Rotational and directional coronary atherectomy

Rotational atherectomy was developed as a second-generation vascular interventional device specifically to address lesions known to be difficult to manage with balloon angioplasty. Commercialized as the Rotablator, this device utilizes a high-speed rotating elliptical burr coated with a fine diamond abrasive to achieve plaque ablation [1]. The very fine diamond abrasive and flexible drive shaft were incorporated into the design to allow normal soft elastic components of the vessel wall to deflect away from the device so that tissue ablation occurs preferentially against the relatively hard and inelastic components of atheromatous plaque [2-6]. This unique property of differential plaque ablation makes the rotational atherectomy ideally suited for treatment of lesions that are unfavorable for balloon angioplasty, especially calcified lesions, bifurcation lesions, ostial stenoses, chronic total occlusions, and diffuse disease [7-14]. Since its introduction in 1990, the Rotablator has undergone a number of design modifications and changes in recommended technique. The device has been used for both lesion modification and plaque debulking on virtually all types of lesions. Its role in the stent era has also been evaluated. The present article summarizes what we have learned over the past decade about the use of the device to treat obstructive atherosclerosis in the coronary circulation. Although much emphasis is placed on lesion selection in the application of rotational atherectomy, patient selection and clinical characteristics require special emphasis. The diamond abrasive of the Rotablator ablates atheromatous plaque into microparticles, which are not retrieved but rather washed out through the distal coronary circulation. Most ablated microparticles are ≤ 10 μm in diameter, but larger particles are also produced, which can obstruct microcirculation and cause ischemic complications or patchy microinfarctions [4, 15]. High-speed rotation of the burr also produces microcavitations as a result of the Bernoulli effect. The microcavitations are in a size range of 60–90 μm, which can also temporarily obstruct the microcirculation for 20–30 sec [16]. Microparticulate embolization and microcavitation contribute to the slow flow and no-reflow, which occurs more frequently with this device than with others [16-19]. Transient ischemic complications thus may be more frequent than with other devices, even though the incidence of non–Q-wave and Q-wave myocardial infarction are not necessarily increased [20]. Patients with compromised ventricular function, poor distal run-off, multivessel disease with contralateral coronary occlusions, and large plaque burdens (lesion lengths ≥ 25 mm) are at greater risk for ischemic complications [21]. Use of this device in these settings, and in the last remaining conduit and with severely compromised LV function, is discouraged unless appropriate measures are taken to protect the patient from ischemic complications, including placement of an intra-aortic balloon counterpulsation pump (IABP) or use of transfemoral cardiopulmonary support (CPS) [22]. Female gender is also a negative predictor, not only of procedural success, but also of ischemic complications [18]. Careful attention to technique and adjunctive pharmacology is crucial to the outcome in these situations. Downsizing to smaller burrs initially with stepwise increments and size is advised [23-25], as is limitation of the runs to ≤ 30 sec each [26-28] and careful attention to rpm drops to keep them to a minimum and preferably ≤ 5,000 rpm [26]. The Rotablator is FDA-indicated for use in single-vessel native atherosclerotic coronary artery disease with stenoses ≤ 25 mm in length that can be crossed with a guidewire, multivessel coronary artery disease that does not pose undue risk to the patient as outlined above, and native coronary artery restenosis lesions following prior percutaneous transluminal coronary angioplasty. Rotational ablation is contraindicated for occlusions through which a guidewire cannot be passed in the true lumen, for treatment of the last remaining vessel in patients with compromised LV function, and in the treatment of saphenous bypass graft stenoses. Rotational atherectomy is also contraindicated in vessels with visible thrombus or dissections. The device is particularly suited for heavily calcified lesions [13, 18, 29] and hard recoiling stenoses, such as aorto-ostial, branch ostial, or bifurcation lesions [30, 31]. The “undilatable” stenosis is also a signature lesion for the Rotablator and is well treated with this device (Fig. 1) [32]. Procedural outcomes in these situations is uniformly high and exceeds 90% for each of these lesion subsets. Complex B2 and C lesions are also more effectively treated with rotational atherectomy than with PTCA or excimer laser angioplasty, provided that there is no outflow obstruction, poor distal run-off, or visible thrombus [18]. Highly angulated stenoses ≥ 60°, or eccentric lesions on bends, especially those where the eccentric lesion is opposite a ≥ 45° bend, are not effectively treated with this device and are at increased risk for dissection and perforation and so should be avoided [18, 33]. A: Long lesion in a dominant RCA vessel. No fluoroscopic calcium is seen. B: Primary stent placement. Note waist in balloon at 16 atm. C: Result after primary stent placement. Note persistent waist. D: Attempt to postdilate with a 20 atm noncompliant balloon. E: Final result after 20 atm postdilatation. Severe stricture within stent persists. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com]. The Rotablator system consists of the burr, drive shaft, advancer, and console (Fig. 2). The original system consisted of an integrated single-use burr, drive shaft, and advancer. The more recent version of the device incorporates a separate advancer and detachable burrs that allows use of multiple burrs with a single advancer. Both the dedicated and exchangeable advancers incorporate a compressed gas (air or nitrogen) turbine to produce high rotational shaft speeds at low torque. The advancer also has a brake to keep the guidewire from moving or rotating during use. As the drive shaft is advanced and spins around the guidewire, there is a fiber optic cable to provide turbine rpm data to the console and a saline flush port to connect to pressurize saline flush for the drive shaft. The compressed air advancer hose also connects to the console so that activation of the air turbine and adjustment of turbine rpm is regulated by the console. The console also has an elapsed timer to record individual run times and cumulative advancer activation times. A low-speed (70,000 rpm) Dynaglide setting is also selectable from the console for purposes of burr exchange and removal. Rotablator console, advancer, burr, and wire clip. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com]. It is crucial that the wire clip be attached to the guidewire at all times when the advancer is activated to keep the wire from spinning when the advancer is activated and the brake is released. It is also essential to provide continuous saline flush to the drive shaft to reduce friction or else the device may stall or lock up from excessive friction and heat. Careful attention must also be paid to the compressed gas tanks to ensure adequate and consistent gas pressures for the entire procedure or else platform rpm speeds may drop or the burr may stall during use. Minimum tank pressures of ≥ 1,000 psi are recommended before each procedure. Placement of a venous is advised for of and as as well as for placement of may to of the microcirculation and with rotational ablation can also and or and Placement of a is thus especially for or coronary artery or when the coronary artery is treated with a contralateral coronary artery to ventricular perforation with placement is as from perforation is more with rotational atherectomy than with other device occurs from is also frequently after the procedure and so may not be the procedure is placement of an intra-aortic balloon counterpulsation pump is also when patient and lesion characteristics are present as outlined [22]. of the high incidence of and with is advised before in patients with a of has also been used with to and reduce the for its use has not been both and is frequent in the treated vessel with rotational A of and was developed to and in with rotational atherectomy This to reduce the incidence of as with and has the to the saline has also been to or treat and before and after each run the incidence of from to as with the Both the and are used in is an of and to reduce friction of the drive shaft on the guidewire during rotational It is to the saline flush and has been to reduce rpm drops and has been to the incidence of non–Q-wave myocardial infarction and vessel dissection and is recommended for use with rotational atherectomy It can be with the in the saline flush and is with The for rotational atherectomy has with the of to activated times of ≥ sec is or sec with the use of has been to reduce the incidence of non–Q-wave and during rotational atherectomy The use of has been [26]. The use of or during rotational atherectomy has not been The size of the should be to the burr to be used to treat the A can up to a mm of ≥ can up to a mm burr, only a mm burr at is of ≥ can up to a mm A 10 is to use the mm coronary or may large a burr is are to provide coronary during times of slow flow and no-reflow, and the selection should be for that provide the of the coronary to an angulated of the burr into the artery and the complications dedicated can be used for rotational The has a and a The also has a but a the and have been produced, which incorporate a and a The are than the guidewire and so provide more but also more and in angulated to a greater This may the burr to the of angulated and at times cause or to be in burrs against bends, and into where and have developed as and may result of the burr at speeds rpm) in these situations may reduce the risk of complications The guidewire is more flexible and has of these and has the of more so that the wire can be more into lesions and away from as to and vessel wall when eccentric lesions or vessels with vessel The guidewire is thus the guidewire used for rotational of a burr to a by stepwise in burr has been to be with procedural and and clinical complications than with larger burrs or a single large burr [18, The of each run and total with the of slow flow and no-reflow, ischemic complications, and procedural [18, individual runs of ≤ 30 sec are with total times not recommended to [18, plaque ablation at the lesion the burr should be activated to the lesion within the coronary artery to a platform and of the burr before lesion platform speeds have with and are rpm for ≤ mm burrs and rpm for mm recent and clinical data that even speeds of rpm may result in distal and ischemic complications restenosis also to be with ablation but the use of platform speeds in this range has not been to a and has not been The of lesion for ablation has also with are over of continuous only with of lesion rpm drops as well as the that the burr It also at the lesion by to and more The risk of ischemic complications and restenosis also with rpm drops ≥ 5,000 rpm sec or more and can be with careful attention to the technique and with continuous of rpm a (Fig. of with a of Rotablator advancer [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com]. The burr size has been a of much and with recent in a Use of larger burrs with an atherectomy burr to artery of does not an or a larger and is with a greater risk of slow flow and as well as of ≥ times normal is also a a restenosis especially when rpm drops of greater than 5,000 rpm which more frequently with larger burrs this a of ≤ is recommended modification and of lesion to be adequate at this of plaque adjunctive PTCA and even in heavily calcified lesions the risk of ischemic coronary atherectomy and have also been to be with in this Rotational atherectomy has been to to balloon in A and lesions and in more B2 and C lesions and lesion rotational atherectomy no over balloon in of procedural or from complications or restenosis and so is not lesions, rotational atherectomy is with procedural and complications as to balloon or excimer laser angioplasty, but restenosis and vessel The use of for balloon the of rotational atherectomy in of complications, but with no on restenosis Use of rotational atherectomy is thus in where the of balloon be but there is no in of of clinical or restenosis in this following rotational ablation has been with much to treat and the stent the more use of adjunctive rotational atherectomy is to in lesions that are for primary calcified lesions, ostial lesions, diffuse and chronic total occlusions Although a that an burr the incidence of diffuse restenosis when a stent is the incidence of Q-wave and non–Q-wave myocardial infarction is and Since no of burr prior to has been and the of of burr size with adjunctive balloon no or to the use of an burr an for rotational atherectomy prior to cannot be of of ≤ is calcified and lesions ≥ mm in length were to a of rotational atherectomy prior to a of Although and were greater with rotational atherectomy prior to stent placement than with balloon and the complications were the and vessel at was no and to be The use of rotational atherectomy in these has application of rotational atherectomy prior to is for heavily calcified lesions, and was a from a that chronic total occlusions have a restenosis with rotational atherectomy prior to an burr of but this lesion has not been to a lesions are known to have high restenosis risk with balloon or Although the use of rotational atherectomy in bifurcation lesions has been to be with risk [30, the restenosis of rotational atherectomy or rotational atherectomy prior to has not been in this The treatment of restenosis with rotational atherectomy is particularly as restenosis lesions are soft calcium and so can be ablated with relatively rpm drops and a low of procedural complications these are of the lesions to treat from a debulking can be in this but the to be the is and adjunctive balloon is of have balloon to rotational atherectomy balloon in the treatment of restenosis and the relatively larger vessels mm with lesions the procedural and were but was following rotational atherectomy of were also greater the smaller relatively smaller vessels mm with lesions mm) a restenosis with rotational atherectomy and balloon as with balloon even though the were The data from these are thus at and so no for the use of rotational atherectomy for restenosis can be particularly in of a high in patients with lesions Use of the balloon may in patients not adjunctive but this has not been Although the use of adjunctive for treatment of restenosis following rotational atherectomy is has not been but a Rotational atherectomy can be or when to stent the the of a and branch with rotational atherectomy for treatment of restenosis can be and is much than the risk of disease in the treatment of native coronary artery lesions rotational atherectomy can be used to and with when other devices, including balloon not Use of burrs is advised with careful attention to technique to when to through stent to calcified lesions with a high calcium The high calcium of the is to to more in the microcirculation and be more Use of a is thus when heavily calcified lesions, as is a stepwise burr very runs of ≤ 30 sec lesions and branch ostial lesions with angulated have a incidence of dissection and Downsizing the and burrs by at size is as is the use of the lesions are treated with of the branch vessel with the or of by the treated even the more vessel is the more adjunctive is to be and an of the branch is advised before including use of burr and adjunctive balloon prior to stent placement. total occlusions can be treated with rotational atherectomy only the guidewire can be to be and the distal can be and to be of adequate is to placement of the guidewire and an adequate distal vessel before are and are and with balloon placement of a stent or is or can also be with embolization to are with complications, including and The burr should be from the lesion at all to of the dissection with activation of the have been with the at the of the or at of or in the guidewire, but only of wire require removal. of the is recommended when the cannot be and the in an vessel. transluminal coronary has been in its in coronary to the of vessel wall high and lesions during the as well as restenosis within following the procedure. to these coronary atherectomy was developed by in the The the in on a after a of recommended that the of the in a to was to PTCA for both and The was and by and was by a for saphenous bypass graft lesions The in over patients to PTCA or for single lesion with the primary of and clinical complications, and clinical restenosis were also The are in and a restenosis in the but high restenosis in both was no in clinical restenosis and in the A in lesions only to or PTCA with was no in restenosis or clinical restenosis in saphenous bypass and only for restenosis with PTCA restenosis for for PTCA with lesion at and was a incidence of non–Q-wave in the for and for A was also with in this of the of a restenosis was to the of at the lesion of the patient PTCA or was the of with greater a risk of This may have not a much restenosis than PTCA in the at the lesion following was only greater than with PTCA of the technique at the of the the of the was that plaque the vessel produce vessel and to and during was with a which large of plaque and large stenoses to the of balloon and the use of balloon after The that in was to a more which produce a large and low This to be for before be so was to the technique with PTCA to its against The was in and consisted of a of patients an procedure to achieve a than stenosis were of a with a high of prior PTCA prior and recent within were and ostial lesions eccentric lesions lesions greater than 10 mm in length bifurcation lesions and to calcium lesions was used to and plaque and at the of the and at the but was not used by to the procedure the procedural was not The primary of the was and clinical Since the of the was to that large be at the lesion more frequent complications, were also including the for coronary bypass Q-wave and non–Q-wave myocardial and lesion complications such as and vascular complications and no were Q-wave in of the and was in for an of The clinical procedural was in in and vessel perforation in with no of vascular complications at the or in of The and are in for the the adjunctive PTCA and the of lesions in The that relatively large vessels mm) were and large were a of mm and a restenosis of clinical of the patients also low in of Q-wave in and in The that the technique larger and achieve and to to the of the in procedural and complications frequent lesion and a of restenosis The increased of complications and in the patients in was not in the in the that lesion increased from to after for of these and the were to (Fig. an result at the lesion with a stenosis of the a plaque within the elastic of the of The also that the primary of restenosis after was rather than procedural of the the of by [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com]. that even more plaque debulking result in a in the of large of plaque at the lesion This was by a of in in which patients were to or adjunctive The was the A plaque of was to in with a restenosis of in Although adjunctive PTCA to the in not produce a restenosis at The and of in the of PTCA to the to PTCA for restenosis when to the of a at a large number of The the 1,000 patients with single native coronary lesions to stenosis or PTCA at The primary for the was restenosis measures of procedural and clinical restenosis and clinical at clinical and characteristics were for the and PTCA vessel mm) and mm) were in the and PTCA stenosis was in of and of PTCA patients The use of an device was more frequent in PTCA patients or than in patients procedural stenosis Q-wave or was in of and of PTCA patients complications were no the and The and lesion are in and in larger than greater at but the at the lesion at were larger in the and restenosis was for than for PTCA which was the primary of the The of was for and PTCA at the of of the initially treated vessel or was the incidence of such was and in the to this not and of the [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com]. at in the within the 30 for a of and in the PTCA within 30 and during for a of Although was more in the there was no and during the procedure for or PTCA of the in the PTCA only patient a procedural the in the patients that were and of the in patients high procedural The of the were that is of larger than which in but clinical restenosis vessel is only by an these were complications or in the following the procedure. the of in the and the of coronary the use of for coronary was so much to and restenosis to the by be with the use of a coronary only to has been and The lesions to or was with an The primary was restenosis at clinical were also characteristics were and procedural was in all lesions. procedural with or were but at the in the stent was smaller than the that was greater in the stent than the was for than for This has not been in a larger have been the that debulking with be used in with to stent and reduce the and restenosis with coronary have very low restenosis and clinical vessel when debulking with was The and of these is the which patients and lesions for prior to coronary was in of patients with low and large was in of patients at a of restenosis in and lesion in of patients at a of which were low to was the that the by at the lesion by was than all of or which have a of have the of debulking the lesion prior to the restenosis by have this by that plaque at the lesion following is of and restenosis The in the by careful at and at in patients coronary stent in native coronary the data of a the of plaque and the of was a in at for a stepwise in the of plaque following stent that the plaque was greater in lesions with lesions Although these are plaque at the lesion prior to reduce the of restenosis in clinical the of an and This patients with native coronary lesions to or with the primary of and the that plaque debulking with can reduce and restenosis following coronary the a the which a in the and of The primary in the of the was to produce a system that was with and lesions with the as a The result was a device with a shaft, and (Fig. The is for all devices, with of for vessel on the size of the balloon as the The a on the of a The that the can the of the and the of calcified or hard The [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com]. The of the have a high of with the The with and of the tissue and have been to or than the system on patient be to of coronary lesions with the The technique of with the system is very to that with the with a changes to the use of than 10 or and the fluoroscopic of the and Since the are more and have than the larger used for the of the can be more in the or coronary to in of the and into the vessel. after the can be difficult to keep the of the in the as the device is advanced through the primary of the The device to the of the coronary and out of the of the device the larger was not to the of the in the for of but with the this is and very to the more of the and the attached the the in the is more difficult to and a of the when the for a an should be with the of the lesion or with a more attention than to the of the The balloon is to the rotating the for each 45° to the at psi and up to psi achieve an atherectomy that be a more result and have a restenosis in a vessel at the size for the device mm vessel with the mm balloon pressures at 30 psi and up to psi to achieve adequate debulking are in which more should be taken with balloon pressures smaller bifurcation lesions, angulated and lesions on Since the is the size for all the only to larger vessels is with the larger balloon size or balloon lesions can be well with the device with the