Transradial Reverse CART

Disclosure: Orlando Marrero reports no conflicts of interest regarding the content herein. Dr. Zaheed Tai reports the following: Terumo (proctor for transradial course), Spectranetics (proctor for laser course, speaker, advisory board), The Medicines Company (speakers bureau). 

Orlando Marrero can be contacted at orlm8597@yahoo.com. Dr. Zaheed Tai can be contacted at zaheedtai@gmail.com.

We report a follow-up case to the question asked in the April 2014 edition of Cath Lab Digest¹ regarding the use of radial access for the treatment of chronic total occlusions.

Case 

A 72-year-old female admitted recently with a history of hypertension, hyperlipidemia, chronic obstructive pulmonary disease (COPD), and tobacco abuse was admitted again with a non-ST-elevation myocardial infarction (NSTEMI) and new onset left ventricular (LV) dysfunction. Cardiac catheterization revealed multi-vessel disease. The proximal left anterior descending coronary artery (LAD) had long, diffuse disease (angiographically not critical) with a focal mid lesion, the circumflex had severe diffuse disease, and there was a chronic total occlusion (CTO) of the obtuse marginal (OM) and a CTO of the right coronary artery (RCA) (Figure 1). The patient was initially referred for surgery, but because of underlying pulmonary disease, she was not considered a reasonable candidate at this time. After discussion with the family, it was felt the best course of action would be to fix the critical LAD lesion, then revascularize the RCA CTO and treat the circumflex medically, as adequate revascularization of the circumflex would require stenting all the way back to the left main. 

The patient underwent successful percutaneous coronary intervention (PCI) of the mid LAD via the radial approach with implantation of a 3.0 x 12 mm Promus Premier stent (Boston Scientific) and was to be staged for the RCA a few weeks later. Nearly one week after the LAD PCI, the patient presented to the hospital with recurrent angina and at this time, an attempted revascularization of the RCA CTO was planned. After review of the previous angiograms, it was felt that an antegrade attempt would be successful. Access was obtained in the right groin and the right radial. A 7 French (Fr) 45 cm Destination sheath (Terumo) was placed in the right groin and an ART3 guide (Boston Scientific) was used to engage the right coronary artery. A Glidesheath Slender (Terumo) sheath (5 Fr outer diameter, 6 Fr inner diameter) was placed in the right radial and a Q 3.5 6 Fr guide (Boston Scientific) was used to engage the left main. 

After simultaneous injection was performed, a 135 cm Corsair (Asahi Intecc) catheter and an Asahi Fielder XT guide wire (Abbott Vascular) were used to try to probe the proximal cap. The wire advanced distally and was followed by the Corsair catheter (Figure 2). Unfortunately, as the wire advanced toward the bifurcation, it was not freely mobile as expected, considering the reconstitution zone. A brief attempt at wire escalation was attempted. Contralateral injection revealed poor visualization of the distal vessel, likely a result of vessel hematoma from a subintimal channel (Figure 3). Given the poor visualization and the desire to preserve both branches, the options were to either switch to a retrograde approach or attempt to use the Stingray CTO re-entry system (Boston Scientific) while aspirating the subintimal channel. We elected to change to the retrograde approach.

Using a Runthrough wire (Terumo) and a 150 cm Corsair catheter, we entered a septal distal to the stent and switched to a Fielder FC wire. Surfing of the collateral was performed with some retrograde crossing into the distal right posterior descending artery (RPDA) via an unintended collateral (on angio, it did not appear to have a direct communication with the distal vessel) (Figure 4). One of the attempts did result in an inadvertent perforation. It appeared to be intramyocardial and no obvious extravasation was noted. The patient remained hemodynamically stable. We elected to proceed with the case (trying to minimize retrograde injections). The Corsair catheter was advanced into the distal RPDA and then we attempted retrograde true-to-true (the simplest version of retrograde PCI. A back-end wire is pushed directly through the blockage to the front end) (Figure 5). Unfortunately, wire attempts resulted in subintimal wire placement (Figure 6). It was unclear if this occurred in the distal or mid RCA; however, we were able to get the wires to align in the mid RCA. Given the small caliber of the collateral and the difficulty advancing the wire and Corsair catheter, a reverse CART seemed to be the best approach. Initially, a 3.5 x 12 mm Emerge balloon (Boston Scientific) was dilated on the antegrade wire and a Pilot 200 wire (Abbott Vascular) was advanced from the retrograde approach. This proved unsuccessful. After further wire manipulation and changing to a Confianza Pro 12 (Asahi) we could not cross retrograde. Re-evaluation of the angiogram and the wire alignment suggested the initial antegrade balloon might have been too small. The reverse CART was attempted with a 4.0 x 15 mm Emerge balloon antegrade (Figure 7). Following balloon inflation and deflation, the Confianza wire advanced retrograde and into the true lumen (Figure 8). Unfortunately, the retrograde Corsair could not be advanced at this point, secondary to “Corsair fatigue”. With the 6 Fr retrograde guide, we could not “trap” the Corsair and switch out for a new catheter. We were able to advance the retrograde wire into the antegrade guide (without torquing the wire) and trap the wire in the guide. At that point, the Corsair was removed from the retrograde channel and a new Corsair (flushed with pure Rotaglide [Boston Scientific]) was advanced easily into the antegrade guide. The Confianza wire was then changed for a Viper wire (CSI) (0.014-inch) tip and externalized from the groin. The retrograde Corsair was pulled back into the RPDA and a 0.9 mm ELCA coronary laser atherectomy catheter (Spectranetics) was advanced (Figure 9). Laser atherectomy was performed in the mid and distal RCA. A 2.5 x 30 mm Emerge balloon was then used to predilate the distal and mid RCA. Following predilation, a 2.5 x 38 mm Promus Premier stent was advanced, but did not make the proximal bend. The stent was removed, and a 3.0 x 30 mm Emerge balloon was used to predilate the mid and proximal bend of the RCA. The stent was then delivered distally and overlapped proximally with a 3.5 x 38 mm Promus Premier stent. Antegrade injection revealed a proximal lesion and dissection distally, extending into the PDA. Initially, prolonged inflation was attempted to address the dissection. When this was not successful, a 2.25 x 16 mm Promus Premier stent was placed distally and a 4.0 x 16 mm Promus Premier stent proximally (Figure 10). The Corsair catheter was advanced back into the antegrade guide and the wire was removed through the Corsair. A Runthrough wire was advanced antegrade into the distal RPDA and the Corsair was removed, as was the retrograde guide. The vessel was post-dilated with noncompliant balloons, and following administration of nitroglycerin, angiography revealed TIMI-3 flow in the RCA, RPDA, and right posterolateral ventricular branch (RPLV). There was no evidence of the perforation via injection of the right system (Figure 11). The radial sheath was removed and a Perclose (Abbott Vascular) of the groin was performed. A post procedure echo demonstrated a small effusion, but the patient was hemodynamically stable. She did drop her pressure approximately 20 minutes later. Repeat echo did not reveal any progression of effusion; however, a repeat angiogram was performed that did not demonstrate any contrast extravasation. She remained stable thereafter and was discharged without incidence. 

Discussion

A previous Cath Lab Digest article¹ addressed some of the issues with a retrograde approach. In this particular case, we used a 6 Fr retrograde guide with the assumption of an antegrade-only case. This was a mistake, as it limits potential options. CTOs can be performed through 6 Fr guides; however, it does limit the ability to use certain tools or techniques. CTOs can also be performed successfully from a radial-only approach, although dual access points may be required in a percentage of patients.² In this case, we were not able to “trap” the wire to exchange the Corsair; however, once we advanced into the antegrade guide, we were able to trap the wire there and complete the exchange.  

Retrograde recanalization involves two main steps: 1) delivery of wire and microcatheter via the collateral, and 2) crossing the CTO. Crossing is achieved with an antegrade crossing using a distal wire marker: true-to-true technique or dissection re-entry. There are two main dissection re-entry strategies from a retrograde approach: the CART and reverse CART. The CART technique involves dilation of a balloon over the retrograde wire and antegrade wiring. The reverse CART involves dilation of a balloon over the antegrade wire and retrograde wiring. Other techniques involve retrograde/antegrade kissing balloons (to rupture the “membrane”) and knuckle wire retrograde with snaring of the wire in the distal aorta. Microcatheters such as the Corsair have made the reverse CART the most common retrograde technique.³ Limitations of this technique include failure to penetrate the space (usually the result of undersizing the antegrade balloon) and recoil of the subintimal space. Intravascular ultrasound (IVUS) may help in understanding the spatial relation of the antegrade and retrograde space.⁴ Another technique is the “stent reverse CART” where a stent is deployed over the antegrade wire, allowing for passage of the retrograde wire. An alternative technique is the Guideliner Reverse CART. This involves advancing a GuideLiner catheter (Vascular Solutions) over the antegrade wire to create a distal target for the retrograde wire. This technique could potentially save time, avoid guide dissection, and shorten the distance the wire has to traverse (avoiding tortuosity, dissection planes, and plaque burden). Advancing the GuideLiner can be difficult, and may require an anchor balloon or proximal vessel treatment to allow advancement. 

As stated in the previous article¹, the retrograde approach can be performed with a reasonable degree of safety by experienced operators. There are many subtleties that need to be recognized; it is important to note that we have by no means provided a comprehensive description of this approach. An article cannot replace proctorship, course attendance, in-lab work, and live exchanges. More information can be found at www. ctofundamentals.org or by contacting your Boston Scientific representative about proctorship. 

References

1. Marrero O, Tai Z. Transradial/transfemoral retrograde CTO revascularization. Cath Lab Digest. 2014 Apr;22(4):1,20. Available online at https://www.cathlabdigest.com/articles/TransradialTransfemoral-Retrograde-CTO-Revascularization. Accessed June 23, 2014.
2. Rinfret S, Joyal D, Nguyen CM, Bagur R, Hui W, Leung R, Larose E, Love MP, Mansour S. Retrograde recanalization of chronic total occlusions from the transradial approach; early Canadian experience. Catheter Cardiovasc Interv. 2011 Sep 1; 78(3): 366-374. doi: 10.1002/ccd.23140.
3. Brilakis ES, Grantham JA, Thompson CA, DeMartini TJ, Prasad A, Sandhu GS, Banerjee S, Lombardi WL. The retrograde approach to coronary artery chronic total occlusions: a practical approach. Catheter Cardiovasc Interv. 2012 Jan 1; 79(1): 3-19. doi: 10.1002/ccd.23004.
4. Dai J, Katoh O, Kyo E, Tsugi T, Watanabe S, Ohya H. Approach for chronic total occlusion with intravascular ultrasound-guided reverse controlled antergrade and retrograde tracking technique: Single center experience. J Interv Cardiol. 2013 Oct; 26(5): 434-443. 
5. Mozid A, Davies JR, Spratt JC. The utility of a guideliner catheter in retrograde percutaneous coronary intervention of a chronic total occlusion with reverse cart – the “capture” technique. Catheter Cardiovasc Interv. 2014 May 1; 83(6): 929-932. doi: 10.1002/ccd.25205.