Enhancing Guide Support During a Complex Coronary Intervention via Transradial Approach

This case series is supported by an educational grant from Medtronic.

Disclosures: Dr. Pancholy reports honoraria from Medtronic, a speaker’s fee from Pfizer, consultancy to Terumo, and research support from Accumed Radial Systems, Inc. Dr. Samir Pancholy can be contacted at pancholys@gmail.com.

The following case is the first in a series of transradial-focused reports directed by section editor Dr. Samir Pancholy. This case series is supported by an educational grant from Medtronic.

History

This is a 65-year-old male with history of type II diabetes mellitus, hypertension and hyperlipidemia. Six weeks prior, he underwent minimally invasive direct coronary artery bypass surgery (MIDCAB) with off-pump left internal mammary artery bypass to left artery descending artery bypass graft to left anterior descending artery. He now presents with staged percutaneous coronary intervention of the right coronary artery (RCA), as a part of a hybrid revascularization strategy. He has resumed physical activity and has developed 2-3 episodes of retrosternal chest tightness associated with moderate exertion. He has been pretreated with enteric-coated aspirin 81 mg orally once daily, and clopidogrel 75 mg orally once daily for 3 weeks. 

Procedure

A 6 French, 11 cm hydrophilic introducer sheath was inserted in the right radial artery after obtaining micropuncture access using a Teflon-sheathed needle and 0.021-inch guide wire, using a counter puncture technique. A 0.035-inch, 260 cm J-tipped guide wire was placed in the ascending aorta and a 6 French MAC 3.5 guide catheter (Medtronic) was placed in the ostium of the RCA. Baseline RCA angiograms were acquired in left anterior oblique (LAO) (Figure 1) and right anterior oblique (RAO) projections. A 0.014-inch, 180 cm Runthrough NS guide wire (Terumo) was placed in the distal RCA. A 3.0 x 20 mm Sprinter Legend balloon (Medtronic) was placed over the guide wire and advanced into RCA, but was unable to reach the lesion. 

The guide wire was exchanged over a FineCross catheter (Terumo) for a 0.014-inch, 300 cm Hi-Torque Wiggle guide wire (Abbott Vascular). After clockwise torquing of the guide catheter with gentle advancement, the 3.0 mm balloon was successfully placed in the distal RCA stenosis and inflated at 14 atmospheres for 30 seconds (Figure 2). Two inflations were performed proximal to the first inflation. A 3.0 x 38 mm Resolute Integrity stent (Medtronic) was placed over the wire and advanced into the RCA. The stent catheter was not able to cross the lesion, despite increasing active support by torque and advancement, and placement of a buddy wire. At this point, a 0.014-inch, 180 cm Runthrough NS guide wire was placed in the conus branch after withdrawing the guide catheter just outside the RCA ostium, and a 2.0 x 15 mm Sprinter Legend balloon was inflated in the conus branch at 6 atmospheres. After securing the guide catheter in the best position, the stent catheter was advanced into the RCA. The stent catheter was successfully placed across the distal RCA stenosis (Figure 4). The conus branch “anchor” balloon was deflated and withdrawn. The stent was deployed at the distal stenosis at 16 atmospheres for 30 seconds. A second 3.0 x 30 mm Resolute Integrity stent was deployed proximal to previous stent, at 16 atmospheres for 30 seconds. The stents were post-dilated with a 3.5 x 15 mm NC Sprinter balloon with 5 inflations at 20 atmospheres for a maximum duration of 20 seconds. An excellent angiographic result was obtained (Figure 5). 

Discussion

Difficult anatomic substrates are becoming more frequent in contemporary percutaneous coronary intervention (PCI) as technology continues to broaden the applicability of catheter-based coronary revascularization. Although improved technology has improved long-term outcomes, procedural success continues to be dictated by technical expertise and operator skill sets. Calcification with tortuosity is a combination with few technological solutions, although improvement in stent technology has improved the ability to reach and treat lesions amidst these unfriendly segments. The operator is required to optimize all aspects of the procedure to ensure success.

In this case, we chose a “multi-aortic curve” or MAC catheter, which has a horizontal distal segment that abuts the right coronary sinus of Valsalva, and hence provides support, or inhibits outward movement of the catheter tip when devices (balloon/stent) are advanced into a high resistance segment of the artery. 

Although a larger size (higher French) guide catheter would provide more passive support in view of its thicker material, the majority of the time, an experienced operator can manipulate smaller-caliber guide catheters to increase forward force transmission, either by applying torque to alter the shape of the distal end of the guide catheter and increasing contact with segments of aortic wall, or by cautious advancement of the catheter tip into the lumen of the coronary artery, with deep intubation, providing similar if not superior guide support. 

A second guide wire, a buddy wire, was tried next, to create a stronger “rail”. This maneuver frequently allows for device delivery through difficult terrain, although as in this case, may not succeed, and in some cases, if calcification is severe, and angulations are sharp, it might worsen the situation by increasing the probability of the device engaging sharp edges of calcium through excessive straightening of the vessel. 

The final common pathway leading the device delivery failure is the backward migration of the guide catheter in response to the forward resistance from the coronary artery. One of the solutions to this problem is to deeply intubate the coronary artery, while maintaining contact with the aortic wall, which may be achievable by “active support maneuvers” or using a guide extender.¹ Another mechanism that will allow successful device delivery is to “lock” the guide catheter in place, and lessen or eliminate the backward migration of the guide catheter. As in this case, it could be accomplished by using an anchor balloon technique. By approaching a proximal branch that can be easily accessed with a guide wire and balloon, the guide catheter can be “anchored” in place, facilitating forward delivery of a stent or other equipment.² 

Transradial access has been perceived as a deterrent to aggressive guide catheter support. This is likely a result of suboptimal choices made by the operator during their learning curve. As operator experience increases, the ability to recruit proper guide catheter support is expected to improve. Anatomically, no major reasons have been identified to associate a specific access site with a guide support disadvantage. 

In summary, complex PCI via transradial access is certainly feasible. Available guide catheters with inner lumen diameters >0.071 inches allow for use of adjunct devices including rotational atherectomy burrs, thrombectomy catheters, simultaneous balloon inflations, and use of intracoronary imaging devices. This virtually eliminates the need for > 6 French systems. The use of the above-mentioned techniques allows the operator to significantly enhance guide support while treating difficult PCI subsets

References

1. Takahashi S, Saito S, Tanaka S, Miyashita Y, Shiono T, Arai F, Domae H, Satake S, Itoh T. New method to increase a backup support of a 6 French guiding coronary catheter. Catheter Cardiovasc Interv. 2004 Dec; 63(4): 452-456.
2. Fujita S, Tamai H, Kyo E, Kosuga K, Hata T, Okada M, Nakamura T, Tsuji T, Takeda S, Bin Hu F, Masunaga N, Motohara S, Uehata H. New technique for superior guiding catheter support during advancement of a balloon in coronary angioplasty: the anchor technique. Catheter Cardiovasc Interv. 2003; 59(4): 482-488.