Demystifying the Quandary of Ostial Stenting

Accurate stent placement is known to be hampered by the anatomical nature of percutaneous coronary intervention (PCI) of ostial lesions, such as aorta-ostial lesions and Medina 001 bifurcation lesions. The Ostial Pro device, the aorta floating wire technique, the stent pull-back technique, the Szabo (tail-wire) techniques, the marker wire technique, the T-stent and small protrusion technique, the cross-over 1-stent technique, and new dedicated ostial stents are some of the techniques used to achieve perfection in precise ostial stent placement. The current state of knowledge about ostial PCI and novel approaches for optimizing these procedures are compiled in this review.

The Use of Bumper Wire Technique and Intravascular Ultrasound for Precise Aorto-Ostial Stenting

Background

Aorto-ostial interventions are challenging due to the limitations of contemporary equipment, imprecise ostial demarcation, and problematic ostial lesion characteristics. Suboptimal stent placement is common and portends worse clinical outcomes. Procedural and long-term outcomes of the bumper wire technique with intravascular ultrasound (IVUS) assessment have not been investigated.

Methods

A single-center retrospective study was conducted. Patients who underwent ostial lesion percutaneous coronary intervention (PCI) with the bumper wire technique between January 2019 and September 2020 were identified. The primary endpoint was to determine the geographic miss rate defined by inadequate ostial coverage or excess stent protrusion of > 2 mm by IVUS or angiography. The secondary endpoint was target lesion failure (TLF) at 6 months after PCI, defined as the composite of cardiovascular death, target vessel myocardial infarction (MI), and target lesion revascularization.

Results

In total, 45 patients were identified. The average age was 71.7 years old, and 85.4% were men. Indication for PCI was acute coronary syndrome in about a third of patients. Twenty-six patients had left main ostial lesions and 19 patients had right coronary artery ostial lesions. Geographic miss was detected in two patients (4.4%): one patient (2.2%) had excess proximal stent protrusion and one patient (2.2%) had an ostial miss. Six patients were lost to follow-up. TLF, stroke, or major bleeding were not observed in any of the patients.

Conclusion

The bumper wire technique is safe and efficient with low rates of geographic miss or adverse clinical outcomes. This is the first study to confirm precise aorto-ostial stent implantation with the bumper wire technique using IVUS confirmation.

Real-time intravascular ultrasound guidance: A novel technique for accurate placement of ostial stents

OBJECTIVES

To describe a novel technique for ostial stent placement using real-time IVUS guidance.

BACKGROUND

Accurate placement of coronary stents at ostial locations is challenging with the true ostium frequently being missed increasing the risk of adverse events. We have developed a novel technique for ostial stent placement and report our benchtop testing and initial clinical experience.

METHODS

Benchtop testing was performed to validate the appearance of the stent and delivery system on IVUS. Benchtop testing of real-time IVUS guided ostial stent positioning was carried out in a left main bifurcation phantom. Real-time IVUS guidance of stent placement in aorto-ostial, ostial left anterior descending (LAD), or ostial circumflex lesions was assessed in a prospective registry.

RESULTS

Bench model IVUS demonstrated clear differences between the appearances of the stent and other components of the delivery system. Positioning of 10 consecutive stents into the ostial LAD using real-time IVUS guidance was assessed in a left main bifurcation model. Median distance from proximal stent edge to LAD ostium was 0.39 mm (interquartile range 0.31 to 0.73). Real-time IVUS guidance of ostial stent placement was performed in 50 patients (51 lesions). Angiographic success was 100%. IVUS post-stenting demonstrated median distance from the proximal stent edge to the ostium was 0.2 mm (interquartile range 0.1 to 0.5 mm). There was one periprocedural myocardial infarction but no other major adverse cardiac events at 30-days.

CONCLUSIONS

We have developed a novel technique using real-time IVUS guidance allowing accurate ostial stent placement.

Contemporary Management of Isolated Ostial Side Branch Disease: An Evidence-based Approach to Medina 001 Bifurcations

The optimal management of bifurcation lesions has received significant interest in recent years and remains a matter of debate among the interventional cardiology community. Bifurcation lesions are encountered in approximately 21% of percutaneous coronary intervention procedures and are associated with an increased risk of major adverse cardiac events. The Medina classification has been developed in an attempt to standardise the terminology when describing bifurcation lesions. The focus of this article is on the management of the Medina 0,0,1 lesion (‘Medina 001’), an uncommon lesion encountered in <5% of all bifurcations. Technical considerations, management options and interventional techniques relating to the Medina 001 lesion are discussed. In addition, current published data supporting the various proposed interventional treatment strategies are examined in an attempt to delineate an evidence-based approach to this uncommon lesion.

Potential value of guard-wire technology in the interventional treatment for ostial coronary lesions

Background

To explore potential value of guard-wire technology during percutaneous coronary intervention (PCI) in patients with ostial coronary lesions.

Methods

Patients, who underwent PCI, were collected between October 2011 and March 2017. Of the 141 patients, 63 (44.7%) have ostial lesions, and 78 (55.3%) have distal bifurcation sites. They were divided into group A (n = 71) and group B (n = 70). Group A received PCI after guard-wire technology. Group B were given balloon dilation and stent after placing guide wire through target lesion vessel. X-ray exposure time, contrast agent dosage, total PCI duration, pressure incarceration times, cases of malignant arrhythmia and cases of failed PCI of all patients were analyzed, respectively.

Results

The general clinical characteristics includes patients age, sex ratio, the proportion of complications, smoking ratio and left ventricular ejection fraction of both groups was not significantly different. X-ray exposure time, contrast agent dosage, PCI total time, stent positioning time, pressure infestation frequency, arrhythmia frequency and complication number of group B were higher than those of group A. There is no case of malignant arrhythmia and case of failed PCI in group A, while there were five malignant arrhythmia and four failed PCI in group B. Contrast agent dosage and cases of failed PCI increased in group B compared with group A.

Conclusion

The guard wire technology is safer and more feasible to patients with ostial coronary lesions who underwent PCI.

Szabo 2-stent technique for coronary bifurcation lesions: procedural and short-term outcomes

BACKGROUND

Provisional 1-stent technique is currently regarded as the default approach for the majority of bifurcation lesions. Nonetheless, 2-stent techniques may be required for complex bifurcations with high compromise risk or fatal consequences of side branch (SB) occlusion. Limitations exist in current approaches, as stents gap, multiple metal layers and stent malapposition caused by imprecise placement with fluoroscopic guide and intrinsic technical defects. This study was designed to investigate the effectiveness of the novel Szabo 2-stent technique for coronary bifurcation lesions.

METHODS

In the Szabo 2-stent technique, one stent is precisely implanted at the SB ostium with Szabo technique resulting in a single strut protruding into the main vessel (MV). After MV rewiring and SB guidewire withdrawal, another stent is implanted in MV followed by proximal optimization technique, SB rewiring, and final kissing inflation (FKI).

RESULTS

The technique tested successfully in silicone tubes (n = 9) with: procedure duration, 31.2 ± 6.8 min; MV and SB rewiring time, 26.8 ± 11.2 s and 33.3 ± 15 s; easy FKI; and 2.3 ± 0.5 balloons/procedure. Bifurcation lesions (n = 22) were treated with angiographic success in MV and SB, respectively: increased minimal lumen diameter (0.63 ± 0.32 mm to 3.20 ± 0.35 mm; 0.49 ± 0.37 mm to 2.67 ± 0.25 mm); low residual stenosis (12.4 ± 2.4%; 12.4 ± 2.3%); and intravascular ultrasound confirmed (n = 19) full coverage; minimal overlap and malapposition; minimal lumen area (2.4 ± 1.2 mm²; 2.1 ± 1.0 mm²); plaque burden (78.1 ± 11.3%; 71.6 ± 15.5%); and minimal stent area (9.1 ± 1.6 mm²; 6.1 ± 1.3 mm²). Periprocedural cardiac troponin increased in 1 asymptomatic patient without electrocardiographic change. There was no target lesion failure (cardiac death, myocardial infarction, target lesion revascularization) at 6-month follow-up.

CONCLUSIONS

The Szabo 2-stent technique for bifurcation lesions provided acceptable safety and efficacy at short-term follow-up.

Angiographic study of the clinical liaison of drug-eluting stent and paclitaxel-eluting balloon in unifocal side branch ostium stenosis (ASCLEPIUS)

A reliable stenting strategy for treating isolated side branch (SB) ostium stenosis is not well established. The purpose of this study was to examine the 6-month angiographic outcome of a novel technique, called the shoulder technique, on this lesion subtype. Symptomatic patients with isolated SB ostium stenosis, defined as ≥75% diameter stenosis at SB ostium and <50% diameter stenosis in main vessel (MV), were treated with paclitaxel-eluting balloon in MV and drug-eluting stent in SB using the shoulder technique. Angiographic restudy was performed at 5-9 months and clinical follow-up was scheduled regularly every 3 months. There were 46 patients of age 66 ± 12 years with male predominance (76%) recruited. Diagonal ostium (67%) was the most frequent target lesion site. The size and length of paclitaxel-eluting balloon and drug-eluting stent used in MV and SB were 3.01 ± 0.25 and 20 ± 4 mm, and 2.39 ± 0.25 and 17 ± 6 mm, respectively. Angiographic restudy was performed on 43 (93.5%) patients at 6.5 ± 1.6 months. The late loss in MV and SB were 0.04 ± 0.19 and 0.19 ± 0.32 mm, respectively. Angiographic restensosis was seen in 2 (4.7%) patients at SB, whereas no stenosis was induced in MV. Improvement of symptom was reported in 36 (78%) patients. At 1-year follow-up, no death, myocardial infarction, and stent thrombosis was observed; target vessel revascularization was performed on 3 (6.5%) patients. Treatment of isolated SB ostium stenosis using the shoulder technique is associated with a favorable short-term angiographic outcome.

Modified flower petal technique in the treatment of Medina type 0,0,1 or 0,1,0 lesions

AIMS

The optimal strategy for patients with isolated ostial bifurcation lesions has not yet been determined. We propose the modified flower petal technique for the treatment of Medina type 0,0,1 or 0,1,0 coronary bifurcation lesions.

METHODS AND RESULTS

We selected 64 patients who had Medina type 0,0,1 or 0,1,0 coronary bifurcation lesions. Percutaneous coronary intervention (PCI) was performed with the modified flower petal technique in all patients. After PCI, all patients were followed up to nine months after the intervention. Quantitative coronary angiography (QCA) analyses were performed for both the main and the side branch at baseline, after the stent implantation and at nine-month follow-up. Twenty patients (31.2%) had ostial left anterior descending artery lesions, nine patients (14.1%) had ostial circumflex artery lesions and the other patients had isolated ostial non-left main bifurcation lesions. The procedural success rate was 100%. There was no death, myocardial infarction, subacute or late stent thrombosis at nine-month follow-up. In one patient, in-stent restenosis requiring reintervention was noted.

CONCLUSIONS

The modified flower petal technique has excellent acute results and midterm clinical outcomes in the management of Medina type 0,0,1 or 0,1,0 coronary bifurcation lesions.

Geographic miss with aorto-ostial coronary stent implantation: insights from high-resolution coronary computed tomography angiography

AIMS

Accurate positioning of aorto-ostial coronary stents is challenging. Coronary CT angiography (CCTA) allows detailed imaging of the coronary sinuses and implanted stents. We utilised CCTA to evaluate the accuracy of aorto-ostial stenting and to assess the efficacy of conventional angiography for guiding these procedures.

METHODS AND RESULTS

We analysed 256-row CCTA scans in 23 patients who had undergone aorto-ostial stenting. Optimal stent positioning was defined as presence of the entire circumference of the proximal stent edge within an aorto-ostial landing zone (AOLZ), located within 1 mm of the aorto-ostial plane. Geographic miss was diagnosed when at least a section of the proximal stent edge was located proximal or distal to the AOLZ. CCTA findings were compared with review of the conventional two-dimensional implantation angiogram (two experienced operators). By CCTA, the entire circumference of the proximal stent edge was located within the AOLZ in only three (13%) cases, with geographic miss in the remainder. Conversely, conventional coronary angiography suggested complete lesion coverage to be present in 95% of cases and optimal location of the proximal stent edge within the AOLZ in 76%.

CONCLUSIONS

Geographic miss was common in aorto-ostial stenting and was underestimated by conventional two-dimensional angiography.

Comparison of floating wire and single wire techniques in right coronary ostial lesions in terms of procedural features and one-year clinical follow-up results

Objective:

The floating wire technique is a special technique for solving interventional problems in aortaostial lesions. There are no long-term data in the literature for the floating wire technique in right aorto-ostial lesions.

Methods:

One hundred twenty six patients were retrospectively analyzed in this study. All of these patients had a critical right coronary aortoostial lesion. The floating wire technique was performed on 64 patients, and the single wire technique was performed on 62 patients. The two groups were compared with each other in terms of lesional and procedural properties. Additionally, 1-year clinical follow-up results were compared between the two groups.

Results:

There was no significant difference in terms of lesion properties between the groups. In the floating wire group, mean stent length, number of stents, mean procedure time, mean contrast volume, and mean fluoroscopy time were significantly lower than in the single wire group. At 1 year, 1 patient from each group had myocardial infarction, and no mortality was observed. In the floating wire group, the number of patients who experienced angina and the target lesion revascularization rate were both significantly lower than in the single wire group.

Conclusion:

The floating wire technique in right coronary ostial lesions provides a significant advantage over the single wire technique according to procedural and clinical follow-up results.

Adenosine-induced temporary block to improve accuracy of ostial coronary stent implantation: adenosine to improve stent implantation accuracy

Implantation of coronary stents should be performed with high precision to ensure optimal clinical results. In some clinical conditions, during the cardiac cycle, significant movement of the predeployed stent may impact its implantation accuracy. We describe a case in which a patient had a short ostial left anterior descending artery stenosis and hyperkinetic left ventricle, resulting in significant movement of the stent inside the vessel lumen during the cardiac cycle. Intracoronary adenosine was used to create temporary heart block to enable accurate stent implantation.

Placement of Tryton Side Branch Stent only; a new treatment strategy for Medina 0,0,1 coronary bifurcation lesions

OBJECTIVES

We propose a new treatment strategy of Medina 0,0,1 bifurcation lesions using a dedicated side branch stent alone (Tryton Side Branch Stent™) without additional main branch stenting, with the advantage of an optimal ostial side branch coverage without the disadvantage of an excessive amount of metal in the main branch.

BACKGROUND

Medina 0,0,1 lesions are relatively rare and there is no consensus on treatment strategy. Several previous techniques have been described, all with considerable disadvantages.

METHODS

Between October 2009 and November 2011, 12 patients with Medina 0,0,1 lesions treated with Tryton alone were included. Clinical outcomes were reported as all-cause mortality, recurrent myocardial infarction (MI), target vessel revascularization (TVR), target lesion revascularization (TLR), and target vessel failure (TVF; defined as the composite of all-cause mortality, MI, and TVR). Procedural success was defined as successful stent placement with residual stenosis <30%, postprocedural TIMI 3 flow, and no in-hospital TVF.

RESULTS

Mean age was 64 years. Median side branch reference vessel diameter was 2.6 [2.5-3.0] mm (median stenosis 75%). Procedural success was 100%. Median clinical follow-up duration was 868 [470-906] days with just one of the patients suffering from a late adverse clinical outcome: TLR at 427 days, resulting in TVF, TVR, and TLR rates of 8.3%.

CONCLUSION

Treatment of Medina 0,0,1 lesions with the Tryton stent alone was associated with a 100% procedural success and only one late clinical adverse event (median follow-up of 868 days). These first positive results need to be confirmed in larger prospective randomized studies.

Transradial Szabo technique for intervention of ostial lesions

OBJECTIVES

The aim of our study is to assess the feasibility and safety of transradial intervention (TRI) of coronary ostial lesions using the Szabo technique.

BACKGROUND

When performing TRI of coronary ostial lesions, precise stent positioning is of paramount importance. TRI has experienced increasing popularity in the U.S.; however, utilization of the Szabo technique has not been systematically evaluated in this setting. We report the results of ostial stent deployment using the Szabo technique for 2 experienced TRI operators and centers.

METHODS

This was a retrospective analysis of 40 consecutive patients who underwent PCI from April 2009 to September 2011. All patients who underwent PCI via the transradial route with the Szabo technique for ostial lesions performed by experienced transradial operators (>200 cases/yr) were included.

RESULTS

In our study of 40 patients with 41 coronary ostial lesions, overall procedural success rate was 100%. Stent dislodgement was seen in 1 patient. Clinical follow up was 100%, with a mean duration of 292.7±200 days. Target lesion revascularization (TLR) was seen in 2 patients (5%). One patient had an episode of transient ischemic attack (TIA) at 33 days after PCI; another experienced subacute stent thrombosis at 81 days while on dual antiplatelet therapy. MACE was 7.5% overall.

CONCLUSION

In our study, treatment of coronary ostial lesions with the Szabo technique via TRI is associated with a high procedural success rate and a low MACE of 7.5%.

Bench top evaluation and clinical experience with the Szabo technique: new questions for a complex lesion

BACKGROUND

The Szabo technique has been described as a method to ensure accurate ostial stent placement. We sought to investigate this novel technique in detail both in vitro and in vivo.

METHODS AND RESULTS

The technique was subjected to bench testing and also undertaken in 26 patients. Each step was recorded with cine angiography and the stents imaged by microcomputed tomography. The ostial LAD was treated in 81% and a DES was implanted in 92%. Angiographic success was 88.5% (one case of stent dislodgement). Repeat angiography was performed in 78% and restenosis observed in two patients. MACE rate at 15.5 ± 5.1 months was 13% (1 TLR, 1 MI, 1 cardiac death). Despite a seemingly excellent immediate angiographic result, we report one case of restenosis at follow up and one case of IVUS examination (performed in four patients) in which significant stent protrusion, into the proximal main vessel, was observed. In vitro bench testing confirmed a significant and asymmetric (carina side) stent protrusion into the main branch, with the last cell of the stent undergoing significant deformation.

CONCLUSIONS

The Szabo technique is not a precise technique to implant a stent at the level of the ostium. The proximal end of the stent undergoes significant and asymmetric deformation, protruding into main branch. Additional concerns with this complex technique include the potential for stent damage or contamination before implantation and the risk of stent dislodgement. We conclude that there are more disadvantages than benefits to this technique which only partially addresses the difficulties encountered in the treating ostial lesions.