Hybrid Catheter Research Articles

Hybrid Catheter Ablation and Surgical Ablation as a “Bail Out” Strategy in Patients With Atrial Fibrillation Resistant to Catheter Ablation

Hybrid Catheter Ablation and Surgical Ablation as a “Bail Out” Strategy in Patients With Atrial Fibrillation Resistant to Catheter Ablation

A Hybrid Catheter Localisation Framework in Echocardiography Based on Electromagnetic Tracking and Deep Learning Segmentation.

Interventional cardiology procedure is an important type of minimally invasive surgery that deals with the catheter-based treatment of cardiovascular diseases, such as coronary artery diseases, strokes, peripheral arterial diseases, and aortic diseases. Ultrasound imaging, also called echocardiography, is a typical imaging tool that monitors catheter puncturing. Localising a medical device accurately during cardiac interventions can help improve the procedure's safety and reliability under ultrasound imaging. However, external device tracking and image-based tracking methods can only provide a partial solution. Thus, we proposed a hybrid framework, with the combination of both methods to localise the catheter tip target in an automatic way. The external device used was an electromagnetic tracking system from North Digital Inc (NDI), and the ultrasound image analysis was based on UNet, a deep learning network for semantic segmentation. From the external method, the tip's location was determined precisely, and the deep learning platform segmented the exact catheter tip automatically. This novel hybrid localisation framework combines the advantages of external electromagnetic (EM) tracking and the deep learning-based image method, which offers a new solution to identify the moving medical device in low-resolution ultrasound images.

Mid-term outcomes of thoracoscopic and hybrid therapy of atrial fibrillation

Aim. To evaluate the efficacy and safety of thoracoscopic and hybrid techniques in patients with various forms of atrial fibrillation (AF).Methods. The results of thoracoscopic ablation of 87 patients with AF were analyzed: 27 (31%) with paroxysmal form, 15 (17%) - with persistent, 45 (52%) - with long-term persistent form at follow-up 18.6±6.7 months. “Box-Lesion” treatments and amputation of left atrial appendage (LAA) were performed in 69 (79.3%) patients, “Box Lesion” without LAA amputation in 12 (13.7%). When atrial tachycardia was recorded for more than 30 seconds after a 3-month “blind” period, patients underwent hybrid catheter intervention.Results. Freedom from atrial arrhythmias in the group of paroxysmal AF was achieved in 84% of patients (21 of 25), in the group of persistent form - in 60% of patients (9 of 15), in the group of long-term persistent form - in 78% (32 of 41) at a given observation period. In the structure of postoperative atrial tachycardia, AF recurrence was 5 (6.25%), typical atrial flutter (AFL) - 3 (3.75%), atypical AFL - 10 (12.5%). The mean LA volume index in patients with stable sinus rhythm was 64.6±11.3 ml/m2 versus 74.65±15.4 ml/m2 in the atrial tachycardia group (Student’s t-test 0.53, p = 0.6). These patients underwent a hybrid intervention. At a follow-up period of 15.9±10.9 months, a stable sinus rhythm was maintained in 15 (83.3%) patients. The overall rate of intra- and postoperative complications of thoracoscopic ablation was 5.7%.Conclusion. Thoracoscopic and hybrid approaches are effective methods for various forms of AF treatment.

Intravascular Molecular Imaging: Near-Infrared Fluorescence as a New Frontier.

Despite exciting advances in structural intravascular imaging [intravascular ultrasound (IVUS) and optical coherence tomography (OCT)] that have enabled partial assessment of atheroma burden and high-risk features associated with acute coronary syndromes, structural-based imaging modalities alone do not comprehensively phenotype the complex pathobiology of atherosclerosis. Near-infrared fluorescence (NIRF) is an emerging molecular intravascular imaging modality that allows for in vivo visualization of pathobiological and cellular processes at atheroma plaque level, including inflammation, oxidative stress, and abnormal endothelial permeability. Established intravascular NIRF imaging targets include macrophages, cathepsin protease activity, oxidized low-density lipoprotein and abnormal endothelial permeability. Structural and molecular intravascular imaging provide complementary information about plaque microstructure and biology. For this reason, integrated hybrid catheters that combine NIRF-IVUS or NIRF-OCT have been developed to allow co-registration of morphological and molecular processes with a single pullback, as performed for standalone IVUS or OCT. NIRF imaging is approaching application in clinical practice. This will be accelerated by the use of FDA-approved indocyanine green (ICG), which illuminates lipid- and macrophage-rich zones of permeable atheroma. The ability to comprehensively phenotype coronary pathobiology in patients will enable a deeper understanding of plaque pathobiology, improve local and patient-based risk prediction, and usher in a new era of personalized therapy.

Advances in IVUS/OCT and Future Clinical Perspective of Novel Hybrid Catheter System in Coronary Imaging.

Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have been developed and improved as both diagnostic and guidance tools for interventional procedures over the past three decades. IVUS has a resolution of 100 μm with a high tissue penetration and capability of assessing the entire structure of a coronary artery including the external elastic membrane, whereas OCT has a higher resolution of 10–20 μm to assess endoluminal structures with a limited tissue penetration compared to IVUS. Recently, two companies, CONAVI and TERUMO, integrated IVUS and OCT into a single catheter system. With their inherent strength and limitations, the combined IVUS and OCT probes are complementary and work synergistically to enable a comprehensive depiction of coronary artery. In this review, we summarize the performance of the two intracoronary imaging modalities—IVUS and OCT—and discuss the expected potential of the novel hybrid IVUS–OCT catheter system in the clinical field.

Late Clinical Outcomes of Hybrid Catheter Intervention for Acute Massive Pulmonary Thromboembolism.

Purpose: We aimed to investigate the long-term outcomes of patients undergoing hybrid catheter intervention for acute massive pulmonary thromboembolism.Material and Methods: Twenty-five patients with hemodynamic impairment were treated with mechanical thrombus fragmentation, an intrapulmonary injection of mt-PA, and manual clot aspiration between August 1999 and June 2002. All patients were discharged after the procedure. Patients’ statuses were checked by medical record examinations and telephone interviews. The median follow-up was 141 months (115-168 months).Results: Ten patients died during follow-up, five for malignancy, three for septic shock, one for cerebral infarction, and one for heart failure. One patient had recurrence of pulmonary thromboembolism because of drug withdrawal by self-judgment. No chronic pulmonary thromboembolism was observed. The 1-year, 5-year, and 10-year survival rates were 87.5 ±6.8%, 83.3±7.6%, and 74.5±9.0%, respectively.Conclusion: Patients who undergo hybrid catheter intervention for acute massive pulmonary thromboembolism show good long-term outcomes.

Endocardial irrigated catheter for volumetric optoacoustic mapping of radio-frequency ablation lesion progression.

Radiofrequency (RF) catheter ablation is widely employed for various minimally invasive procedures, including treatment of tumors, cardiac arrhythmias and varicose veins. Accurate real-time monitoring of the ablation treatments remains challenging with the existing clinical imaging modalities due to the lack of spatial or temporal resolution or insufficient tissue contrast for differentiating thermal lesions. Optoacoustic (OA) imaging has been recently suggested for monitoring temperature field and lesion progression during RF interventions. However, strong light absorption by standard metallic catheters hindered practical implementations of this approach. Herein, we introduce a new RF ablation catheter concept for combined RF ablation and OA lesion monitoring. The catheter tip encapsulates a multimode fiber bundle for OA excitation with near-infrared (NIR) light, whereas the electric current is conducted through the irrigation solution, thus avoiding direct exposure of the metallic parts to the excitation light. We optimized the catheter diameter and the saline flow rate in order to attain uniform and deep lesions. The newly introduced hybrid catheter design was successfully tested by real-time monitoring of the ablation process in smooth ventricle and rough atrium walls of a blood-filled ex vivo porcine heart, mimicking in vivo conditions in the clinical setting.

Hybrid thoracoscopic surgical and transvenous catheter ablation versus transvenous catheter ablation in persistent and longstanding persistent atrial fibrillation (HARTCAP-AF): study protocol for a randomized trial

BackgroundSuccess rates with conventional transvenous endocardial pulmonary vein isolation in patients with persistent and longstanding persistent atrial fibrillation (AF) are variable due to advanced electrical and structural remodeling of the atria. As a consequence, more extensive endocardial lesions, minimally invasive thoracoscopic surgical techniques, and hybrid ablation (combining thoracoscopic epicardial surgical and endocardial catheter ablation) have been developed.HypothesisThe HARTCAP-AF trial hypothesizes that hybrid AF ablation is more effective than (repeated) transvenous endocardial catheter ablation in (longstanding) persistent AF, without increasing the number of associated major adverse events.MethodsThis randomized controlled trial will include 40 patients with persistent or longstanding persistent AF who will be 1:1 randomized to either hybrid ablation or (repeated) catheter ablation. The procedures and follow-up are conducted according to the guidelines. The primary effectiveness endpoint is freedom from any supraventricular arrhythmia lasting longer than 5 min without the use of Vaughan-Williams class I or III antiarrhythmic drugs through 12 months of follow-up after the last procedure. In the catheter ablation arm, a second procedure planned within 6 months after the index procedure is allowed for obtaining the primary endpoint. Additionally, adverse events, cost-effectiveness, and quality of life data will be recorded.Trial registrationClinicalTrials.gov, NCT02441738. Registered on 12 May 2015.

Dosimetric feasibility of an anthropomorphic three-dimensional PRESAGE® dosimeter for verification of single entry hybrid catheter accelerated partial breast brachytherapy

AbstractPurposeTo determine the feasibility of an anthropomorphic breast polyurethane-based three-dimensional (3D) dosimeter with cavity to measure dose distributions and skin dose for a commercial strut-based applicator strut-adjusted volume implant (SAVI™) 6–1.Materials and methodsAn anthropomorphic breast 3D dosimeter was created with a cavity to accommodate the SAVI™ strut-based device. 2 Gy was prescribed to the breast dosimeter having D95 to planning target volume evaluation (PTV_EVAL) while limiting 125% of the prescribed dose to the skin. Independent dose distribution verification was performed with GAFCHROMIC® EBT2 film. The dose distribution from the 3D dosimeter was compared to the distributions from commercial brachytherapy treatment planning system (TPS) and film. Point skin doses, line profiles and dose–volume histogram (DVHs) for the skin and PTV_EVAL were compared.ResultsThe maximum difference in skin dose for TPS and the 3D dosimeter was 4% whereas 41% between the TPS and EBT2 film. The maximum dose difference for line profiles between TPS, 3D dosimeter, and film was 4·1%. DVHs of skin and PTV_EVAL for TPS and 3D dosimeter differed by a maximum of 4% at 5 mm depth and skin differed by a maximum 1·5% between TPS and 3D dosimeter. The criterion for gamma analysis comparison was 92·5% at ±5%±3 mm criterion. The TPS demonstrated at least ±5% comparability in predicting dose to the skin, PTV_EVAL and normal breast tissue.Conclusions3D anthropomorphic polyurethane dosimeter with cavity gives comparable results to the TPS dose predictions and GAFCHROMIC® EBT2 film results in the context of HDR brachytherapy.

Atherectomy using a solid-state laser at 355 nm wavelength.

Peripheral arterial disease (PAD), caused by atherosclerotic processes, is allied with an increased risk of ischemic events, limb loss, and death. Recently, the use of a solid-state laser at 355nm within a hybrid catheter was suggested for that purpose. In this work, short nanosecond pulses of a solid-state laser at 355nm delivered through a hybrid catheter, composed of optical fibers and a blunt mechanical blade, are used to conduct a pre-clinical study and two clinical cases. The pre-clinical study consisted of an atherosclerotic calcified cadaveric leg and a porcine in vivo trial within the iliac artery, respectively. The clinical cases include chronic total occlusions with a calcified lesion. The occluded cadaveric leg is recanalized successfully and no evidence of thermal necrosis is indicated in the histopathology analysis of the porcine study. No arterial wall damage is demonstrated on the animals' treated arteries and no significant impact on blood count and biochemistry analysis is noted in the animal trial. Successful recanalization of the occluded arteries followed by balloon angioplasty is obtained in both clinical cases. Our work constitutes a proof of concept for using a solid-state pulsed laser at 355 nm in atherectomy.

Selective tissue ablation using laser radiation at 355 nm in lead extraction by a hybrid catheter; a preliminary report.

Current lead extraction (LE) devices can harm the blood vessel endothelium, increasing the risk of perforation. Proof of concept for using a solid-state pulsed laser at 355 nm with a hybrid catheter in LE. A hybrid catheter was used comprising optical fibers for the delivery of 355 nm laser pulses at 30 Hz and 6 J/cm(2) combined with a blunt mechanical blade. Specific parameters were chosen to enable selectivity in ablation, thereby reducing the risk of blood vessel perforation. The design exploits differences in the mechanical properties of the fibrotic tissue and the normal blood vessel. Ex vivo ablation was performed to evaluate a hybrid catheter operation on various tissues. Two ex/in vivo pig studies used a free-floating electrode to which three bovine tendon pieces were glued. Finally, two in vivo dog model studies were performed on specimens with 4-5-year-old pacing lead implants, followed by a histopathology study. Catheter penetration rate in the ex vivo experiments was 0.1 mm/seconds for bovine tendon, 0.025 mm/seconds for porcine superior vena cava and 0.033 mm/seconds for porcine aorta. In the ex/in vivo pig study, the three tissue blocks were successfully dissected. In the in vivo dog study, the two leads were successfully extracted. In all in vivo tests, hemodynamic stability was maintained. Gross histopathology did not reveal any injury. Ablation using 355 nm laser pulses in combination with a mechanical blunt blade may potentially constitute a viable alternative for LE.

Present Status and Future Direction of NIRS-IVUS Multimodality Direct Coronary Imaging

Intracoronary near-infrared spectroscopy (NIRS)-IVUS is a direct coronary imaging catheter for the identification and quantification of lipid core plaque (LCP). NIRS is combined with traditional grayscale IVUS in a hybrid catheter that provides co-registered architectural and compositional plaque characterization data. The novel capability of the NIRS catheter component is its ability to directly identify LCP, which underlies the majority of vulnerable and unstable plaques. NIRS-IVUS has potential to optimize percutaneous coronary intervention (PCI) by delineating precise lesion length, assuring adequate stent expansion and apposition, detection of stent edge dissection, and predicting periprocedural myocardial infarction (PMI). NIRS-IVUS may also be important in the identification of vulnerable plaques at risk to cause future events.

Hybrid Surgical and Catheter Treatment for Atrial Fibrillation

Advances in surgery for atrial fibrillation from cut and sew technique to thoracoscopy and new energy source have enabled minimally invasive approach which avoids median sternotomy and cardiopulmonary bypass. However, minimally invasive approach is unable to match the outcome of classic surgical technique due to difficulty in creating some of linear ablation lines. Hybrid procedure using catheter mapping and ablation in addition to minimally invasive surgical ablation has gained interest to combine the advantages of both procedures. No large study has been conducted to date comparing this new technique to other existing treatments. The aim of this paper is to review the data on hybrid procedure for atrial fibrillation and assess its early outcome and efficacy.

Usefulness of Corsair microcatheter to cross stent struts in bifurcation lesions

Side branch compromise after stenting in bifurcation lesions is a matter of concern. It may happen that even low-profile balloon catheters do not cross stent struts after rewiring. The Corsair catheter is a hybrid catheter that has features of a microcatheter and a support catheter. The present study evaluated usefulness of the Corsair catheter to facilitate advancing a low-profile balloon catheter through stent struts in bifurcation lesions. After rewiring, low-profile balloon catheters failed to cross stent struts of 29 bifurcation lesions. The Corsair microcatheter successfully crossed stent struts in all lesions except one (97%) where a stent was implanted to treat in-stent restenosis (stent-in-stent). Low-profile balloon catheters were able to advance into the side branch of all bifurcation lesions where the Corsair microcatheter crossed stent struts. In conclusion, the Corsair microcatheter may be utilized if low-profile balloon catheters are unable to cross stent struts in bifurcation lesions.

New Developments in Hybrid Optical Coherence Tomographic Imaging: Current Status and Potential Implications in Clinical Practice and Research

Optical coherence tomography (OCT) is a relatively new imaging technique that was introduced to overcome limitations of previous imaging modalities. OCT provides high resolution cross-sectional images of the coronaries which permit detailed evaluation of the luminal morphology and assessment of coronary artery pathology. These unique qualities render OCT a useful tool in clinical practice and research arena. However, apart from its significant advantages OCT imaging has also considerable limitations. To overcome the pitfalls of OCT, fusion of this modality with other imaging techniques has been proposed. Today several hybrid catheter and sophisticated data fusion methodologies have been developed for this purpose, which appear to provide a complete and comprehensive assessment of plaque characteristics and vessel pathophysiology. The aim of this review article is to describe the available OCT based hybrid imaging modalities, present the advantages and limitations of these approaches and discuss their potential value in clinical practice and research arena.

Dosimetric Verification of a Commercial Brachytherapy Treatment Planning System for a Single Entry APBI Hybrid Catheter Device by Presage® and Radiochromic Film

dose distributions were more sensitive than I or Cs to placement uncertainties. Conclusions: The 2003 ABS report recommendation of a 2e3mm tumor margin for COMS plaque size selection may be inadequate due to insufficient dosimetric coverage of the tumor base and tumor volume when assuming prescription dose based solely on the tumor apex coverage. Better tumor coverage is achieved when using a GTV-to-PTV total basal expansion ofO3mm and/or prescribing beyond the tumor apex.

P-017 Intermediate catheters: experience, cost and complication rates at two high volume centers

IntroductionStable access to target lesions is foundational to endovascular therapy, be it in hemorrhagic or ischemic disease. Continued evolution in access technology has resulted in next generation catheters that afford...

Accelerated partial breast irradiation using the strut-adjusted volume implant single-entry hybrid catheter in brachytherapy for breast cancer in the setting of breast augmentation

Purpose Accelerated partial breast irradiation (APBI) has gained popularity as an alternative to adjuvant whole breast irradiation; however, owing to limitations of delivery devices for brachytherapy, APBI has not been a suitable option for all the patients. This report evaluates APBI using the strut-adjusted volume implant (SAVI) single-entry catheter to deliver brachytherapy for breast cancer in the setting of an augmented breast. Methods and Materials The patient previously had placed bilateral subpectoral saline implants; stereotactic core biopsy revealed estrogen receptor- and progesterone receptor-positive ductal carcinoma in situ of intermediate nuclear grade. The patient underwent needle-localized segmental mastectomy of her left breast; pathologic specimen revealed no residual malignancy. An SAVI 8-1 device was placed within the segmental resection cavity. Treatment consisted of 3.4 Gy delivered twice a day for 5 days for a total dose of 34 Gy. Treatments were delivered with a high-dose-rate 192Ir remote afterloader. Results Conformance of the device to the lumpectomy cavity was excellent at 99.2%. Dosimetric values of percentage of the planning target volume for evaluation receiving 90% of the prescribed dose, percentage of the planning target volume for evaluation receiving 95% of the prescribed dose, volume receiving 150% of the prescribed dose, and volume receiving 200% of the prescribed dose were 97.1%, 94.6%, 22.7 cc, and 11.6 cc, respectively. Maximum skin dose was 115% of the prescribed dose. The patient tolerated treatment well with excellent cosmetic results, and limited acute and late toxicity at 8 weeks and 6 months, respectively. Conclusions Breast augmentation should not be an exclusion criterion for the option of APBI. The SAVI single-entry catheter is another option to successfully complete APBI using brachytherapy for breast cancer in the setting of an augmented breast.

Whole shaft visibility and mechanical performance for active MR catheters using copper-nitinol braided polymer tubes.

BackgroundCatheter visualization and tracking remains a challenge in interventional MR.Active guidewires can be made conspicuous in "profile" along their whole shaft exploiting metallic core wire and hypotube components that are intrinsic to their mechanical performance. Polymer-based catheters, on the other hand, offer no conductive medium to carry radio frequency waves. We developed a new "active" catheter design for interventional MR with mechanical performance resembling braided X-ray devices. Our 75 cm long hybrid catheter shaft incorporates a wire lattice in a polymer matrix, and contains three distal loop coils in a flexible and torquable 7Fr device. We explored the impact of braid material designs on radiofrequency and mechanical performance.ResultsThe incorporation of copper wire into in a superelastic nitinol braided loopless antenna allowed good visualization of the whole shaft (70 cm) in vitro and in vivo in swine during real-time MR with 1.5 T scanner. Additional distal tip coils enhanced tip visibility. Increasing the copper:nitinol ratio in braiding configurations improved flexibility at the expense of torquability. We found a 16-wire braid of 1:1 copper:nitinol to have the optimum balance of mechanical (trackability, flexibility, torquability) and antenna (signal attenuation) properties. With this configuration, the temperature increase remained less than 2°C during real-time MR within 10 cm horizontal from the isocenter. The design was conspicuous in vitro and in vivo.ConclusionWe have engineered a new loopless antenna configuration that imparts interventional MR catheters with satisfactory mechanical and imaging characteristics. This compact loopless antenna design can be generalized to visualize the whole shaft of any general-purpose polymer catheter to perform safe interventional procedures.

New Techniques of Mapping and Ablation for Tachyarrhythmias in Children

Advancement in mapping and ablation technologies in the past decade has made arrhythmia treatment in children safer and more effective. Electroanatomical mapping systems with features of nonfluoroscopic navigation, 3D-geometry construction and color-coded arrhythmia mapping have been extensively used to map and ablate tachycardias in children. In addition, a variety of cooled radiofrequency ablation systems have been used in selected patients to create larger and deeper lesions. Cryoenergy ablation, with its reversible nature of tissue injury during the cooling phase, is emerging as the energy of choice for ablating perinodal arrhythmias to minimize the risk of inadvertent conduction block. Other evolving ablation systems, including cryoballoon, high-intensity focused ultrasound balloon and a hybrid catheter capable of delivering both radiofrequency and cryoenergy, are also under investigation. Finally, a remote navigation system that minimizes radiation exposure and will enable physicians of all skill levels to reach difficult target sites in children is on the horizon.