Coronary bifurcation bench test using multimodality imaging: Impact of stent strut link location on stent deformity and jailed side-branch orifices during re-proximal optimizing technique

A Novel Strategy to Simplify the Procedures in Treating Complicated Coronary Bifurcation Lesions: From a Bench Test to Clinical Application

Background

Although provisional stenting strategy based on jailed balloon side branch (SB) protection could be useful for high-risk bifurcation lesion in certain clinical scenarios, its complexity still gives rise to procedure complications. We proposed a novel strategy, the jailed balloon proximal optimization technique (JB-POT), to simplify the procedures in treating complex coronary bifurcation lesions (CBLs). The present study was designed to verify the safety and efficacy of JB-POT under bench testing and clinical circumstances.

Methods

After a stent was deployed in main vessel (MV) with a balloon jailed in SB, POT and post-dilation of the stent were performed without retrieving the jailed balloon. A re-POT was performed 2 mm away from SB branching point to minimize proximal stent malapposition. The JB-POT procedure was performed on 10 samples of a silicone bifurcation bench model, and optical coherence tomography (OCT) was utilized to evaluate stent deployment. From December 2018 to July 2021, a total of 28 consecutive patients with true CBLs treated with JB-POT were enrolled. Immediate procedure results were observed, and clinical follow-ups were performed.

Results

The bench test showed that JB-POT did not induce significant stent malapposition, underexpansion or distortion, as indexed by the malapposition rate, minimum stent area (MSA), eccentricity index and symmetry index determined through OCT. Under clinical circumstances, JB-POT did not induce significant malapposition, underexpansion or distortion. Among the 30 lesions, there was no primary endpoint event defined as SB occlusion, need to rewire the SB with a polymer-covered guide wire, or failure to retrieve a jailed wire or balloon. One rewiring event and 0 double stenting events occurred as secondary endpoint events. One patient died of heart failure in the 8th month after discharge.

Conclusions

The JB-POT protocol, which tremendously simplifies the current standard provisional stenting procedure in complicated bifurcation lesions, shows acceptability in safety and efficacy. Hence, it might become an applicable strategy for treating high-risk bifurcation lesions, especially those with multiple risked SBs.

Effect of proximal optimization technique on coronary bifurcation stent failure: Insights from the multicenter randomized PROPOT trial

OBJECTIVE

We investigated the effect of proximal optimization technique (POT) on coronary bifurcation stent failure (BSF) in cross-over stenting by comparing with the kissing balloon technique (KBT) in a multicenter randomized PROPOT trial.

BACKGROUND

POT is recommended due to increased certainty for optimal stent expansion and side branch (SB) wiring.

METHODS

We randomized 120 patients treated with crossover stenting into the POT group, which was followed by SB dilation (SBD), and the KBT group. Finally, 52 and 57 patients were analyzed by optical coherence tomography before SBD and at the final procedure, respectively. Composite BSF was defined as a maximal malapposition distance of >400 μm, or malapposed and SB-jailed strut rates of >5.95% and >21.4%, respectively.

RESULTS

Composite BSF before SBD in the POT and KBT groups was observed in 29% and 26% of patients, respectively. In the POT group, differences in stent volumetric index between the proximal and distal bifurcation (odds ratio [OR] 60.35, 95% confidential interval [CI] 0.13-0.93, p = 0.036) and between the proximal bifurcation and bifurcation core (OR: 3.68, 95% CI: 1.01-13.40, p = 0.048) were identified as independent risk factors. Composite BSF at final in 27% and 32%, and unplanned additional procedures in 38% and 25% were observed, respectively. Composite BSF before SBD was a risk factor for the former (OR: 6.33, 95% CI: 1.10-36.50, p = 0.039) and the latter (OR: 6.43, 95% CI: 1.25-33.10, p = 0.026) in the POT group.

CONCLUSION

POT did not result in a favorable trend in BSF. Insufficient expansion of the bifurcation core after POT was associated with BSF.

Bifurcation percutaneous coronary intervention of left main trunk treated using a proximal optimizing technique and proximal balloon edge dilation technique

We present a case of bifurcation percutaneous coronary intervention (PCI) of the left main trunk (LMT) using a proximal balloon edge dilation (PBED) technique following a proximal optimizing technique (POT). The procedure of the PBED technique entailed precise positioning of the balloon for SB dilation, with the proximal radiopaque marker lying in the cross-sectional plane of the stent struts at the left circumflex artery (LCx) ostium. The PBED technique might prevent stent deformation induced by side branch (SB) dilation and eliminates the need for the second POT procedure in the re-POT sequence. In fact, three-dimensional reconstruction of optical coherence tomography (3D-OCT) revealed good opening of stent cells overlying the LCx ostium without deformation of stent struts causing incomplete stent apposition at the site opposite the LCx, so the second POT procedure was unnecessary in this case.

<Learning objective: This is the first case report to describe bifurcation PCI of the LMT using POT-PBED procedures under 3D-OCT guidance. POT-PBED procedures might offer excellent acute results for cross-over single-stent implantation in LMT bifurcation lesions and could eliminate the second POT procedure in the re-POT sequence.>

Proximal optimisation technique versus final kissing balloon inflation in coronary bifurcation lesions: the randomised, multicentre PROPOT trial

BACKGROUND

Clinical implications of the proximal optimisation technique (POT) for bifurcation lesions have not been investigated in a randomised controlled trial.

AIMS

This study aimed to investigate whether POT is superior in terms of stent apposition compared with the conventional kissing balloon technique (KBT) in real-life bifurcation lesions using optical coherence tomography (OCT).

METHODS

A total of 120 patients from 15 centres were randomised into two groups - POT followed by side branch dilation or KBT. Finally, 57 and 58 patients in the POT and KBT groups, respectively, were analysed. OCT was performed at baseline, immediately after wire recrossing to the side branch, and at the final procedure.

RESULTS

The primary endpoint was the rate of malapposed struts assessed by the final OCT. The rate of malapposed struts did not differ between the POT and KBT groups (in-stent proximal site: 10.4% vs 7.7%, p=0.33; bifurcation core: 1.4% vs 1.1%, p=0.67; core's distal edge: 6.2% vs 5.3%, p=0.59). More additional treatments were required among the POT group (40.4% vs 6.9%, p<0.01). At one-year follow-up, only one patient in each group underwent target lesion revascularisation (2.0% vs 1.9%).

CONCLUSIONS

POT followed by side branch dilation did not show any advantages over conventional KBT in terms of stent apposition; however, excellent midterm clinical outcomes were observed in both strategies.

Impact of Coronary Stent Design in Proximal Balloon Edge Dilation Technique for Bifurcation Percutaneous Coronary Intervention

The proximal optimizing technique (POT) -proximal balloon edge dilation (PBED) sequence for side branch (SB) dilatation with cross-over single-stent implantation decreases both strut obstruction at the SB ostium and stent deformation at the main branch (MB).The purpose of this experimental bench test was to assess the impact of stent design on stent deformation, obstruction by stent struts at a jailed SB ostium, and stent strut malapposition in the POT-PBED sequence.Fractal coronary bifurcation bench models (60- and 80-degree angles) were used, and crossover single-stent implantation (3-link stent: XIENCE Sierra, Abbott Vascular, Santa Clara, CA, n = 10; 2-link stent: Synergy, Boston Scientific, Marlborough, MA, n = 10) was performed from the MB using the POT-PBED sequence. Jailing rates at the SB ostium, stent deformation, and stent strut malapposition of the bifurcation segment were assessed using videoscopy and optical coherence tomography.After SB dilatation using the PBED technique, jailing rates at the SB ostium and stent deformation did not differ significantly between the two types of stents. Conversely, the rate of malapposed struts of the bifurcation segment after the PBED procedure was significantly lower with 3-link stents than with 2-link stents for both 60- and 80-degree angles (60-degree angle: 4.3% ± 4.4% versus 22.0% ± 11.1%, P = 0.044; 80-degree angle: 20.8% ± 15.1% versus 57.2% ± 17.0%, P < 0.001, respectively).In the POT-PBED sequence, 3-link stents might be a preferable coronary bifurcation stent, maintaining a jailed SB ostium while significantly reducing stent strut malapposition of the bifurcation segment when compared with 2-link stents.

Difference in basic concept of coronary bifurcation intervention between Korea and Japan. Insight from questionnaire in experts of Korean and Japanese bifurcation clubs

The coronary bifurcation intervention varies among countries due to the differences in assessment of lesion severity and treatment devices. We sought to clarify the difference in basic strategy between South Korea and Japan. A total of 19 and 32 experts from Korean (KBC) and Japanese Bifurcation Clubs (JBC), respectively, answered a survey questionnaire concerning their usual procedure of coronary bifurcation intervention. JBC experts performed less two-stent deployment in the left main (LM) bifurcation compared to KBC experts (JBC vs. KBC: median, 1–10% vs. 21–30%, p < 0.0001) instead of higher performance of side branch dilation after cross-over stenting in both LM (60% vs. 21%, p = 0.001) and non-LM bifurcations (30% vs. 5%, p = 0.037). KBC experts more frequently performed proximal optimization technique (POT) in non-LM bifurcation (41–60% vs. 81–99%, p = 0.028) and re-POT in both LM (1–20% vs. 81–99%, p = 0.017) and non-LM bifurcations (1–20% vs. 81–99%, p = 0.0003). JBC experts more frequently performed imaging-guided percutaneous coronary intervention, whereas KBC experts more often used a pressure wire to assess side branch ischemia. JBC experts used a rotablator more aggressively under the guidance of optical coherence tomography. We clarified the difference in the basic strategy of coronary bifurcation intervention between South Korea and Japan for better understanding the trend in each country.

Effect of proximal balloon edge dilation technique for opening a side branch ostium in repetitive-proximal optimizing technique sequence

OBJECTIVE

The purpose of this experimental bench test was to compare stent deformation, obstruction of stent struts at a jailed side branch (SB) ostium, and stent strut malapposition between SB inflation using proximal balloon edge dilation (PBED) technique and SB inflation using conventional balloon dilation in repetitive-proximal optimizing technique (re-POT) sequence.

BACKGROUND

The second proximal optimizing technique (POT) procedure in the re-POT sequence might increase obstruction of stent struts at a jailed SB ostium, because deformation of stent cells at the main branch (MB) occurred during SB inflation for opening the SB ostium.

METHODS

A fractal coronary bifurcation bench model made of flexible urethane was used, and crossover single-stent implantation (Xience Sierra, Abbott Vascular, Santa Clara, CA, n = 12) was performed from the MB with the re-POT sequence. During the re-POT sequence, the jailing rate at the SB ostium assessed by videoscopy was compared between SB inflation using PBED technique (PBED group, n = 6) and SB inflation using conventional balloon dilation (conventional group, n = 6).

RESULTS

The jailing rate after the second POT procedure tended to be lower in the PBED group than in the conventional group (26 ± 12% vs. 34 ± 8%, p = .211), and the change in the jailing rate during the second POT procedure was significantly smaller in the PBED group than in the conventional group (4.8 ± 5.3% vs. 11.6 ± 3.5%, p = .026).

CONCLUSIONS

In the re-POT sequence, the PBED technique with a short balloon for SB inflation might minimize worsening of the jailing rate at the SB ostium during the second POT procedure.