Balloon-Assisted Tracking in Dealing With Radial Artery Loop by Transradial Approach: A Technical Report

Abstract: The transradial approach for various coronary procedures has gained worldwide popularity because it reduces bleeding complications and increases patient comfort level. There may be difficulties encountered at various anatomical levels from radial artery to coronary artery level by this approach. Radial artery loop is one of the most common anatomical reasons for deferring or failure of transradial approach and shifting to the femoral route. Balloon-assisted tracking of catheters may help deal with radial artery loops without injuring the endothelium and increase the success rate of the coronary procedure. 

J INVASIVE CARDIOL 2014;26(5):E61-E62

Key words: transradial approach, radial artery loop,nballoon-assisted tracking

____________________________

Transradial approach for coronary angiography and intervention is gradually becoming a preferred alternative to standard femoral approach. There can be difficulties encountered at various anatomical levels beginning from radial artery to coronary artery level. Radial artery loop is one of the anatomical difficulties and is associated with the highest failure rate. This anatomical variation is present in 1.1% of patients undergoing their first transradial coronary procedure and is more commonly seen in the elderly.¹ Balloon-assisted tracking has been shown to overcome many of the anatomical difficulties by transradial approach.² Here, we describe two cases of radial artery loop successfully traversed using this technique.

Case 1

A 69-year-old female patient with a known history of ischemic heart disease and hypertension was admitted to our institution with complaint of angina with 6-month duration. Three years prior, she had undergone percutaneous coronary intervention with stenting in her left anterior descending coronary artery via right femoral approach at another institution. A 12-lead electrocardiogram revealed significant ST-segment depression in the lateral leads. Transthoracic echocardiography revealed normal left ventricular systolic function. After informed consent, coronary angiography was planned. After insertion of a 5 Fr radial sheath (Radifocus; Terumo), a 0.035˝ guidewire could not be negotiated through the radial artery. Contrast injection through the radial sheath revealed a small-caliber radial artery with 360˚ loop in its proximal segment (arrow, Figure 1; Video 1). Then, balloon-assisted tracking of a TIG catheter (Terumo Corporation) was planned. The loop was crossed with a 0.014˝ BMW PTCA guidewire (Abbott Vascular), over which the 5 Fr TIG catheter was tracked and placed distal to the loop. At the tip of the catheter, the balloon portion of 1.5 x 15 Voyager PTCA balloon catheter (Abbott Vascular) was positioned, keeping 5 mm protruding outside the TIG catheter, and was then inflated at 4 atm. Then, the catheter was pushed gently with clockwise rotation and the loop was successfully crossed (Figure 2; Video 2).  Before negotiating the catheter further, the entire assembly was slowly pulled back to straighten the loop. Coronary angiography was performed in the usual manner, with no significant lesion. 

Case 2

A 63-year-old male was referred to our institution for invasive management of unstable angina. He had recently diagnosed hypertension and underwent diagnostic coronary angiography via right femoral approach (initially attempted via right radial approach), revealing a significant lesion in the mid left anterior descending coronary artery. A 12-lead electrocardiogram revealed T-wave inversion in anterior precordial leads. Transthoracic echocardiography revealed normal left ventricular systolic function. After 5 Fr radial sheath (Radifocus) insertion, a 0.035˝ guidewire couldn’t be negotiated. Contrast injection through 5 Fr EBU Launcher guide catheter (Medtronic, Inc) revealed a 360˚ loop in the proximal segment of the radial artery (arrow, Figure 3; Video 3). The loop was crossed with 0.014˝ BMW PTCA guidewire. As in the above case, balloon-assisted tracking of the 5 Fr EBU guide catheter was successfully performed (Figure 4; Video 4). The loop was successfully crossed and the procedure was completed without any complication.          

Discussion

Balloon-assisted tracking is a new technique dealing with various anatomical difficulties during coronary interventions by transradial approach. This technique helps deal with difficulties with small and tortuous radial artery anatomy, radial artery perforation, and subclavian loop, and also during deep intubation of guide catheter for direct thromboaspiration in patients with acute myocardial infarction.^2-4 Radial artery loop is a common reason for deferring transradial coronary procedures and changing to femoral route. Moreover, radial artery loop is more commonly seen in elderly patients, who are mostly benefited by TRA in terms of decreasing the complication rate and increasing the comfort level as compared to femoral approach.⁵ In this technique, the PTCA balloon is kept at the tip of the catheter with the distal half portion in the artery and inflated at low pressure (3-4 atm). The low-pressure inflation helps the catheter negotiate extreme curves and loops, as in our cases. The main advantage of balloon-assisted tracking is in preventing the “razor effect” of the catheter tip to the radial artery endothelium.⁶ This technique may be useful in both diagnostic and selective coronary interventions with 5 Fr catheters. The same technique can be used to track 6 Fr guide catheters across the loop, but the frequency of radial artery spasm increases, which may cause difficulty in maneuvering the catheter during complex coronary interventions. 

Conclusion

This balloon-assisted catheter tracking technique may be useful in overcoming the difficulties of radial artery loops via transradial approach for various coronary procedures. 

Acknowledgment. The authors would like to thank Mr Yash Soni for his invaluable assistance in preparation of the images.

References

1. Norgaz T, Gorgulu S, Dagdelen S. Arterial anatomic variations and its influence on transradial coronary procedural outcome. J Intervent Cardiol. 2012;25(4):418–424.
2. Patel T, Shah S, Pancholy S. Balloon-assisted tracking of a guide catheter through difficult radial anatomy: a technical report. Catheter Cardiovasc Interv. 2013;81(5):E215-E218.
3. Deora S, Shah S, Patel T. Balloon-assisted tracking of guide catheter dealing with radial artery perforation and subclavian loop during percutaneous coronary intervention by transradial approach. Int J Cardiol. 2013;167(6):e161-e162. Epub 2013 May 4. 
4. Deora S, Shah S, Patel T. Balloon-assisted deep intubation of guide catheter for direct thromboaspiration in acute myocardial infarction — a technical report. Int J Cardiol. 2013;168(1):545-547. Epub 2013 Feb 20.  
5. Achenbach S, Ropers D, Kallert L, et al. Transradial versus transfemoral approach for coronary angiography and intervention in patients above 75 years of age. Catheter Cardiovasc Interv. 2008;72(5):629-635.
6. Patel T, Shah S, Pancholy S, et al. Balloon-assisted tracking: a must-know technique to overcome difficult anatomy during transradial approach. Catheter Cardiovasc Interv. 2014;83(2):211-220. Epub 2013 May 9.