Cath Lab Basics. Balloons and Stents. Tushar Raina MBBS MD MRCP Consultant Cardiologist Cheltenham General Hospital

Transcription

1 Cath Lab Basics Balloons and Stents Tushar Raina MBBS MD MRCP Consultant Cardiologist Cheltenham General Hospital I have no conflicts of interest to declare

2 Evolution of Percutaneous Coronary Intervention Balloon Angioplasty 1977 Bare Metal stents 1993 Andreas Grüntzig Drug Eluting stents 2002

3 Restenosis Major limitation of PCI Pre procedure Post procedure 5 months later

4 Pathophysiology of restenosis X X Rajagopal V, Rockson SG Am J Med 2003

5 Patient characteristics Diabetes mellitus Predictors of ISR Lesion characteristics Vessel calibre Lesion length Proximal LAD and ostial location Bifurcation disease and chronic occlusions Vein grafts Procedural characteristics Suboptimum stent deployment Degree of vascular injury

6 Basic structure of a PTCA balloon The tip The balloon The shaft The hub The coating

7 Monorail Types of balloons Compliant Semi compliant Non compliant Over The Wire Cutting / Scoring High pressure Drug-eluting

8 Terminology Nominal pressure The pressure at which the balloon reaches it s nominal diameter (diameter on the label) Rated burst pressure Bench testing has shown with 95% confidence that 99.9% of balloons will not burst below this Mean burst pressure The mathematical mean pressure at which a balloon bursts

9 Balloon sizing Use guide catheter width for calibration Select reference vessel Aim for balloon : artery ratio of 0.9 to 1.1 Sometimes QCA or IVUS is needed

10 Structure of balloon catheters

11 Structure of balloon catheters Majority Monorail Rapid exchange Transition Transition Angle Inner Body Guide-wire GW Exit Port Outer Body Distal Segment Other The Wire Usually used for CTO / Rotablation PCI Guide-wire Outer Lumen Inner Lumen

12 OTW vs Monorail balloons OTW Monorail Advantages Allows for easy guide wire exchange / tip shaping etc Provides extra support / pushability Disadvantages Requires either a 300 cm guide wire / balloon trapping in guide / magnet / blow off wire / wire extension Takes longer / learning curve Indications CTO Rotoblation Advantages Standard guide wire Rapid device exchange Easier to use Disadvantages Not able to exchange guide wires Less pushability than OTW Indications Majority of cases

13 We use balloons to Create a tract Prepare a lesion for stent implantation Assess lesion and vessel characteristics Provide additional support during wiring Exchange wires Confirm distal wire position using angiography Post-dilate stents Treat ISR (cutting / drug-eluting balloons) Treat ostial disease (cutting / scoring balloons)

14 Post-dilatation Calcified lesions may not yield to compliant balloons which can lead to dog-boning at either end of the lesion causing dissection An appropriately sized non-compliant balloon allows the calcified lesion to be inflated to a high pressure while the balloon increases only marginally in size

15 Indications for compliant balloons Standard PCI Tortuous anatomy Pre-stent deployment Vessel and lesion assessment

16 Indications for non-compliant balloons Calcified lesions Eccentric lesions Resistant lesions Post- dilatation ISR and ostial disease

17 Bare metal stents (BMS) Types of stents Drug eluting stents (DES) Genous (anti CD34 EPC capture stents) Covered stents ( PTFE, pericardium ) Biabsorbable / biodegradable scaffolds

18 Bare metal stents Previously made of 316L stainless steel Now more complex alloys and thinner struts Higher incidence of ISR Lower incidence of late and very late ST Require shorter duration of antiplatelet therapy

19 Drug-eluting stents Combination of metal, polymer and antiproliferative drug Similar late mortality as BMS Lower incidence of ISR Small but incremental excess of late and very late ST Require longer duration of antiplatelet therapy

20 Other stents Genous CD34 antibody coated stents EPC capture technology Disappointing early clinical results Improvements underway Aneugraft The over and under stent Pericardium coated Useful in SVG PCI and for sealing coronary perforations

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