A Step-by-Step Description of the Retrograde Approach: Collateral Examination, Guidewire and Microcatheter Selection AR Galassi, MD, FACC, FESC, FSCAI Head of Cardiac Catheterization and Interventional Cardiology Unit, Division of Cardiology, Ferrarotto Hospital Associate Professor of Cardiology University of Catania, ITALY

Alfredo R. Galassi, MD I have no real or apparent conflicts of interest to report.

Why Retrograde Approach? By Ochiai/Japan

Why Retrograde Approach? By Ochiai/Japan

Indications of Retrograde Approach as a Primary Procedure Antegrade wiring seems very difficult in terms of anatomical factors (complex CTO) The patient has visible and continuous collaterals The donor vessel is healthy Re-attempt after previous failure

EuroInterv 2008; 4 : 84-92

Treatment Strategy Sianos et al EuroInterv 2008

Success and Indications of Retrograde Approach Personal Experience 2007-2010

Standardized Procedures of Retrograde Approach A 7 Fr guiding catheter with a side hole is inserted from left femoral or left brachial artery • Super-selective dye injection from a microcatheter is performed to identify the “visible”collateral Septal collaterals are preferred usually, because they are dilatable • A slippery wire with a microcatheter is employed

Tip Microcatheter Injection Non-selective channel injection Selective channel injection 10

Collateral Connection Size CC0 = no continuous connection CC1 = (blue arrows) continuous threadlike connecrtion CC2 = (green arrows) continuous small side branch–like size collateral 11

Collateral Course and Their Appearance Depending on Different Multiple Orthogonal Views 12

Characteristics of Specific Collateral Channels By Katoh O/Japan 13

Classifications of Collateral Corkscrew-like Morphology By Katoh O/Japan 14

What the Guidewire Looks Like When it is Introduced by Retrograde 15

Collateral Channel at a 90° Angle Take-off 16

Retrograde/CART Experiences 2008-2010 Center Overall Success Author Journal/Venue Toyohashi 133/157 (84.7%) Rathore Circ Intv 2009 JACC Intv 2010 Predictors of failure were primarily related to characteristics of the collateral channel. There were no significant CTO morphologic or anatomic predictors of retrograde success or failure.

Standardized Procedures of Retrograde Approach Slippery wires used for collaterals: - Epicardial Runthrough (Terumo), Whisper (Abbott) Sion (Asahi) - Septal Fielder FC (Asahi), Fielder XT (Asahi) - Cork screw Fielder XT, Fielder XT-R (Asahi) After the successful delivery of a slippery wire, the microcatheter is advanced towards the distal coronary artery via collaterals If the microcatheter cannot be advanced, septal dilatation may be performed with a 1.0-1.25 mm OTW balloon to 2-3 atm

Wires for Retrograde Approach to Cross the Lesion Soft wires may cross the lesion, especially by use of channel dilator, otherwise stiffer wires are generally necessary to cross the lesion Runthrough, Fielder FC or XT or XT-R Miracle 3.0 or 4.5 or 6.0 Confianza Pro 9.0 gr Confianza Pro 12.0 gr 19

OTW Microcatheters for CTOs Manufacturer Microcatheter Shaft lenght Crossing Profile Inner lumen size Asahi Stride 130, 150 cm 0.029”/0.73 mm/2.2 Fr 0.016” Balt Vasco+10 155 cm 0.025”/0.63 mm/1.9 Fr 0.0165” Boston Excelsior 1018 175 cm 0.026”/0.66 mm/2.0 Fr 0.019” Tracker Excel 14 150 cm 0.025”/0.63 mm/1.9Fr 0.017” Excelsior SL 10 0.022”/0.56 mm/1.7Fr Cordis Prowler 14 Prowler 10 0.015” Rapid Transit 0.030”/0.76 mm/2.3Fr EV3 Echelon 14 Echelon 10 0.022”/0.56 mm/1.7 Fr Spectranectis Quick Cross 135 cm Terumo Finecross 130, 150 cm 0.024”/0.60 mm/1.8 Fr Progreat 2.4 110, 130 cm 0.031”/0.80 mm/2.4 Fr 0.021” Progreat 2.0 Vascular solution Skyway 138 cm

Advantage of the use of a microcatheter for collateral channel crossing 21

Dedicated Microcatheters for CTO Manufacturer Microcatheter Shaft lenght & diameter Inner lumen size Characteristics Asahi Tornus 135 cm 2.6 Fr 0.016” Rotational burrowing microcatheter 135 cm 2.1 Fr Corsair 135-150 cm 2.6 Fr 0.015” Channel dilator catheter for retrograde approach Vascular solution Twin Pass 138 m 1.9 Fr Double lumen microcatheter Gopher 142 cm 3.0 Fr 0.017” Rotational support microcatheter St. Jude Venture 145 m 2.2 Fr 0.019” Flexible tip microcatheter manually manoeuvred

The Channel Dilator Catheter (Corsair) For tip flexibility & vessel trackability Provides superior tip flexibility which enables smooth approaches to narrow tortuous vessels, such as septal channels ø 0.82mm (2.5Fr) ø 0.86 mm (6) ø 0.86mm (2.6Fr) Marker coil Polyurethane resin + Tungsten powder Tungsten braiding Courtesy of Dr Kato

Advantages of ASAHI Corsair ASAHI Corsair vs Microcatheters Microcatheter has a marker closer to the tip compared to OTW Balloon Catheter which makes it easy to identify the distal tip under fluoroscopy Unlike other general microcatheters, ASAHI Corsair has soft tip with tungsten powder mixed, and on top of that, it has a 0.8 mm platinum marker coil situated at 5 mm from the tip General Microcatheter 5mm Soft tip with tungsten powder 0.8mm Platinum marker coil Marker Courtesy of Dr Kato

Experience with Channel Dilator (Corsair): 90/93 Channel Crossing Tsuchikane et al, JACC Intv 2010

Corsair: Extraordinary trackability (O. Katoh)

Would You Believe that this Epicardial Channel can be Crossed Without Perforation?

I Was Sure That Was Impossible….. O. Katoh

OTW Balloons < 1.5 mm Diam for CTOs Shaft lenght & diameter Manufacturer Balloon Shaft lenght & diameter Balloon size (diameter x lenght) Entry tip profile crossing profile Terumo Riujin OTW 135, 148 cm 2.5-2.7 Fr 1.25-1.5 mm X 10-15-20 mm 0.0165” 0.023” Boston Apex 140 cm 2.3-2.4 Fr 1.5 mm X 8-12-15-20 mm 0.017” Invatec Falcon Piccolo 145 cm 2.2-2.7 Fr 0.0168” 0.022”-0.023” Falcon CTO 145, 160 cm 1.0-1.25-1.5 mm X 10-14-20mm 0.016” 0.021” Abbott Voyager 135 cm 2.7-3-3 Fr 1.5 mm X 12-15 mm Medtronic Sprinter 138 cm 1.5 mm X 6-12-15-20 mm CID Acrostak Across CTO 150 cm 2.5-2.8 Fr 1.1-1.5 mm X 0.015 Clearstream Ezecto 140 cm 1.25-1.5 mm X 15 mm 0.022” SIS Medical AG NIC nano 160 cm 0.85 mm X 10-15 mm 0.0195” NIC 1.1 OTW 1.1 mm X 10-12-15-17-20 mm 0.0205”

IVUS-Guided Reverse CART: 31 cases Rathore et al, JACC Intv 2010; also Banerjee et al, JIC 2010

Retrograde Stepwise Approach in 2010 Retrograde wire crossing (Channel Dilator) Kissing wire Retrograde knuckle wire technique and antewire crossing CART/ reverse CART

Thank You For Your Attention Conclusions Retrograde approach might be choosen as primary strategy, if: 1) The CTO has several unfavorable anatomical features 2) The CTO is relatively long ( ≥15~20mm) 3) The distal vessel receives visible collaterals 4) The donor vessel is healthy (or can be treated before) 5) The procedure is re-attempt after previous failure • With the use of new guide wires, devices (Channel Dilator, Corsair) and techniques, the overall success of retrograde approach has increased significantly during the last years but still predictors of failure were primarily related to characteristics of the collateral channels • The operator should learn to be versatile and be ready to adopt different techniques during the same procedure Thank You For Your Attention argalassi@virgilio.it