The Confluent Balloon Technique–Two Cases Illustrating a Novel Method to Achieve Rapid Wire Crossing of Chronic Total Occlusion

The Confluent Balloon Technique – Two Cases Illustrating a Novel Method to Achieve Rapid Wire Crossing of Chronic Total Occlusion during Retrograde Approach Percutaneous Coronary Intervention ABSTRACT: We describe two cases of a retrograde approach to treat a chronic total occlusion (CTO) of the right coronary artery in which we were initially unable to achieve wire crossing. A novel technique of pushing both antegrade and retrograde balloons into the CTO lesion so that the balloons overlapped each other during inflation created a new confluent subintimal space allowing easy, reliable and rapid passing of the retrograde wire into the antegrade true lumen. This novel “confluent balloon” method is recommended to other operators who may struggle with wire crossing during a retrograde approach to CTOs. J INVASIVE CARDIOL 2009;21:539–542 Recently, there has been an increased use of the retrograde approach through collateral channels for percutaneous coronary intervention (PCI) in chronic total occlusions (CTOs). Initially, this technique was used in Japan,1 but it rapidly spread to other countries.2 Many centers are beginning to use these new techniques in their patients with some success. The retrograde approach requires a considerable investment in time, contrast load and effort before the wire can reach the CTO. Consequently, during wire manipulation through the CTO, with CART (controlled antegrade and retrograde tracking) or reverse CART techniques, the operator is often faced with limited available residual fluoroscopy time and contrast volume. In these cases, there is a need for an easy, rapid and reliable method to achieve wire crossing of the CTO. We report on two cases where the use of the confluent balloon technique provided a novel, easy, rapid and reliable way to achieve wire crossing in CTOs. We believe this method may be helpful to other operators who face difficult CTO lesions under the limitations of contrast volume and procedure time. Case 1. A 57-year-old male with an old anterior ST-elevation myocardial infarction (STEMI) treated with primary PCI returned for a retrograde approach re-attempt PCI to the right coronary artery (RCA) CTO. A 7 French (Fr) EBU 3.5 Launcher guide with side holes (Medtronic, Inc., Minneapolis, Minnesota) and a 7 Fr JR 4 Vista Brite Tip guide (Cordis Corp., Miami Lakes, Florida) were placed in the left and right coronary ostia via the right and left femoral arteries, respectively. Bilateral angiography demonstrated a long CTO with an excellent septal collateral from the distal left anterior descending artery (LAD) to the RCA (Figure 1A). A Rinalto/Prowater wire (Asahi Intecc Co., Ltd., Aichi, Japan) in an Ichiban microcatheter (Kaneka, Kanagawa, Japan) was passed through the previous stent, and a Fielder FC wire (Asahi Intecc) was used to negotiate the septal collateral channel into the distal RCA (Figure 1B). A 1.25 x 10 mm over-the-wire Ryujin Plus balloon (Terumo Corp., Tokyo, Japan) was used to dilate the septal channel at 3 atmospheres (atm), and a 2.5 x 20 mm over-the-wire Maverick balloon (Boston Scientific Corp., Natick, Massachusetts) was exchanged on the retrograde wire for anchor support. Despite a lengthy attempt to cross the lesion with dedicated CTO wires (Miracle 3 gr wire and Conquest Pro 9g/ Confianza 9g, Asahi Intecc) in both antegrade and retrograde methods, including the use of the CART technique, we were unable to achieve wire crossing of the CTO (Figure 1C). Therefore, a 1.5 x 10 mm balloon (Ottimo, Kaneka) and the 2.5 x 15 mm balloon were pushed into the CTO from the antegrade and retrograde sides, respectively, ensuring that the two balloons overlapped in the CTO (Figure 1D). Both balloons were simultaneously inflated to 6 atm and then deflated. The 2.5 mm balloon on the retrograde wire was then pulled back 5 mm and re-inflated to 8 atm to keep the subintimal space open. The Conquest Pro wire was removed from the retrograde balloon and exchanged for a Rinalto/Prowater wire. The antegrade balloon was withdrawn into the antegrade guide and the retrograde Rinalto/Prowater wire easily negotiated the subintimal space into the antegrade guide. The retrograde balloon managed to pass through the CTO into the antegrade guide (Figure 1E), and the Rinalto wire was exchanged for a 300 cm BMW wire (Abbott Vascular, Abbott Park, Illinois), which was passed from the retrograde side into the antegrade guide and out of the left femoral sheath. A series of stents (Promus 2.75 x 28, 3.5 x 28, 3.5 x 28, 3.5 x 28, 4 x 16; Boston Scientific) were placed via the antegrade end of the 300 cm wire into the RCA, with an excellent final angiographic result (Figure 1F). Case 2. A 75-year-old female with a past history of hypertension, hypercholesterolemia, anterior STEMI, LAD stenting and ischemic cardiomyopathy presented to our center for CTO PCI. Her coronary angiogram showed a long CTO in the RCA (Figure 2A). A 7 Fr EBU 3.75 short 90 cm Launcher guide with side holes and a 7 Fr JR 3.5 Vista Brite Tip guide with side holes were placed in the left and right coronary ostia via the right and left femoral arteries, respectively. A Rinalto/Prowater wire in a Finecross microcatheter (Terumo) was passed into the septal branch and a Fielder FC wire (Asahi Intecc) was used to negotiate the septal collateral channel. However, we experienced considerable difficulty crossing the septal collateral channel and had to exchange for a Fielder XT wire (Asahi Intecc), which was able to negotiate the channel and reach the distal RCA (Figure 2B). A 1.25 x 10 mm Ryujin Plus over-the-wire balloon was used to dilate the septal channel at 3 atm and a 2.5 x 20 mm over-the-wire Ryujin balloon was passed into the distal RCA for anchor support. After a lengthy attempt to cross the CTO in retrograde and antegrade fashion, including the use of dedicated CTO wires (Conquest Pro/Confianza Pro 9g and 12g, Asahi Intecc), a side branch anchoring balloon on the antegrade side, and both CART and reverse CART methods, we were not able to cross the CTO (Figure 2C). Therefore, we proceeded to use the confluent balloon technique by passing the 2.5 mm balloon and a new Ottimo 2.0 x 15 mm balloon (Kenaeka) into the CTO from the retrograde and antegrade routes, respectively. When there was overlap of the balloons, both balloons were inflated to 6 atm simultaneously (Figure 2D). After balloon deflation, the retrograde balloon was pulled back 5 mm and re-inflated to 8 atm, and a Rinalto wire was exchanged for the Conquest Pro. This wire easily navigated through the confluent subintimal channel, and we were able to pass it into the aorta and subsequently into the antegrade guiding catheter (Figure 2E). After dilatation of the CTO with the retrograde balloon, antegrade wiring was performed and Resolute stents (Medtronic) were placed in the vessel, with excellent final angiographic results (Figure 2F). Discussion Many methods of wire crossing CTOs in a retrograde approach PCI have been described.1,3–5 The retrograde wire can be used merely as a marker wire, and it becomes a target for the antegrade wire to navigate towards (Figure 3A). The retrograde wire can also be pushed into the CTO and become an intra-occlusion marker wire in a kissing-wire technique (Figure 3B). The retrograde wire can pass through the CTO into the antegrade true lumen in the simple retrograde wire-crossing technique (Figure 3C). A balloon can be used to dilate the subintimal space on the retrograde side of the CTO, and the antegrade wire can be used to puncture this subintimal space using the CART technique (Figure 3D). The reverse can be performed, where the retrograde wire is used to puncture a subintimal space made by an antegrade balloon inside the antegrade side of the CTO in what is known as the “reverse CART” technique (Figure 3E). Intravascular ultrasound guidance, anchoring balloon use and parallel-wire techniques used alongside these CTO techniques can usually achieve wire crossing in the hands of Japanese experts. However, these techniques may be inadequate to achieve wire crossing, even in a very experienced operator’s hands. We therefore described a novel technique using simultaneous confluent balloon inflation to cause the subintimal space to become confluent, allowing wire passage through the CTO. When two overlapping balloons inserted in the retrograde and antegrade subintimal spaces are inflated simultaneously (Figure 4A), the subintimal spaces join together, with the balloon inflation leading to confluence of the subintimal space (Figure 4B). This allows the retrograde wire to pass easily through this newly created confluent subintimal space (Figure 4C). There are a few tips to improve this technique. The slight withdrawal of the retrograde balloon before passing the retrograde wire is useful, as sometimes the retrograde balloon tip is against the wall in the subintimal space, and this slight withdrawal allows easier wire passage. Inflating the retrograde balloon is also helpful, as this holds the subintimal space open for wire passage. In our experience, we have found this technique to be invaluable when faced with an impassible CTO in a patient facing prolonged fluoroscopy time and limited residual contrast volume. However, we must recognize that the retrograde approach and, in particular, the confluent balloon technique, are advanced interventional techniques and should not be attempted by inexperienced operators. We would also advise caution regarding balloon size. It is important not to use balloons that are too large, as combined inflation of large balloons may lead to vessel rupture. Theoretically, this technique can also be used in conjunction with the channel dilator by inflating the antegrade balloon in a position overlapping with the tip of the channel dilator, and then pulling the dilator back to pass the wire after balloon deflation. Conclusion We report on a novel technique to achieve wire crossing of CTOs using a retrograde-approach PCI. This technique provides a rapid, reliable and easy method to accomplish wire crossing, and is particularly useful when the patient has minimal residual fluoroscopy time or contrast volume for the procedure. We highly recommend this method for other operators faced with difficult wire crossing during retrograde PCI to treat CTOs. Acknowledgements. We acknowledge that there are probably other operators in Japan who have used this technique in their cases. However, the authors were unable to find any published report of this technique, thus, we have submitted these cases for publication. From the Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, Chinese University Hong Kong. The authors report no conflicts of interest regarding the content herein. Manuscript submitted March 27, 2009, provisional acceptance given April 27, 2009, final version accepted May 4, 2009. Address for correspondence: Eugene Brian Wu, MRCP, MD, Division of Cardiology, Department of Medicine and Therapeutics, Prince of Wales Hospital, Chinese University Hong Kong, Ngan Shing Street, Shatin, Hong Kong. E-mail: ebwu@netvigator.com

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. Sianos G, Barlis P, Di Mario C, et al. European experience with the retrograde approach for the recanalisation of coronary artery chronic total occlusions. A report on behalf of the Eurocto Club. Eurointervention 2008;4:84–92.

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. 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. Catheter Cardiovasc Interv 2007;69:826–832.