Adjunctive Balloon Postdilatation after Stent Deployment: Is It Still Necessary with Drug‐Eluting Stents?

Deployment of bare metal stents (BMS) with current stent delivery systems is often associated with suboptimal stent expansion. Adjunctive postdilatation with noncompliant balloons has improved stent expansion with BMS and has been associated with less need for target vessel revascularization (TVR). Drug-eluting stents (DES) have proven highly effective in reducing restenosis and TVR and are now being used in the great majority of percutaneous coronary interventions. Because of the very low rates of TVR with DES, many operators have felt that postdilatation may no longer be necessary. In this review, we present data showing that stent expansion of DES (like BMS) using current stent delivery systems is frequently suboptimal. Furthermore, smaller mimimal stent area (MSA) and stent underexpansion following deployment of DES are strong predictors of stent thrombosis and TVR. Adjunctive postdilatation with noncompliant balloons can increase MSA and decrease the frequency of suboptimal stent deployment and potentially can reduce the frequency of stent thrombosis and TVR. Despite the lack of evidence from randomized clinical trials, we believe the observational data support the use of adjunctive balloon postdilatation following deployment of DES in the great majority of patients.     

Extensive coronary dissection caused by balloon rupture at high pressure during stent deployment

A patient with severe stenosis of the right coronary artery underwent successful stent placement. During high pressure postdilatation, the balloon ruptured, causing an extensive proximal dissection of the right coronary artery managed with the deployment of several additional stents. Strategies aimed at avoiding or minimizing the consequences of high pressure balloon rupture are discussed. © 1996 Wiley-Liss, Inc.     

Is adjunctive balloon postdilatation necessary after coronary stent deployment? Final results from the POSTIT trial

Early-generation balloon-expandable stents required postdilatation with noncompliant balloons at high pressure to optimize stent deployment. The need for adjunctive balloon postdilatation with modern stent delivery systems is unknown. Patients undergoing elective stenting were randomized to Boston Scientific NIR, Guidant Tri-Star/Tetra, and Medtronic AVE S670 stents. The primary endpoint was optimum stent deployment defined as a minimal stent diameter (MSD) >/= 90% of the average reference lumen diameter assessed by intravascular ultrasound (IVUS) performed immediately following stent deployment. If, by operator assessment, the primary endpoint was not achieved with the stent delivery system, adjunctive postdilatation with noncompliant balloons was performed. Of 256 patients with IVUS studies adequate for core laboratory analysis, only 29% achieved optimum stent deployment with the stent delivery system. None of the baseline clinical or angiographic variables predicted optimum stent deployment. Of the procedural variables, the type of stent and nominal stent size were not predictors, but higher deployment pressures were associated with a higher frequency of optimum stent deployment (< 12 atm 14% vs. >/= 12 atm 36%; P = 0.007). The inability to achieve optimum stent deployment was not due to undersizing the stent delivery balloon, but rather to an inability of the stent delivery balloon to expand fully the stent to nominal size. In patients who underwent postdilatation, the frequency of achieving optimum stent deployment increased from 21% to 42%, minimal stent area increased from 6.6 +/- 2.2 to 7.8 +/- 2.3 mm(2), and MSD increased from 2.6 +/- 0.5 to 2.8 +/- 0.4 mm. These data stress the continued need for adjunctive balloon postdilatation with modern stent delivery systems. Cathet Cardiovasc Intervent 2003;59:184-192.     

Initial clinical experience with the Protégé EverFlex long self-expanding nitinol stent in the superficial femoral artery

AIMS: Clinical results following stent implantation in the superficial femoral artery (SFA) are limited due to restenosis, often caused by stent fractures. Therefore new stent devices are desirable. The present study details our initial experience with the routine use of the novel Protégé EverFlex long self-expanding nitinol stent for treatment of long SFA total occlusions or stenoses. METHODS AND RESULTS: Between February and March 2006 a total of 15 EverFlex nitinol stents were implanted in 12 patients with either total SFA occlusions (n = 9) or long stenoses (n = 3), mean lesion length 14.9 cm (+/- 10.4 cm). All patients presented with claudication stage Fontaine IIb (Rutherford category 3). Stent lengths were 10 cm (n = 6), 12 cm (n = 1), or 15 cm (n = 8), stent diameters were 6 mm (n = 14) and 7 mm (n = 1). Access was gained either by the crossover (n = 9), antegrade (n = 2), or popliteal approach (n = 1). After predilatation, stent placement and postdilatation were performed with 100% technical success. Clinical and apparative follow-up after 6-8 weeks indicated the absence of restenosis or reocclusion in all cases. CONCLUSION: The novel long self-expanding EverFlex nitinol stent (10 cm/12 cm/15 cm in length) exhibits excellent technical handling characteristics with good short-term clinical results. Mid-term and long-term clinical results as well as potential stent fractures need to be further examined.     

A self-expandable coronary stent system to treat complex coronary stenosis complicated by poststenotic aneurysm: an optical coherence tomographic evidence-based case report

Coronary artery aneurysm is a relatively uncommon disorder characterized by coronary artery dilatation with diameter that exceeds 50% of the normal adjacent segments with atherosclerosis being the most common etiology. Aneurysms can be adjacent to a stenosis in a post- or prestenotic location. Both anatomical conditions are technically challenging regarding their percutaneous treatment because of the large discrepancy in size between the stenotic and dilated segments, and require careful choice of the most appropriate technique and device. We have successfully treated a coronary stenosis complicated by a poststenotic aneurysm in a 60-year-old patient with atypical angina using a novel self-expandable coronary stent system implanted with optical coherence tomography (OCT) guidance. OCT scan after implantation showed residual stent malapposition inside the aneurysm despite postdilatation. Thanks to the ability of this stent to self-expand over time, 6-month OCT follow-up showed an optimal result in terms of stent apposition, strut coverage, and absence of in-stent restenosis.     

后扩张治疗对老年冠状动脉钙化病变PCI术的疗效和安全性研究

目的观察常规后扩张治疗对老年冠状动脉钙化病变经皮冠状动脉介入治疗（PCI）的疗效和安全性。方法选择血管造影成功的老年钙化病变冠心病患者124例,随机分为后扩张组（治疗组,62例）和常规置入组（对照组,62例）。观察两组术中并发症发生率,住院期间及1年后支架内血栓、再狭窄和主要不良心脏事件（MACE）发生率。结果后扩张组和常规置入组患者PCI中并发症发生率比较差异无统计学意义（6．5％比4．8％,P〉0．05）。1年后的随访结果显示,后扩张组的MACE事件发生率较对照组降低（4．8％比12．9％,P〈0．05）;支架内血栓和支架内再狭窄发生率较常规置人组均明显减少（1．6％比4．8％,4．4％比14．3％）,差异有统计学意义（P〈0．05）。结论在老年冠状动脉钙化病变PCI中常规后扩张治疗安全、有效,能减少术后不良心脏事件从而改善预后。     

药物洗脱支架断裂的影像认识

目的借助冠状动脉造影和血管内超声的影像资料,确定支架断裂的发生和类型。方法回顾性分析北京大学人民医院2 021例冠状动脉造影和183例血管内超声（IVUS）影像资料。结果共发现3例患者的6处支架断裂,其中2例经IVUS证实。3例支架断裂均发生在西罗莫司药物洗脱支架,且均发生在冠状动脉介入术后1年以内。冠状动脉造影证实4处支架断裂为完全断裂伴断裂处支架移位。IVUS证实3处支架断裂为完全断裂,2处为部分断裂;1处断裂靠近支架重叠处;1处支架断裂伴有血管瘤形成。结论冠状动脉造影和IVUS可以帮助确定支架断裂的诊断。     

12-month clinical outcomes after Magmaris percutaneous coronary intervention in a real-world cohort of patients: Results from the CardioHULA registry

Introduction and objectivesClinical evidence on the bioresorbable magnesium scaffolds (BRS) is still scarce. We aim to assess clinical outcomes after magnesium BRS deployment in a real-world cohort of patients.MethodsWe included in a non-randomized, prospective, single-center registry of all patients treated with at least one Magmaris device in our cath lab. Pre and postdilatation with optical coherence tomography guidance, as part of the 4Ps strategy, were performed in all cases. The primary endpoint was target lesion failure (TLF) at 12 months.Results42 patients (with 42 lesions) underwent Magmaris percutaneous coronary intervention (PCI) between June 2016 to April 2017. PCI was performed in an acute setting in 54.76% cases; the most treated vessel was the anterior descending artery, with a mean diameter of 3.30±0.25 mm. All lesions underwent predilatation and postdilatation, with a mean postdilatation pressure of 19.2 atm. Procedural success rate was 100%. TLF rate was 4.7% at 12 months. None of our patients died or suffered myocardial infarction. Two patients (4.7%) underwent clinically-driven target lesion revascularization due to in-stent restenosis. No stent thrombosis was detected.Conclusion12-months clinical outcomes after Magmaris PCI demonstrate its safety and feasibility when deployed in a 4Ps strategy.     

Improved technique for use of half-stents remounted on a stent delivery system

The use of half-length intracoronary Johnson & Johnson stents has been described in a number of settings. Half-stents are useful for very short lesions, avoidance of bifurcations or side-branches, ostial stenosis, covering gaps between adjacent stents, and for dissection adjacent to stents caused by postdilatation. Previously described methods for use of half-stents have involved bare stents, or significant manipulation of either the stent or the delivery sheath for remounted half-stents. We describe a method for half-stent preparation and delivery that does not involve distortion of the stent or the delivery sheath. The risk of stent loss, as can occur with bare stents, is diminished. The geometry of the stent is preserved since it is not expanded and then recrimped, and the end of the delivery sheath is not flared or distorted, which may interfere with stent delivery. © 1996 Wiley-Liss, Inc.     

Drug-eluting stents for coronary bifurcations: bench testing of provisional side-branch strategies.

The objective of this study was to bench-test provisional bifurcation stenting strategies to provide insights on how best to perform these with drug-eluting stents (DESs). Bifurcation stenting with DESs reduces restenosis compared with bare metal stents (BMSs). Outcomes with a single DES are better than with two DESs but if the main branch is stented, there needs to be a reliable strategy for provisionally stenting the side-branch with full ostial scaffolding and drug application. Stents were photographed in a phantom after deployment with different strategies. With provisional T-stenting, placement of the side-branch stent without gaps is difficult. The internal (or reverse) crush strategy fully scaffolds the side-branch ostium but is experimental. The culotte technique providing excellent side-branch ostial coverage is easier to perform with open-cell or large-cell stent design. In general, kissing balloon post-dilation improves stent expansion, especially at the ostium, and corrects distortion. However, a main-branch kissing balloon of smaller diameter than the deploying balloon causes distortion. Final main-branch postdilatation or sequential postdilatation prevents distortion after the internal crush strategy.     

Stent malapposition caused by improper rewiring during left main intervention: The role of intravascular ultrasound in avoidance and management—A case report

The optimal technique for bifurcation stenting of distal Left main (LM) lesions remains unestablished and controversial. Some techniques with superior stent apposition, such as culotte technique were supposed to be associated with lower rate of stent thrombosis. However, with culotte technique, the double‐stent layer at the carina and in the proximal part of the bifurcation, may lead to difficult or improper rewiring of the side branch before final kissing balloon postdilatation (KBP). We describe a case of distal LM disease associated with distal left circumflex (LCX) and posterior descending artery stenosis. During LM stenting using culotte technique, improper rewiring of LCX before final KBP caused malapposition of the inner sent layer at the mid part of LM. Despite the optimal angiographic result, intravascular ultrasound (IVUS) was able to detect stent malapposition and guided further management to achieve complete stent apposition. The present case indicates that IVUS is an essential tool for LM stenting particularly when applying double stent strategy requiring final rewiring before KBP. Moreover, we suggest that some tools, such as Crusade and Venture catheters, can be used to ensure proper rewiring and hence, prevent subsequent stent malapposition, which may lead to catastrophic complications such as early and late LM stent thrombosis. © 2011 Wiley‐Liss, Inc.     

Clinical and angiographic outcomes after overdilatation of undersized sirolimus-eluting stents with largely oversized balloons: an observational study.

The purpose of this study was to assess the safety and effectiveness of sirolimus-eluting stent (SES) postdilatation with largely oversized balloons. We evaluated the clinical outcome of 68 consecutive patients enrolled in the Rapamycin-Eluting Stent Evaluated at Rotterdam Cardiology Hospital (RESEARCH) registry who underwent percutaneous coronary intervention with SES implantation and further postdilatation with balloons > 1 mm larger than the stent nominal size. Angiographic follow-up was either scheduled for selected subgroups or clinically driven. Overall, 75 lesions were treated. The procedure was successful in 98.5% of the cases. One patient (1.5%) underwent emergency coronary bypass surgery for acute vessel occlusion. During 10.1 +/- 1.7 months of follow-up, three patients (4.5%) died, one (1.5%) had acute myocardial infarction, and four (6%) had target vessel revascularization. At angiographic follow-up, loss index was 0.13 +/- 0.34 and restenosis rate was 7.7%. Although not routinely recommended in every patient, SES postdilatation with largely oversized balloons appears a safe and effective strategy for selected patients.     

Balloon to Artery Ratio, Not Inflation Pressure, Correlates with Adequate Stent Deployment: Size Is More Important than Pressure

To investigate the relative importance of balloon to artery ratio (BAR) and poststent inflation pressure (IP), we retrospectively analyzed the IVUS (intravascular ultrasound) data available for patients (n = 30) who underwent coronary stent implantations (n = 31) between May 1993 and April 1996 under various stent deployment strategies. Choice for sizing of the postdilatation balloon varied widely with BAR ranging from 0.7.5 to 1.34 (mean = 1.07 ± 0.14). IP also varied profoundly from 4 to 22 atm (mean = 14.7 ± 3.7 atms). Although there was no uncovered dissection or subintimal hemorrhage by IVUS, the adequacy of the stent deployment as assessed by relative stent expansion (RSE) varied significantly from 44.0% (very poor deployment) to 141.7% (overstretching of the arterial segment). Strikingly, BAR, not IP, correlated significantly with RSE (correlation coefficient [CC] of BAR =0.77, P <0.0001; CC of IP =0.13, P > 0.5; stepwise linear regression analysis). No stent postdilated by a balloon with a BAR of ≤ 1.0 achieved a RSE of 100%, while BARS ≤ 1.2 uniformly resulted in RSEs ≤ 100%. In contrast, despite postdilation IP of ≤ 15 atm, only 6 (33.3%) of 18 stem achieved RSE > 100%. Moreover, high RSEs were obtained by IP as low as 8 atms. Thus, BAR was much more strongly correlated with RSE, an index of optimal stent deployment, while IP was not correlated with RSE. These data suggest that BAR may be more important than IP for maximal stent implantation in the majority of patients. However, further larger scale, prospective studies are required to determine the importance of BAR versus IP to achieve optimal stent deployment.     

The characteristics of dissemination of embolic materials during renal artery stenting.

BACKGROUND: Though one of the major complications of renal artery stenting is dissemination of embolic materials which may cause deterioration of renal function, the characteristics of this phenomenon are unclear. We investigated the characteristics of embolization in renal artery stenting by intrarenal duplex ultrasound monitoring. METHOD: A total of 17 patients with 21 lesions that underwent primary renal artery stenting were prospectively included. Intrarenal artery blood flow velocity spectra exhibiting microembolic signals (MES) were examined during renal artery intervention. RESULT: Renal artery stenting was successful in all cases. Predilatation was needed in eight cases, and direct stenting without predilatation was performed in 13 cases. Postdilatation or flare formation was performed in 13 cases. Multiple stenting was not performed in any patients, though stenting of both renal arteries was performed in four cases. Major embolization and no reflow/slow flow were not determined by angiography. Except for one case of technical kidney failure, real-time intrarenal duplex ultrasound monitoring was possible and the study protocol was completed. MES were detected during all procedural phases. The number of cardiac beats with MES was significantly higher in stenting (11.1 +/- 2.8) following postdilatation/flare formation (8.3 +/- 4.1) than in predilatation (3.3 +/- 2.1) (predilatation vs. stenting: P < 0.001, predilatation vs. postdilatation/flare: P = 0.009, stenting vs. postdilatation/flare: P = 0.03). The mean creatinine value was 1.31 +/- 0.68 mg/dl at baseline and 1.54 +/- 1.08 at 1 month. Deterioration of renal function was observed in 43% (3/7) of patients with renal impairment, whereas 10% (1/10) of patients without renal impairment experienced deterioration of renal function (P = 0.250). CONCLUSION: Dissemination of embolic materials was detected in all procedures. Higher MES were detected in stenting following postdilatation/flare formation. Pre-existing renal impairment yielded a trend toward the deterioration of renal function after renal artery stenting during the short-term follow-up. Protected renal artery stenting might be considered advisable, at least in atherosclerotic renal artery stenosis patients with renal impairment though a larger number and long-term study will be required.     

Usefulness of high-pressure post-dilatation to optimize deployment of drug-eluting stents for the treatment of diffuse in-stent coronary restenosis

Drug-eluting stents (DESs) may represent a simple, effective treatment for in-stent restenosis (ISR); however, the underexpansion of stents is a significant cause of target vessel failure. It was hypothesized that high-pressure postdilatation would be necessary to optimize DES expansion and minimize the risk for restenosis when treating patients with ISR. Fifteen patients with diffuse ISR were treated by predilatation (including cutting balloons), DES deployment, and high-pressure postdilatation, with the measurement of luminal and stent dimensions by intravascular ultrasound after each intervention. After initial deployment, DES underexpansion was present in 10 of 15 patients (66%); after high-pressure postdilatation, there was a significant increase in luminal dimensions, including minimum luminal area (4.3 +/- 0.3 to 5.6 +/- 0.4 mm(2), p <0.001) and a doubling in the proportion of patients with optimal stent expansion. At long-term follow-up (median 11 months), target lesion revascularization occurred in 1 patient (7%) because of edge restenosis; there was no restenosis within the DES.     

Very delayed coronary stent fracture: A case report

A stent fracture is an emerging complication of the coronary stents. There are numerous risk factors for stent fractures; which include forceful exaggerated motion in the atrioventricular groove seen in right coronary artery, long stent, an ostial lesion at the point of maximum curvature in a tortuous vessel, stent over-expansion, stent overlapping with different size stents, complex lesion after stenting of a totally occluded vessel, Cypher stent and a highly mobile segment causing high mechanical stress. Furthermore, chronic stretch at specific vessel sites as bends may lead to late occurrence of fracture.Here we report a case of 40-year-old male who had two overlapping Cypher stents (3.0 × 13 mm and 2.75 × 18 mm) deployed at mid left anterior descending artery 2 years earlier presented with progressive chest pain.     

Prevalence and clinical impact of stent fractures after femoropopliteal stenting

OBJECTIVES: The aim of this study was to investigate the occurrence and the clinical impact of stent fractures after femoropopliteal stenting. BACKGROUND: The development of femoral stent fractures has recently been described; however, there are no data about the frequency and the clinical relevance. METHODS: A systematic X-ray screening for stent fractures was performed in 93 patients. In total, 121 legs treated by implantation of self-expanding nitinol stents were investigated after a mean follow-up time of 10.7 months. The mean length of the stented segment was 15.7 cm. RESULTS: Overall, stent fractures were detected in 45 of 121 treated legs (37.2%). In a stent-based analysis, 64 of 261 stents (24.5%) showed fractures, which were classified as minor (single strut fracture) in 31 cases (48.4%), moderate (fracture of >1 strut) in 17 cases (26.6%), and severe (complete separation of stent segments) in 16 cases (25.0%). Fracture rates were 13.2% for stented length < or =8 cm, 42.4% for stented length >8 to 16 cm, and 52.0% for stented length >16 cm. In 21 cases (32.8%) there was a restenosis of >50% diameter reduction at the site of stent fracture. In 22 cases (34.4%) with stent fracture there was a total stent reocclusion. According to Kaplan-Meier estimates, the primary patency rate at 12 months was significantly lower for patients with stent fractures (41.1% vs. 84.3%, p < 0.0001). CONCLUSIONS: There is a considerable risk of stent fractures after long segment femoral artery stenting, which is associated with a higher in-stent restenosis and reocclusion rate.     

Carotid stent fracture: Diagnosis and management

With increasing numbers of carotid stent implantations, stent fractures likely will be detected in this vessel region. The authors report two cases of stent fracture: one balloon expandable and one self expandable stent fractured and caused symptoms. CT angiography identified the stent fractures. One partial stent fracture in the internal carotid artery caused a significant restenosis. One complete stent fracture in the common carotid artery caused neurological symptoms, but no significant restenosis. Computerized tomographic angiography (CTA) findings were confirmed by conventional angiography and treated by repeated stent implantation. In a 12‐month follow‐up period, both patients remained further neurologically asymptomatic and there was no restenosis in duplex sonography or CTA. © 2009 Wiley‐Liss, Inc.     

Superimposed stents in the management of acute recoil after Palmaz-Schatz stenting

We report a patient in whom aorto-ostial stenting with a Palmaz-Schatz coronary stent was complicated by significant acute elastic recoil, despite appropriate positioning of the stent and full expansion of a high-pressure, postdilatation balloon. Superimposing a Palmaz biliary stent overcame the inward radial force of this lesion and achieved an adequate lumen. Cathet. Cardiovasc. Diagn. 44:407–410, 1998. © 1998 Wiley-Liss, Inc.     

Meta-analysis of incidence, clinical characteristics and implications of stent fracture

A meta-analysis of published studies was conducted to evaluate the incidence, predictors, and clinical outcomes of stent fractures. Eight studies with 108 stent fractures in 5,321 patients were analyzed using the Bayesian method. Study end points included in-stent restenosis (ISR) and target lesion revascularization (TLR). The mean incidence of stent fracture per patient was 4.0% (95% confidence interval 0.4% to 16.3%). All cases, except 1, were reported with sirolimus-eluting stents. The incidence of stent fracture was 30.4% in the left anterior descending coronary artery, 10.9% in the left circumflex coronary artery, 56.4% in the right coronary artery, < 0.01% in the left main coronary artery, and 1.7% in saphenous vein grafts. The probability of stent fracture was significantly higher in the right coronary artery than in the left anterior descending and left circumflex lesions (p < 0.01). Left main stents were less likely to fracture compared to those in all other vessels (p < 0.01). The probability of stent fracture was significantly increased in overlapping stents (7.5% vs 2.1%, p = 0.01) and long stents (46 vs 32.5 mm, p < 0.01). Lesions with stent fractures had higher rates of ISR (38% vs 8.2%, p < 0.01) and TLR (17% vs 5.6%, p < 0.01). Conversely, the probability of stent fractures was higher in patients with ISR (12.8% vs 2.1%, p < 0.01) and TLR (8.8% vs 2.7%, p < 0.01). In conclusion, although not always associated with clinical sequelae, the probability of ISR and TLR is increased with stent fracture. Conversely, the probability of stent fractures is increased in lesions with ISR or TLR, thus raising the need for surveillance and management guidelines for at-risk patients.