Transradial Approach for Post-Coronary Artery Bypass Graft Angiography: What Works From the Leg, Works From the Wrist!

Patients referred for diagnostic angiography after coronary artery bypass graft (CABG) surgery are more frequently older and present with much comorbidity compared with those undergoing angiography with/without percutaneous coronary intervention (PCI) for native coronary artery disease.¹ The transradial approach for coronary angiography and intervention has been extensively proven safer in terms of access-site related complications compared with the transfemoral approach among a broad spectrum of patients and scenarios. Indeed, it appears that while facing sicker and higher-risk patients, more benefits are provided when the transradial approach is performed.^2,3 Yet, as coined by the term “the radial paradox,” it has been observed that radial access is more often used in lower-risk patients. This might suggest that technical issues with higher-risk patients, such as post-CABG elderly patients, might hamper wider use of the transradial approach.

In this issue of the Journal of Invasive Cardiology, Pasley et al⁴ have confirmed the feasibility and safety of left radial access in post-CABG patients undergoing diagnostic angiography. The authors report a retrospective analysis of 326 post-CABG patients (254 femoral and 72 left radial approach) studied between 2008-2012. There was no significant difference between the two approaches in procedure time and radiation exposure. Notably, two-thirds of the study population presented with acute coronary syndrome; however, due to potential confounders that may have affected primary and secondary outcomes, patients who underwent PCI were excluded. As expected, major complications, although infrequent, tended to be more frequent in the transfemoral group. Of note, 3 transradial patients needed crossover to transfemoral and 1 transfemoral patient needed crossover to radial. 

Certainly, the transradial approach keeps the advantages, from early ambulation to the avoidance of access-site related complications and bleeding, which may prolong hospitalization and impact delayed prognosis. 

It is well known that most radial operators prefer using the right radial access and can successfully perform left internal mammary artery (LIMA) angiography from this route.⁵ However, since the vast majority of post-CABG patients have a LIMA grafted on the left anterior descending artery, the left radial approach remains the default access for post-CABG patients undergoing repeat angiography. Notably, the left radial approach is not only better due to the easier access to the LIMA graft, but also in terms of catheter torqueability and further support/contact-point conferred by the contralateral wall of the aorta when a saphenous vein graft (SVG) to the left system needs to be engaged and/or undergo PCI. 

Tips for CABG angiography and interventions from the wrist. The first step should be deciding which would be the access side. Thus, if the right internal mammary artery (RIMA) was used as a graft, then choose the right radial access; otherwise, the left radial access is preferred. In terms of catheter shapes, it is important to remember that there is no need for special/dedicated radial catheters, and one should simply use the same preferred routine material as for standard femoral approach. Therefore, to perform selective cannulation of native coronary ostia, we prefer the Judkins left (JL) and right (JR) catheters. To cannulate the left coronary ostium from the left radial approach, JL 4.0 is usually preferred to the JL 3.5, which is the one used from the right radial approach.

Internal mammary graft cannulation. The internal mammary artery (IMA) catheters, preferably the modified-IMA catheters, are a good choice. The modified-IMA catheter has a second curve proximally that permits an easier engagement and avoids backward motion (disengagement) while injecting. Also, it is useful for those patients presenting with a LIMA takeoff at the level of the ascending portion of the subclavian artery or at its corner toward the horizontal portion (this also applies to the RIMA). In cases where the left radial artery was surgically removed and used as a graft, the LIMA can be cannulated from the right wrist in more than 90% of cases. In order to provide enough support for advancing the catheter, it is crucial to place a 0.035˝ hydrophilic guidewire (eg, Glidewire; Terumo Corporation) beyond the shoulder, so “as far as possible” deep into the brachial artery (preferably at the level of the elbow; Figure 1A). This technique provides support for the advancement of the diagnostic catheter (eg, modified IMA, radial brachial, Tig) over the wire (Figure 1B). If it is not possible to advance the wire deep into the brachial artery, it is useless to try to advance the catheter since it will always flip back into the aorta. If there is not enough support to advance the catheter through the left subclavian artery, even with a proper deep wire placement, external compression of the left arm (brachial or radial/cubital artery) is advised in order to maintain/fix the wire and increase further support. This can also be achieved by inflating a blood pressure cuff or by the elbow flexion technique.⁵ 

Although rare (<10% of cases), if PCI is needed at the level of the anastomosis or further on the native artery, a long (300 cm) coronary PCI guidewire like a Balance Heavyweight (BHW; Abbott Vascular) or Balance Middleweight Universal II (BMW; Abbott Vascular) can be advanced through the diagnostic catheter, cross the lesion, and be placed at the distal portion of the native vessel. Then, the diagnostic catheter is removed and a 5 Fr guiding catheter is advanced. If Extra-Backup (Cordis) is available, all 5 Fr guiding catheters come with the Long Brite Tip feature, which allows deep intubation while preventing LIMA dissection. Importantly, if a regular 190 cm coronary guidewire was used, then ask for a DOC guidewire extension (Abbott Vascular) to exchange the diagnostic catheter by the guiding catheter.

Saphenous vein graft cannulation. For an SVG to the right coronary artery (RCA), after RCA angiography with a JR 4, the same catheter usually reaches the SVG ostium (Figures 2A and 2B). However, after unsuccessful attempts or inability to selectively cannulate the SVG, we prefer to switch to a multipurpose catheter (Figure 2G), as it offers a more coaxial cannulation. If it fails again, then we switch to an Amplatz left (AL) curve 1, 2, or 3 depending on the ascending aorta diameter. If PCI is needed, we prefer a Multipurpose first followed by an AL curve. When the right radial access is initially obtained, first try a Multipurpose or AL curve. If PCI is needed, either a Multipurpose or AL will sit well. 

For SVGs to the left coronary system, a JR 4 may allow cannulation of the SVG ostium (Figures 2C-2F). However, if it fails, we prefer to switch to an AL-1 (Figure 2H), AL-2, or AL-3 depending on the ascending aorta diameter followed by a left coronary bypass (LCB) catheter. When the right radial access is used, first try an AL curve, then a Tig or LCB catheter. If PCI is needed, we prefer AL curves since JR or LCB catheters do not provide much support. Notably, when using the right radial approach, a one-size bigger catheter would also be advised, ie, AL-1 from the left radial and AL-2 from the right radial. 

We provide an algorithm following the “keep it simple and straightforward” concept, with the different catheters of choice based on the selected approach (Figure 3). The technique used to engage an SVG/radial graft to either left/right coronary system and by left/right radial approach is the same.

In summary, once the learning period is completed, the transradial approach is technically as feasible as the femoral approach for post-CABG angiography and PCI, yet it retains the significant safety advantages of radial access. It is now the responsibility of every training program to involve exposure of new fellows to post-CABG patients using both femoral and radial access for diagnostic angiography and PCI. 

References

1.    Malenka DJ, Leavitt BJ, Hearne MJ, et al. Comparing long-term survival of patients with multivessel coronary disease after CABG or PCI: analysis of BARI-like patients in northern New England. Circulation. 2005;112(9 Suppl):I371-1376. 

2.    Bernat I, Abdelaal E, Plourde G, et al. Early and late outcomes after primary percutaneous coronary intervention by radial or femoral approach in patients presenting in acute ST-elevation myocardial infarction and cardiogenic shock. Am Heart J. 2013;165:338-343.

3.    Bernat I, Horak D, Stasek J, et al. ST-segment elevation myocardial infarction treated by radial or femoral approach in a multicenter randomized clinical trial: the STEMI-RADIAL trial. J Am Coll Cardiol. 2014;63:964-972. 

4.    Pasley TF, Ali K, Yen LY, Newcombe R, Humphreys H, El-Jack S. Left radial vs femoral access for coronary angiography in post-coronary artery bypass graft surgery patients. J Invasive Cardiol. 2016;28:81-84. Epub 2016 Feb 15.

5.    Patel T, Shah S, Patel T. Cannulating LIMA graft using right transradial approach: two simple and innovative techniques. Catheter Cardiovasc Interv. 2012;80:316-320.

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From the ¹London Health Sciences Centre, Ontario, Canada; and ²Quebec Heart & Lung Institute, Quebec City, Canada.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.

Address for correspondence: Olivier F. Bertrand, MD, PhD, FSCAI, Interventional Cardiology, Quebec Heart & Lung Institute, 2725 Chemin Sainte-Foy, Quebec City (QC), G1V 4G5 Canada. Email: olivier.bertrand@criucpq.ulaval.ca