Chapter 34. Coronary Atherectomy: Concepts and Practice
Which of the following rotational atherectomy techniques is associated with increased microparticulate debris and platelet aggregation?
A. Using a burr-to-artery ratio <0.7
B. Allowing decelerations of the burr >5,000 rpm
C. Limiting atherectomy speeds to 140,000 to 160,000 rpm
D. Limiting atherectomy runs to less than 30 seconds
E. Using a back-and-forth pecking motion instead of continuous lesion engagement
Most clinical studies have reported no reflow and abrupt vessel closure rates associated with rotational atherectomy of approximately 1%. Larger burrs, a burr-to-artery ratio of 0.7 to 0.8, atherectomy speeds >160,000 rpm, and long continuous atherectomy runs have been shown to increase platelet aggregation. An increase in acute angiographic complications has been associated with larger burr sizes, but without an impact on clinical outcomes. Thermal injury can also be caused by long runs of continuous engagement of the coronary lesion with the atherectomy burr or by decelerations >5000 rpm, which indicate more friction and force being applied to the vessel wall. Thermal injury can lead to red blood cell aggregation and platelet activation and has been associated with increased restenosis. Therefore, it is recommended that a back-and-forth pecking motion be used, instead of forceful advancement of the burr.
Which of the following is not a complication associated with rotational atherectomy?
A. Abrupt vessel closure and no reflow
B. Coronary dissections and perforations
E. Asymmetric atherectomy and formation of deep eccentric fissures and aneurysms
In the major clinical trials comparing a strategy using rotational atherectomy versus a strategy using routine therapy, there have been no differences in short- or long-term mortality. Abrupt vessel closure and no reflow occur about 1% of the time during atherectomy. Treatment with prophylactic vasodilators such as nitroprusside, adenosine, and verapamil has been shown to reduce the incidence of this complication. Coronary dissections and perforations were seen in 3.3% and 1.7% of patients, respectively, in the ROTAXUS study and 3.4% and 1.8% of patients, respectively, in the ORBIT II study. Transient heart block can be seen, particularly with interventions on the right coronary artery or dominant left circumflex. Smaller burr sizes and shorter runs significantly diminish the occurrence of these events such that many operators do not prophylactically place temporary pacemakers. When atherectomy is performed, however, a transvenous pacer and appropriate ...