and is there any advantage to doing so?

We do the majority of our coronary interventions through a 6 French (Fr) guide catheter; however, there are occasions when we will use a 7 Fr sheath (see our case in CLD’s July 2010 issue, https://tinyurl.com/access-cld) or go smaller and use a 5 Fr sheath. There are some limitations to the use of smaller sheath sizes. 

Case presentation

A 76-year-old female presented with dypnea on exertion. She has a history of coronary artery disease, status post bypass x 5 vessels in 2000, to include:

• Left internal mammary artery to the left anterior descending coronary artery (LIMA –> LAD);
• Saphenous vein graft (SVG) –> D1 (diagonal branch);
• SVG –> first obtuse marginal (OM1);
• SVG –> OM2;
• SVG –> right posterior descending artery (RPDA). 

A previous angiography in 2008 showed an atretic LIMA –> LAD. The native LAD had an approximately 50% to 60% stenosis and no vein graft to OM1 was visualized. She underwent diagnostic angiography with similar angiographic findings (Figure 1); however, given her symptoms, fractional flow reserve (FFR) measurement of the LAD was recommended for further assessment.

The right radial artery was accessed with a 6 French Glide sheath (Terumo). A 5 Fr Radial Back-up Left (RBL) guide (Boston Scientific) was used to engage the left coronary system (Figure 2). Heparin was administered, the prime wire Prestige (Volcano Corp.) was normalized in the proximal LAD, and then advanced distally. A baseline FFR was 0.92. Upon completion of intravenous adenosine at 140 mcg/kg/min for 2 minutes, the FFR was 0.76 (Figure 3). This was a positive finding based on the FAME trial; therefore, we proceeded with intervention. The wire was pulled back, demonstrating normalization across the intermediate lesion, which was the site of the LIMA anastamosis.

Given the angiographic findings, we elected to use a Rotablator (Boston Scientific) to facilitate stent delivery. A Runthrough wire (Terumo) was advanced and exchanged distally through an over-the-wire balloon for a Rota floppy wire (Boston Scientific). A 1.25 mm burr was used to perform rotational atherectomy (Figure 4). The wire was changed out to a Wiggle wire (Abbott Vascular) and then we predilated with a 2.5 x 15 mm Angiosculpt (AngioScore) balloon. A 2.5 x 32 mm Promus drug-eluting stent (Boston Scientific) was advanced, covering the entire lesion length, and deployed at 12 atmospheres, then re-inflated to 14 atmospheres (Figure 5). Final angiography revealed TIMI-3 flow. The patient became bradycardic and subsequent repeat angiography demonstrated distal embolization to the apical LAD with loss of distal branches. She was given an intracoronary eptifibatide (Integrilin, Millenium Pharmaceuticals) bolus. Repeat angiography demonstrated recovery of flow in the apical branch (Figure 6). The patient tolerated the procedure well and was asymptomatic throughout the remainder of her hospital course. She was discharged the following morning.

Discussion

Advantages of the transradial approach include, but are not limited to, a reduction in bleeding complications, improved patient comfort, and the potential for early ambulation and potential discharge. However, procedural success can be limited by operator experience, as well as certain anatomical considerations (loops, high origin radial, etc.) and small diameter arteries. These can lead to increased spasm as well post procedural issues. It is in these instances that a 5 Fr guide may increase procedural success. Limitations of the 5 Fr guide include less guide support, limited use of adjunctive devices, and poorer visualization when compared to a larger guide.¹ However, there is data to suggest equivalent success rates with a 5 Fr guide instead of a 6 Fr.²  The large lumen guides (Medtronic and now, Boston Scientific) have a 0.58-inch lumen. This allows for passage of standard equipment as well as adjunctive devices such as intravascular ultrasound (IVUS), FFR, excimer laser (0.9 mm fiber) (Spectranetics) and the Rotablator (1.25 mm burr). Although the package insert for the burr suggests a 0.60-inch lumen, this case clearly demonstrates that a large lumen 5 Fr guide is large enough to accommodate the burr. Larger adjunctive devices, as well as infusion balloons (ClearWay) and aspiration catheters, will not fit in the 5 Fr system. Use of a buddy wire may provide additional guide support for stent delivery; however, it prohibits use of plaque-modifying ballons (such as the Cutting Balloon [Boston Scientific] and Angiosculpt) in a 5 Fr system. Although both guides are large lumen, the Boston Scientific guides are specifically designed for a transradial approach. They have some additional curves for anatomical variants, as well as hydrophilic coating on the body of the catheter to minimize potential spasm while maintaining guide control.   

Currently, we use the 5 Fr system for Type A and B1 lesions. Use in more complicated cases depends on the patient and lesion characteristics (heavy calcification vs. thrombus, etc.). Retrospectively at our institution, it appears we have used a 5 Fr system more in females, small stature patients, low body weight individuals, and those that have experienced spasm during the diagnostic angiogram. The potential advantages of the 5 Fr guide include a smaller puncture site and less contrast usage, with lower risk of nephrotoxicity.³ The small access site may reduce the incidence of spasm, as well as radial artery occlusion. This may be less of an issue with the new 5/6 Fr hybrid sheath by Terumo, which has a 5 Fr outer diameter but a 6 Fr inner diameter, allowing for use of 6 Fr guides.

Disclosure: Orlando Marrero reports no conflicts of interest regarding the content herein. Dr. Zaheed Tai reports the following: Terumo (proctor for transradial course), Spectranetics (proctor for laser course, speaker, advisory board), Medicines Company (speakers bureau).

Orlando Marrero can be contacted at orlm8597@yahoo.com. Dr. Zaheed Tai can be contacted at zaheedtai@gmail.com.

References 

1. Schobel WA, Spyridopoulos I, Hoffmeister HM, Seipel L. Percutaneous coronary interventions using a new 5 French guiding catheter: results of a prospective study. Cathet Cardiovasc Intervent. 2001; 53: 308-312.
2. Dahm JB, Vogelgesang D, Hummel A, Staudt A, Völzke H, Felix SB. A randomized trial of 5 vs. 6 French transradial percutaneous coronary interventions. Catheter Cardiovasc Interv. 2002 Oct; 57(2): 172-176.
3. McCullough PA, Wolyn R, Rocher LL, Levin RN, O’Neill WW. Acute renal failure after coronary intervention: Incidence, risk factors, and relationship to mortality. Am J Med. 1997; 103: 368-375.