Disclosure: Orlando Marrero reports he works for Mercator MedSystems and is a consultant for Boston Scientific. Dr. Zaheed Tai reports the following: Terumo (proctor for transradial course), Spectranetics (proctor for laser course, speaker, advisory board), The Medicines Company (speakers bureau).

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

Question: The physicians at our institute use a 7 French (Fr) system for bifurcation lesions. What are the limitations of bifurcation lesions in a radial approach?

Answer: It depends on the lesion and what technique is being utilized. In general, we stick with a 6Fr system in the radial, although we have often used a 7Fr and on rare occasion, even an 8Fr system (depending on the patient). The use of a 6Fr system does not allow for a simultaneous two-stent technique (kissing stents), but other techniques can be used with modification.

History

This is a 54-year-old gentleman with history of coronary artery disease, status post bypass with subsequent cardiac catheterization revealing a patent left internal mammary artery to the left anterior descending coronary artery (LIMA to LAD), a high-grade stenosis in the circumflex, and a chronic total occlusion (CTO) of the right coronary artery (RCA). Because of the patient’s ongoing symptoms and a markedly positive stress test, he was refereed for revascularization of the circumflex and staged percutaneous coronary intervention (PCI) of the RCA.

Procedure

The right radial artery was prepped and draped in a sterile fashion. The right radial artery was accessed with a Slender sheath (Terumo). Because it was thought this lesion might involve a short CTO, the sheath was upsized to a 7Fr system in order to accommodate some of the CTO equipment and allow for trapping, if needed. An Extra Back Up (EBU) 3.5 guide catheter (Medtronic) was used to engage the left main.  

On the initial angiogram, it was unclear whether the lesion was a short CTO or bridge. The initial plan was to advance a Runthrough 0.014-inch 190cm wire (Terumo) to the proximal cap with the support of a balloon and exchange for a tapered tip wire (Fielder XT, Abbott Vascular), but the Runthrough was able to pass distally through the circumflex. There was a micro channel with a long 99% stenosis ofapproximately 25-30mm (Figure 1). Once luminal entry was confirmed, an 0.9mm excimer laser coronary atherectomy (ELCA) catheter (Spectranetics) was used to make multiple passes, debulking the circumflex after the obtuse marginal (OM) 1 (Figure 2). A 2.0 balloon was used to predilate (Figure 3), a 2.25 x 30mm Resolute stent (Medtronic) was placed distally (Figure 4), and then we had to return to cross the OM 1. We 

placed a wire in the first OM and then stented across it with a 2.5 x 15mm Resolute stent, overlapping the previous stent. An Asahi Sion Blue wire (Abbott Vascular) was used to rewire the OM 1. We removed the previously placed Runthrough wire (underneath the stent) that was in the OM 1, and advanced a 2.5 x 8mm Glider balloon (TriReme Medical). A 2.5 x 12mm Emerge balloon (Boston Scientific) was placed on the Runthrough wire going into the OM 2 and a kissing balloon inflation was performed at the bifurcation (Figure 5), with an excellent angiographic result, both balloons going to nominal. Distally, there was an excellent angiographic result (Figure 6), but with the guide engagement the patient was experiencing ventricularization and chest pain. The ostial circumflex was intermediate angiographically. The distal wire was exchanged for a fractional flow reserve (FFR) wire that was placed in OM 2. Baseline FFR was 0.93 and with an adenosine infusion, FFR was 0.76 after 2 minutes. After removal of the Sion Blue wire from OM 1 (Figure 7), a 3.5 x 15mm stent was placed from the proximal circumflex back to the left main and post dilated with a 4.0 x 12mm Quantum balloon (Boston Scientific). Final angiographyrevealed TIMI-3 flow without dissection, perforation, or embolization (Figure 8). Final angiography demonstrated improved collateral filling of the distal right posterior descending artery bed. 

Discussion

Bifurcation lesions remain a challenge in interventional cardiology. Despite various techniques, there is no accepted method. Treatment approach will vary depending on the size of the branch vessel and myocardium involved. In general, a provisional T-stent strategy is preferable to a two-stent strategy.¹ This approach can be performed with a 6Fr system, as can most complex bifurcation techniques, with some 

modification. A discussion of bifurcation techniques and how to manage them is beyond the scope of this article. 

Bifurcation techniques utilize a “stent and retrieve” strategy, which involves stenting of the main branch, and balloon angioplasty of the side branch with or without stenting. The final step of this strategy involves finalkissing balloon inflation, requiring crossing the previously deployed stent with a wire and a balloon.  Difficulty or failure re-crossing and delivering the side branch balloon through the struts of the main branch stent can occur 10-15% of the time.² The rate of occurrence may vary depending on the angle of the side branch, the makeup of the main branch, and the bifurcation technique utilized. Modern balloons and guide wires facilitate crossing the struts and dilating the side branch most of the time. Leaving a “jailed wire” behind facilitates crossing and dilatation by providing a visual marker as well as altering the angle between the side branch and main branch. Jailing a wire has the potential to trap the wire. Predilation of the side branch can be performed; however, this could result in ostial dissection of 

the side branch and hinder recrossing.³ 

The Glider balloon (TriReme Medical) (Figure 9) is a torqueable percutaneous transluminal coronary angioplasty (PTCA) balloon catheter. The skived tip and unique balloon design allow for easier crossing into the sidebranch and more complete side branch ostial coverage with balloon dilation. Another potential advantage is the ability to stretch a stent cell and appose the struts at the side branch origin, without damaging the distal side branch. The balloon design is supposed to allow more complete coverage of the side branch ostium than conventional balloon dilation.⁴ The main limitation is incompatibility of the thick shaft of the Glider balloon with another monorail balloon inside a large lumen 6Fr guiding catheter.

References

1. Hildick-Smith D, de Belder AJ, Cooter N, Curzen NP, Clayton TC, Oldroyd KG, et al. Randomized trial of simple versus complex drug-eluting stenting for bifurcation lesions: the British Bifurcation CoronaryStudy: old, new, and evolving strategies.Circulation. 2010; 121(10): 1235-1243.
2. Kaplan S, Barlis P, Dimopoulos K, La Manna A, Goktekin O, Galassi A, Tanigawa J, Di Mario C. Culotte versus T-stenting in bifurcation lesions: Immediate clinical and angiographic results and midterm clinical follow-up. Am Heart J. 2007; 154: 336-343.
3. Brunel P, Lefevre T, Darremont O, Louvard Y. Provisional T-stenting and kissing balloon in the treatment of coronary bifurcation lesions: Results of the French multicenter ‘‘TULIPE‘‘ study. Catheter Cardiovasc Interv. 2006; 68: 67-73.
4. Secco, GG, Rittger H, Hoffmann S, et al. The Glider registry: a prospective multicentre registry of a new ultrashort dedicated balloon for side-branch ostial dilatation. Catheter Cardiovasc Interv. 2013 Jun1. doi: 10.1002/ccd.25040. [Epub ahead of print]