Original Contribution

Feasibility and Safety of Performing Complex Coronary Interventions by Distal Radial Artery Using the Railway Sheathless Vascular System

Giuseppe Colletti, MD1; Jacques Auslender, MD1; Antoine De Meester, MD1; Adel Aminian, MD2; Peter Kayaert, MD3; Claudiu Ungureanu, MD1

Giuseppe Colletti, MD1; Jacques Auslender, MD1; Antoine De Meester, MD1; Adel Aminian, MD2; Peter Kayaert, MD3; Claudiu Ungureanu, MD1

Abstract: Aims. The aim of this clinical study is to assess the feasibility and safety of the 7 Fr Railway sheathless access system (Cordis Corporation) for complex percutaneous coronary interventions (PCI) using distal radial artery access. Methods and Results. Over a 2-month period, we enrolled 20 patients (all those undergoing complex PCI) where a 7 Fr guide catheter was deemed necessary. Multiple bifurcation techniques and calcified plaque modifying tools were used. The primary endpoint was procedural success (95%) without need for access-site crossover (0%) or major adverse cardiovascular event within the first month (0%), while our secondary endpoint was the access-site complication rate (arterial spasm in 1 case [5%]). Conclusion. Distal radial access with the 7 Fr Railway sheathless access system was a feasible and safe access option for complex PCI in our very high-risk study population. This approach could be a valuable option for decreasing the risk of a major bleeding event or vascular complication in cases that require a large guide catheter.

J INVASIVE CARDIOL 2020;32(12):459-462. Epub 2020 September 22.

Key words: 7 Fr, chronic total occlusion, complex coronary intervention, distal radial artery, rotational atherectomy, sheathless

Transradial access (TRA) is strongly recommended by European guidelines1 due to its multiple advantages over transfemoral access (TFA) both in elective and acute settings.2-6 Still, in complex percutaneous coronary interventions (PCIs), a larger guide catheter (>6 Fr) is sometimes preferred and in some patients, especially women, the radial artery may not accommodate larger-bore introducer sheaths.7-10 In such cases, many operators still use TFA regardless of the higher complication rates and worse outcomes.11

The use of the thin-wall 7 Fr Glidesheath Slender (Terumo) for traditional forearm radial12 or more recently for distal radial access13 has proved to be feasible and safe. However, radial artery occlusion (4.8%), severe spasm (11%), and other vascular access-site complications (4.7%) do occur.12 Dedicated guide catheters (Eaucath; Asahi Intecc) that can be used without an introducer sheath (“sheathless”) are an alternative, but shapes are limited.14-17

Distal TRA for coronary angiography and PCI has been shown to be feasible, but when larger introducer sheaths (>6 Fr) are used, severe spasm and pain can be induced.13,18-23 The 7 Fr Railway Sheathless (RS) access system (Cordis Corporation) has recently become available. The RS system offers the choice of two dilators that are compatible with 0.021˝ or 0.035˝ guidewires. Both dilators fit in a conventional 7 Fr guide catheter of any shape. Once assembled, the “dilator within guide” can be smoothly advanced through the skin into the radial artery over a guidewire. The dilator is then removed and only the 7 Fr guide catheter is left in the artery. 

Our study aimed to assess the feasibility and safety of the 7 Fr RS access system for complex PCIs using distal TRA. 


Over a 2-month period (December 2019-January 2020), we prospectively collected all consecutive cases of PCI performed with a 7 Fr guide catheter. The distal radial artery was the first attempted vascular access; in the event of failure, we planned to convert to another vascular access (TRA or, if necessary, TFA). 

The radial artery was punctured distally in its portion running through the anatomical snuffbox (Figure 1A), an area located medially in the dorsal side of the wrist (fovea radialis), delineated by the edges of tendon of the extensor pollicis longus posteriorly and the tendons of the extensor pollicis brevis and abductor pollicis longus anteriorly.

First, the snuffbox was checked for the presence of radial pulse and, with the arm pronated, the area was disinfected. A solution of 3 mg of mepivacaine hydrochloride and 1 mg of isosorbide dinitrate was then injected subcutaneously. The puncture was done with a 21 gauge bare needle from lateral to medial with an angle of ~35°. Care was taken to only puncture the anterior vessel wall, thus avoiding possible patient discomfort caused by contact of the needle with the periosteum of the trapezium and scaphoid bones. 

After acquiring access, a 5 Fr sheath was inserted and a conventional 0.035˝ J wire was advanced up to the ascending aorta (Figure 1B). The 5 Fr sheath was then removed and the 7 Fr guide catheter, preloaded with the 0.035˝-wire compatible Railway dilator (Figure 1C and 1D), was advanced in the aortic arch (Figure 1E). The Railway dilator was retrieved and the target coronary artery was cannulated. At the end of procedure, 5 minutes of manual compression was applied, followed by a compression bandage for 2 hours. 

Study endpoints. The primary endpoint of the study was procedural success without access-site crossover and no major adverse cardiovascular events within the first month, while the secondary endpoints were the rate of major bleedings and access-site complications (arterial spasm, forearm and distal radial artery occlusion at 24 hours and 1-month follow-up, non-occlusive injury, hand ischemia, or cutaneous radial nerve damage).


Twenty patients were included in the study. Clinical and procedural characteristics are shown in Table 1. The patients were treated for complex coronary disease: distal left main disease (n = 8 ), complex non-left main bifurcation disease (n = 7), and chronic total occlusions (n = 4), with severely calcified disease requiring rotational atherectomy (n = 9), intravascular lithotripsy (n = 2), or specific balloons (cutting or ultra high-pressure balloons) (n = 3). Several two-stent bifurcation techniques were utilized.24 

Left distal TRA was used in 30% of cases and was mainly reserved when the need for more guide support was expected. More than 1 vessel was treated during the same procedure in 7 patients (35%), with 3 of these requiring guide-catheter exchange. No patient required conversion to a different vascular access site. 

We achieved a 95% procedural success rate (1 chronic total occlusion case was unsuccessful despite attempting both antegrade and retrograde approaches) and all patients were event free up to 1 month after hospitalization. No major vascular complications, forearm/distal radial artery occlusion, or bleeding events were observed during hospitalization or at 1-month follow-up (good pulse at both distal and proximal level of the radial artery was suggestive of artery patency). One patient (5%) experienced severe spasm later in the procedure (when the 7 Fr guide catheter was already in place) requiring anxiolytic and analgesic medications. 


Distal TRA potentially has multiple potential advantages over proximal TRA with regard to vascular complications.25 However, in comparison with the more proximal part of the radial artery, the distal part is on average 0.5 mm smaller.26,27 As a consequence, when using distal TRA, the use of slender techniques and miniaturization should be preferred in order to avoid a large sheath-to-artery mismatch, which has unfavorable consequences.7,8,28-30

Despite the use of large 7 Fr guide catheters in our series, we didn’t find any (clinical) evidence for radial artery occlusion and only 1 patient (5%) suffered discomfort during the procedure due to arterial spasm. This may be explained by the measurements of the devices used in our study (Figure 2). The outer diameter of a 7 Fr guide catheter (2.33 mm) is comparable to the outer diameter of a regular 5 Fr introducer sheath (2.29 mm) and is therefore significantly smaller than the outer diameter of a traditional 7 Fr introducer sheath or even a 7 Fr Glidesheath Slender (Terumo) (2.95 mm and 2.7 mm, respectively).  

Our study shows that when a 7 Fr RS is used, the distal radial artery can accommodate large 7 Fr guide catheters, thereby enabling the performance of highly complex PCI without major bleeding events, radial artery occlusion, or other access-site related complications. 

Study limitations. Our pilot series is limited by its sample size and relatively low percentage of women (20%), who are known to have smaller radial arteries. Radial artery occlusion was only assessed by clinical examination of the arterial pulse. All procedures were performed by highly experienced radial operators who have an important expertise in the treatment of very calcified coronary lesions; therefore, the observed results may not be widely reproducible.


Our study suggests that distal TRA using a 7 Fr guide catheter and the RS access system for complex PCI is feasible and safe. When large-bore guide catheters (>6 Fr) are needed for complex PCI, one should consider using the 7 Fr RS and distal TRA in order to potentially reduce access-site related complications and improve patient outcomes.

From the 1Jolimont Hospital — Cardiology Department, La Louvière, Belgium; 2CHU Marie Curie Hospital — Cardiology department, Charleroi, Belgium; 3Ghent University Hospital — Cardiology department, Ghent, Belgium. 

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Aminian reports consultant income from Terumo. The remaining authors report no conflicts of interest regarding the content herein.

Final version accepted April 21, 2020.

Address for correspondence: Colletti Giuseppe, MD, Jolimont Hospital — Cardiology Department, Rue Ferrer, 159, La Louvière 7100, Belgium. Email: giucol85@gmail.com

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