Use of the Kissing Microcatheter Technique to Exchange a Retrograde Wire (Full Title Below)

Use of the Kissing Microcatheter Technique to Exchange a Retrograde Wire for an Antegrade Wire in the Retrograde Approach to Intervention in Chronic Total Occlusion

ABSTRACT: The retrograde approach to chronic total occlusions (CTOs) is a great advance in percutaneous coronary intervention (PCI). When the retrograde wire has been passed into the antegrade guiding catheter, a microcatheter is advanced into the antegrade guiding catheter and the retrograde wire is exchanged for a 0.014 inch, 300 cm guidewire to keep both ends accessible. However, this maneuver takes a long time, as advancing the guidewire is slowed due to marked resistance. We report a case where successful retrograde recanalization of an RCA CTO lesion was performed using the “kissing microcatheter technique”. This technique involves placing a microcatheter inside the antegrade guiding catheter and manipulating the retrograde guidewire to pick up the tip of the antegrade microcatheter and enter it retrogradely. The retrograde microcatheter and antegrade microcatheter are on the same retrograde wire. After advancing the antegrade microcatheter until both tips kiss each other, the antegrade microcatheter is advanced to the distal portion of the CTO lesion, pulling the retrograde microcatheter back. The retrograde guidewire is pulled out and an antegrade guidewire is advanced to the distal true lumen through the antegrade microcatheter. This novel technique is a safe, feasible strategy for placing an antegrade guidewire across a CTO lesion. J INVASIVE CARDIOL 2010;22:E74–E77 Recently, in the field of coronary intervention for chronic, total occlusions (CTOs), a retrograde approach through collateral channels and the combined “controlled antegrade and retrograde subintimal tracking” (CART) technique have been introduced and increased the initial success of wire crossing. ^1,2 In the technique that uses a retrograde approach, a septal collateral channel has most frequently been used as an access route to the distal site of left anterior descending artery (LAD) or right coronary artery (RCA) CTO lesions. ^2,3 Several different strategies and techniques have been used after successful crossing via collateral channels. ³ When the retrograde guidewire can be passed across the CTO lesion and enters the antegrade guiding catheter, a retrograde microcatheter is advanced into the antegrade guiding catheter and the retrograde wire is exchanged for a 0.014 inch, 300 cm guidewire, keeping both ends accessible. ⁴ The balloon and stent can then be delivered antegradely with robust back-up. However, this maneuver takes a long time because of significant resistance in the microcatheter, and carries a risk of collateral channel injury caused by the shaft of the wire during the procedure. It was previously reported that use of a 300 cm Rotablator® floppy guidewire (Boston Scientific Corp., Natick, Massachusetts) can reduce the resistance in the microcatheter because this wire has a smaller diameter. ³ To reduce complications, we report a novel strategy — we have termed “the kissing microcatheter technique” — that is technically easier than changing to a 0.014 inch, 300 cm guidewire, and that also saves a wire. Case Report. A 75-year-old male with a past history of coronary artery bypass graft surgery (CABG) due to triple-vessel disease 18 years previously presented with stable exertional angina (Canadian Cardiovascular Society [CCS] Class I). His most recent coronary angiography revealed that the native LAD was totally occluded distal to the first septal branch and the distal LAD was filled via the left internal thoracic artery (LITA) graft (Figures 1 A and B). The native RCA was totally occluded at segment 2 and the saphenous vein graft (SVG) to the RCA was also occluded (Figures 1 C and D). The RCA distal to the CTO lesion was filled from the LAD by the first and the second septal branches (Figures 1 A and B). The culprit lesion was considered to be the RCA CTO lesion, and we decided to perform PCI to resolve the ischemia. We attempted a retrograde approach using a 7 Fr XB 3.5 SH guiding catheter (Cordis Corp., Miami Lakes, Florida) to intubate the left coronary artery (LCA). The first septal collateral was selected with an Asahi Suoh wire (Asahi Intecc, Tokyo, Japan) and a collateral channel was negotiated to the RCA. After passage through the channel to the distal end of the RCA CTO lesion, the septal channel was dilated using a Sapphire™ 1.5 mm balloon (OrbusNeich, Hong Kong) with low-pressure inflation. Selective contrast dye injection via a Finecross MG catheter (Terumo Medical Corp., Somerset, New Jersey) revealed that the distal end of the CTO was of the abrupt type (Figures 2 A and B). We therefore changed to an antegrade approach using a 6 Fr JR 4.0 guiding catheter to intubate the RCA. A Fielder XT wire (Asahi Intecc) was advanced with the Finecross MG into the CTO lesion, but did not reach the distal end of the CTO. In a retrograde fashion, a Miracle 3g wire (Asahi Intecc) with the Finecross MG catheter successfully penetrated the distal fibrous cap and advanced to the proximal portion of the RCA (Figures 2 C and D). After dilatation of the CTO lesion by a retrograde 1.5 mm balloon, we tried to cross a Fielder XT wire through the CTO lesion in an antegrade fashion, but failed due to complex dissection and residual stenosis. We therefore decided to perform the “kissing microcatheter” technique. After we exchanged the retrograde 1.5 mm balloon for a Finecross MG catheter and advanced a retrograde Miracle 3g wire into the antegrade JR 4.0 guiding catheter, we inserted another Finecross MG catheter into the JR 4.0 guiding catheter antegradely. We then advanced the retrograde Miracle 3g wire into the antegrade Finecross MG catheter (Figure 3A). Two microcatheters (both Finecross MG catheters) were on the same wire. We advanced the antegrade Finecross MG catheter to the tip of the retrograde Finecross MG catheter (Figure 3B). After kissing microcatheters were established, the antegrade Finecross MG catheter was advanced into the CTO lesion, pulling the retrograde Finecross MG catheter back (Figure 3C). When the tip of the antegrade Finecross MG catheter was located distal to the CTO portion, the retrograde Miracle 3g wire was removed. An Asahi Suoh wire was then advanced distal to the CTO lesion through the antegrade Finecross MG catheter and the antegrade Finecross MG catheter was removed (Figure 3 D). We dilated with an antegrade 2.0 mm balloon and 3 sirolimus-eluting stents were deployed from 4PL to the RCA ostium. The final angiogram revealed optimal stent expansion and thrombolysis in myocardial infarction (TIMI) 3 flow (Figure 4). Discussion. In the retrograde approach to the coronary CTO lesion, after the retrograde wire has successfully crossed the CTO lesion and predilatation has been achieved by using a small balloon, the operator should switch to the antegrade approach for stent implantation. ⁵ Sometimes however, it is difficult to pass an antegrade guidewire through the predilated CTO lesion because of residual stenosis and complex dissection. ³ In this situation, when the retrograde guidewire and microcatheter have been advanced into the antegrade guiding catheter, the retrograde guidewire can be exchanged for a 0.014 inch, 300 cm guidewire with subsequent threading of the distal tip of the guidewire out of the proximal end of the antegrade guiding catheter. After this procedure, the stent can be delivered through this wire in an antegrade manner, with robust support. However, the shaft of a 0.014 inch, 300 cm guidewire is stiff and may cause injury during passage through the collateral channel. If a 0.014 inch, 300 cm guidewire is used, the collateral channel should be protected by the microcatheter throughout the procedure. Although a Rotablator floppy guidewire is flexible and of a smaller diameter and can reduce both the resistance in the microcatheter and the risk of channel injury, it takes time to cross two guiding catheters. The kissing microcatheter technique described here is helpful and carries a lower risk of channel injury than does exchanging the 0.014 inch, 300 cm guidewire. After passing the antegrade microcatheter distal to the CTO, the retrograde guidewire is pulled out and passed into the antegrade microcatheter in order to change to an antegrade approach. Thus, there is no need for another new, long guidewire. Crucial to picking up the tip of the antegrade microcatheter is keeping the tip of the antegrade microcatheter at the bending segment of the guiding catheter. At the bending segment, the microcatheter tip is on the outer curve of the guiding catheter and it is easy to pick up the tip. We have performed this novel strategy, which we call the “kissing microcatheter technique”, in a total of 3 cases to date. No complications occurred in any of these cases. This strategy may be performed using a small over-the-wire-balloon, a channel dilator catheter and a Tornus catheter (Asahi Intecc). Septal channel perforation has previously been documented in several cases as one of the complications of the retrograde approach. ^{2, 3} These complications were due to wire-handling and excessive balloon dilatation. Although it was rare for these complications to result in significantly hemodynamic effects on patients, Matsumi et al reported a case where a guidewire-induced septal channel perforation resulted in cardiac tamponade that required emergency surgical drainage. ⁶ The operator must therefore be careful to avoid septal collateral channel perforation, especially due to the guidewire shaft or balloon shaft tearing the channel wall.

References

1. Surmely JF, Tsuchikane E, Katoh O, et al. New concept for CTO recanalization using controlled antegrade and retrograde subintimal tracking: The CART technique. J Invasive Cardiol 2006;18:334–338. 2. Surmely JF, Katoh O, Tsuchikane E, et al. Coronary septal collaterals as an access for the retrograde approach in the percutaneous treatment of coronary chronic total occlusions. Catheterization and Cardiovascular interventions 2007; 69:826–832. 3. Saito S. Different strategies of retrograde approach in coronary angioplasty for chronic total occlusion. Catheter Cardiovasc Interv 2008;71:8–19. 4. Ozawa N. A new understanding of chronic total occlusion from a novel PCI technique that involves a retrograde approach to the right coronary artery via a septal branch and passing of the guidewire to a guiding catheter on the other side of the lesion. Catheter Cardiovasc Interv 2006;68:907–913. 5. Wu EB, Chan WWM, Yu CM. Retrograde chronic total occlusion intervention: Tips and tricks. Catheter Cardiovasc Interv 2008;72:806–814. 6. Matsumi J, Adachi K, Saito S. A unique complication of the retrograde approach in angioplasty for chronic total occlusion of the coronary artery. Catheter Cardiovasc Interv 2008;72:371–378.

________________________________________________________________ From Cardiovascular center, Kyoto-Katsura Hospital, Kyoto, Japan. The authors report no conflicts of interest regarding the content herein. Manuscript submitted August 31, 2009 and accepted September 21, 2009. Address for correspondence: Atsushi FUNATSU, MD, Cardiovascular center, Kyoto-Katsura Hospital, 17 Yamada-Hirao-cho, Nishikyo-ku, Kyoto, Japan 615-8256. E-mail: kcvc.funatsu@katsura.com