Innovation in interventional cardiology

Corsair Pro XS is the new generation of microcatheter by Asahi Intecc Co., Ltd. (Japan). Its key characteristic is the SHINKA-Shaft: a new 14-wire braid that completely changes the rotational shaft design, increasing the performance of the device in retrograde approach. This type of braided wire allows the microcatheter to be rotated many more times than the previous generations of Corsair, which is why it is indicated in cases requiring a microcatheter (antegrade or retrograde approach) with a high degree of rotation to cross the plaque. The tip entry profile is 1.3 Fr (0.44 mm), like the Corsair Pro, but with a distal shaft outer diameter of 2.1 Fr (0.71 mm), smaller than the 2.6 Fr (0.87 mm) of the Corsair pro. The soft tapered tip is shorter than other similar catheters, 6.5 mm vs 10 mm, which facilitates plaque penetration. It has a 70 cm hydrophilic coating (normally 60 cm) and a hypotube that is more flexible and resistant to mechanical fatigue, a common problem in long procedures.

This represents a great advance in device innovation for complex percutaneous procedures.

Palabras clave: microcatéter, oclusión coronaria crónica total. Keywords: microcatheter, chronic total occlusion.

When performing catheterisation via radial access, interventional cardiologists use a coated guidewire. If the arteries are excessively tortuous or severely calcified, it may be necessary to use a hydrophilic polymer-coated guide wire, which carries the risk of perforating secondary branches, as these guidewires slip easily, but provide limited tip control. In some cases, coronary angioplasty guidewires are needed to negotiate a highly-tortuous radial artery, but they lack the sufficient support to advance the catheter.

The Silverway guidewire (Asahi Intecc Co, LTD., Japan) represents a great innovation in endovascular guidewires: it facilitates access in these difficult situations and has substantially better performance and safety than other commonly-used guidewires. It is a 0.035’’ metal guidewire, with a double coil structure at the distal tip and a multi-wire coil with ACT ONE technology in the proximal shaft. This structure is the same as that of angioplasty guidewires. It has a hybrid coating along its entire length. The distal 15 cm have a silicone coating that provides tactile feedback from the tip to the hand. This silicone coating improves safety, as it prevents the guidewire from perforating the vessel. Proximal to these 15 cm, the guidewire has a hydrophilic coating that facilitates smooth delivery in the arteries. The proximal shaft is silicone-coated, to provide better control of the guidewire and 1 to 1 torque transmission to the tip.

Among the available lengths, of note is the 180 cm version, which allows exchange of catheters in the ascending aorta while maintaining the desired position of the guidewire and the 1.5 mm J shape, which is easily straightened manually. The tip of the guidewire is radio-opaque, allowing it to be visualised at all times. This guidewire can be used for any access that is difficult to navigate due to tortuosity or calcification.

In my opinion, this guidewire represents innovation in a field in which I thought nothing remained to be invented.

Palabras clave: guía endovascular. Keywords: endovascular guidewire.

New Valve Technology (Switzerland) recently received CE mark approval for the treatment indication of percutaneous implantation of the ALLEGRA aortic valve in a degenerated bioprosthesis.

The ALLEGRA valve has two main characteristics: firstly, it is a self-expanding supra-annular valve with flexible commissures, and secondly, it has a low frame height that minimizes potential occlusion of the coronary ostium.

This approval came after extensive in vitro research on the behaviour of the ALLEGRA valve when implanted in the more commonly-used bioprostheses,1 followed by some very promising clinical results from the VIVALL study.2

Internationally, close to 100 cases of ALLEGRA valve implantation in degenerated surgical bioprostheses have been performed with very favourable outcomes in terms of residual gradient, paravalvular leak, and pacemaker implantation. In the VIVALL study,2 a reduction in transvalvular gradient (invasive measurement) from 37.1 ± 13.3 mmHg to 11.6 ± 3.7 mmHg was observed, with a 30-day mortality of 0%, and no paravalvular leaks or pacemaker implantations; the effective orifice area increased from 1.18 ± 0.58 cm2 to 1.4 ± 0.52 cm2.

Currently, patients of this type are being recruited for the post-marketing clinical study FOLLOW; when complete, this data will expand the clinical evidence on this percutaneous valve.

REFERENCES

1. Sedaghat A, Sinning JM, Werner N et al. In vitro hydrodynamic and acute clinical performance of a novel self-expanding transcatheter heart valve in various surgical bioprostheses. EuroIntervention. 2018;13:2014-2017.

2. Schaefer U, Butter C, Landt M et al. Thirty-day outcomes of a novel transcatheter heart valve to treat degenerated surgical valves - The “VIVALL” multi-center, single-arm, pilot study. EuroIntervention. 2019;15:e757-e763.

Palabras clave: prótesis valvular percutánea. Keywords: percutaneous valve prothesis.

The guide extension catheter has become an essential device for treating stenotic lesions in complex coronary interventional procedures. When the guide catheter has limited support, reaching a target lesion for balloon dilatation and stent implantation can become mission impossible. Guide extension catheters, an extension of the guide catheter, facilitate safe device passage. It is amazing to see how they are able to reach lesions that balloons or stents would not even get near.

A new guide catheter extension has been released, called Boosting (QX Medical, USA), which has some new features that others do not have. The catheter is hydrophilic along its entire length, with a rounded tip to avoid a razor-blade effect on the atheroma plaque.

At the transition zone, a unique characteristic is worthy of note: the proximal part of the catheter is very wide, and its lumen accommodates the guide catheter without leaving a space between the two. This feature prevents flow between the guide catheter and the extension, so that, if fluid or contrast is given, it goes straight to the tip of the guide catheter extension. Also, if we want to advance a guidewire it can be introduced directly into the extension, without the risk of passing outside it. The portion that is used to push is made of two soldered wires with great flexibility and pushability that are integrated directly with the shaft of the catheter.

Palabras clave: Extensor de catéter guía. Keywords: Guide extension catheter.

Nagare bidirectional steerable sheath

The Nagare bidirectional steerable sheath (Terumo, Japan) is a catheter that allows controlled navigation in all chambers of the heart. The sheath has bidirectional movement thanks to its TrueVector technology: the device is manufactured with a coaxial mesh in the shaft, unlike others that use pull wire systems to move the tip of the catheter. This mesh, which is Kevlar-coated, can move freely, and since it is pulled proximally along with the shaft, only the tip is deflected, with accuracy and stability. This prevents the classic whipping effect of other similar catheters in which deflection occurs along the length of the catheter rather than just the tip; this is an interesting improvement.

The Nagare bidirectional steerable sheath has an external sheath diameter of 12 Fr and an internal diameter of 8.8 Fr, with a usable catheter length of 73.7 cm. Its size allows other devices to be passed through it. It has a smooth transition to the dilator for a 0.032’’ guidewire. It can be deflected 90° or 180° on its longitudinal axis with a turning radius of 25 mm.

This device is indicated for controlled transseptal puncture. Structural interventional procedures that are performed on the left side of the heart often require a posterior puncture below the interatrial septum. A steerable sheath of this type allows better control of the puncture site.

Palabras clave: introductor deflectable, punción transeptal. Keywords: steereble sheath, transseptal puncture.

True Flow balloon valvuloplasty catheter

Aortic balloon valvuloplasty requires rapid cardiac pacing with a pacemaker to avoid the balloon moving while it is inflated and causing injury to the leaflets or even the annulus if it slips uncontrollably. In addition, during valvuloplasty, the inflated balloon (inflated for approximately 5 s) causes left ventricular outflow tract obstruction and ischemia, which in some patients may cause significant hemodynamic compromise.

True Flow (Bard, USA) is a valvuloplasty balloon catheter that allows continued blood flow while it is inflated. It has an outer fiber-based shell that prevents the balloon from sliding when it is opened onto the valve leaflets, so a pacemaker is not required. This shell is made of high-molecular weight polyurethane, polyester and aramid fibers (a structural component of Kevlar) and has minimal stretch and high resistance to rupture. The inside of the balloon has 8 small balloons around the edge of the main balloon, with an inner lumen between them where blood can flow. The device measures 3.5 cm long and is available in six sizes, with diameters from 18 mm to 26 mm. The smaller models are compatible with an 11 Fr sheath and the largest, with a 16 Fr sheath.

This type of balloon catheter allows valvuloplasty to be performed for 60 s or more without rapid pacing, with a 1/3 reduction in the mean aortic pressure while the balloon is inflated, which means a 50% reduction in the aortic gradient. This could be especially useful in patients with severe dysfunction.

Palabras clave: valvuloplastia aórtica, balón de valvuloplastia. Keywords: aortic valvuloplasty, valvuloplasty balloon.

Capbuster

Several challenges may arise for the clinician performing an interventional procedure on coronary arteries with chronic total occlusion. One such challenge is that of an impenetrable plaque. Possible solutions to this problem include active and passive support techniques, as well as devices such as the Tornus (Asahi Intech, Japan) and the Turnpike Gold (Teleflex, USA). However, these devices require high passive support and they are not always effective.

The CapBuster (Capsos Medical, Ireland) is a balloon catheter combined with a special guide wire designed to perforate impenetrable plaques. The microcatheter balloon is inflated inside the coronary artery, proximal to the plaque. This balloon provides, within the coronary artery, the active support required to allow the guidewire to be advanced through the plaque. Another of its benefits is that, once inflated, the tip of the microcatheter centers in the coronary artery to ensure an excellent central, coaxial alignment with the plaque.

One the balloon is inflated, the guidewire is advanced as if it were a lag screw: it is turned clockwise to advance it and, one the plaque has been crossed, it is turned anticlockwise to remove it. Once the plaque has been penetrated, a standard guidewire for chronic total occlusion can be used as per the interventionist’s choice.

It is estimated that the CapBuster will obtain the CE mark in 2021. Until then, we will have to wait be this device that, in theory, will help solve these important problems.

Palabras clave: placa coronaria impenetrable, oclusión coronaria crónica. Keywords: uncrossable coronary plaque, chronic total occlusion.

Forma tricuspid repair system

Tricuspid regurgitation is a significant clinical problem, with complex palliative solutions that carry a high surgical risk. Industry continues to dedicate substantial resources to the development of devices to allow percutaneous treatment.

The Forma system (Edwards, USA) has been under research for several years. It has been modified following the results from a clinical trial involving an initial compassionate use experience in patients with tricuspid regurgitation who are unsuitable for surgery.1

The Forma system is inserted via axillary access with a 24 French sheath. Through this sheath, a balloon catheter is advanced to the right ventricular apex, where the guiding rail is anchored to the ventricular wall. Using this rail, a 15 mm or 18 mm cylindrical spacer is positioned perpendicular to the tricuspid valve in the gap between the leaflets. The leaflets coapt onto this cylindrical spacer, substantially reducing the regurgitant volume from the right ventricle. One the position is confirmed by visualization on 3D echocardiography, the rail is pulled taught and fixed in the subcutaneous space next to the insertion zone in the subclavian vein.

Four-year results are now available from the first clinical trial,2 which show an improvement in quality of life, functional status based on NYHA (New York Heart Association) classification, and 6-minute walk test.

Two other clinical trials are currently underway, one of which involves 75 patients in Canada and Europe (EU/Canada SPACER trial NCT02787408).

REFERENCES

1. Rodés-Cabau J. Transcatheter Tricuspid Valve Therapies 3: FORMA. Description, Results and a Case. En: Transcatheter Cardiovascular Therapeutics 2016; 2016 November 1, 2016; Washington, USA. Available at: https://www.tctmd.com/slide/transcatheter-tricuspid-valve-therapies-3-forma-description-results-and-case. Accessed 03 Abr 2020.

2. Muntane-Carol M, Del Val D, Bedard E et al. Transcatheter innovations in tricuspid regurgitation: FORMA device. Prog Cardiovasc Dis. 2019;62:496-499.

Palabras clave: Insuficiencia tricuspídea, intervencionismo percutáneo estructural. Keywords: tricuspid regurgitation, percutaneous structural interventions.