Modified leopard-crawl technique using intravascular lithotripsy balloon in calcified coronary lesions.

Intravascular lithotripsy (IVL) has emerged as a novel therapy for the treatment of coronary calcification. Numerous studies have reported the safety and efficacy of IVL in calcified coronary lesions, while IVL balloon-uncrossable calcified coronary lesions are sometimes encountered in clinical practice. This case report represents a novel technique called "modified leopard-crawl" to advance the IVL balloon antegradely by creating significant calcium cracking forward when the enhanced stent visualization system reveals that the distal emitter seems adjacent to calcification. This technique might be a valuable alternative when conventional procedures fail and has the potential to enhance the clinical applicability of IVL in daily practice.

Comparison of the OPTIVUS-Complex PCI Multivessel Cohort With the Historical CREDO-Kyoto Registry Cohort-3.

BACKGROUND: There is a paucity of data on the effect of optimal intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) compared with standard PCI or coronary artery bypass grafting (CABG) in patients with multivessel disease.Methods and Results: The OPTIVUS-Complex PCI study multivessel cohort was a prospective multicenter single-arm study enrolling 1,021 patients undergoing multivessel PCI including the left anterior descending coronary artery using IVUS aiming to meet the prespecified criteria for optimal stent expansion. We conducted propensity score matching analyses between the OPTIVUS group and historical PCI or CABG control groups from the CREDO-Kyoto registry cohort-3 (1,565 and 899 patients) fulfilling the inclusion criteria for this study. The primary endpoint was a composite of death, myocardial infarction, stroke, or any coronary revascularization. In the propensity score-matched cohort (OPTIVUS vs. historical PCI control: 926 patients in each group; OPTIVUS vs. historical CABG control: 436 patients in each group), the cumulative 1-year incidence of the primary endpoint was significantly lower in the OPTIVUS group than in the historical PCI control group (10.4% vs. 23.3%; log-rank P<0.001) or the historical CABG control group (11.8% vs. 16.5%; log-rank P=0.02). CONCLUSIONS: IVUS-guided PCI targeting the OPTIVUS criteria combined with contemporary clinical practice was associated with superior clinical outcomes at 1 year compared with not only the historical PCI control, but also the historical CABG control.

Coil Embolization for Coronary Artery Perforation: A Retrospective Analysis of 110 Patients.

OBJECTIVE: Coil embolization (CE) for coronary artery perforation (CAP) has not been thoroughly evaluated. This study aimed to evaluate the extent of myocardial damage and impact on cardiac function after CE for CAP. METHODS: A total of 110 consecutive patients treated with CE for CAP were retrospectively identified. The degree of myocardial damage and impact on cardiac function were evaluated. RESULTS: Forty-nine (44.5%) cases involved chronic total occlusions. A guidewire was the cause of perforation in 97 (88.2%) patients. The success rate of CE was 98.2%. Almost all patients were prescribed either antiplatelet drugs or anticoagulant medication or both. Patients with perforation types III and IV were found to be prone to creatinine kinase (CK) elevation and epicardial main vessel perforation, thereby causing myocardial damage. No changes were noted in the ejection fraction (EF) in patients with type V distal perforation and collateral channel perforation, while patients with perforation of the epicardial main vessel may show impaired cardiac function afterward. CONCLUSIONS: CE is safe and effective for treating CAP, especially when collateral channels and distal vessels are involved. Meanwhile, efforts should be taken to prevent CAP in epicardial main vessels since it may be difficult to treat with CS and cause myocardial damage when bailed out with CE leading to vessel sacrifice. We found that it was not necessary to change the anticoagulant regimen after CE owing to its ability to achieve robust hemostasis.

Comparison of Drug-Eluting Stent and Plain Old Balloon Angioplasty After Rotational Atherectomy in Severe Calcified and Large Coronary.

Drug-eluting stent (DES) is well known to be effective in severely calcified lesion after rotational atherectomy (ROTA). However, there are still some situations when stents should be avoided and plain old balloon angioplasty (POBA) should be the preferred option. The present study aims to explore whether POBA is comparably effective to DES in large and calcified coronary pretreated by ROTA in clinical outcomes.Consecutive patients treated for severely calcified lesions in the large (≥ 3 mm) coronary using ROTA + DES or ROTA + POBA were retrospectively analyzed. The major adverse cardiac events (MACE), including all-cause/cardiac death and target lesion revascularization (TLR) at 1 year and 2 years posttreatment, were compared between groups using the Cox regression analysis to identify independent predictors of TLR and MACE.The analysis included 285 cases in the ROTA + DES group and 47 cases in the ROTA + POBA group, without relevant differences in clinical baseline characteristics. Of note, lesion length was greater in the ROTA + DES group (37.2 versus 19.3 mm, P < 0.001); the ROTA + DES group had a higher rate of chronic total occlusion (CTO) lesions, with 8.4%, and the ROTA + POBA group had none. The inhospital/30-day mortality rate (5.3%, ROTA + DES; 6.4%, ROTA + POBA) and the 12- and 24-month all-cause/cardiac mortality rate (9.3%, ROTA + DES; 7.7%, ROTA + POBA) were not significantly different between the two groups. TLR rates were not significantly different between the two groups at 12 (4.6%, ROTA + DES; 4.3%, ROTA + POBA) and 24 (5.3%, ROTA + DES; 6.4%, ROTA + POBA) months.Outcomes were comparable for ROTA + DES and ROTA + POBA in severely calcified large coronary artery intervention with respect to midterm death or TLR rate, especially for short lesion of < 20 mm.

Reappraisal Value of a Modified Rotational Atherectomy Technique in Contemporary Coronary Angioplasty Era.

OBJECTIVES: To introduce a modified rotational atherectomy (RA) procedure and investigate the early and midterm outcomes of the RA-facilitating diversified percutaneous coronary intervention (PCI) in a large group of aged patients with higher cardiovascular risk. BACKGROUND: Previous studies about the outcomes of RA were limited with small sample size and low-risk population. METHODS: Between January 2013 and November 2015, 1169 consecutive patients treated with modified RA-facilitated PCI were retrospectively enrolled, including de novo calcified lesions and in-stent restenosis. Patients were regularly followed up for at least 1 year. Major adverse cardiac events (MACE) were analyzed for all participants by different strategies. Cox regression analysis was performed to identify risk factors for the events. RESULTS: The median age of patients was 75 years, with 11.7% of patients on maintenance hemodialysis. Most lesions (99.9%) were complex (American Heart Association type B2/C), and 68.3% were treated with RA + drug-eluting-stent (DES). Successful angiography was achieved in 97.8% cases, with 1.7% (20/1169) experiencing coronary perforation (including guidewire perforation). The incidence of MACE was 20.5% and 26.8% at 1-year and 2-year follow-up and were mainly driven by target lesion revascularization (TLR) (10.3% and 12.5%, respectively). The strategy of RA + DES had the lowest 2-year MACE, compared with the RA + drug-coated balloon and RA + plain old balloon angioplasty (14.5%, 30.5%, and 26.0%, respectively). CONCLUSIONS: The modified RA technique is a safe and effective tool in the contemporary PCI era, even in high-risk patients. The TLR rate was relatively high but acceptable in such complex lesions.

Evolut Self-Expanding Transcatheter Aortic Valve Replacement in Patients with Extremely Horizontal Aorta (Aortic Root Angle ≥ 70°).

Because of its rigidity and non-steerability, the presence of a horizontal aortic root poses a major anatomical issue during transcatheter aortic valve replacement (TAVR) with Evolut self-expanding valve. Previous studies have elucidated the difficulties of coaxial implantation of the self-expanding valve in patients with horizontal aorta, often resulting in increased complications and a lower device success rate. To date, most patients with extremely horizontal aorta (aortic root angle ≥ 70°) have been excluded from major TAVR clinical trials. Therefore, available data on TAVR with Evolut in this challenging anatomy are limited, and standardized treatment strategies and clinical results remain unknown. Herein, we report a clinical case series of TAVR with Evolut in extremely horizontal aorta. Among seven patients (aged 80-92 years; STS score, 12.6% ± 7.9%) who underwent TAVR with Evolut system, aortic root angle ranged from 71° to 83° (mean, 75.1°± 4.5°). All patients achieved device success with dedicated strategies and were clinically stable at 3-month follow-up. None of the patients had more than mild paravalvular leakage (PVL) at any point during follow-up.Complications in three patients included complete atrioventricular block requiring a permanent pacemaker implantation, cerebral infarction because of atrial fibrillation 3 days after TAVR, and cardiac tamponade requiring pericardiocentesis. In this case series, Evolut self-expanding TAVR in extremely horizontal aorta was effective and feasible with a high device success rate. Based on anatomical features, some dedicated strategies majorly contribute to the success of this procedure. Large-scale multicenter studies are required to confirm our findings.

Predictors of clinical outcomes after coronary implantation of bioresorbable polymer sirolimus-eluting Ultimaster stents in all-comers: A report of 1,727 cases.

BACKGROUND: Although bioresorbable polymer sirolimus-eluting Ultimaster stents (BP-SESs) are likely useful for percutaneous coronary interventions (PCIs), the clinical data from real-world cases are insufficient. Furthermore, the predictors of adverse clinical outcomes after BP-SES implantation have not been fully investigated. OBJECTIVES: This study evaluated the 1-year clinical outcomes after BP-SES implantation in real-world PCI cases and identified the predictors of adverse outcomes. METHODS: In this single-center, all-comers study, we consecutively implanted BP-SESs in all patients who required coronary stents between October 2015 and August 2016. We conducted a clinical follow-up assessment of these patients. RESULTS: The sample comprised 1,727 patients; 67% were men, the mean age was 72 years, and 37% had diabetes. Of the 2,085 lesions detected, 88% were type B2/C lesions, 4% were chronic total occlusions (CTOs), and 23% were bifurcations. The cumulative incidences of target lesion revascularization (TLR) and target lesion failure (TLF) at 1-year were 2.4% and 5.2%, respectively. A multivariate analysis revealed that hemodialysis (HD) (hazard ratio [HR] 8.40) and CTO (HR 4.21) were independent predictors of TLR. Stent sizes ≤2.5 mm were not associated with either TLR or TLF. CONCLUSIONS: The current study indicates that patients on HD and those with CTO were more likely to experience adverse clinical outcomes after BP-SES implantation. In contrast, small vessel diameter was not significantly related to adverse outcomes. The 1-year clinical outcomes after BP-SES implantation were found to be favorable among all-comer PCI cases, including patients receiving HD and those with in-stent restenosis.

Initial results of a first-in-human study on the PlasmaWire™ System, a new radiofrequency wire for recanalization of chronic total occlusions.

OBJECTIVES: To examine the safety, efficacy, and efficiency of the PlasmaWireTM System to recanalize coronary chronic total occlusions (CTO) using controlled ablation inside the CTO. BACKGROUND: The PlasmaWireTM System is a new bipolar radiofrequency (RF) wire system utilizing plasma-mediated ablation to facilitate wire crossing in CTOs. Two independent PlasmaWireTM wires are used in tandem for channel creation by applying RF energy between the tips so as to localize the ablation. METHODS: Prospective, nonrandomized, single-arm, multicenter study in seven patients with CTOs indicated for percutaneous coronary intervention (PCI). RESULTS: In this study, both wires were antegradely delivered to the distal end of CTO for antegrade re-entry in two cases and bidirectionally (antegrade and retrograde) delivered to the CTO for retrograde re-entry in five cases. In all cases, channel creation was achieved within a few seconds and was confirmed on angiogram or intravascular ultrasound (IVUS) and CTO recanalization was successfully achieved without any major adverse cardiac and cerebrovascular events (MACCE) or other minor complications. The clinical follow-up showed no clinical event at 1 month. CONCLUSIONS: The PlasmaWireTM System was shown to be safe and effective in obtaining CTO recanalization through a re-entry channel utilizing plasma-mediated ablation while reducing procedure time. The PlasmaWire™ System is a new bi-polar RF wire system utilizing plasma-mediated ablation for channel creation to facilitate CTO recanalization. This first-in-human study in which seven patients were enrolled was conducted to demonstrate the safety, efficacy, and efficiency of this system for CTO recanalization. Channels through the CTOs were successfully created within a few seconds by applying RF energy between the tips of two independent PlasmaWireTM wires and recanalization was achieved in all cases without any complication. The PlasmaWireTM System may safely facilitate CTO recanalization with less vessel injury and improve initial results of CTO PCI while reducing procedure time.

Rotational atherectomy and new-generation drug-eluting stent implantation.

OBJECTIVES: The aim of this study was to evaluate the clinical outcomes of rotational atherectomy (RA) followed by new-generation drug-eluting stent (DES) implantation in patients with an extensive amount of calcified and fibrotic plaque. BACKGROUND: RA followed by new-generation DES implantation for complex lesions has not been thoroughly evaluated. METHODS: A total of 744 consecutive patients (770 lesions) treated with new-generation DES implantation following RA for de novo lesions between January 2013 and November 2015 were retrospectively identified using our institutional database. Clinical outcomes at 12 months were evaluated and the independent predictors of all-cause death and target vessel failure (TVF) were assessed using Cox regression models. RESULTS: Target lesion revascularization occurred in 22 lesions (2.9%) and TVF occurred in 51 lesions (6.6%). In a multivariate analysis, hemodialysis, non-ST-segment elevation acute coronary syndrome, low ejection fraction, and HbA1c ≧ 7% were associated with 12-month mortality. Hemodialysis and right coronary artery were identified as independent predictors of TVF (hazard ratio (HR) 4.107, 95% confidence interval (CI) 2.194-7.685, P < .001; HR 2.491, 95% CI 1.023-6.062, P = .044, respectively). CONCLUSIONS: A good debulking with RA followed by new-generation DES implantation is recommended for patients with an excessive amount of calcified and fibrotic plaque, as this will likely improve the clinical outcomes.

Treatment for in-stent restenosis requiring rotational atherectomy.

OBJECTIVES: This study aimed to evaluate the outcomes of patients with in-stent restenosis (ISR) who underwent rotablation (RA) followed by balloon angioplasty (BA), drug-eluting stent (DES) implantation, or drug-coated balloon (DCB) angioplasty. BACKGROUND: Interventional treatment of ISR is occasionally challenging. Despite the availability of various percutaneous treatments, the optimal solution remains unclear. METHODS AND RESULTS: A total of 200 patients with ISR who underwent RA were retrospectively identified from our institutional database. Clinical outcomes at 12 months and independent predictors of target lesion revascularization (TLR) were assessed. Of patients, 90, 55, and 55 underwent BA, DES implantation, and DCB angioplasty, respectively. The incidence of all-cause death, cardiac death, and hospitalization due to heart failure was low in all groups. Moreover, no definite stent thrombosis was observed in the three groups. The TLR rate of BA, DES implantation, and DCB angioplasty following RA for ISR were 40.7%, 35.0%, and 27.3%, respectively. The adjusted outcomes for TLR using the inverse probability of treatment weighting method based on propensity scores indicated that DCB angioplasty following RA was superior to BA after RA. Intraprocedural complications, which could be successfully managed with interventional treatment, were identified in only three cases. CONCLUSIONS: TLR at 12 months is dismal. RA is not effective for ISR requiring RA. In unfavorable settings, DCB angioplasty following RA is the most effective treatment option in patients with ISR requiring debulking strategy.

Steep right anterior oblique view of self-expandable transcatheter aortic valve to timely detect stent under-expansion or non-uniform expansion before final release: a case series.

Background: Severely calcified aortic valves are a major limitation of transcatheter aortic valve replacement, because eccentric and heavy calcification of the aortic valve occasionally inhibits self-expansion of the valve frame, resulting in stent under-expansion, including non-uniform expansion or infolding. Nevertheless, the two-dimensional nature of fluoroscopic projection imaging can limit detection of stent under-expansion prior to the final release. Case summary: We present two cases demonstrating the importance of the steep right anterior oblique (RAO) view (>50°) in detecting significant stent under-expansion of a self-expanding valve prior to the final release. In Case 1, despite enough pre-dilatation, the partially deployed transcatheter heart valve (THV) appeared to be a substantial under-expansion, which was detected only in steep RAO view. Immediately after the final release, the THV was spontaneously embolized into the ascending aorta (the so-called 'pop-up' phenomenon). Emergent implantation of balloon-expandable valve proved to be successful as a bailout. In Case 2, significant stent distortion and infolding, especially on the non-coronary cusp side, was successfully diagnosed only in a steep RAO view prior to the final release. This finding allowed THV recapture and replacement with a new THV. Discussion: Notably, the steep RAO view can visualize the THV from its short axis while eliminating parallax, allowing for accurate diagnosis of THV under-expansion particularly in patients with severe calcification in the non- or right-coronary cusp. Therefore, the steep RAO view allows timely detection of THV under-expansion before the final release, enabling THV recapture and the adoption of several management strategies.

Comparative 2-year outcomes of the Misago stent versus other self-expandable nitinol stents for the endovascular treatment of aortoiliac disease.

BACKGROUND: The Misago iliac stent has not been compared with other stents. This study aimed to evaluate the 2-year clinical outcomes between the Misago stent and other self-expandable nitinol stents for symptomatic chronic aortoiliac disease. METHODS: This retrospective, single-center observational study enrolled 138 patients (180 limbs; Rutherford classification, between categories 2 and 6) treated with a Misago stent (N.=41) or self-expandable nitinol stent (N.=97) between January 2019 and December 2019. The primary endpoint was patency for up to 2 years. The secondary endpoints were technical success, procedure-related complications, freedom from target lesion revascularization, overall survival, and freedom from major adverse limb events. Multivariate Cox proportional hazards analysis was used to investigate predictors of restenosis. RESULTS: The mean follow-up duration was 710±201 days. The 2-year primary patency rate was comparable between the groups (Misago, 89.6% and self-expandable nitinol stent, 91.0%, P=0.883). The technical success rate was 100% in both groups, and procedure-related complications were equivalent between the groups (1.7% and 2.4%, respectively; P=0.773). Freedom from target lesion revascularization was not significantly different between the groups (97.6% and 94.4%, respectively; P=0.890). The overall survival rate and freedom from major adverse limb events were not significantly different between the groups (77.2% and 70.8%, respectively, P=0.209; 66.9% and 58.4%, respectively, P=0.149). Statin therapy was positively associated with primary patency. CONCLUSIONS: The Misago stent for aortoiliac lesions demonstrated comparable and acceptable clinical results of safety and efficacy for up to 2 years compared with other self-expandable stents. Statin use predicted the prevention of patency loss.

Incidence, Predictors, and Clinical Impact of the Impeded-By-Stent Phenomenon After Placing Two-Linked Design New Generation Drug-Eluting Stents.

BACKGROUND: When a catheter device is delivered during percutaneous coronary intervention, its passage can be disrupted by a deployed in a coronary artery. However, the condition and details of this phenomenon, that is impeded-by-stent phenomenon (ISP), remain unclear. METHODS: We designed a prospective, open-label, single-center, observational study to clarify the incidence, predictors, and clinical impact of ISP in drug-eluting stents (DESs). Two independent operators observed and judged the occurrence of ISP, which was defined as all disturbances to a device delivery by deployed DESs. We consecutively used the Ultimaster™ (Terumo, Tokyo, Japan) DES for one month (109 patients, October 2018), followed by the Synergy™ (Boston Scientific Corporation, Marlborough, MA, USA) DES the next month (119 patients, November 2018). RESULTS: DESs (2.5-4.0 mm in diameter) were implanted in 230 de novo coronary vessels. ISPs were observed in 17 of 239 stented segments (7.1 %). Multivariate analysis showed that bifurcation lesions (adjusted odds ratio [OR], 4.2; 95 % confidence interval [CI], 1.5-12.6; p = 0.008), predilatation balloon diameter (mm) (OR, 0.2; 95 % CI, 0.1-0.9; p = 0.03), and Ultimaster™ use (OR, 6.0; 95 % CI, 1.9-27.2; p = 0.002) were independent predictors of ISPs. During the 1.5-year follow-up period, no repeat revascularization or stent thrombosis occurred in patients with ISP. CONCLUSIONS: ISP itself does not trigger notable clinical outcomes, including repeat revascularization and stent thrombosis. However, caution should be considered regarding the latent risk of procedural complications.

Rationale and design of the INVICTUS Registry: (Multicenter Registry of Invasive and Non-Invasive imaging modalities to compare Coronary Computed Tomography Angiography, Intravascular Ultrasound and Optical Coherence Tomography for the determination of Severity, Volume and Type of coronary atherosclerosiS).

BACKGROUND: Coronary CT angiography (CCTA) is a first-line noninvasive imaging modality for evaluating coronary artery disease (CAD). Recent advances in CCTA technology enabled semi-automated detection of coronary arteries and atherosclerosis. However, there have been to date no large-scale validation studies of automated assessment of coronary atherosclerosis phenotype and coronary artery dimensions by artificial intelligence (AI) compared to current standard invasive imaging. METHODS: INVICTUS registry is a multicenter, retrospective, and prospective study designed to evaluate the dimensions of coronary arteries, as well as the characteristic, volume, and phenotype of coronary atherosclerosis by CCTA, compared with the invasive imaging modalities including intravascular ultrasound (IVUS), near-infrared spectroscopy (NIRS)-IVUS and optical coherence tomography (OCT). All patients clinically underwent both CCTA and invasive imaging modalities within three months. RESULTS: Patients data are sent to the core-laboratories to analyze for stenosis severity, plaque characteristics and volume. The variables for CCTA are measured using an AI-based automated software and assessed independently with the variables measured at the imaging core laboratories for IVUS, NIRS-IVUS, and OCT in a blind fashion. CONCLUSION: The INVICTUS registry will provide new insights into the diagnostic value of CCTA for determining coronary atherosclerosis phenotype and coronary artery dimensions compared to IVUS, NIRS-IVUS, and OCT. Our findings will potentially shed new light on precision medicine informed by an AI-based coronary CTA assessment of coronary atherosclerosis burden, composition, and severity. (ClinicalTrials.gov: NCT04066062).

Determination of lipid-rich plaques by artificial intelligence-enabled quantitative computed tomography using near-infrared spectroscopy as reference.

BACKGROUND AND AIMS: Artificial intelligence quantitative CT (AI-QCT) determines coronary plaque morphology with high efficiency and accuracy. Yet, its performance to quantify lipid-rich plaque remains unclear. This study investigated the performance of AI-QCT for the detection of low-density noncalcified plaque (LD-NCP) using near-infrared spectroscopy-intravascular ultrasound (NIRS-IVUS). METHODS: The INVICTUS Registry is a multi-center registry enrolling patients undergoing clinically indicated coronary CT angiography and IVUS, NIRS-IVUS, or optical coherence tomography. We assessed the performance of various Hounsfield unit (HU) and volume thresholds of LD-NCP using maxLCBI4mm ≥ 400 as the reference standard and the correlation of the vessel area, lumen area, plaque burden, and lesion length between AI-QCT and IVUS. RESULTS: This study included 133 atherosclerotic plaques from 47 patients who underwent coronary CT angiography and NIRS-IVUS The area under the curve of LD-NCP<30HU was 0.97 (95% confidence interval [CI]: 0.93-1.00] with an optimal volume threshold of 2.30 mm3. Accuracy, sensitivity, and specificity were 94% (95% CI: 88-96%], 93% (95% CI: 76-98%), and 94% (95% CI: 88-98%), respectively, using <30 HU and 2.3 mm3, versus 42%, 100%, and 27% using <30 HU and >0 mm3 volume of LD-NCP (p < 0.001 for accuracy and specificity). AI-QCT strongly correlated with IVUS measurements; vessel area (r2 = 0.87), lumen area (r2 = 0.87), plaque burden (r2 = 0.78) and lesion length (r2 = 0.88), respectively. CONCLUSIONS: AI-QCT demonstrated excellent diagnostic performance in detecting significant LD-NCP using maxLCBI4mm ≥ 400 as the reference standard. Additionally, vessel area, lumen area, plaque burden, and lesion length derived from AI-QCT strongly correlated with respective IVUS measurements.

Factors Contributing to Efficient Recanalization Procedures for Chronic Total Occlusion of the Superficial Femoral Artery.

BACKGROUND: This study aimed to clarify the factors for efficient procedures (EP) in superficial femoral artery (SFA) chronic total occlusion (CTO). METHODS: We retrospectively analyzed 200 consecutive limbs that underwent treatment for SFA CTO. The patients were divided into three groups according to the main strategies: subintimal angioplasty (SIA) (n = 123), Crosser use (n = 50), and 0.014″ CTO guidewire (CTO-GW) (n = 27). To determine the factors for an EP (EP; contrast volume <130 mL and procedure time <20 min; derived from non-CTO [control] procedures), the variables (P < 0.2) underwent multivariate analysis. RESULTS: SIA included more Trans-Atlantic Inter-Society Consensus C/D lesions and contralateral femoral approaches, and additional GW use (P < 0.05). CTO-GW presented a shorter occlusion length and elapsed time, and used less retrograde approach than the other strategies (P < 0.05). Crossers had a higher incidence of perforation (P = 0.002). The prompt retrograde approach had a similar actual retrograde procedure time, but a shorter total procedure time, compared to that of the delayed adoption (P < 0.001). EP was achieved in 14 limbs (7.0%). Multivariate analysis revealed that occlusion length (adjusted odds ratio [OR], 0.89; 95% CI, 0.81-0.96; P = 0.004) and SIA (OR, 8.71; 95% CI, 1.32-175.27; P = 0.02) were associated with EP. CONCLUSIONS: SIA contributed to EP. The timing of the retrograde approach was crucial because its delay resulted in an excessive procedure time.

The "Needle bypass" technique: Percutaneous anatomical bypass with needle rendezvous for patients with peripheral arterial disease that have no other surgical options.

BACKGROUND: The ideal method for recanalization of complex peripheral lesions has not been determined, despite the use of the latest endovascular devices. We describe a novel method for a fully percutaneous anatomical bypass, named the "needle bypass" technique, for treatment of complex vascular lesions with failed previous surgical therapy. MAIN TEXT: A 68-year-old male patient with chronic limb-threatening ischemia presented to our department. He previously had received surgical treatment 10 years prior that included the removal of the right distal common femoral artery and two surgical bypasses, an axillary-femoral bypass and an iliofemoral bypass, because he had repeated infections. He was referred to our center in order to have peripheral interventions. Since the previous conventional bridging/revascularization of the removed common femoral bifurcation had failed, the "needle bypass" technique was then used. With this novel technique, the tips of two percutaneous and bidirectional inserted needles were aligned ("needle rendezvous") for the externalization of a guidewire in a through-and-through manner. Once this was achieved, an endovascular stent graft and an interwoven stent were deployed to cover and connect the lesion. This new technique is a minimally invasive anatomical bypass that directly connects artery to artery without any disturbance of the venous flow, and this technique, as the only option available, was performed successfully in our no-option patient. CONCLUSIONS: The "needle bypass" technique is an effective percutaneous treatment method in patients with no other surgical options.

The "Fracking" technique: a novel approach to crack deep calcified plaque in the common femoral artery with hydraulic pressure.

BACKGROUND: The patency achieved by conventional peripheral interventions for atherosclerotic lesions in the common femoral artery (CFA), called the "no stenting zone", is not superior to that achieved by surgical endarterectomy due to calcified plaque occupying the area. Plaque modification strategies to obtain acute gain in CFA patency provide the better clinical outcomes than standard balloon angioplasty. Atherectomy devices, which focus on the modification of superficial calcifications, contribute to the improvement of clinical outcomes. However, deep calcifications resist vessel expansion such that luminal gain is not easily achieved. MAIN TEXT: We propose a novel calcified plaque modification technique, named the "fracking technique" (FT). The term fracking refers to how a rock is fractured by the high hydraulic pressure. In this technique, deep calcifications are cracked with hydraulic pressure via a balloon indeflator through an 18-gauge needle, which punctures calcifications to achieve greater acute luminal gain. Case 1 involved an 81-year-old male with eccentric calcified plaque in the right CFA. Conventional balloon angioplasty for the lesion yielded a suboptimal minimal lumen area (MLA), which increased from 6.2 to 10.7-mm2 on intravascular ultrasound (IVUS). The FT was implemented to obtain a larger MLA. After the FT was repeated at three locations at up to 8-atm, a greater MLA of 27.1-mm2 was achieved without complications. Case 2 involved a 72-year-old male undergoing hemodialysis due to diabetes mellitus who presented with ischemic pain in his right limbs at rest due to severe stenosis with eccentric calcification in the distal CFA. The MLA on IVUS before and after balloon angioplasty was 10.0-mm2 and 13.1-mm2, respectively, and this result was still suboptimal. The FT was attempted and successfully yielded a greater MLA of 28.9-mm2 without complications. Restenosis has not been detected for 2 years follow-up period. CONCLUSIONS: The FT is an effective option for treating calcified CFA lesions to achieve a larger lumen area. Long-term follow-up studies are necessary.

The "Direct tip injection in occlusive lesions (DIOL)" fashion.

BACKGROUND: The successful intervention for peripheral artery disease is limited by complex chronic total occlusions (CTOs). During CTO wiring, without the use of intravascular or extravascular ultrasound, the guidewire position is unclear, except for calcified lesions showing the vessel path. To solve this problem, we propose a novel guidewire crossing with plaque modification method for complex occlusive lesions, named the "Direct tip Injection in Occlusive Lesions (DIOL)" fashion. MAIN TEXT: The "DIOL" fashion utilizes the hydraulic pressure of tip injection with a general contrast media through a microcatheter or an over-the-wire balloon catheter within CTOs. The purposes of this technique are 1) to visualize the "vessel road" of the occlusion from expanding a microchannel, subintimal, intramedial, and periadventitial space with contrast agent and 2) to modify plaques within CTO to advance CTO devices safely and easily. This technique creates dissections by hydraulic pressure. Antegrade-DIOL may create dissections which extend to and compress a distal lumen, especially in below-the-knee arteries. A gentle tip injection with smaller contrast volume (1-2 ml) should be used to confirm the tip position which is inside or outside of a vessel. On the other hand, retrograde-DIOL is used with a forceful tip injection of moderate contrast volume up to 5-ml to visualize vessel tracks and to modify the plaques to facilitate the crossing of CTO devices. Case-1 involved a severe claudicant due to right superficial femoral artery occlusion. After the conventional bidirectional subintimal procedure failed, we performed two times of retrograde-DIOL fashion, and the bidirectional subintimal planes were successfully connected. After two stents implantation, a sufficient flow was achieved without complications and restenosis for two years. Case-2 involved multiple wounds in the heel due to ischemia caused by posterior tibial arterial occlusion. After the conventional bidirectional approach failed, retrograde-DIOL was performed and retrograde guidewire successfully crossed the CTO, and direct blood flow to the wounds was obtained after balloon angioplasty. The wounds heeled four months after the procedure without reintervention. CONCLUSIONS: The DIOL fashion is a useful and effective method to facilitate CTO treatment.

The "needle re-entry" technique for infrainguinal arterial calcified occlusive lesions.

BACKGROUND: Vascular calcification is a predictor of poor clinical outcome during and after endovascular intervention. Guidewire crossing techniques and devices have been developed, but chronic total occlusions (CTOs) with severe calcification often prevent subintimal re-entry. We propose a novel guidewire crossing approach combined needle rendezvous with balloon snare technique, named the "needle re-entry" technique, for treatment of complex occlusive lesions. MAIN TEXT: A 73-year-old female with severe claudication in her right calf with ankle brachial index of 0.62, and a computed tomography angiogram showed a long occlusion with diffuse calcification in superficial femoral artery. She was referred to our department to have peripheral interventions. Since the calcified vascular wall of the lesion prevented the successful re-entry, the "needle re-entry" was performed. First, a retrograde puncture of the SFA, distally to the occlusion, was performed and an 0.018-in. guidewire with a microcatheter was inserted to establish a retrograde fashion. Second, an antegrade 5.0-mm balloon was advanced into a subintimal plane and balloon dilation at 6 atm was maintained. Third, an 18-gauge needle was antegradely inserted from distal thigh to the dilated 5.0-mm balloon. After confirming a balloon rupture by the needle penetration, we continued to insert the needle to meet the retrograde guidewire tip. Then, a retrograde 0.014-in. guidewire was carefully advanced into the needle hole, named the "needle rendezvous" technique. After further guidewire advancement to accomplish a guidewire externalization, the needle was removed. Finally, since the guidewire was passing through the 5.0-mm ruptured balloon, the balloon was withdrawn, and the guidewire was caught with the balloon and successfully advanced into the antegrade subintimal space, named the "balloon snare" technique. After the guidewire was advanced into the antegrade guiding sheath and achieved a guidewire externalization, an endovascular stent graft and an interwoven stent were deployed to cover the lesion. After postballoon dilation, an angiography showed a satisfactory result without complications. No restenosis, reintervention, and limb loss have been observed for one year follow-up period after this technique. CONCLUSIONS: The "needle re-entry" technique is a useful guidewire crossing technique to revascularize femoropopliteal complex CTOs with severe calcification which prevent the achievement of guidewire crossing with the conventional procedures.