Coronary Atherectomy and Transradial Access Part II of III: Rotational Atherectomy

Question: You have shown cases in the past using atherectomy. Do you think one is better than the other, and is there a preference from a radial approach?

Answer: Fortunately, we have access to all 3 forms of coronary atherectomy in our lab (laser, rotational, and orbital atherectomy). In addition, all 3 devices can be utilized from a radial approach. I choose my particular device based on the clinical scenario and angiographic characteristics. In this second article in the series, we will present cases illustrating the clinical applications of each device followed by a brief discussion. Part I (CLD August 2016) discussed laser atherectomy. In Part II, we will discuss rotational atherectomy, to be followed by Part III, focusing on orbital atherectomy, in an upcoming issue. 

Case 1

This is a 63-year-old male with history of coronary artery disease status post coronary artery bypass graft surgery (CABG), hyperlipidemia, hypertension, and tobacco abuse. He had been complaining of exertional angina and underwent a stress test with his primary cardiologist. The stress test revealed a large area of inferior wall ischemia. Subsequent cardiac catheterization revealed an occluded saphenous vein graft-right posterior descending artery (SVG-RPDA) and intermediate angiographic disease of the native left circumflex (LCx). The native right coronary artery (RCA) was 100% occluded and the SVG to the obtuse marginal (OM) was occluded. There was evidence of left-to-right collaterals (septals to small PDA, and epicardials from LCx to right posterolateral ventricular branch [RPLV]) (Figure 1A). He was referred for chronic total occlusion (CTO) revascularization of the RCA. 

Dual access was obtained in the right radial with a 7 French [Fr] Extra Backup [EBU] 3.5 to the left and in the  right groin, with an 8 Fr hockey stick guide to the RCA. Initial retrograde crossing with a Corsair (Asahi Intecc) and Asahi Sion wire (Abbott Vascular) was attempted from the septals. The wire crossed into the PDA and after a series of wire exchanges (Sion, Asahi Fielder XT [Abbott Vascular] and Pilot 200 [Abbott Vascular]), the Pilot wire advanced retrograde in a subintimal fashion (Figure 1B). The plan was to set up for reverse CART (controlled antegrade and retrograde tracking). Antegrade wiring was performed with a Pilot 200 and Gaia Second (Asahi Intecc) (Figure 1C). Following a series of wire exchanges and microcatheters (Corsair, Finecross [Terumo] and Micro 14 [Cook Medical]), the wire advanced; however, the catheter would not follow the advancing wire secondary to calcification (Figure 1D). A “knuckle” was pushed and advanced distally into the PLV, but no catheter could follow (Figure 1E). Following laser atherectomy for 3 minutes, the Micro 14 catheter advanced past the proximal cap. Balloon-assisted angioplasty was performed, followed by further advancement of the Finecross (other catheters did not advance). The microcatheter was still short of the bifurcation. An initial attempt to wire with a Rotablator wire (Boston Scientific) was unsuccessful. The lesion was rewired with a Fielder XT and then a new Corsair advanced a little further (Figure 1F). We were able to advance a Rotablator wire distally (but no microcatheter) (Figure 1G). We then used a 1.25 burr at 150-160 revolutions per minute (rpm) and after making a polishing run in vessel, exchanged out for a workhorse wire (Figure 1H). The vessel was ballooned, and using a microcatheter and a Pilot 200, we advanced antegrade (Figure 1I). The retrograde wire was used as a marker, the vessel was crossed, and the antegrade P200 advanced into the retrograde Corsair (Figure 1J). We then proceeded to complete revascularization of the RCA CTO (Figure 1K).

Case 2

An 80-year-old male with history of moderate aortic stenosis (1.3), hypertension and history of gastrointestinal bleed presented with angina. Cardiac catheterization was performed, revealing an intermediate left anterior descending (LAD) lesion and a heavily calcified mid RCA (Figure 2A). Given his history of gastrointestinal bleeding, the patient was started on dual antiplatelet therapy (DAPT) and medical therapy. He continued to have angina pain and was referred for revascularization of the RCA.

The right radial was accessed and a 7 Fr Amplatz left (AL) 0.75 guide was used to engage the RCA. A Runthrough wire (Terumo) was used to navigate the stenosis and then an 0.9 mm excimer laser coronary atherectomy (ECLA) catheter was advanced (Figure 2B). The laser was unsuccessful in crossing. At that point, we decided to perform rotational atherectomy. An attempt was made to pass a 1.5 Euphora balloon (Medtronic), a Threader (Boston Scientific), a Finecross and finally, a Corsair. None of the catheters crossed distally; however, the Corsair advanced far enough into the lesion to allow us to switch out for a Rotawire (Boston Scientific). We used a 1.25 burr followed by a 1.5 mm burr (Figure 2C). The lesion was predilated with a 3.0 x 15 mm Emerge balloon (Boston Scientific) (Figure 2D) with failure to expand. Therefore, a 3.0 x 15 mm AngioSculpt (Spectranetics) was used with full expansion of the balloon. The vessel was then stented with a 3.5 x 38 mm Resolute drug-eluting stent (Medtronic) and post dilated (Figure 2E). 

Discussion

Rotational atherectomy has been utilized for over 25 years. It initially emerged in the 1990s, as means to remove plaque in order to treat vessels. Much like laser, the initial intent for use was as a possible alternative to balloon angioplasty. Rotational atherectomy later proved to be complementary in facilitating balloon and stent delivery and expansion. Currently, atherectomy use accounts for <5% of all PCIs.¹ Despite the benefits rotational atherectomy can offer in achieving procedural success, there has not been consistent data demonstrating a long-term benefit for reduction in major adverse cardiac events (MACE).

Mechanism of action

Rotational atherectomy results in lumen enlargement by the removal of plaque and plaque modification. Ablation occurs using a diamond-encrusted elliptical burr rotating at high speeds. The burr preferentially ablates the hard, inelastic material that does not “deflect” away from the advancing burr (i.e., the healthier part of the vessel), resulting in differential cutting. Longitudinal high-speed rotational movement of the burr results in orthogonal displacement of friction. The guidewire is designed to keep the burr coaxial with the vessel lumen, but tortousity and angulation can result in wire bias, which, in turn, can cause dissection or perforation. Lumen enlargement occurs by plaque ablation without significant arterial expansion. Interaction of the burr and plaque generates heat. The heat generated is related to the severity of deceleration; therefore, it is recommended to keep decelerations to 4000-6000 rpm.² Decelerations can also result in emboli and periprocedural myocardial infarction. Optimal technique, which includes a pecking motion, atherectomy speeds of 150-180 rpm, and avoiding decelerations >5000 rpm may be helpful in minimizing microembolization, no reflow, and platelet aggregation.³

Procedural technique

Complications from rotational atherectomy are the same as PCI and include dissection, perforation, closure, side branch loss, and no reflow.⁴ In addition, burr entrapment can occur. Proper burr sizing can reduce potential complications and the recommendation is a burr-to-artery ratio of <0.7. Typically a 1.5 mm burr is the workhorse for most cases. 

Smaller sheaths will reduce vascular complications and also permit radial access in a larger percentage of patients. Retrospective studies have demonstrated similar procedural success and times utilizing a radial access compared to a femoral access for rotational atherectomy.⁵ In addition, a 1.75 mm burr will fit through the lumen of a large lumen 6 Fr guide. This may allow more aggressive modification of plaque via the radial approach. 

Burr entrapment can occur as result of jumping across the lesion or severe deceleration. Once the burr is advanced on Dynaglide mode, it is advisable to stop short of the lesion and “burp” the catheter. This can be done by releasing the burr and “milking” the line, and then hitting the pedal. This maneuver will minimize the burr jumping forward. Proceed with a pecking motion, keeping runs <20 seconds. If burr entrapment should occur, options include passing a wire and balloon next to the burr to the balloon and freeing up the burr, or disassembling the apparatus. If these techniques are unsuccessful, then surgical removal may be required. If the burr is not advancing after 2 minutes, you can increase the burr speed or consider changing the burr size.^6-8

Rotational atherectomy is most commonly used in calcified vessels, chronic total occlusions (once the wire has crossed), ostial lesions, and bifurcations. It has also been used for diffuse in-stent restenosis. Rotational atherectomy can also be used to ablate struts in an under-deployed stents. Contraindications include saphenous vein grafts, thrombus, dissection, and inability to pass a wire. Relative contraindications include absence of surgical backup, unprotected left main, severe left ventricular dysfunction, excessive angulation (>45 degrees) and long lesions (>25 mm).

References

1. Mota P, Santos R, Pereira H, et al. Facts on rotational atherectomy for coronary artery disease: multicentric registry (abstr). Paper presented at: EuroPCR; May 21, 2013; Paris, France.
2. Reisman M, Shuman BJ, Harms V. Analysis of heat generation during rotational atherectomy using different operational techniques. Cathet Cardiovasc Diagn. 1998; 44: 453-455.
3. Reisman M, Shuman BJ, Dillard D, et al. Analysis of low-speed rotational atherectomy for the reduction of platelet aggregation. Cathet Cardiovasc Diagn. 1998; 45: 208-214.
4. Cavusoglu E, Kini AS, Marmur JD, Sharma SK. Current status of rotational atherectomy. Catheter Cardiovasc Interv. 2004; 62: 485-498.
5. Watt J, Oldroyd KG. Radial versus femoral approach for high-speed rotational atherectomy. Catheter Cardiovasc Interv. 2009; 74: 550-554.
6. Sulimov DS, Abdel-Wahab M, Toelg R, Kassner G, Geist V, Richardt G. Stuck rotablator: the nightmare of rotational atherectomy. EuroIntervention. 2013; 9: 251-258.
7. Sakakura K, Ako J, Momomura S. Successful removal of an entrapped rotablation burr by extracting drive shaft sheath followed by balloon dilatation. Catheter Cardiovasc Interv. 2011; 78: 567-570.
8. Cunnington M, Egred M. GuideLiner, a child-in-a-mother catheter for successful retrieval of an entrapped rotablator burr. Catheter Cardiovasc Interv. 2012; 79: 271-273.

Disclosure: Dr. Zaheed Tai reports the following: Terumo (speaker, proctor for transradial course), Spectranetics (proctor for laser course, speaker, advisory board member), and Boston Scientific (speaker, CTO proctor).

Dr. Zaheed Tai can be contacted at zaheedtai@gmail.com.