Revascularization of a Left Main Chronic Total Occlusion via Transradial Access

Indications

A 79-year-old male has a history of coronary artery disease status post bypass with heart catheterization, done 1/25/2013. He has had a left internal mammary artery (LIMA) to the diagonal, vein graft to the obtuse marginal (OM), and a vein graft to the right coronary artery (RCA), as well as an aortic valve replacement, done in 2002. Heart catheterization at that time revealed a high-grade stenosis of the vein graft to the right posterior descending artery (RPDA), and the patient underwent a successful stent with a 4.0 x 20 mm Integrity bare-metal stent (Medtronic). He also had borderline angiographic disease of the left main (LM) with a positive fractional flow reserve (Volcano) of the non-bypassed left anterior descending coronary artery (LAD). His operative reports LIMA to LAD, although it is clearly going to a diagonal. The patient presents now for a staged intervention of the LM.

Procedure note

The right radial artery was prepped and draped in a sterile fashion. The right radial artery was accessed with a 6 French (Fr) Glidesheath (Terumo) and then was upsized to a 7 Fr sheath. We were unable to pass the 7 Fr guide into the left main, past the innominate into the ascending aorta, and therefore, we engaged with a 6 Fr EBU 3.5 guiding catheter (Figure 1). We did access the right groin with a 4 Fr sheath using a micropuncture kit in the event that an intra-aortic balloon pump would be warranted.

Interventional notes

Given the patient’s angiographic finding, we used a 1.25 x 6 mm Sprinter balloon (Medtronic) and a Runthrough wire (Terumo), and went distally into the LAD. We exchanged for a Rotowire extra support (Boston Scientific). A 1.75 mm burr was used to make three passes in the LM (Figure 2). Following rotational atherectomy, we performed intravascular ultrasound (IVUS) (Volcano), demonstrating the vessel was about 4 to 4.5 mm. We then predilated with a 3.5 x 15 mm AngioSculpt balloon (AngioScore) at 22 atmospheres, quarter-sizing the balloon (Figure 3).

A 4.0 x 20 mm Promus drug-eluting stent (Boston Scientific) was deployed (Figure 4). The stent was post dilated with a 4.5 mm Quantum balloon and final IVUS demonstrated good stent apposition and sizing, without any residual stenosis (Figure 5). Final angiography revealed TIMI-3 flow without embolization (Figures 6a-6b).

 Engagement of the LM with the guide at this point did not result in ventricularization or dampening, as was the case pre-intervention. The patient tolerated the procedure well. The guide was removed after orthogonal views revealed TIMI-3 flow. A TR Band (Terumo) was placed over the radial artery. The femoral sheath was removed after two hours of the discontinuation of bivalirudin (Angiomax, The Medicines Company). 

Plan

1. Dual antiplatelet therapy
2. Risk factor modification and medical therapy
3. Consider angiographic follow-up.

Discussion      

Left main disease is traditionally surgical disease. Recently, data has demonstrated the safety and feasibility of PCI.¹ This is particularly relevant when patients have a contraindication to surgery or refuse surgery as a revascularization option. LM PCI remains a high risk subset and femoral access is usually the preferred route. There is a paucity of data for LM PCI via the radial approach, particularly with rotational atherectomy. Gioia et al² reported their experience in 16 patients. The majority were 7F access. Ziakis et al³ reported on their experience in 27 patients. The 6F system is feasible; however, there are some limitations. Use of a large lumen guide (Ikari, MDT, etc) will provide added support. This will also accommodate a burr size up to 1.75 mm. This may provide adequate debulking with further plaque modification being achieved with the use of a plaque-modifying balloon (an AngioScore or Cutting Balloon [Boston Scientific]). If the bifurcation is involved, the modified crush technique, mini crush, T-stent or Cullote are feasible within the 6F guiding system.⁴ An alternative approach may include dual radial access and the use of simultaneous guiding catheters. Despite the limitations of the radial approach in terms of size of vascular access, accommodation of certain techniques, and inability to deploy a balloon pump, complex disease can still be managed via this approach. Use of a large lumen supportive guide, modification of certain techniques, and careful planning will allow successful management of LM disease via the radial approach in select cases. 

References

1. Seung KB, Park DW, Kim YH, et al. Stents versus coronary-artery bypass grafting for left main coronary artery disease. N Engl J Med. 2008;358:1781–1792.
2. Gioia G, Comito C, Moreyra AE. Coronary rotational atherectomy via transradial approahc: a study using radial artery intravascular ultrasound. Catheter Cardiovasc Interv. 2000;51:234-238.
3. Ziakis A, Klinke P, Mildenberger R, Fretz E, Williams MB, Della Siega A, Kinloch RD, Hilton JD. Comparision of the radial and femoral approaches in left main PCI: a retrospective study. J Invasive Cardiol. 2004;16:129-132.
4. Lim PO, Dzavik V. Balloon crush: treatment of bifurcation lesions using the crush stenting technique as adapted for transradial approach of percutaneous coronary intervention. Catheter Cardiovasc Interv. 2004;63:412-416.

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