Successful Expansion of an Underexpanded Stent by Rotational Atherectomy

The current routine use of intracoronary stents in percutaneous coronary intervention (PCI) has significantly reduced rates of restenosis, compared with balloon angioplasty alone. On the contrary, small post-stenting luminal dimensions due to undilatable, heavily calcified plaques have repeatedly been shown to significantly increase the rates of in-stent restenosis. Rotational atherectomy of lesions is an alternative method to facilitate PCI and prevent underexpansion of stents, when balloon angioplasty fails to successfully dilate a lesion. Stentablation, using rotational atherectomy to expand underexpanded stents deployed in heavily calcified plaques, has also been reported. We report a case via the transradial approach of rotational-atherectomy–facilitated PCI of in-stent restenosis of a severely underexpanded stent due to a heavily calcified plaque. We review the literature and suggest rotational atherectomy may have a role in treating a refractory, severely underexpanded stent caused by a heavily calcified plaque through various proposed mechanisms.     

The effectiveness of excimer laser coronary atherectomy with contrast medium for underexpanded stent: The findings of optical frequency domain imaging

Stent underexpansion is a risk factor for in‐stent restenosis (ISR) and stent thrombosis. Although excimer laser coronary atherectomy (ELCA) with contrast medium was shown to be effective to improve stent underexpansion in undilatable lesions, precise mechanism of this technique was not well understood. We report a case of ISR with stent underoptimal implantation within a circumferential‐calcified atherosclerotic plaque beneath the stent strut that could not be dilated by repeated high‐pressure balloon inflations. After rotational atherectomy, the mechanism of the underexpanded lesion could be obtained by optical frequency domain imaging (OFDI). High‐pressure balloon could not dilate the underexpanded stent. Since ELCA with saline flush only gave intimal erosions and minor dissections, additional high‐pressure balloon was also ineffective. Finally, ELCA with contrast medium could disrupt the calcific lesion beneath the underexpanded stent. The angiographic and OFDI findings confirmed the full stent expansion could be accomplished by further balloon dilatation with an ordinary pressure. ELCA with contrast medium is feasible to improve stent underexpansion by disrupting the calcified plaque behind the stent strut. © 2015 Wiley Periodicals, Inc.     

Usefulness of the SafeCut Dual Wire PTCA catheter for the treatment of calcified lesions

Calcified lesions are a cause of stent underexpansion, which significantly increases the subsequent risks of restenosis and stent thrombosis, even when drug-eluting stents are used. In this report, we describe how a novel balloon catheter, the SafeCut Dual Wire percutaneous transluminal coronary angioplasty catheter, enabled adequate dilatation in a calcified lesion that was unresponsive to conventional balloon catheters.     

Use of SafeCut Balloon for treatment of in-stent restenosis of a previously underexpanded sirolimus-eluting stent with a heavily calcified plaque

Calcified lesions are a cause of stent underexpansion which significantly increases the subsequent risks of in-stent restenosis and thrombosis, even when drug-eluting stents are used. In this report, we describe a novel balloon catheter (SafeCut) that enabled adequate dilatation of in-stent restenosis in a previously underexpanded sirolimus-eluting stent that was unresponsive to high-pressure inflation using a conventional balloon after aggressive rotational atherectomy to treat a heavily calcified plaque.     

Intravascular ultrasound evaluation of the effect of rotational atherectomy in obstructive atherosclerotic coronary artery disease.

BACKGROUND. High-speed rotational atherectomy uses a diamond-coated, elliptical burr to abrade occlusive atherosclerosis, especially noncompliant calcified plaque. METHODS AND RESULTS. Intravascular ultrasound (IVUS) was used to analyze 28 patients after atherectomy. Arteries treated and imaged were left main (three), left anterior descending (12), left circumflex (five), right coronary (seven), and saphenous vein graft (one). Twenty patients had adjunct balloon angioplasty. Twenty-two (79%) target lesions were calcified; the intimal arc of calcium was 160 +/- 126 degrees (range, 0-360 degrees). After atherectomy, the intima-lumen interface was unusually distinct and circular. The lumen was larger than the largest burr used for both stand-alone (1.19 +/- 0.19-fold the largest burr size) and adjunct balloon procedures (1.30 +/- 0.15-fold the largest burr). Three-dimensional reconstruction of the ultrasound images showed a smooth lumen, especially in calcified plaque. Deviations from cylindrical geometry occurred only in areas of soft plaque or superficial tissue disruption of calcified plaque. Five patients were studied before and after rotational atherectomy. IVUS showed an increase in lumen size, a decrease in plaque-plus-media area and in arc of target lesion calcification, and no change in target lesion external elastic membrane cross-sectional area. CONCLUSIONS. Rotational atherectomy causes atheroablation with only moderate evidence of barotrauma in heavily calcified arteries, even after adjunct balloon angioplasty. The lumen is cylindrical, especially in areas of calcified plaque, and somewhat larger than the largest burr tip used.     

Excimer laser in management of underexpansion of a newly deployed coronary stent

We report the successful management of underexpansion of a newly deployed coronary stent refractory to balloon dilatations. Direct stenting was performed for a lesion in the mid left anterior descending artery (without angiographically apparent heavy coronary calcification). The stent remained underexpanded despite repeated balloon dilatations including with high‐pressure inflations. Subsequently, an excimer laser catheter was used in an attempt to vaporize the plaque by the accoustomechanical effect of the rapidly exploding bubbles. The overall angiographic result was good after further balloon dilatation with ordinary pressure and full stent expansion was achieved. Management of underexpansion of a newly deployed stent is a potential indication of laser angioplasty. © 2013 Wiley Periodicals, Inc.     

Bailout Intravascular Lithotripsy for the Treatment of Acutely Underexpanded Stents in Heavily Calcified Coronary Lesions: A Case Series

Stent underexpansion is a common problem in heavily calcified coronary lesions treated with percutaneous coronary intervention, and has been associated with in-stent restenosis, stent thrombosis and, subsequently, poor clinical outcomes. Adequate preparation of heavily calcified coronary lesions (e.g. using non-compliant balloons, cutting/scoring balloons, rotational/orbital atherectomy or intravascular lithotripsy) prior to stent implantation is essential in preventing stent underexpansion. However, in certain cases the deployed stent may remain underexpanded despite extensive lesion preparation. To date, no consensus exists on how to treat stent underexpansion in this scenario.We present a cases series in which post-stenting intravascular lithotripsy was performed to treat acute stent underexpansion in heavily calcified lesions, describing the technical aspects, angiographic results as well as clinical outcomes at mid-term follow-up.     

Current status of rotational atherectomy

Despite the increasing use of percutaneous transluminal coronary angioplasty and intracoronary stent placement for the treatment of obstructive coronary artery disease, a large subset of coronary lesions cannot be adequately treated with balloon angioplasty and/or intracoronary stenting alone. Such lesions are often heavily calcified or fibrotic and undilatable with the present balloon technology and attempts to treat them with balloon angioplasty or intracoronary stent placement often lead to vessel dissection or incomplete stent deployment with resultant adverse outcomes. Rotational atherectomy remains a useful niche device for the percutaneous treatment of such complex lesions, usually as an adjunct to subsequent balloon angioplasty and/or intracoronary stent placement. In contrast to balloon angioplasty or stent placement that widen the coronary lumen by displacing atherosclerotic plaque, rotational atherectomy removes plaque by ablating the atherosclerotic material, which is dispersed into the distal coronary circulation. Other lesion subtypes amenable to treatment with this modality include ostial and branch‐ostial lesions, chronic total occlusions, and in‐stent restenosis. This review discusses the technique and principles of rotational atherectomy, the various treatment strategies for its use (including adjunctive pharmacotherapy), the lesion‐specific applications for this device, and the complications unique to this modality. Recommendations are also made for its use in the current interventional era. Catheter Cardiovasc Interv 2004;62:485–498. © 2004 Wiley‐Liss, Inc.     

Intravascular Ultrasound Predictors of Angiographic Restenosis in Lesions Treated With Palmaz-Schatz Stents

Objectives. This study sought to evaluate the clinical, procedural, preinterventional and postinterventional quantitative coronary angiographic (QCA) and intravascular ultrasound (IVUS) predictors of restenosis after Palmaz-Schatz stent placement.Background. Although Palmaz-Schatz stent placement reduces restenosis compared with balloon angioplasty, in-stent restenosis remains a major clinical problem.Methods. QCA and IVUS studies were performed before and after intervention (after stent placement and high pressure adjunct balloon angioplasty) in 382 lesions in 291 patients treated with 476 Palmaz-Schatz stents for whom follow-up QCA data were available 5.5 ± 4.8 months (mean ± SD) later. Univariate and multivariate predictors of QCA restenosis (≥50% diameter stenosis at follow-up, follow-up percent diameter stenosis [DS] and follow-up minimal lumen diameter [MLD]) were determined.Results. Three variables were the most consistent predictors of the follow-up angiographic findings: ostial lesion location, IVUS preinterventional lesion site plaque burden (plaque/total arterial area) and IVUS assessment of final lumen dimensions (whether final lumen area or final MLD). All three variables predicted both the primary (binary restenosis) and secondary (follow-up MLD and follow-up DS) end points. In addition, a number of variables predicted one or more but not all the end points: 1) restenosis (IVUS preinterventional lumen and arterial area); 2) follow-up DS (QCA lesion length); and 3) follow-up MLD (QCA lesion length and preinterventional MLD and DS and IVUS preinterventional lumen and arterial area).Conclusions. Ostial lesion location and IVUS preinterventional plaque burden and postinterventional lumen dimensions were the most consistent predictors of angiographic in-stent restenosis.     

Intravascular ultrasonography in the evaluation of results of coronary angioplasty and stenting

The main advantage of intravascular ultrasonography (IVUS) over angiography in assessing the effect of coronary interventions is the ability of IVUS to directly visualize the vessel wall. IVUS often reveals a high residual plaque burden after angiographically successful angioplasty, and this can motivate the operator to use additional, more aggressive measures in an attempt to increase lumen dimensions. Studies using IVUS imaging before and after balloon angioplasty have shown that luminal gain after percutaneous transluminal coronary angioplasty (PTCA) results from a combination of plaque reduction and vessel wall stretch. Minimal luminal area and residual area stenosis after PTCA and stent deployment, as measured by IVUS, have been shown to be predictors of restenosis. IVUS studies have pointed to vessel shrinkage, not intimal hyperplasia, as the main mechanism of restenosis after PTCA. IVUS guidance of stent deployment has often revealed inadequate stent expansion despite optimal results on angiography, leading to high-pressure stent deployment with significant additional luminal gain. Restenosis rates may be lower with IVUS-guided stent deployment.     

Treatment of calcified ostial disease by rotational atherectomy and adjunctive cutting balloon angioplasty prior to stent implantation

Both heavily calcified and ostial lesions are difficult to deal with by percutaneous transluminal coronary angioplasty (PTCA) alone. Acute results are often sub-optimal, complications are more frequent, and long-term results are disappointing. Optimal stent deployment may not be possible unless satisfactory lesion dilatation is achieved and the lesion made more compliant. The use of rotational atherectomy and cutting balloon angioplasty to a calcified ostial lesion in the left circumflex coronary artery prior to stent implantation is reported. (Int J Cardiovasc Intervent 2004; 6: 134-136)     

旋磨术联合切割球囊成形术治疗冠状动脉重度钙化病变

目的血管内超声评价旋磨术联合切割球囊成形术治疗冠状动脉重度钙化病变的安全性及有效性。方法收集冠状动脉造影及血管内超声检查确认至少1处病变为高度钙化,并行旋磨术处理的冠心病患者80例,根据是否使用切割球囊分为单纯旋磨组34例和旋磨联合切割组46例。患者在支架置入前及置入后均行血管内超声检查,评价支架置入效果。结果单纯旋磨组与旋磨联合切割组最大钙化弧度分别为(215.88±21.81)°vs(226.55±21.59)°,钙化长度比为(0.72±0.06)vs(0.78±0.05),支架置入前最小管腔面积为(2.52±0.07)mm2 vs(2.46±0.09)mm2,2组比较差异无统计学意义(P>0.05)。支架置入后,旋磨联合切割组最小支架面积(6.12±0.37)mm2和即刻管腔获得面积(3.66±0.34)mm2,单纯旋磨组分别为(5.42±0.24)mm2和(2.90±0.24)mm2,2组比较差异有统计学意义(P=0.016)。2组术中并发症的发生比例比较,差异无统计学意义(P>0.05)。结论在冠状动脉重度钙化病变中,使用旋磨术联合切割球囊成形术可以获得更好的支架置入后效果。     

Intravascular ultrasound-guided high-pressure balloon predilatation for optimal drug-eluting stent deployment in restenosis of a stent implanted 7 years earlier. Do we know the right technique for in-stent restenosis restenting?

Although off-label, drug-eluting stent (DES) implantation is a preferred intervention for in-bare metal stent restenosis (BMS ISR). Off-label DES implantation appears to be associated with a higher risk of stent thrombosis and lesion recurrence. Accordingly, routine BMS ISR restenting with DES is associated with more frequent subsequent thrombosis. Intravascular ultrasound (IVUS) studies point to stent underexpansion as the major mechanism of late DES failure. We report a case of a patient with BMS ISR in whom IVUS clarified initial BMS expansion; consequently, high-pressure predilatation with an angiographically oversized conventional balloon was applied prior to DES deployment; and finally, IVUS verified the stent expansion.     

Prediction of Coronary Stent Underexpansion by Pre-Procedural Intravascular Ultrasound–Based Deep Learning

ObjectivesThe aim of this study was to develop pre-procedural intravascular ultrasound (IVUS)–based models for predicting the occurrence of stent underexpansion.BackgroundAlthough post-stenting IVUS has been used to optimize percutaneous coronary intervention, there are no pre-procedural guidelines to estimate the degree of stent expansion and provide preemptive management before stent deployment.MethodsA total of 618 coronary lesions in 618 patients undergoing percutaneous coronary intervention were randomized into training and test sets in a 5:1 ratio. Following the coregistration of pre- and post-stenting IVUS images, the pre-procedural images and clinical information (stent diameter, length, and inflation pressure; balloon diameter; and maximal balloon pressure) were used to develop a regression model using a convolutional neural network to predict post-stenting stent area. To separate the frames with from those without the occurrence of underexpansion (stent area <5.5 mm²), binary classification models (XGBoost) were developed.ResultsOverall, the frequency of stent underexpansion was 15% (5,209 of 34,736 frames). At the frame level, stent areas predicted by the pre-procedural IVUS-based regression model significantly correlated with those measured on post-stenting IVUS (r = 0.802). To predict stent underexpansion, maximal accuracy of 94% (area under the curve = 0.94) was achieved when the convolutional neural network– and mask image–derived features were used for the classification model. At the lesion level, there were significant correlations between predicted and measured minimal stent area (r = 0.832) and between predicted and measured total stent volume (r = 0.958).ConclusionsDeep-learning algorithms accurately predicted incomplete stent expansion. A data-driven approach may assist clinicians in making treatment decisions to avoid stent underexpansion as a preventable cause of stent failure.     

Successful excimer laser angioplasty following unsuccessful primary balloon angioplasty

We report five patients where excimer laser coronary angioplasty facilitated successful balloon dilatation of heavily calcified lesions that could not be dilated by conventional angioplasty techniques alone. In each case, the lesion was crossed successfully with a guide wire. Conventional angioplasty failed because of inability to cross the lesion with a balloon (four lesions) or inability to dilate the lesion with balloon inflation (two lesions). These cases illustrate an indication for excimer laser coronary angioplasty as an adjunctive procedure in heavily calcified coronary stenoses. © 1993 Wiley-Liss, Inc.     

Morphological effects on in-stent restenosis assessed by intravascular ultrasound imaging.

The purpose of this study was to evaluate the rupture and dissection of the vessel wall immediately after balloon dilatation by intravascular ultrasound (IVUS) imaging and to predict restenosis in patients who underwent subsequent coronary stent implantation. Stent implantation improves the long-term results of coronary angioplasty by reducing lesion elastic recoil and arterial remodeling. However, several studies have suggested that neointimal hyperplasia is the cause of instant restenosis. We recruited 60 patients in whom IVUS studies were performed immediately after successful balloon dilatation and just before stent implantation. We compared IVUS parameters with 6-month follow-up quantitative coronary angiography. This was performed in 51 lesions of 51 patients (85%). Qualitative analysis included assessment of plaque composition, plaque eccentricity, plaque fracture and the presence of dissection. In addition, minimal luminal diameter, percent diameter stenosis, percent area stenosis and plaque burden were quantitatively analyzed. Two morphological patterns after balloon dilatation were classified by IVUS. Type I was defined as absence or partial tear of the plaque without disclosure of the media to lumen (22 lesions). Type II was defined as a split in the plaque or dissection of the vessel wall with disclosure of the media to the lumen (29 lesions). At 6 months follow-up, angiographic restenosis occurred in 17 of the 51 lesions (33%). Restenosis was significantly (p < 0.05) more likely to occur in type II (13/29: 45% incidence) than in type I (4/22: 18% incidence). The assessment of plaque morphology immediately after balloon dilatation and before stent implantation provides important therapeutic and prognostic implications.     

Balloon pin‐hole rupture during percutaneous coronary intervention for recurrent,calcified in‐stent restenosis: A case report

Percutaneous coronary intervention (PCI) for patients with in‐stent restenosis (ISR) is generally considered safe and effective. However, due to increased tissue hardness, PCI for calcified intra‐stent ISR is technically challenging. Here, we report severe angioplasty‐related complications in a patient presenting with calcified, recurrent ISR following PCI. After receiving drug‐coated balloon (DCB) angioplasty for an initial ISR, the patient developed recurrent ISR during the follow‐up period. Intravascular imaging revealed intra‐stent calcifications and balloon angioplasty was subsequently performed. During the angioplasty, a pin‐hole balloon rupture occurred, consequently causing coronary dissection as visualized by intravascular imaging. To prevent acute coronary occlusion, stent implantation was required. The present case report suggests that, following detection of intra‐stent calcified stenosis, both careful balloon inflation as well as optimal ablation device selection are required to prevent potential complications and obtain successful procedural outcomes.     

Successful predilation of a resistant,heavily calcified lesion with cutting balloon for coronary stenting: A case report

A 65-year-old man with a restenotic lesion of the mid LAD was scheduled for Wiktor stent placement. The IVUS revealed circumferential severe calcification. Two conventional, non-compliant angioplasty balloons inflated to high pressures failed to achieved sufficient dilatation and both ruptured. At this point, we selected high pressure inflation of the Cutting Balloon. The Cutting Balloon achieved adequate dilation for stenting and proved to be useful in predilating a circumferential, heavily calcified lesion. Cathet. Cardiovasc. Diagn. 44:420–422, 1998. © 1998 Wiley-Liss, Inc.     

IVUS-guided rotational atherectomy for unexpandable paclitaxel-eluting stent: A case report and review of literature

We describe a patient suffering from late stent thrombosis in a paclitaxel-eluting stent which had an underexpanded ring due to the three-hundred-sixty-degree circumferential calcified plaque. Intravas...     

IVUS-Guided Stent Implantation to Improve Outcome: A Promise Waiting to be Fulfilled

The use of intravascular ultrasound (IVUS) to improve acute angiographic results was already shown in the prestent era. Various studies demonstrated the efficacy of IVUS in balloon sizing and estimating the extent of positive remodeling. With the introduction of drug-eluting stents (DES) the rate of restenosis has been significantly reduced but a new concern, the risk of stent thrombosis, has emerged. The association of stent underexpansion with stent thrombosis was observed for bare metal stents (BMS) and DES. Until now, the criteria for IVUS optimization used in different studies have relied on distal reference or on mean reference vessel for stent or postdilatation balloon sizing. Furthermore, an important recent innovation not available in previous studies is the use of noncompliant balloons to perform high pressure post-dilatation. Universal and easily applicable IVUS criteria for optimization of stent implantation as well as randomized studies on IVUS-guided DES implantation are necessary to minimize stent malapposition and underexpansion, which in turn can positively influence the rates of stent restenosis and thrombosis.