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

Mechanical performances of balloon post-dilation for improving stent expansion in calcified coronary artery: Computational and experimental investigations

Stent deployment in a calcified coronary artery is often associated with suboptimal outcomes such as stent underexpansion and malapposition. Post-dilation after stent deployment is commonly used for optimal stent implantation. There is no guideline for choosing the post-dilation balloon diameter and inflation pressure. In this work, ex-vivo/in-silico experiments were performed to investigate the efficacy of post-dilation balloon diameter and inflation pressure in improving the stent expansion in a calcified lesion. Post-dilations with three balloon diameters (3 mm, 3.5 mm, and 4 mm) were performed. For each balloon diameter, three inflation pressures (10 atm, 20 atm, and 30 atm) were sequentially applied. In ex-vivo experiments, optical coherence tomography images were acquired during the stenting procedure, i.e., pre- and post-deployment of 3 mm diameter stent, as well as after each post-dilation. The results from in-silico experiments were compared with ex-vivo experiments in terms of lumen area. In addition, stretch ratio analysis was developed to predict the stent-induced lumen area, along with the strain analysis and the in-silico experiments. Results have shown that target lumen area could be achieved with an oversized nominal balloon diameter of +0.5 mm (i.e., 0.5 mm greater than reference lumen diameter) at an inflation pressure of 20 atm. After each post-dilation, fibrotic tissue demonstrated a larger strain, contributing to improved lumen gain. However, minimal changes were observed in calcification. Moreover, a strong correlation (R² = 0.95) between the stretch ratio of fibrotic tissue and lumen area after each post-dilation was observed. This indicated that the morphology of the fibrotic tissue could be a potential marker to predict the lumen gain. The detailed mechanistic quantifications of a single lesion cannot be generalized to all clinical cases. However, this work could be used to provide a fundamental understanding of the post-dilations, to develop experimental protocols for producing generalized guidelines, and to exploit their potential for optimal pre- and post-stent strategies.

Efficacy of the Wolverine cutting balloon on a circumferential calcified coronary lesion: Bench test using a three-dimensional printer and computer simulation with the finite element method

Heavy calcification is one of the factors that hinder the success of coronary angioplasty, and a cutting balloon is used for such lesions. This study aimed to explore the optimal method of dilation of highly calcified lesions using a cutting balloon. Calcification models were developed from patient computed tomography and intravascular ultrasound data, and were constructed using three-dimensional printers. The lesions were dilated using a Wolverine™ cutting balloon and NC Emerge™ noncompliant balloon catheter, and the success rate of dilation and maximum dilation pressure were compared. The maximum first principal stresses in calcified lesions were also evaluated by computer simulation using the finite element method. In the bench test, the dilation success rate of the Wolverine™ cutting balloon was higher and the maximum dilation pressure required was lower (p < 0.01 in all analyses), compared with that of the NC Emerge™ balloon catheter. Finite element analysis showed that the cutting blade increased the maximum first principal stresses in calcified lesions, thus allowing for successful dilation at low pressures. The highest stress was obtained when the cutting blade was positioned at the thinnest part of the calcification. The cutting balloon allows for efficient calcification expansion by concentrating the stresses in the blade. When a cutting balloon is used, if the calcified lesion cannot be expanded in a single dilation, dilation success may be achieved after the balloon is rotated and the position of the blade is changed.

Biologically-engineered mechanical model of a calcified artery

Vascular calcification is a commonly occurring pathological process and is recognized as an independent prognostic marker for cardiovascular morbidity and mortality. Recent progress in developing novel therapies to modify vascular calcification is critically hampered due to the lack of reliable in vitro experimental models that recapitulate the structural and mechanical attributes of calcified arteries. In this study, we show the ability to model the behavior of diffuse vascular calcification in vitro using biologically-engineered grafts approximating the composition, structure, and mechanical properties of arteries. Transmural calcification was achieved by exposing the acellular grafts of collagenous ECM to complete medium containing elevated Calcium (Ca) and Phosphate (P) concentrations. It was found that increasing the serum concentration from 2% to 10% increased the extent and degree of calcification based on histochemical, ultrastructural, chemical and thermal analyses. The presence of variably-sized spherical calcific deposits within the matrix further confirmed its morphological similarity to pathologic calcification. Mechanical testing demonstrated up to a 16-fold decrease in compliance due to the calcification, consistent with prior reports for calcified arteries. The model developed thus has potential to improve the design and development of interventional devices and therapies for the diagnosis and treatment of arterial calcification. STATEMENT OF SIGNIFICANCE: The presence of extensive vascular calcification makes angiographic/interventional procedures difficult due to reduced arterial compliance. Current attempts to develop safe and effective non-surgical adjunctive techniques to treat calcified arteries are largely limited by the lack of a physiologically relevant testing platform that mimics the structural and mechanical features of vascular calcification. Herein, we developed an off-the-shelf calcified artery model, with the goal to accelerate the pre-clinical development of novel therapies for the management of arterial calcification. To the extent of our knowledge, this is the first report of an in vitro tissue-engineered model of diffuse arterial calcification.

Prolonged Inflation Technique Using a Scoring Balloon for Severe Calcified Lesion

Percutaneous coronary intervention for the treatment of a severe calcified lesion is still one of the most technically challenging areas of interventional cardiology. 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 the usefulness of prolonged inflations using a scoring balloon catheter (Scoreflex) for severe calcified lesions. Prolonged inflation using a scoring balloon enables an adequate dilation for treatment of a severe calcified plaque that was unresponsive to conventional technique with or without rotational atherectomy.

PCI IN PATIENT WITH HEAVY CALCIFIED LESION. MANAGEMENT AND BALLOON RUPTURE COMPLICATION

Balloon angioplasty in calcified coronary lesions may have a decreased success rate and an increased incidence of complications. This lesion remain a technical challenge in interventional cardiology despite novel approaches and devices. We describe a case with heavy calcified coronary lesion in LAD that was not only resistant to high-pressure inflation of conventional, non-compliant balloons and cutting balloon but the inflations also results in balloon rupture. Even, the first balloon became fracture and entrapment in LAD. The fractured balloon could be removed using second baloon inflation in LCX. The angioplasty balloon was successfully performed after rotational atherectomy by rotablator and succesfully continued by implantation stent DES.

Towards the characterisation of carotid plaque tissue toughness: Linking mechanical properties to plaque composition

The morphological manifestation of calcification within an atherosclerotic plaque is diverse and the response to cutting balloon angioplasty remains an elusive target to predict in the presence of extensive calcification. This study examines the resistance of plaque tissue to blade penetration by characterising the underlying toughness properties and stratifying the upper and lower scale toughness limits based on the strong mechanical influence of calcification. Mechanical toughness properties of the common, bifurcation and internal carotid artery (n=62) were determined using guillotine-cutting tests measuring the energy required to pass a surgical blade through a unit length of plaque tissue. The corresponding structural composition of the dissected plaque segments was characterised using Fourier transform infrared analysis, electron microscopy and energy dispersive x-ray spectroscopy. Mechanical results reveal a clear distinction in toughness properties within each region of the carotid vessel with significantly tougher properties localised in the bifurcation (p=0.004) and internal region (p=0.0003) compared to the common. The severity of the intra-plaque variance is highest in plaques with high toughness localised in the bifurcation region (p<0.05). Structural examination reveals that the diverse mechanical influence of the level of calcification present is characteristic of specific regions within the carotid plaque. The energy required to overcome the calcific resistance and propagate a controlled cut in the calcified tissue at each region varies further with the degree of plaque progression. The identification of the localised calcification characteristics is a key determinant in achieving successful dissection of the severely toughened plaque segments during cutting balloon angioplasty.

STATEMENT OF SIGNIFICANCE

Calcification plays a fundamental role in plaque tissue mechanics and demonstrates a diverse range of material moduli properties. This work addresses the characterisation of the toughness properties in human carotid plaque tissue using a fracture mechanics approach. Toughness determines the energy required to propagate a controlled cut in the plaque material. This parameter is crucial for predicting the cutting forces required during endovascular cutting balloon angioplasty intervention. Results demonstrate that a strong relationship exists between the structural calcification configurations, fracture mechanisms and associated toughness properties that are characteristic of specific regions within the carotid artery plaque. The identification of the morphological characteristics of localised calcification may serve as a valuable quantitative measure for cutting balloon angioplasty treatment.

Intensive plaque modification with rotational atherectomy and cutting balloon before drug-eluting stent implantation for patients with severely calcified coronary lesions: a pilot clinical study

BACKGROUND

This study investigated whether, for patients with severely calcified coronary lesions, use of a cutting balloon (CB) during rotational atherectomy (RA) before placing a drug-eluting stent will improve periprocedural outcomes, compared to RA with a conventional plain balloon.

METHODS

In a randomized controlled trial, patients with severely calcified lesions of calcium arc ≥180° were apportioned to receive intensive plaque modification with RA and CB (RA + CB; n = 35) or RA with conventional plain balloon (RA; n = 36). Intravascular ultrasound was applied for quantitative or qualitative analyses of percutaneous coronary intervention outcomes. The primary outcome was acute lumen gain after drug-eluting stent.

RESULTS

The RA + CB and RA groups were similar in baseline mean arcs of superficial calcium, and minimum lumen cross-sectional areas (CSAs). The mean minimum stent CSA after percutaneous coronary intervention (PCI) of the RA + CB group (5.9 ± 1.7 mm(2)) was significantly larger than that of the RA group (5.0 ± 1.4 mm(2); P = 0.021). Patients in the RA + CB group achieved significantly larger acute CSA gain after PCI (4.5 ± 1.5 mm(2)) relative to the RA group (3.8 ± 1.5 mm(2); P = 0.035). The groups were similar in rates of periprocedural complications, but at the 1-year follow-up the RA + CB had a lower rate of revascularization for restenosis of the target vessel and MACE (5.7 %) than did the RA group (22.2 %, P = 0.046).

CONCLUSION

Aggressive plaque preparation with RA and CB seems to be safe and effective for patients with severely calcified coronary lesions.

TRIAL REGISTRATION

Current Controlled Trials ChiCTR-INR-16008274 . Retrospectively registered 12 April 2016.

Cutting-balloon angioplasty before drug-eluting stent implantation for the treatment of severely calcified coronary lesions

Background

Severely calcified coronary lesions respond poorly to balloon angioplasty, resulting in incomplete and asymmetrical stent expansion. Therefore, adequate plaque modification prior to drug-eluting stent (DES) implantation is the key for calcified lesion treatment. This study was to evaluate the safety and efficacy of cutting balloon angioplasty for severely calcified coronary lesions.

Methods

Ninety-two consecutive patients with severely calcified lesions (defined as calcium arc ≥ 180° calcium length ratio ≥ 0.5) treated with balloon dilatation before DES implantation were randomly divided into two groups based on the balloon type: 45 patients in the conventional balloon angioplasty (BA) group and 47 patients in the cutting balloon angioplasty (CB) group. Seven cases in BA group did not satisfactorily achieve dilatation and were transferred into the CB group. Intravascular ultrasound (IVUS) was performed before balloon dilatation and after stent implantation to obtain qualitative and quantitative lesion characteristics and evaluate the stent, including minimum lumen cross-sectional area (CSA), calcified arc and length, minimum stent CSA, stent apposition, stent symmetry, stent expansion, vessel dissection, and branch vessel jail. In-hospital, 1-month, and 6-month major adverse cardiac events (MACE) were reported.

Results

There were no statistical differences in clinical characteristics between the two groups, including calcium arc (222.2° ± 22.2° vs. 235.0° ± 22.1°, P = 0.570), calcium length ratio (0.67 ± 0.06 vs. 0.77 ± 0.05, P = 0.130), and minimum lumen CSA before PCI (2.59 ± 0.08 mm²vs. 2.52 ± 0.08 mm², P = 0.550). After stent implantation, the final minimum stent CSA (6.26 ± 0.40 mm²vs. 5.03 ± 0.33 mm²; P = 0.031) and acute lumen gain (3.74 ± 0.38 mm²vs. 2.44 ± 0.29 mm², P = 0.015) were significantly larger in the CB group than that of the BA group. There were not statistically differences in stent expansion, stent symmetry, incomplete stent apposition, vessel dissection and branch vessel jail between two groups. The 30-day and 6-month MACE rates were also not different.

Conclusions

Cutting balloon angioplasty before DES implantation in severely calcified lesions appears to be more efficacies including significantly larger final stent CSA and larger acute lumen gain, without increasing complications during operations and the MACE rate in 6-month.

The Design of an Improved Force Focused Angioplasty Catheter

Atherosclerosis is a disease that causes obstructions to develop within the arterial system; these obstructions can result in an acute vascular event such as a heart attack or stroke, and potentially death. In the majority of cases a standard angioplasty balloon is sufficient to dilate the site of an obstruction; however difficult obstructions, such as heavily calcified lesions require specialist dilation solutions. One such example of a device is Boston Scientific's cutting balloon. An analysis of the Food and Drug Administration's (FDA) Manufacturer and User Facility Device Experience (MAUDE) database demonstrates that the original cutting balloon has a number of distinct adverse events associated with it. In this study we describe the design, manufacturing, and testing of a new force focused angioplasty balloon that has the potential to reduce or eliminate the adverse events associated with the Boston Scientific cutting balloon. This design incorporates two elastomeric materials to aid recoiling of the device namely: nitinol and a silicone elastomer. New methods of manufacturing are described in this study, that ensure that precision molding and assembly can occur. To determine the effectiveness of our device, we simulated concentric calcified lesions with a surrogate chalk model. These results demonstrate that our device has a significantly lower lesion burst pressure in comparison to a standard angioplasty balloon, 174 atm versus 12.48 atm. To determine if our device reduced potential snagging, and thus reduced the risk of withdrawal resistance being encountered, we performed a withdrawal resistance test. A noticeably lower withdrawal force is associated with our device, the high peaks on the Boston Scientific device indicate that there may be wings forming on the balloon and these are catching on the tip of the introducer sheath. Finally, we demonstrated in vivo efficacy of our device in a porcine model. By the use of elastomeric recoiling features in a new cutting balloon design we have been able to overcome the three main reported adverse events associated with the Boston Scientific cutting balloon. Subsequently we experimentally demonstrated this improved efficacy for one particular peripheral balloon size (e.g., 5 mm diameter).

Cutting balloon angioplasty in percutaneous carotid interventions

PURPOSE

To report a prospective feasibility study of cutting balloon angioplasty (CBA) applied in the predilation phase of carotid artery stenting (CAS) in highly calcified lesions.

METHODS

From January 2003 to February 2007, 178 consecutive patients (109 men; mean age 73.1+/-7.3 years) with highly calcified carotid lesions underwent CAS with CBA applied as a pre-specified strategy in the predilation phase of the procedure. All steps in the procedure were performed under cerebral filter protection. The cutting balloon ranged in diameter from 3 to 4 mm and was inflated at nominal pressures in the target lesion. Pre-CBA dilation with a low-profile coronary balloon was performed only when the cutting balloon was not able to cross the lesion. Selection of the filters and stents was at the operator's discretion. Primary endpoints were the all stroke and death rates at 30 days and 6 months. Secondary endpoints included cutting balloon success (positioning and full balloon inflation), CAS technical success (residual angiographic stenosis <30%), CAS procedural success (technical success and no complications), and in-hospital major complications.

RESULTS

Cutting balloon success was achieved in all 178 patients. In 32 (18.0%), pre-CBA dilation was necessary due to inability to cross the lesion with the cutting balloon initially. CAS technical success was achieved in all patients. One (0.6%) patient suffered transient neurological intolerance due to flow cessation from massive debris in the distal filter; this event was completely resolved after the filter was removed (CAS procedural success 99.4%). One patient suffered a major stroke at day 15 (0.6% 30-day all stroke and death rate). At the 6-month follow-up, 174 (97.7%) patients were evaluated; 1 patient died from myocardial infarction at day 35, and 2 patients died from non-neurological or cardiac causes at days 103 and 158. The cumulative all stroke and death rate was 2.2%.

CONCLUSION

These data suggest that CBA performed during the predilation phase of CAS in highly calcified lesion is a safe and useful method to prepare this lesion subset for stenting.

Carotid artery stenting for calcified lesions

BACKGROUND AND PURPOSE

Our aim was to assess the feasibility of carotid artery stent placement (CAS) for calcified lesions.

MATERIALS AND METHODS

Using embolic protection devices (EPDs), we performed 51 CAS procedures in 43 patients with severe carotid artery stenosis accompanied by plaque calcification. Before intervention, all lesions were subjected to multidetector-row CT. The arc of the circumferential plaque calcification was measured on axial source images at the site of maximal luminal stenosis, and the total volume of the plaque calcification was determined. The angiographic outcome immediately after CAS, and intra- and postoperative complications were recorded.

RESULTS

The mean arc of calcification was 201.1 +/- 72.3 degrees (range, 76-352 degrees ), and the mean of the total calcification volume was 154.9 +/- 35.4 mm(3) (range, 92-2680 mm(3)). Balloon rupture occurred in 1 procedure (2.0%) at predilation angioplasty; all 51 CAS procedures were successful without clinical adverse effects. Although there was a correlation between the arc of plaque calcification and residual stenosis (r = 0.6, P < .001), excellent dilation with residual stenosis < or =30% was achieved in all lesions. There was no correlation between the total volume of calcification and residual stenosis. None of the patients developed stroke or death within 30 days of the CAS procedure.

CONCLUSION

CAS by using EPDs to treat lesions with plaque calcification is feasible even in patients with near-total circumferential plaque calcification.

Cutting balloon inflation for drug-eluting stent underexpansion due to unrecognized coronary arterial calcification

Unrecognized calcification is a cause of stent underexpansion which significantly increases the subsequent risks of restenosis and/or stent thrombosis. We describe the use of cutting balloon inflation within the implanted stent which overcame calcific restraint unresponsive to high pressure inflations with non-compliant balloons.

Delayed appearance of coronary artery perforation following cutting balloon angioplasty

Coronary artery perforation is a potential complication of percutaneous coronary intervention (PCI). It usually develops immediately following PCI, particularly when an atheroablate device is used. We report a case in which coronary artery perforation developed 4 days after PCI with a nondebulking device, a cutting balloon catheter.

Extraction of previously deployed stent by an entrapped cutting balloon due to the blade fracture

During treatment for in-stent restenosis, entrapment of cutting balloon occurred because of the blade fracture. Removal of the balloon caused stent extraction, inducing acute occlusion of the coronary artery. Application of cutting balloon for in-stent restenosis requires every caution against such type of complications.

Cutting balloon percutaneous transluminal angioplasty for salvage of lower limb arterial bypass grafts: feasibility

PURPOSE

To evaluate the feasibility of cutting balloon percutaneous transluminal angioplasty (PTA) for treatment of neointimal hyperplasia in peripheral arterial bypass grafts.

MATERIALS AND METHODS

Fifteen consecutive patients (six women, nine men; age range, 57-89 years; mean age, 71 years) were treated with cutting balloon PTA for 16 anastomotic stenoses after infrainguinal bypass (prosthetic grafts, seven patients; prosthetic-vein composite grafts, two; venous grafts, five; and ileofemoral stent-graft, one). Cutting balloon PTA was followed by conventional PTA to improve anastomotic diameter. Patients with stenotic vein grafts underwent cutting balloon PTA after failed conventional PTA; the other patients were treated primarily with cutting balloon PTA. Criteria for success were a lumen diameter improvement of greater than 50% or residual stenosis of 20% or less. Follow-up was performed with color duplex ultrasonographic surveillance. Patency rates and durations were calculated with Kaplan-Meier survival curves and log-rank statistics.

RESULTS

Attempted conventional PTA (n = 6) prior to cutting balloon PTA was unsuccessful. Cutting balloon PTA was technically successful in 15 (94%) of 16 lesions, without clinical complications. Two local restenoses and one graft occlusion occurred between 5 and 7 months. The cumulative 6-month primary and secondary graft patency rates were 84% and 92%, respectively. At 12 and 18 months, they were 67% (95% CI: 0.34, 0.86) and 83% (95% CI: 0.48, 0.96), respectively; mean follow-up was 10.0 months.

CONCLUSION

Cutting balloon PTA proved feasible for treatment of resistant peripheral arterial bypass graft stenosis, commonly caused by neointimal hyperplasia, with excellent technical success. Short-term patency with this technique appears to be superior to that with conventional PTA, and it compares well with patency of atherectomy for salvage of infrainguinal bypass grafts.

Cutting balloon angioplasty for treatment of calcified coronary lesions

The aim of the study was to evaluate the feasibility, safety, and efficacy of cutting balloon angioplasty in treatment of angiographically moderate and severe calcified coronary lesions. Thirty-seven calcified coronary lesions (29 patients) detected by angiography were dilated with cutting balloon. Predilatation with plain balloon was performed in 27 (73.0%) lesions and stent was implanted in 23 (62.2%) lesions following cutting balloon. Acute gain following cutting balloon in predilated lesions was compared to the acute gain following plain balloon predilatation. For predilated lesions, acute gain after cutting balloon was significantly greater compared with plain balloon predilatation (1.51 +/- 0.49 vs. 0.77 +/- 0.42; P = 0.01). This result was achieved with larger size and lower pressure of cutting balloon compared with plain balloon (3.28 +/- 0.46 vs. 2.94 +/- 0.55, P = 0.01; 10.38 +/- 1.64 vs. 13.19 +/- 3.63, P = 0.001, respectively). The final gain following cutting balloon dilatation was significantly higher than the expected gain obtained by using a plain balloon of the same size (1.51 +/- 0.49 vs. 0.93 +/- 0.48; P < 0.0001), which was inflated at significantly higher pressure compared with cutting balloon. When we compared acute gain following cutting balloon in lesions with and without predilatation, we found no significant difference (P = 0.31). Angiographic success was achieved in 36 (97.3%) lesions and procedural success in 33 (89.1%) lesions. In-hospital major adverse cardiac event (MACE) occurred in three (10.3%) patients. Follow-up MACE was reported from three (10.3%) patients. In conclusion, cutting balloon angioplasty is feasible and safe in treatment of angiographically moderate and severe calcified lesions. Dilating efficiency of cutting balloon seems to be greater compared with a plain balloon of the same size, which was inflated at significantly higher pressure compared with cutting balloon. These results can be achieved with low in-hospital MACE and are associated with a good long-term outcome.

Excimer laser facilitated percutaneous coronary intervention of a nondilatable coronary stent

A patient is described in which excimer laser percutaneous coronary intervention is performed inside a suboptimally expanded stent due to nondilatable calcified plaque. The use of excimer laser facilitated full expansion of the stent with a balloon.

[The practical clinical guidelines of the Sociedad Española de Cardiología on interventional cardiology: coronary angioplasty and other technics]

Interventional cardiology has had an extraordinary expansion in last years. This clinical guideline is a review of the scientific evidence of the techniques in relation to clinical and anatomic findings. The review includes: 1. Coronary arteriography. 2. Coronary balloon angioplasty. 3. Coronary stents. 4. Other techniques: directional atherectomy, rotational atherectomy, transluminal extraction atherectomy, cutting balloon, laser angioplasty and transmyocardial laser and endovascular radiotherapy. 5. Platelet glycoprotein IIb/IIIa inhibitors. 6. New diagnostic techniques: intravascular ultrasound, coronary angioscopy, Doppler and pressure wire. For the recommendations we have used the classification system: class I, IIa, IIb, III like in the guidelines of the American College of Cardiology and the American Heart Association.