Douglas G. Fraser

Objectives To compare susceptibility of five different stent platforms with longitudinal stent deformation (LSD) using a clinically relevant bench testing model simulating both short and long malapposed lengths. Background Recent data suggest that design modifications to the Promus Element stent which led to the Promus Premier stent has reduced susceptibility to LSD. However, susceptibility to LSD at long malapposed lengths has not been tested. Furthermore, the mechanisms behind susceptibility to LSD are as yet unclear. Methods The Omega, Integrity, Multilink 8, Biomatrixand Promus Premier stent platforms were tested. The Omega, Integrity and Multilink 8 platforms were used in place of their drug-eluting equivalents. 3.5 mm stents were deployed in a stepped tube with the distal portion fixed and the proximal test section exposed. The force required to compress stents by a fixed distance at different exposed lengths was compared. Symmetrical and point loading were used. Results The Promus Premier was longitudinally as strong as Multilink and Integrity at a short exposed length (4 mm) but weaker, in between Omega and the other platforms, at longer exposed lengths (12 mm). As previously noted, the Omega (Promus Element) platform was significantly weaker than the other stents and Biomatrix was the strongest stent. Conclusion Susceptibility to LSD varies depending on length of malapposed segment when tested using a clinically relevant model as in this study. The mechanisms behind the susceptibility are likely multifactorial, including connector number, strut thickness, connector alignment and ring orientation but remain to be elucidated.

The Official Journal of EuroPCR and the European Association of Percutaneous Cardiovascular Interventions (EAPCI)

The lumen of the radial artery in many patients is smaller than the outer diameter of a 6F radial sheath frequently leading to procedural pain, trauma to the radial artery and contributing to radial occlusion. Chronically, neointima formation reduces luminal size further, limiting successful re-intervention in some patients. Sheathless guides are 1–2F sizes smaller than corresponding sheaths and so may potentially reduce radial artery trauma. Although not currently recommended for routine use, the 6.5F Asahi EauCath Sheathless guide has a lower profile than a 5F sheath and the same inner lumen as a 6F guide and has been shown to be especially useful for interventional procedures requiring 6F techniques in patients with small radial arteries. Similarly, the 7.5F Asahi EauCath has a lower profile than a 6F sheath and the same inner lumen as a 7F guide and is useful for procedures requiring a large bore guide catheter. Alternatives include the MediKit Works 5F sheathless system and long dilators designed to allow the sheathless introduction of conventional guides. The recently approved ‘Flip’ dilator is now available outside Japan; however, experience is currently limited.

The Official Journal of EuroPCR and the European Association of Percutaneous Cardiovascular Interventions (EAPCI)

The Official Journal of EuroPCR and the European Association of Percutaneous Cardiovascular Interventions (EAPCI)

The Official Journal of EuroPCR and the European Association of Percutaneous Cardiovascular Interventions (EAPCI)

Transradial access for coronary intervention significantly reduces vascular complications and may be associated with a reduced risk of major adverse cardiovascular events. However, the small caliber of the radial artery has been considered a limitation to performing complex coronary intervention. Fifty-three patients with true bifurcation disease, in whom a two-stent strategy was felt to be indicated, were scheduled to undergo crush stenting via the transradial approach. Procedural outcome was recorded and 6- and 18-month clinical follow-up was performed. Successful crush stenting via the radial artery was performed in 51/55 lesions (93%). Crush stenting was performed in 53 lesions overall and successful final kissing inflation was achieved in 51/53 (96%). There were no in-hospital or procedural complications. The overall rate of death, myocardial infarction, or target vessel revascularization was 9.8% at 18-month follow-up. Complex percutaneous coronary intervention requiring large-bore catheters can be performed successfully in a high proportion of patients via the transradial approach. Crush stenting, with a very high rate of final kissing inflation, was associated in this series with excellent procedural and medium-term outcomes.