Difference in security of stent jail between Palmaz-Schatz, NIR, and Multi-Link stents: the effect of balloon inflation through stent struts

Current Challenges in Coronary Bifurcation Interventions

Coronary bifurcation lesions account for a significant proportion of all percutaneous coronary interventions (PCIs). Interventional treatment of coronary bifurcations is related to significant technical challenges, high complication rates, and worse angiographic and long-term clinical outcomes. This review covers the specific features and structure of coronary bifurcation and explores the main challenges in the interventional treatment of these lesions. This review evaluates various methodologies designed to address these lesions, considering factors such as plaque distribution and bifurcation geometry. It also emphasizes the limitations associated with current techniques. A novel combined optimization approach applied in the interventional treatment of coronary bifurcation may offer superior procedural and long-term outcomes. This combined technique could potentially address the drawbacks of each method, providing a more effective solution for optimizing stent placement in bifurcation lesions. Refining and evaluating these combined techniques is essential for improving clinical outcomes in patients with bifurcation lesions.

Characteristics of drug-eluting stent platforms potentially influencing bifurcated lesion provisional stenting procedure

AIMS

We aimed to review the technical characteristics of DES platforms which have been documented to influence bifurcation stenting procedures conducted according to the provisional approach.

METHODS AND RESULTS

DES platforms have remarkable technical differences (side cell diameter, shape, deformability, etc.). We reviewed the literature data and performed original virtual bench tests to highlight the characteristics of DES platforms which influence the following phases of bifurcation stenting conducted according to the provisional approach: stent implantation in the main vessel across side-branch take-off ("crossover" stenting), proximal optimisation technique, rewiring and kissing balloon inflation. Available data show that the response of different DES platforms to the various procedural steps of provisional stenting is different.

CONCLUSIONS

When treating bifurcated lesions according to the provisional stenting approach, the search for an ideal matching between individual bifurcated anatomy and DES selection should take into account an articulated series of technical parameters.

Technical Aspects of Provisional Stenting in Percutaneous Treatment of Complex Bifurcation Lesions

Drug-eluting stent (DES) implantation using the 'provisional' approach is the gold standard for percutaneous treatment of patients with unselected bifurcated lesions. Nevertheless, many operators still consider the provisional approach unsuitable for coronary patients with complex bifurcation anatomies. Yet, the provisional approach may be so differently carried out that its procedural outcome is often unpredictable. Some technical refinements may help to anticipate or manage procedural difficulties, which may occur during the management of complex patients. We sought to overview the issues related with DES selection as well as some technical points, which may increase the effectiveness of provisional stenting. In particular, the DES characteristics influencing bifurcation interventions and the technical refinements, which may be considered during a provisional stenting procedure are discussed. Indeed, main vessel stent sizing, proximal optimisation, side branch protection modality, side branch rewiring, kissing balloon and side branch rescue techniques are all pivotal to increase the safety and efficacy of the provisional strategy especially in the setting of complex anatomies and patients.

Coronary bifurcation stenting: insights from in vitro and virtual bench testing

The various techniques and devices that have been proposed for the treatment of coronary bifurcation lesions have differing levels of complexity and each has one or more limitations. Two highly complementary ex vivo methods are available to study the treatment of bifurcation lesions: in vitro and virtual bench testing. Both methods can be used to develop, evaluate and optimise bifurcation stenting techniques and dedicated devices. The basics, the evolution, the advantages and limitations of both methods are discussed in this paper. Subsequently, a literature overview of the main insights gained from ex vivo testing in the field of bifurcation stenting is given.

A new stent design with multiple radio-opaque markers for protection of side-branch vessels in bifurcation lesions: HJ stents

BACKGROUND

Loss of side-branch vessels is a serious complication following stent implantation in parent vessels of bifurcation lesions. The purpose of this study was to introduce and test a new stent design for the protection of side-branch vessels in the management of bifurcation lesions.

METHODS AND MATERIALS

This stent has multiple radio-opaque markers in its central portion, whose presence is useful in avoiding stent-strut placement across the side-branch orifice and in correctly directing the insertion of a second guide wire through the struts into the side branch to minimize jailing of side branches during stent deployment in the parent vessel. In vitro tests of the acrylic resin bifurcation phantom model were performed under fluoroscopic guidance in the catheterization laboratory with 10 stents with multiple radio-opaque markers and 10 stents without. Kissing balloon angioplasty was performed across the side branch after stent implantation in the parent vessel in both groups. Side-branch jailing by the stent (presence of any stent struts crossing the side-branch orifice) was determined visually and compared between the two groups.

RESULTS

The jailed side branch with the stent struts was observed in one of 10 new stents and in five of 10 conventional stents without them.

CONCLUSIONS

The in vitro tests demonstrated the superiority of a new stent design for the reduction of side-branch jailing in bifurcation lesions.

Limited balloon expansion through the struts of the Palmaz-Schatz and NIR stents compared with the Multi-Link stent

After placing a stent in the main vessel of a bifurcation lesion, it is sometimes necessary to perform further balloon inflation in order to treat an ostial lesion in a side branch. The stent struts may prevent full balloon expansion at the ostium of a side branch, resulting in residual ostial stenosis. The degree of completeness of balloon inflation may vary significantly depending on the stent design and structure. A model of a bifurcation lesion with an angle of 45 degrees was created from acrylic resin. The diameters of the main vessel and the side branch were both 3.5 mm. Deployment of the Palmaz-Schatz stent (n=5), NIR stent (n=5) or Multi-Link stent (n=5) was performed in the main vessel with a 3.5-mm balloon catheter inflated to 12 atm. A 3.5-mm balloon catheter was then inflated to 12 atm through the stent struts of the main vessel and into the ostium of the side branch. The degree of completeness of balloon inflation (% balloon expansion) was calculated as (smallest diameter of balloon catheter/reference diameter of balloon catheter) x 100%. The minimal lumen diameter (MLD) and cross-sectional area (CSA) at the ostium of the side branch created with the stent struts were also measured. Limited balloon expansion through the struts was observed with the Palmaz-Schatz stent and the NIR stent, but almost full balloon expansion was observed with the Multi-Link stent (% balloon expansion: Palmaz-Schatz stent 80%, NIR stent 60%, Multi-Link stent 94%, p<0.01). The MLD and CSA of the dilated struts, representing the ostium of the side branch, of the Palmaz-Schatz stent (2.2+/-0.1 mm, 4.5+/-0.3 mm2) and the NIR stent (1.8+/-0.1 mm, 3.1+/-0.3 mm2) were significantly smaller compared with those of the Multi-Link stent (3.0+/-0.2 mm, 8.4+/-0.6 mm2) (p<0.01). The struts of the Palmaz-Schatz stent and the NIR stent deployed in the main vessel of a bifurcation prevent full expansion of a balloon catheter inflated at the side branch ostium. In contrast, almost full balloon expansion through the struts of the Multi-Link stent is achieved.

Application of beta-irradiation through the struts of a previously deployed stent

The application of beta-radiation in coronary arteries is a promising new technique for the treatment of in-stent restenosis. This is the first case in which the 5 F. delivery catheter of the Beta-Cath trade mark system was advanced through the struts of a stent, previously deployed in an adjacent branch, so as to deliver radiation to the target vessel.