Overcoming the 360 degree radial artery loop

Supported by the EuroIntervention Journal

Authors

Karthick Manoharan¹, Pitt O Lim¹

Case summary

A 77-year-old man was admitted for an elective diagnostic coronary angiogram. He had CABG in 2012 and has had multiple coronary interventions over the past 2 years for graft failures. Previous right radial access was unsuccessful because of difficulty in advancing any catheter beyond the elbow, likely to be due to wiring of the straight but small radial recurrent artery, now with hindsight (Panel A). Prior left radial approach was hindered by left subclavian artery tortuosity and a kinked catheter, and femoral access was complicated by significant groin haematoma.

On this occasion, following insertion of a 6Fr sheath into the distal right radial artery, a radial angiogram was performed upfront which showed a complete 360 degree radial artery (loop). Under normal circumstances, an alternative access site should be sought, as straightening such a loop is painful “if it could be done at all” and catheter exchanges would be traumatic and difficult, if not impossible. However, in view of the above experiences, we decided to persist with the strategy described below which has not been tested in the past.

An angioplasty 0.014” guidewire was advanced down the radial artery traversing the loop into the brachial artery. A 5Fr JR4 guide was then advanced into the loop, but it failed to cross because of wire bias. To overcome this, a 4Fr Pigtail catheter was introduced into the 5Fr JR4 guide; firstly, to provide a graduated telescopic tapering tip, secondly, the tip is curved to allow the system to take the shape of the loop which overcomes the “razor tip phenomenon” (Panel B), and thirdly, it provides support to increase the pushability of the 5Fr JR4 guide. Once the system crossed the loop, it was twisted anticlockwise to straighten the loop, and this allowed the system to be advanced into the aorta. Next, a J-tipped 0.035” 260 cm exchange length wire was inserted with the tip parked in the aortic root, and then the catheters were removed.

Finally, a 6Fr 90 cm hydrophilic guiding sheath (Cook Medical, Bloomington, IN, USA) was pushed across the straightened loop (Panel C) into the ascending aorta, and a short haemostatic valve (Terumo Corporation, Tokyo, Japan) was attached to the other end turning this into an 'extra-long' sheath to allow painless and seamless multiple catheter exchanges to complete the procedure.

Conflict of interest statement

The authors have no conflict of interest to declare.

Affiliation

1. Department of Cardiology, St George’s Hospital, London, UK