Rotablation - An overview

A review of Rotablation technology, its application, and usage in the catheterization laboratory. Ideal for Interventional Cardiology Fellows.

1. Rotablation – a review

2. Introduction

3. What we’re going to discuss Principles Indications Contraindications Equipment and Technology – ROTABLATOR TM (Boston Scientific) Do’s, Don’ts; Tips and Tricks Complications Current Status of Rotablation Conclusion

4. Introduction Introduced 30 years ago by Jerome Ritchie, David Auth, and colleagues For the endovascular treatment of obstructive atherosclerotic disease Initially explored as an alternative to balloon angioplasty RA proved complementary to stenting of complex lesions, especially heavily calcified lesions

5. Introduction Use is infrequent today But maintains relevance in the Cath lab

6. principles

7. Principles Physical removal of plaque and reduction in plaque rigidity, facilitating dilation Rotablator ablates plaque using a diamond encrusted elliptical burr rotated at high speeds (140,000 to 180,000 rpm) by a helical driveshaft that advances gradually across a lesion over a guidewire

8. Principles Burr preferentially ablates hard, inelastic material, such as calcified plaque, that is less able to stretch away from the advancing burr than healthy arterial wall This is referred to as “differential cutting”

9. Principles Guidewire helps to keep the burr’s abrasive tip coaxial with the lumen Wire bias in highly tortuous or angulated segments may predispose to dissection or perforation Guidewire should be positioned Distal to the target lesion in the largest distal vessel, Avoiding small side branches and distal narrow vasculature, Avoiding bends, kinks, or loops

10. Principles Balloon angioplasty tends to produce intimal splits and medial dissections in calcified lesions RA yields a relatively smooth luminal surface with cylindrical geometry and minimal tissue injury

11. Principles Lumina are not always cylindrical after RA In regions of tortuosity or eccentric plaque, crater or gutter formation can occur - Referred to as lesion bias This may impede stent deployment OR yield lumen enlargement greater than burr size

12. Principles Friction between the burr and plaque generates heat Heat varies with technique from 2.6C using intermittent ablation and permitting minimal decelerations (4,000 to 6,000 rpm), to 13.9C using continuous ablation allowing excessive decelerations (14,000 to 18,000 rpm) in experimental modeling

13. Principles Thermal injury may contribute to increased risk of periprocedural myocardial infarction (MI) and restenosis associated with excessive decelerations Modern technique, favoring gradual, intermittent ablation with a pecking motion, and slower RPMs (140,000 – 150,000) aims to minimize decelerations and thermal injury

14. Principles RA particulate must traverse coronary microvasculature before clearance by the RES Microvascular obstruction can cause reduced contractility in myocardium, slow-flow/no-reflow, and MI Most particles are small enough to readily pass; 98% are <10 mm, with a mean diameter of 5 mm (smaller than normal mature erythrocytes)

15. Indications and contraindications

16. indications Heavily calcified lesions (HCCL) - localized or extended Presence of a circumferential calcium ring where the lesion is undilatable by balloon angioplasty From Petros S. Dardas . Rotablation in the Drug Eluting Stent Era. INTECH Open Access Publisher; 2012.

17. indications Ostial lesions with severe fibrosis with or without calcification Balloon-inaccessible lesions, provided that the Rotawire can cross the lesion Failed PCI is either due to inability to cross the lesion or dilate Bifurcation lesions CTO - inability to cross with a balloon catheter From Petros S. Dardas . Rotablation in the Drug Eluting Stent Era. INTECH Open Access Publisher; 2012.

18. Contraindications Occlusions through which guidewire will not pass Last remaining vessel with compromised LV function Coronary dissection Evidence of thrombus Severe tortuosity Relatively contraindicated in vein grafts (increased risk of dissection and distal embolization)

19. Equipment and set-up

20. ROTABLATOR Setup

21. Tips and tricks

22. Case selection Treating certain types and/or locations of lesions or patients with certain conditions is inherently riskier Important to be aware of the higher risk when treating such patients and the lack of scientific evidence for treatment in 1. Patients who are not candidates for coronary artery bypass surgery 2. Patients with severe, diffuse three-vessel disease (multiple diseased vessels should be treated in separate sessions) 3. Patients with unprotected left main coronary artery disease 4. Patients with ejection fraction less than 30% 5. Lesions longer than 25 mm 6. Angulated (≥ 45°) lesions. There has been limited experience with the brachial approach

23. Case selection The decision to use rotablation should be made early, before large dissections appear

24. Guide Catheter Selection & Sizing

25. Guide Catheter Selection & Sizing Preferable to use guides with side-holes to improve flow through the vessel Guide must be co-axial to the vessel to avoid wire bias Use a guide size that will accommodate the final burr to be used (if stepped approach is planned) Avoid guides with abrupt primary and secondary curves

26. BURR Selection Ideal Burr to Artery ratio of 0.6/0.7 : 1.0 A stepped approach and gradually increasing burr size is ideal when multiple burrs are required This ensures smaller size of particles generated, lesser decrement in RPMs while ablating and reduces chances of the burr getting embedded in the lesion (nightmare in the lab!)

27. Wire selection To cross the lesion, use a workhorse wire and exchange for Rota wire with a OTW catheter Finish the intervention on a workhorse wire Ensure that the Rota wire is not kinked Between the Rota wires, the stiffer wire produces unfavorable bias sometimes; Though this bias can sometimes be used to advantage in angulated lesions

28. Wire precautions Always ensure that the guide wire is visible proximally Watch the tip Ensure beforehand that the wire clip torquer is on - it prevents the guidewire from spinning when brake defeat is activated

29. Wire precautions

30. Temporary pacemaker Prophylactic temporary pacemaker is commonly used with rotational atherectomy of the LCx or RCA Protects against the risk of complete temporary A-V block

31. Tips and tricks Testing the System When testing the rotation, ensure not to allow the rotating burr to come in contact with exterior surfaces (towel, tray table etc.) Never operate the Rotablator Advancer without saline infusion Flowing saline is essential for cooling and lubricating the working parts of the advancer Operating the advancer without proper saline infusion may result in permanent damage to the Rotablator advance

32. Tips and tricks Advancing the burr : Advance the non-activated burr to reach the lesion Dynaglide is not recommended for advancement because the rotational speed does not fall when resistance is met Dynaglide is a control that sets the rotation speed at 50.000-90.000 rpm and is used for reducing friction when removing the device

33. ABLATION 3 S Slow Smooth Short Representative video in a training model

34. ablation Do not push the rotablator into the lesion Use “Pecking” technique Avoid crossing the entire lesion during the initial passage Pecking” motion prevents “trenching” into arterial wall, allows wire to reposition as vessel compliance changes with debulking Ablation is best performed in 15 second runs

35. Ablation precautions During the ablation, excessive deceleration (>5,000 rpm) must be avoided Results in improper ablation and increases the risk of vessel injury, formation of large particles, and ischemic complications related to excessive heat generation Avoid stopping or starting the burr in the lesion Avoid stopping burr distal to lesion Avoid adjusting rpm's during ablation Avoid keeping the burr in one position while rotating at high speeds Avoid advancing rotating burr to the spring tip (radiopaque) tip of the wire Avoid burring in the guide catheter

36. ABlation In case Rotablation is planned at two tandem lesions, the position of the platform will have to been changed after ablating at the proximal lesion Representative video in a training model To do so, hold the black advancer knob in place, while your assistant advances the platform itself, the burr stays in position

37. Rotaflush - cocktail CARAFE study ( C ocktail A ttenuation of R otational A blation F low E ffects) Showed that use of local irrigation with a cocktail of normal saline with heparin 20U/ml, verapamil 10 mcg/ml, NTG 4 mcg/ml through the 4F sheath of the advancer virtually eliminates “Slow Flow” and “No-Reflow” phenomenon However some operators feel this produces hypotension and may not be appropriate in patients with LV dysfunction too

38. Feedback During Ablation Visual Monitor decelerations – drop in RPM from pre-set desired RPM while resistance is met Smooth advancement under fluoroscopy Contrast injection to discern lesion contours and borders Auditory Pitch changes relative to resistance encountered by burr Tactile Advancer knob resistance Excessive drive shaft vibration - excessive load on burr advanced too rapidly

39. Ablation- final run Finish with one polishing run With no drop in rpm And no resistance Representative video in a training model

40. Removal of the Burr catheter Representative video in a training model Dynaglide is a control that sets the rotation speed at 50.000-90.000 rpm and is used for reducing friction when removing the device

41. complications

42. complications STUCK ROTABLATOR Advancer stops Stall light lights up Slow Flow / No Reflow Perforation

43. Stuck Rotablator Entrapment of rotablation burr or trapped rotablator occurs rarely (0.6% incidence) Dreaded complication Small burr can be advanced beyond a heavily calcified plaque before sufficient ablation, especially when the burr is pushed firmly at high RPMs Burr can also be entrapped within a severely calcified long lesion, especially angulated and concomitant coronary spasm

44. Stuck Rotablator – what to do? STEP 1 : Pray Hard STEP 2 : Keep calm Simplest method to retrieve the entrapped burr is pulling back the rotablator system manually Some cases the stuck burr can be withdrawal successfully by manual traction with on-Dynaglide or off-Dynaglide rotation

45. But.. Vessel may be injured (proximal segment) if the guiding catheter gets pulled in too deep Guiding catheter can be disengaged and another wire kept in the aorta to inadvertent avoid deep engagement

46. Also.. Extreme force on the burr and burr shaft may also result in shaft fracture

47. Parallel wire strategy Re-crossing another guide wire just beside the entrapped burr and making a crack between the burr and vessel wall by inflating a balloon catheter has been reported Hyogo M, Inoue N, Nakamura R, Tokura T, Matsuo A, Inoue K et al. Usefulness of conquest guidewire for retrieval of an entrapped rotablator burr. Catheterization and Cardiovascular Interventions. 2004;63(4):469-472

48. Parallel wire strategy May not be able to pass another wire if a 6F guide is being used (Rota catheter profile approx. 4.3F) Sakura et al. demonstrated a novel idea to remove the drive shaft sheath after cut off the system near the advancer The rotablator system can be cut off (disassembled) distal to the advancer (including sheath, driveshaft and Rotawire)

49. Dual catheter strategy Or can use another vascular access and guide to introduce second wire and balloon after disengaging first guide

50. Snare strategy Use of a snare advance over the drive shaft of a disassembled Rota catheter (similar to previous technique) Allows application of local traction just proximal to the lesion Requires 7F guide Method is inspired by pacemaker lead extraction techniques Prasan A, Patel M, Pitney M, Jepson N. Disassembly of a rotablator: Getting out of a trap. Catheterization and Cardiovascular Interventions. 2003;59(4):463-465

51. Mother-in-child technique Deep intubation with subsequent pullback of all devices can be useful to focus the force on the burr and to protect the rest of the coronary artery Once again this can be facilitated by cutting off the system and introducing a second smaller guiding or extension catheter over the drive shaft By simultaneous traction on the burr shaft and counter-traction on the child catheter, the catheter tip can act as a wedge between the burr and the surrounding plaque, which may exert a larger and more direct pulling force to retrieve the burr Kimura M, Shiraishi J, Kohno Y. Successful retrieval of an entrapped rotablator burr using 5 Fr guiding catheter. Catheterization and Cardiovascular Interventions 2011;78(4):558-564

52. Last Resort An emergent open surgery would be the most reliable and always the last option for removing the entrapped burr But Invasive Time-consuming Not immediately possible in hemodynamically unstable patients

53. Stuck ablator Interventional cardiologists using rotablator should be familiar with these tips and tricks to avoid and rescue this complication Sulimov D, Abdel-Wahab M, Toelg R, Kassner G, Geist V, Richardt G. Stuck rotablator: the nightmare of rotational atherectomy. EuroIntervention . 2013;9(2):251-258.

54. Slow Flow/ No re-flow

55. Advancer stops Check all connections Check air source – make sure it is on & delivering 90-110 PSI Likely a lack of saline allowed “burn out”, which happens quickly New advancer needed if no saline drip through advancer

56. Stall light lights up As a safety feature, the system automatically stalls whenthere is a > 15,000 rpm drop for a ½ second or more Ensure the burr is not lodged Pullback and re-platform proximal to the lesion Ensure all connections are secure (air supply, saline)

57. perforation Stent-graft implantation OR Emergency Surgery

58. Current status of rotablation

59. Current status Rotablation now plays a role as a tool to make PCI possible in de-novo complex lesions with moderate or severe calcification when clinical variables make PCI appropriate

60. Current status For patients with ISR, Rotablation is reserved as a second choice in select cases Rotablation may be useful when a lesion cannot be crossed with a balloon, or when multiple jailed side branches exist, using plaque debulking to minimize “snow plow” plaque displacement with balloon dilation In cases where metallic stent struts contribute directly to luminal obstruction, rotablation may be utilized for stent ablation Otherwise, non-RA strategies, such as high pressure balloon, drug-coated balloon, or cutting balloon dilation, are preferred, especially for cases of stent under expansion

61. Conclusion

62. conclusion Rotablation remains an integral tool to permit optimal angiographic outcomes in treatment of complex coronary disease involving moderately to severely calcified lesions However evidence has yet to demonstrate that routine RA before DES reduces restenosis It is possible that the impact of RA on repeat revascularization is most pronounced for a subset of heavily calcified lesions IVUS or OCT is useful in identifying features of plaque morphology predictive of benefit

63. conclusion Experience is of utmost importance – outcomes are directly related to operator experience Complications may be dreadful and careful selection of patients is a must Interventionists should be prepared for complications and remain vigilant

64. Thanks for listening….