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

Interventional Applications for an Ostial Protection Guidewire-The WALPO Technique

Coronary atherosclerotic lesions at the ostium and proximal coronary arteries pose significant challenges in percutaneous coronary interventions (PCI), especially in the left main coronary artery (LMCA). Guide catheter-induced damage can lead to severe complications such as vessel dissection or myocardial infarction. Ostial stent placement with drug-eluting stents offers mechanical support and reduces restenosis but is technically challenging due to the anatomical complexity of the ostium. Complications like longitudinal stent deformation and hydraulic dissection from contrast media are specific concerns. The aortic free-floating wire technique, expanded in this article to Wire in Aorta for Localization and Protection of the Ostium (WALPO), provides a method for safely locating and protecting the ostium during PCI, aiming to improve the safety and efficacy of PCI at this location.

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.

Left Main Percutaneous Coronary Revascularization

Left main (LM) coronary artery disease accounts for approximately 4-6% of all percutaneous coronary interventions (PCIs). There has been mounting evidence indicating the non-inferiority of LM PCI as a revascularization option, particularly for those with a low SYNTAX score. The EXCEL and NOBEL trials have shaped current guidelines. The European Society of Cardiology assigned a class 2a (level of evidence B) for isolated LM disease involving the shaft and ostium and a class IIb (level of evidence B) for isolated LM disease involving the bifurcation or additional two- or three-vessel disease and a SYNTAX score <32. However, data on the use of a single stent or an upfront two-stent strategy for distal LM disease are conflicting, wherein the EBC Main trial reported similar outcomes with a stepwise provisional approach and the DKCRUSH-V trial reported better outcomes with an upfront two-stent strategy using the 'double-kissing' crush technique. Although several studies have noted better immediate results with image-guided PCI, there are few data on outcomes in LM disease specifically. In fact, the uptake of imaging in the aforementioned landmark trials was only 40%. More importantly, the role of mechanical circulatory support (MCS) has been less well studied in LM PCI. Indiscriminate use of MCS for LM PCI has been noted in clinical practice. Trials evaluating the benefit of MCS in high-risk PCI demonstrated no benefit. This review highlights contemporary trials as they apply to current practice in LM PCI.

Buddy Balloon versus Buddy Wire Technique Regarding Accuracy of Stent Placement during Percutaneous Coronary Intervention

We aimed to evaluate whether the buddy balloon technique (BBT) is superior to the buddy wire technique (BWT) with regard to the accuracy of stent placement during percutaneous coronary intervention (PCI).We enrolled patients who had been identified with significant stent movement before the stent was dilated at five hospitals and were randomly converted to either the BBT or BWT technique. The primary endpoints were the incidence of technical success and major adverse cardiovascular events (cardiac death, myocardial infarction, target lesion revascularization, and in-stent restenosis) at 2 years of follow-up. The secondary endpoints were the contrast volume used for the procedure and the total procedural time.From August 2018 to July 2019, 66 patients were enrolled, with 33 patients in each group. All patients were successfully followed up to 2 years. At the primary endpoints, compared with patients treated using BWT, those in the BBT group showed significantly better technical success (93.94% versus 39.39%, respectively; P < 0.0001). There was no significant difference in the incidence of major cardiovascular adverse events (6.06% versus 12.12%, respectively; P = 0.392). At the secondary endpoints, the contrast volume used for the procedure was lower with BBT (85.97 ± 22.45 versus 115.00 ± 21.45 mL, respectively; P < 0.0001); similarly, the total procedural time was shorter with BBT (65.94 ± 12.14 versus 74.33 ± 15.36 minutes, respectively; P < 0.0001).BBT could better restrict stent movement and facilitate precise stent deployment, with significant superiority over BWT. In addition, BBT can reduce the procedural time and contrast dose.

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 &gt; 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.

One-year outcome of single-stent crossover versus accurate ostial stenting for isolated left anterior descending ostial stenosis

BACKGROUND

The optimal strategy of percutaneous coronary intervention (PCI) for isolated left anterior descending (LAD) ostial lesions remains debatable. This study aimed to compare clinical outcomes of patients with isolated LAD ostial stenosis treated by single-stent crossover versus accurate ostial stenting.

METHODS

A total of 216 eligible consecutive patients with isolated de novo LAD ostial stenosis were enrolled, and were stratified according to the stenting techniques. Clinical follow-up was performed by review of medical charts or telephone contact with the patients, and repeat angiography was made at 9-12 months after the procedure. Major adverse cardiovascular events (MACE) including cardiac death, myocardial infarction, non-fatal stroke and target vessel revascularization (TVR) were recorded.

RESULTS

Single-stent crossover and accurate ostial stenting were applied to 78 (36%) and 138 (64%) patients, respectively. During a mean of 13 ± 4.1 months of follow-up, the rate of composite MACE (19.6 vs. 8.9%; P = 0.040) was higher in LAD ostial stenosis patients treated with accurate ostial stenting than those treated with single-stent crossover technique, mainly driven by more frequent TVR (17.4 vs. 7.7%; P = 0.048). PCI strategy was an independent predictor of MACE (hazard ratio 2.561; 95% CI, 1.041-6.299; P = 0.021) in the multivariable Cox regression analysis.

CONCLUSIONS

Our retrospective study suggests that the single-stent crossover technique is associated with a better 1-year clinical outcome compared with accurate ostial stenting in patients with isolated LAD ostial stenosis.

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.

A 3-year experience of a simple, novel technique for accurate ostial/non-ostial coronary stenting: The buddy balloon anchor stent technique

OBJECTIVE

To evaluate the safety and efficacy of a new technique for accurate ostial/non-ostial coronary stenting in percutaneous coronary intervention (PCI).

BACKGROUND

Accurate stent localization is a key factor impacting the postoperative success of patients undergoing PCI. However, the accurate localization of some lesions, especially ostial lesions, is very difficult to achieve, because they are often complicated by bobbing or to-and-fro movement of the stent during cardiac contractions.

METHODS

We report a novel technique of precise ostial/non-ostial stenting based on the buddy balloon anchor stent (BBAS) technique. Between May 2014 and July 2017, 47 patients with significant ostial/non-ostial coronary stenosis that required accurate stenting were included in this study. Of them, 23 patients were treated using the conventional method and the remaining 24 patients were treated using (BBAS) technique. Evaluation was then performed using intravascular ultrasound (IVUS) in the procedural, or coronary computed tomography angiography (CCTA) in the follow up.

RESULTS

Using the BBAS technique, the procedural success was achieved in all 24 (100%) cases. IVUS was performed in seven patients (29.17%) and no procedural complications occurred. All six failed cases that occurred among patients with right coronary artery and left anterior descending artery ostial stenosis treated using the conventional method, the lesions were subsequently successfully re-stented using the BBAS technique. After a follow-up of 3-36 months, CCTA was performed in 11 patients (45.83%), all the stents were in the accurate position. There were no major cardiovascular events of death, myocardial infarction, or target lesion revascularization.

CONCLUSION

BBAS is a simple, highly successful and safe technique for accurate stenting of difficult ostial/nonostial coronary stenosis lesions.

Three-dimensional optical coherence tomography reconstruction of bifurcation stenting using the Szabo anchor-wire technique

Ostial lesions present unique challenges for percutaneous coronary intervention (PCI). These lesions are often more calcified, fibrotic, rigid, and more prone to elastic recoil. Intervention on these lesions is associated with higher procedural complications and higher rates of restenosis. Ostial lesions require precise stent placement in the ostium with the absence of side branch compromise. Accurate stent placement in the ostium without side branch compromise is difficult to accomplish with angiography alone. The Szabo technique uses two coronary guidewires for the correct placement in the aorto-ostial or bifurcation lesion. One guidewire is passed through the final cell of the stent strut and acts as the anchor wire. It helps to prevent migration of the stent beyond the ostium and facilitates the precise stenting at the ostium. This technique has several advantages including less reliance on angiography, lower rates of stent malposition and lower rates of incomplete stent coverage. Potential disadvantages include stent distortion and dislodgement from stent manipulation. We describe two cases of successful PCI to bifurcation lesions using the Szabo technique and confirmation of correct placement in the ostium with optical coherence tomography.

Procedural outcomes with use of the flash ostial system in aorto-coronary ostial lesions

BACKGROUND

The Flash Ostial system (Ostial Corporation, Sunnyvale, CA) was designed to optimize implantation of aorto-ostial coronary stents by flaring the proximal stent struts against the aortic wall.

METHODS

We retrospectively reviewed the medical record, angiograms, and intravascular ultrasound images of 22 aorto-ostial percutaneous coronary interventions performed at our institution between March and September 2015. The Flash Ostial system was used in 13 cases (59%).

RESULTS

Mean age was 67 ± 8 years and all patients were men. The target vessel was the right coronary artery (59%), left main (27%), or a saphenous vein graft (14%); 59% of the lesions had moderate/severe calcification. The mean number of predilation balloons was 1.8 ± 1.6, mean Flash ostial balloon diameter was 3.3 ± 0.5 mm and mean inflation pressure was 13.1 ± 4.0 atmospheres. Intravascular ultrasonography (available for 19 patients) revealed mean ostial minimum lumen cross-sectional area (MLA) of 9.2 ± 3.0 mm² and reference MLA of 8.5 ± 2.7 mm² . The percent difference between ostial and reference MLA was higher in cases in which the Flash Ostial system was used versus those where it was not (9.6 ± 5.5% vs. 4.0 ± 2.8%, P = 0.03). All stent struts were well apposed. Technical success was 100%. One patient developed a left groin pseudoaneurysm treated with thrombin injection and one patient had a periprocedural myocardial infarction. Median contrast, fluoroscopy time, and procedure time were 235 mL, 33 min, and 118 min, respectively.

CONCLUSIONS

The Flash Ostial system can be successfully used in aorto-ostial stenting, resulting in large ostial vessel MLA. © 2016 Wiley Periodicals, Inc.

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.

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%.