European Bifurcation Club white paper on stenting techniques for patients with bifurcated coronary artery lesions

Abstract

Background: Defining the optimal conduction of percutaneous-coronary-intervention (PCI) to treat bifurcation lesions has been the subject of many clinical studies showing that the applied stenting technique may influence clinical outcome. Accordingly, bifurcation stenting classifications and technical sequences should be standardized to allow proper reporting and comparison.

Methods: The European Bifurcation Club (EBC) is a multidisciplinary group dedicated to optimize the treatment of bifurcations and previously created a classification of bifurcation stenting techniques that is based on the first stent implantation site. Since some techniques have been abandoned, others have been refined and dedicated devices became available, EBC promoted an international task force aimed at updating the classification of bifurcation stenting techniques as well as at highlighting the best practices for most popular techniques. Original descriptive images obtained by drawings, bench tests and micro-computed-tomographic reconstructions have been created in order to serve as tutorials in both procedure reporting and clinical practice.

Results: An updated Main-Across-Distal-Side (MADS)-2, classification of bifurcation stenting techniques has been realized and is reported in the present article allowing standardized procedure reporting in both clinical practice and scientific studies. The EBC-promoted task force deeply discussed, agreed on and described (using original drawings and bench tests) the optimal steps for the following major bifurcation stenting techniques: (a) 1-stent techniques ("provisional" and "inverted provisional") and (b) 2-stent techniques ("T/TAP," "culotte," and "DK-crush").

Conclusions: The present EBC-promoted paper is intended to facilitate technique selection, reporting and performance for PCI on bifurcated lesions during daily clinical practice.

Keywords: DES; PCI; bifurcation lesions; personalized medicine; stenting technique.

FIGURE 1

MADS-2 classification of bifurcation stenting techniques. The figure comprises two panels. Upper panel shows the standard techniques while the lower panel shows the “inverted” techniques. Blue capital letters describe ballooning techniques (see text for explanation). Common combinations of ballooning techniques are described as the sequential blue capital letters

FIGURE 2

Recommended steps for provisional and inverted provisional technique. (a) provisional technique. (1) MV stenting across SB take-off with DES sized 1:1 according to distal MV diameter. (2) POT with balloon sized 1:1 to proximal MV. Note that, due to long stented area in the proximal MV, two inflations were needed to appropriately post-dilate the entire proximal MV stent segment. (3) Distal SB rewiring according to the pullback technique. Note the double bended guidewire tip shape that allows entering easily the distal part of SB ostium. (4) Simultaneous kissing balloon inflation with MV balloon sized 1:1 according to distal MV and SB balloon sized 1:1 according to SB diameter. (5) Repeat POT with balloon sized 1:1 to proximal MV. (b) Inverted provisional technique. (1) Stent implantation from proximal MV into the SB across distal MV with DES sized 1:1 according to SB. (2) POT with balloon sized 1:1 to proximal MV. Note that, due to long stented area in the proximal MV, two inflations were needed to appropriately post-dilate the whole proximal MV. (3) Distal MV rewiring according to the pullback technique. Note the double bended guidewire tip shape that allows entering easily the distal MV ostium. (4) Simultaneous kissing balloon inflation with MV balloon sized 1:1 according to distal MV and SB balloon sized 1:1 according to SB diameter. (5) Repeat POT with balloon sized 1:1 to proximal MV

FIGURE 3

Micro-CT image of stent deformation obtained by provisional and inverted provisional in the same bifurcation model. (a,b) Result after provisional using a 3.5 mm DES (this micro-CT has been obtained in the bench test reported in Figure 2). (c,d) Result after inverted provisional using a 3.0 DES (this micro-CT has been obtained in the bench test reported in this Figure 2)

FIGURE 4

Recommended steps for T/TAP stenting technique. (1) The recommended steps of provisional have been followed up to kissing balloon inflation. (2) SB stent and MV balloon positioning: an appropriately sized SB stent is placed in the SB and a balloon sized 1:1 according to the distal MV is advanced in the distal MV. (3) SB stenting: when the best position (to allow cover the SB ostium and minimally protruding inside the MV) for SB stent has been selected, the SB stent is delivered with the MV balloon left uninflated. (4) SB ostium post-dilation and kissing balloon inflation: after SB stent deployment, the balloon of the stent is slightly pulled back and repeated inflation at high pressure is performed in order to warrant optimal stent expansion at the level of SB ostium (the balloon inside the MV is still kept uninflated during this phase). Then, after alignment of the MV balloon and SB stenťs balloon, kissing balloon inflation is performed by inflating simultaneously the two balloons. (5) Repeat POT. This step is not mandatory. If this step is adopted, the POT balloon is inflated in the proximal MV in a position that is far from the metallic neocarina

FIGURE 5

Micro-CT image of T/TAP stenting with different neocarina length. (a,b) T/TAP stenting sequence applied successfully and resulting in full bifurcation coverage and appreciable neocarina (this micro-CT has been obtained in the bench test reported in this figure). (c,d) T/TAP stenting sequence applied successfully and resulting in full bifurcation coverage and virtual absence of neocarina (true T configuration)

FIGURE 6

Culotte stenting. (a) Recommended steps for culotte stenting (in the case of elective double stenting). (1) Stent implantation from proximal MV into the SB across distal MV with DES sized 1:1 according to SB. When culotte is used for elective double stenting, usually a short proximal MV coverage may be selected in order to limit the area with overlapping stents. (2) POT with balloon sized 1:1 to proximal MV. (3) Distal MV rewiring and dilation. Distal MV rewiring is performed according to the pullback technique. Distal MV dilation may be performed either using kissing balloon inflation (see inverted provisional) or by simple balloon dilation with balloon selected 1:1 according to distal MV size. (4) MV stenting followed by repeat POT: after SB guidewire removal, stent implantation across the side-branch with DES diameter selected 1:1 according to the distal MV size is performed. Thereafter, repeat POT with balloon sized 1:1 to proximal MV is done. (5) Distal SB rewiring and kissing: distal SB rewiring is performed according to the pullback technique. Simultaneous kissing balloon inflation (usually with non-compliant balloons at high pressure) is performed selecting MV balloon sized 1:1 according to distal MV and SB balloon sized 1:1 according to SB diameter. 5. Final POT: performed with balloon sized 1:1 to proximal MV. (b,c) Micro-CT image of stent conformation obtained by culotte

FIGURE 7

DK-crush. (a) Recommended steps for DK-crush. (1) SB stenting. While the MV balloon is kept un-inflated into the MV, the stent (sized 1:1 according to SB) is implanted in the SB protruding inside the proximal MV for 2–3 mm. After SB stent deployment, the balloon of the stent might be slightly pulled back and repeated inflation at high pressure can be performed (the balloon inside the MV is still kept uninflated during this phase). (2) Balloon crush. After removal of SB stenťs balloon and the SB guidewire, the protruding struts of the SB are crushed by an appropriately sized balloon. Of note, the ideal balloon size to warrant optimal crushing is a balloon sized 1:1 to proximal MV. During the clinical practice, smaller balloons are often selected but this is theoretically associated with risk of incomplete stent crush resulting in floating struts in the MV. (3) Non-distal SB rewiring and first kissing. The SB is rewired using a guidewire with an appropriately bended tip aiming at crossing the SB ostium through a non-distal cell. The absence of unintended distal tracking at the ostium level should be carefully checked before further steps are done. Two non-compliant balloon (eventually after undersized balloon SB dilation) are advanced in the SB (diameter size 1:1 according to SB) and in the MV (diameter size 1:1 according to distal MV) and kissing balloon inflation is performed according to a sequential technique (alternating isolated high pressure inflations of each followed by final simultaneous kissing). (4) MV stenting followed by repeat POT: after SB guidewire removal, stent implantation across the SB take-off with DES diameter selected 1:1 according to the distal MV size is performed. Thereafter, repeat POT with balloon sized 1:1 to proximal MV is done. (5) SB rewiring and second kissing: the SB is rewired using a guidewire with an appropriately bended tip aiming at crossing the SB ostium through a non-distal cell. The “centrality” of rewiring should carefully checked before further steps are done. Simultaneous kissing balloon inflation (usually with non-compliant balloons at high pressure according to the sequential technique) is performed selecting MV balloon sized 1:1 according to distal MV and SB balloon sized 1:1 according to SB diameter. (5) Final POT: performed with balloon sized 1:1 to proximal MV. (b,c) Micro-CT image of stent conformation obtained by DK-crush