Rotational atherectomy: an Update.

As we known, drug-eluting stents (DES) reduce the risk of restenosis and represent an important advance in coronary intervention. Newer-generation DES with thin struts releasing limus-family drugs from durable or biodegradable polymers have further improved clinical outcomes, as compared with early-generation DES releasing sirolimus or paclitaxel. The risk of stent thrombosis has become exceedingly low, that is, the improved safety profile of newer DES comes without compromising their effectiveness. Therefore, DES should be used in most clinical settings unless pateints have contraindications to the use of dual antiplatelet therapy.[1] For better stent apposition to improve clinical outcomes, debulking may be needed in ostial lesions, in diffuse disease, and in calcified segments before stent implantation. The rotablator is uniquely suited for these indications.[2] Rotational atherectomy (RA) was developed to differentially remove inelastic and even harder calcified atherosclerotic plaque without damaging normal arterial wall by the rotating burr.[3] Actually, rotablator is the only surviving debulking device nowadays for lesion preparation before stent implantation, i.e., to remove the most calcified and unyielding elements of the plaque, leaving a soft tissue rim to dilate and stent.[2] In this issue of the Journal of Geriatric Cardiology, Dr. Chen and Hsieh recommended that a strategy combining the RA technique and DES implantation is a safe and effective treatment option for patients with complex lesions.[4] It should be considered as an essential technique in certain lesions, especially the calcified lesions visible by fluoroscopy, circumferential calcific lesions, or lesions uncrossable with the intravascular ultrasound catheter. Given that the population is getting older, and that the proportion of patients with coronary calcified lesions will increase in proportion with the octogenarians, RA should be offered in all the catheterizarion laboratories.

Traditionally, RA was used to ablate previously undilatable lesions and heavily calcified lesions. With refinement of technique, more recently, the indications of RA have been extended beyond those traditionally ones and rotablator has been confirmed as a predictable device in the treatment of more complex lesions in experienced centers.[5] In this issue, Chiang et al.[6] reported their exprerience of using RA to treat heavily calcified left-main coronary diseases (LMCA), which was previously considered a formidable challenge for percutaneous interventions. Their results clearly demonstrated that in experienced hands, plaque modification with RA before stenting of heavily-calcified LMCA could be safely accomplished in those elderly patients with high-surgical-risk, with a minimal complication rate and favorable long-term outcomes.

Coronary stent implantation in a severely calcified vessel may result in stent underexpansion, leading to life-threatening complication, such as stent thrombosis.[7] In this issue, Ku, et al.[8] reported a patient suffered from late stent thrombosis due to under-deployment of a paclitaxel-eluting stent in a lesion with circumferential calcification. This rare but serious complication was sucessfully treated by RA, represented a new indication of rotablation. Intravascular ultrasound revealed that rotablator could successfully ablate both the underexpanded metallic struts of the stent and the calcified ring. The ablated segment was scaffolded with a new paclitaxel-eluting stent, which was well opposed.

However, despite such a wide range of applications of RA, why is it that the widespread use of RA has been hampered? One of the reasons is that RA is a demanding technique requires training and experience to perform. Moreover, RA is associated with complications such as coronary vasospasm, slow flow, etc. Furthermore, a concern for device specific complictions exists.[9],[10] One of the rare but devastating device specific complications during rotablation is entrapment of the burr within calcified lesion, which is really a nightmare of interventional cardiologist. In this issue, Lin et al.[11] reported a series of 5 cases of this particular complication. They also discussed the possible mechanisms, proposed methods to rescue the complication percutaneously, and the tips and tricks to avoid such a serious complication.

In conclusion, RA can improve acute results in difficult lesion subsets and is now considered as a niche device in coronary intervention. However, many operators are reluctant to use RA extensively and still reserve it for the most difficult lessions which cannot be treated by any other methods. This extreme selection bias may prevent operators from getting the experiences to use the device effectively and have a negative impact on the procedure outcomes. It is believed that proctorships and training courses should improve results and acceptance of RA in the future. If increasing numbers of operators are able to obtain predictable results from improved technique, if more favorable data are obtained from randomized trials, if the equipment becomes more user-friendly, and if its cost becomes more competivie, then RA will be established as a major tool in percutaneous treatment of coronary heart disease.