Catheter-based Devices Research Articles

Role of Embolic Protection in Percutaneous Coronary Intervention without Saphenous Venous graft lesions in ST-elevation myocardial infarction - a systematic review and meta-analysis.

Embolic protection devices are catheter-based devices that can be used to capture atherosclerotic remnants released during percutaneous coronary intervention (PCI). We aim to study the efficacy and safety of EPDs in PCIs without saphenous vein grafts (SVG) in ST-elevation myocardial infarction(STEMI). 3 electronic databases of MEDLINE, Web of Science, and Embase were searched from inception to Apr 10, 2024, to identify relevant randomized controlled trials (RCTs) that compared outcomes of patients subjected to EPD during PCI with control group where EPDs were not utilized. The primary outcome was 30-day all-cause mortality. Secondary outcomes were major adverse cardiovascular and cerebrovascular events (MACCE) at 30 days, post-PCI Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow attainment, ST-segment resolution at 90 minutes post-procedure and post-procedure angiographically detectable signs of distal embolization. The effect estimates of outcomes were assessed using risk ratio (RR) with a 95% confidence interval (CI). Random-effects meta-analysis was conducted using the restricted maximum likelihood method given the inter-study variance was inevitable. We included 3 RCTs enrolling 741 patients (age 61.6 ± 12.15 years, 22% females) undergoing PCI without SVG lesions. As opposed to the control group, the use of EPD did not yield a significant effect on all-cause mortality (RR, 0.76; 95% CI, 0.31-1.86; I2 = 0%), MACCE (RR, 0.66; 95% CI, 0.34-1.27; I2 = 0%), post-PCI TIMI 3 flow (RR, 1.18; 95% CI, 0.86-1.62; I2 = 77%) and ST segment resolution at 90 minutes post-procedure (RR, 1.05; 95% CI, 0.90-1.22; I2 = 0%). However, EPD significantly decreased angiographically detectable signs of distal embolization (RR, 0.60; 95% CI, 0.36 to 0.99; I2 = 0%). EPD significantly reduced angiographically detectable signs of distal embolization in PCI without SVG lesions in STEMI, though there were no clinical signs of improved flow or mortality. Further trials are necessary to thoroughly evaluate the potential benefits and requirements of EPD usage in such procedures.

Performance, safety, and biocompatibility of a novel PFO closure device in a long-term porcine model

BackgroundAs the catheter-based device closure of the patent foramen ovale (PFO) is expanding, novel devices aim to address the limitations of first-generation occluders (e.g. bulk, erosion, dislodgment). The second-generation device from Encore Medical (Eagan, MN, USA) features an articulating frame structure which allows the device to better conform to atrial anatomies, has lower disc thickness and metal mass/surface area, and is fully retrievable at any point in the procedure. The aim of the study was to evaluate the feasibility and safety of a novel low-profile, fully retrievable, Encore PFO closure device in the animal model. MethodsSix swine underwent implantation of the novel PFO occluder under fluoroscopic and intra-cardiac echocardiography guidance and survived for 140 days. Interim transthoracic echocardiography (TTE) was conducted on Day 29. Following terminal angiography and TTE at 140 days, the hearts were subjected to gross and histopathologic analysis. ResultsAll animals were successfully implanted and survived for 140 days. Interim TTE revealed proper device retention with no blood flow across the septum or thrombus in any of the animals. X-ray and pathology results showed preserved implant integrity with no fractures, and complete integration of the devices into the septum with complete re-endothelialization and nearly complete coverage by a mature, relatively thin neoendocardium. No surface fibrin deposition or thrombosis was reported. ConclusionsIn the standard porcine model, device retention and biocompatibility remained favorable following structural and functional device modifications exemplified by the second-generation PFO occluder from Encore Medical, including marked reduction of metal mass.

Emerging Catheter-Based Devices: A New Era for Heart Failure Management

Heart failure (HF) remains a major cause of morbidity and mortality worldwide despite advancements in its management. Although existing therapies such as beta-blockers, angiotensin receptor-neprilysin inhibitors, and implantable cardiac defibrillators (ICD) have improved clinical outcomes, the need for more advanced treatment modalities is pressing [1]. Recently, catheter-based devices have emerged as promising interventions, targeting key pathophysiological mechanisms in HF progression [2]. The editorial highlights the potential of these novel devices in managing HF patients and the challenges ahead.

A High Fidelity and High Frequency Physical Simulator for Mitral Annulus Kinematics

Cardiovascular medical devices that operate within the heart are subjected to millions of loading cycles that can compromise the structural integrity of the implant over time. Accelerated structural testing is a major challenge in the design of implantable cardiac devices, particularly in the emerging realm of catheter-based devices used to treat conditions like mitral valve regurgitation (MR). In this work, we design a bench-top simulator for accelerated structural testing of devices that operate in or near the mitral valve. We first use four-dimensional computed tomography (4DCT) data to create a molded replica of the mitral valve and identify the most deformation-inducing time points in the cardiac cycle. We then kinematically analyze the motion of the mitral annulus using screw theory and create an electromechanical simulation device that mimics this motion at high frequencies. The final apparatus allows for multiple patient-specific scenarios and accurate closed loop displacement control of the screw-based kinematics of the mitral annulus. The test apparatus operates with less than 1 dB of passband ripple up to its 25.7 Hz bandwidth. The proposed device moves toward a desirable paradigm in accelerated structural testing that is less reliant on computational models, animal models, and high-risk early feasibility clinical trials.

Development of a 3D Printed Benchtop Model of the Pulmonary System to Assist in the Development of Device to Treat Large Pulmonary Thrombo-embolic Disease

Pulmonary embolism (PE) can be life-threatening and is the third most common cause of cardiovascular mortality. For patients suffering from high and medium risk PE, potential treatments include a thrombolytic drug which is injected into the blood stream to dissolve the embolism. However, this treatment can increase the risk of bleeding occurring, particularly in susceptible patients. To reduce the level of drug required, it can be delivered directly to the site of the embolism through catheter-directed thrombolysis. Benchtop models have the potential to accelerate the development of catheter-based devices. Good benchtop models enable tests that allow issues to be identified and solved at an earlier stage in the development lifecycle, saving both time and money. In the present work, a patient-specific benchtop model of the relevant vascular anatomy has been proposed. Three different commercially available materials, namely Clear, Elastic, and Flexible from Formlabs, were evaluated for their capacity to represent the native anatomy. These materials were all 3D printable via stereolithography. Standard tensile and flexural testing samples were prepared and tested. The elastic material was far superior in resembling blood vessel’s mechanical properties. Computer tomography (CT) scans were used to develop a patient-specific benchtop model which includes Vena Cava, Right Heart, and Pulmonary Artery Computer Aided Design (CAD) models. Elastic material was used to 3D print the patient-specific models and assemble them for prototyping. A catheter was used for the demonstration of the developed benchtop model. The proposed methodology and material have shown successful candidacy to be used as a rapid method to create benchtop models that can test and validate catheter-based medical devices for the pulmonary system.

Demonstration of proof-of-concept of StrokeShield system for complete closure and occlusion of the left atrial appendage for non-valvular atrial fibrillation therapy.

In the US, the most significant morbidity and mortality associated with non-valvular atrial fibrillation (NVAF) is embolic stroke, with 90% of thrombus originating from the left atrial appendage (LAA). Anticoagulation is the preferred treatment for the prevention of stroke in NVAF patients, but clinical studies have demonstrated high levels of non-compliance and increased risk of bleeding or ineligibility for anticoagulation therapy, especially in the elderly population where the incidence of NVAF is highest. Alternatively, stroke may be preventing using clinically approved surgical and catheter-based devices to exclude or occlude the LAA, but these devices continue to be plagued by peri-device leaks and thrombus formation because of residual volume. To overcome these limitations, Cor Habere (Louisville, KY) and the University of Louisville are developing a LAA closure device (StrokeShield) that completely occludes and collapses the LAA to minimize the risk of stroke. The StrokeShield device is a collapsible occluder (nitinol reinforced membrane) that completely covers the LAA orifice with an expandable conical coil anchor that attaches to the myocardium. The device is designed for catheter-based delivery and expands to completely occlude the LAA orifice and collapse the LAA. The primary advantages of the StrokeShield system are a completely sealed LAA (no peri-device flow or residual space) and smooth endothelialized connection to the left atrial wall with minimal risk of cardiac bleeding and tamponade. We tested proof-of-concept of a prototype StrokeShield device in acute (n = 2) and chronic 60-day (n = 2) healthy canine models. Acute results demonstrated that the conical coil securely attached to the myocardium (5N pull-out force) and the Nitinol umbrella fully deployed and covered the LAA ostium. Results from the chronic implants demonstrated long-term feasibility of device placement with no procedural or device-related intra- or post-operative complications, secure placement and correct positioning of the device with no device migration. The device successfully occluded the LAA ostium and collapsed the LAA with no interference with the mitral valve, circumflex coronary artery, or pulmonary veins. Necropsy demonstrated no gross signs of thrombus or end-organ damage and the device was encapsulated in the LAA. Histology demonstrated mature neointima covering the device with expected foreign body inflammatory response. These early positive results will help to guide the iterative design process for the continued development of the StrokeShield system.

Comparison of preoperative, intraoperative, and follow-up functional luminal imaging probe measurements in patients undergoing myotomy for achalasia

The functional luminal imaging probe (FLIP) is a novel catheter-based device that measures esophagogastric junction (EGJ) distensibility index (DI) in real time. Previous studies have demonstrated DI to be a predictor of post-treatment clinical outcomes in patients with achalasia. We sought to evaluate EGJ DI in patients with achalasia before, during, and after peroral endoscopic myotomy (POEM) and laparoscopic Heller myotomy (LHM) and to assess the correlation of DI with postoperative outcomes. DI (defined as the minimum cross-sectional area at the EGJ divided by distensive pressure) was measured at 4 time points in patients undergoing surgical myotomy for achalasia: (1) during outpatient preoperative endoscopy (preoperative DI), (2) at the start of each operation after the induction of anesthesia (induction DI), (3) at the conclusion of each operation (postmyotomy DI), and (4) at routine follow-up endoscopy 12 months postoperatively (follow-up DI). Routine Eckardt symptom score, endoscopy, timed barium esophagram, and pH study were obtained 12 months postoperatively. Forty-six patients (35 POEM, 11 LHM) underwent FLIP measurements at all 4 time points. Preoperative and induction mean DI were similar for both groups (POEM, 1 vs .9mm2/mm Hg; LHM, 1.7 vs 1.5mm2/mm Hg). POEM resulted in a significant increase in DI (induction .9 vs postmyotomy 7mm2/mm Hg, P< .001). There was a subsequent decrease in DI in the follow-up period (postmyotomy 7 vs follow-up 4.8mm2/mm Hg, P< .01), but DI at follow-up was still significantly improved from preoperative values (P< .001). ForLHM patients, DI also increased as a result of surgery (induction 1.5 vs postmyotomy 5.9mm2/mm Hg, P< .001); however, the increase was smaller than in POEM patients (DI increase 4.4 vs 6.2mm2/mm Hg, P< .05). After LHM, DI also decreased in the follow-up period, but this change was not statistically significant (5.9 vs 4.4mm2/mm Hg, P= .29). LHM patients with erosive esophagitis on follow-up endoscopy had a significantly higher postmyotomy DI compared with those without esophagitis (9.3 vs 4.8mm2/mm Hg, P<.05). EGJ DI improved dramatically as a result of both POEM and LHM, with POEM resulting in a larger increase. Mean DI decreased at intermediate follow-up but remained well above previously established thresholds for symptom recurrence. DI at the conclusion of LHM was predictive of erosive esophagitis in the postoperative period, which supports the potential use of FLIP for calibration of partial fundoplication construction during LHM.

How much oxygen for the injured brain - can invasive parenchymal catheters help?

Each year in the United States there are over 2.5 million visits to emergency departments for traumatic brain injury (TBI), 300,000 hospitalizations, and 50,000 deaths. TBI initiates a complex cascade of events which can lead to significant secondary brain damage. Great interest exists in directly measuring cerebral oxygen delivery and demand after TBI to prevent this secondary injury. Several invasive, catheter-based devices are now available which directly monitor the partial pressure of oxygen in brain tissue (PbtO2), yet significant equipoise exists regarding their clinical use in severe TBI. There are currently three ongoing multicenter randomized controlled trials studying the use of PbtO2 monitoring in severe TBI: BOOST-3, OXY-TC, and BONANZA. All three have similar inclusion/exclusion criteria, treatment protocols, and outcome measures. Despite mixed existing evidence, use of PbtO2 is already making its way into new TBI guidelines such as the recent Seattle International Brain Injury Consensus Conference. Analysis of high-fidelity data from multimodal monitoring, however, suggests that PbtO2 may only be one piece of the puzzle in severe TBI. While current evidence regarding the use of PbtO2 remains mixed, three ongoing clinical trials are expected to definitively answer the question of what role PbtO2 monitoring plays in severe TBI.

S2778 The Dangers of Seeing the Light: Importance of Forward-Facing Orientation for Endoscopic Capsule Deployment

INTRODUCTION: Since 2001 video capsule endoscopy (VCE) has been widely applied to assess small bowel bleeding, iron deficiency anemia (IDA), inflammatory bowel disease, refractory celiac disease and polyposis syndromes. Limitations include the inability to intervene, lack of familiarity with reading video and handling software, as well as time required to interpret findings. The aim of this case series is to present 4 cases of lens damage to the VCE from the VCE capsule holder used during endoscopic placement. CASE DESCRIPTION/METHODS: 86 VCE studies were reviewed; 4 showed structural VCE lens damage after endoscopic placement. These were all placed with lens towards the releasing device rather than forward-facing. No signs of lens damage were observed in the remaining 82 capsule studies. The first case was a 60-year-old woman with IDA and normal VCE study. The second patient was an 84-year-old man with IDA, with small ulcerations throughout the small bowel on VCE. Third was a 30-year-old woman with iron deficiency and normal hemoglobin level, with a non-diagnostic VCE. Last was an 89-year-old man with IDA, with VCE showing duodenal polyp. DISCUSSION: Appropriate endoscopic deployment technique involves the use of a catheter-based device to which a cup is attached to hold the capsule, with a moveable metal core that pushes it out of the cup (US Endoscopy, Mentor, Ohio), allowing deployment. The optical dome of the video capsule should be placed in this holder forward-facing with the lens pointing away from the endoscope. Some physicians insert the capsule with the opposite orientation to confirm deployment by visualizing light source after release. This practice can result in damage to the lens when the metal core is fired, thereby affecting obtained images and decreasing study quality. In this series, each VCE showed a linear scratch on the lens. This scratch can be misinterpreted as a lesion, as well as interfere with the reading of the study. Summary: It is important to take into consideration orientation of the VCE with a forward-facing lens when loading into the endoscopic deployment device. This will prevent lens damage and ensure that the highest quality images possible are obtained during study, optimizing VCE efficacy. Physician awareness is needed to prevent this potential pitfall.Figure 1.: Proper orientation of the capsule device into the endoscopic deployment device.Figure 2.: Capsule images with evidence of lens damage, causing linear scratches on images.Figure 3.: Capsule images with evidence of lens damage, causing linear scratches on images.

Catheter-Based Left Ventricular Assist Device for the Management of Cardiogenic Shock Complicating Acute Myocardial Infarction: A First-in-Singapore Experience

Catheter-Based Left Ventricular Assist Device for the Management of Cardiogenic Shock Complicating Acute Myocardial Infarction: A First-in-Singapore Experience

Left Atrial Appendage Anatomy: Implications for Endocardial Catheter-based Device Closure.

This clinical review focuses on both current devices approved by the United States Food and Drug Administration and investigational devices available for left atrial appendage (LAA) closure. Specifically, the article describes the anatomical considerations that are particularly relevant from a procedural standpoint. In addition, we have also focused on the technical aspects of the procedure.

Computational modeling of drug transport and mixing in the chemofilter device: enhancing the removal of chemotherapeutics from circulation.

Intra-arterial chemotherapy (IAC) is the preferred treatment for non-resectable hepatocellular carcinoma. A large fraction of IAC drugs, e.g., Doxorubicin, pass into systemic circulation, causing cardiac toxicity and reducing effectiveness of the procedure. These excessive drugs can be captured by the Chemofilter-a 3D-printable, catheter-based device deployed in a vein downstream of the liver during IAC. In this study, alternative configurations of the Chemofilter device were compared by evaluating their hemodynamic and filtration performance through multiphysics computational fluid dynamics simulations. Two designs were evaluated, a honeycomb-like structure of parallel hexagonal channels (honeycomb Chemofilter) and a cubic lattice of struts (strutted Chemofilter). The computationally optimized Chemofilter design contains three honeycomb stages, each perforated and twisted, which improved Doxorubicin adsorption by 44.6% compared to a straight channel design. The multiphysics simulations predicted an overall 66.8% decrease in concentration with a 2.9mm-Hg pressure drop across the optimized device compared to a 50% concentration decrease observed during in-vivo experiments conducted with the strutted Chemofilter. The Doxorubicin transport simulations demonstrated the effectiveness of the Chemofilter in removing excessive drugs from circulation while minimizing pressure drop and eliminating flow stagnation regions prone to thrombosis. These results demonstrate the value of the multiphysics modeling approach in device optimization and experimental burden reduction.

Functionalization of endovascular devices with superparamagnetic iron oxide nanoparticles for interventional cardiovascular magnetic resonance imaging.

Presently, cardiovascular interventions such as stent deployment and balloon angioplasty are performed under x-ray guidance. However, x-ray fluoroscopy has poor soft tissue contrast and is limited by imaging in a single plane, resulting in imprecise navigation of endovascular instruments. Moreover, x-ray fluoroscopy exposes patients to ionizing radiation and iodinated contrast agents. Magnetic resonance imaging (MRI) is a safe and enabling modality for cardiovascular interventions. Interventional cardiovascular MR (iCMR) is a promising approach that is in stark contrast with x-ray fluoroscopy, offering high-resolution anatomic and physiologic information and imaging in multiple planes for enhanced navigational accuracy of catheter-based devices, all in an environment free of radiation and its deleterious effects. While iCMR has immense potential, its translation into the clinical arena is hindered by the limited availability of MRI-visible catheters, wire guides, angioplasty balloons, and stents. Herein, we aimed to create application-specific, devices suitable for iCMR, and demonstrate the potential of iCMR by performing cardiovascular catheterization procedures using these devices. Tools, including catheters, wire guides, stents, and angioplasty balloons, for endovascular interventions were functionalized with a polymer coating consisting of poly(lactide-co-glycolide) (PLGA) and superparamagnetic iron oxide (SPIO) nanoparticles, followed by endovascular deployment in the pig. Findings from this study highlight the ability to image and properly navigate SPIO-functionalized devices, enabling interventions such as successful stent deployment under MRI guidance. This study demonstrates proof-of-concept for rapid prototyping of iCMR-specific endovascular interventional devices that can take advantage of the capabilities of iCMR.

Pathology Approaches to Determine Safety and Efficacy of Cardiac Ablation Catheters.

Cardiac electrophysiology utilizes nonimplantable, catheter-based devices for diagnosis and treatment of arrhythmias as well as electroanatomical mapping of cardiac chambers. Gross pathology and histopathological assessments in preclinical studies play critical roles in determining the safety and efficacy of cardiac ablation systems used to treat tachyarrhythmias. The pathologist must assess ablation sites, adjacent structures and organs, and downstream organs to characterize the effects of the ablation treatment and determine whether adverse local reactions, collateral injury, or downstream thromboembolism are present. Histopathological assessment serves as an adjunct to electroanatomical data in determining efficacy in preclinical studies. Histopathology is the standard in definitively demonstrating transmurality of ablation lesions, which is necessary for complete conduction block, as well as showing the linear or circumferential distribution of a contiguous, transmural ablation lesion necessary for electroanatomical isolation of entire target structures such as pulmonary veins and the cavotricuspid isthmus, which are involved in propagating certain arrhythmias. This article will detail gross and histological methods for the pathology assessment of preclinical studies evaluating the safety and/or efficacy of cardiac ablation catheter systems as well as discuss correlation of pathology data with other supporting evidence for safety and efficacy such as acute, electroanatomical data.

Echocardiography of the patent ductus arteriosus in premature infant.

Management of the patent ductus arteriosus (PDA) in the premature infant has been a point of controversy for decades as smaller and earlier gestational age infants have been surviving. Increasing experience with catheter-based device closure has generated a new wave of interest in this subject. In this era, echocardiography plays a central role for collaboration within a multispecialty team. Reliability of echocardiography is improved by applying an institutionally derived standard approach to imaging, data collection, and reporting. The key aspects of both the physiology and anatomy of the PDA to distinguish infants that may benefit from intervention are described.

Toward predictive modeling of catheter-based pulmonary valve replacement into native right ventricular outflow tracts.

Pulmonary insufficiency is a consequence of transannular patch repair in Tetralogy of Fallot (ToF) leading to late morbidity and mortality. Transcatheter native outflow tract pulmonary valve replacement has become a reality. However, predicting a secure, atraumatic implantation of a catheter-based device remains a significant challenge due to the complex and dynamic nature of the right ventricular outflow tract (RVOT). We sought to quantify the differences in compression and volume for actual implants, and those predicted by pre-implant modeling. We used custom software to interactively place virtual transcatheter pulmonary valves (TPVs) into RVOT models created from pre-implant and post Harmony valve implant CT scans of 5 ovine surgical models of TOF to quantify and visualize device volume and compression. Virtual device placement visually mimicked actual device placement and allowed for quantification of device volume and radius. On average, simulated proximal and distal device volumes and compression did not vary statistically throughout the cardiac cycle (P = 0.11) but assessment was limited by small sample size. In comparison to actual implants, there was no significant pairwise difference in the proximal third of the device (P > 0.80), but the simulated distal device volume was significantly underestimated relative to actual device implant volume (P = 0.06). This study demonstrates that pre-implant modeling which assumes a rigid vessel wall may not accurately predict the degree of distal RVOT expansion following actual device placement. We suggest the potential for virtual modeling of TPVR to be a useful adjunct to procedural planning, but further development is needed.

The Application of Mitraclip in the Treatment of Mitral Regurgitation: A Clinical Policy

Context: The mitral valve conducts blood flow from the left atrium to the left ventricle. Mitral regurgitation occurs when the valve couldn’t be closed properly at the end of ventricular filling. Mitraclip, a catheter-based device that can reduce mitral regurgitation without requiring open surgery, is routinely used for patients with unacceptable risk of conventional mitral valve repair or replacement. The purpose of this study is assessing the safety, efficacy, and economic aspects of Mitraclip treatment for mitral regurgitation. Evidence Acquisition: The Cochrane Library, the TRIP database, and Google Scholar have been searched through appropriate strategies. Seven studies were included in the final phase based on the inclusion and exclusion criteria. Data collected from these studies were analyzed based on four main themes; applications, safety, efficacy, and economic evaluation. Results: The most potential side effects were related to an improper transfer of catheters and low durability of the device. One of the included studies showed that improved outcomes of the New York Heart Association (NYHA) was more in the clip group with better quality of life that were observed after 1 to 12 months in 192 patients and also one-year mortality rate after using clip ranged between 10% and 24%. This included study found that 72% to 100% of patients with Mitraclip have been successfully treated and the duration of hospital stays in these patients was between 5 to 10 days. The cost-effectiveness of the procedure still needs more robust evidence. Conclusions: Given the lack of high quality evidence and relatively high cost of Mitraclip, it seems that until further robust evidence is produced; it should be used in research and in high risk patients selected after detailed examination with strict indications and appropriate opinions of cardiologists.

Tips and Tricks of TEE in CHD Intervention

Transesophageal echocardiography (TEE) now is considered an essential part of diagnostic and monitoring during modern cardiac and thoracic aortic surgery. Perioperative TEE is a major component of patient management, and important for surgical and anesthetic decision making. Frazin first introduced the clinical use of transesophageal echocardiography (TEE) in 1976. However, the pediatric TEE probe was established and use clinically in 1990. In 2009, the new microTEE probe (s8-3t Philip) was developed and brings benefits of the TEE to use in patients under 3Kg. Clinical management of congenital heart lesions by using the TEE can be achieved by surgical repair, via catheter-based device closure and during hybrid surgery. Therefore, in this presentation we review our experiences of using intraoperative TEE in pediatric patients who underwent different types of congenital heart surgery, interventional therapy and hybrid surgery. We reported that intraoperative TEE for 256 consecutive neonates and infants undergoing complex congenital heart surgery. TEE was successful performed in 97% of infants with CHD during surgery and only 3% failed due to systemic arterial hypotension and saturation in 7 infants (4 in TAPVC and 3 in CoA) only 5.6 % patients with inadequate surgical repair and need immediate revised. Interventional techniques for treatment of congenital heart disease are evolving rapidly and have become established routine in a large number of centers worldwide. TEE image was used to evaluate the size, number and location of the defects, selection of appropriate device, guiding the procedures and confirmed the results. Hybrid surgery for CHD, a new medical trend. It combined minimally-invasive method with traditional surgical techniques and catheter based procedure. Hybrid for HLHS (single ventricle palliation combing surgical PAB with catheter ductal stenting), periventricular closure of VSD, periventricular pulmonary stenosis, periventricular aortic valve replacement. In conclusion, TEE is routinely and successfully used during pediatric CHD surgery repair, intervention procedures and hybrid surgery to improve the quality of surgical repair and to potentially reduce the morbidity and mortality.

Treatment of severe mitral regurgitation with MitraClip system — a single-centre study

Introduction. MitraClip (MC) is a catheter-based device to treat mitral regurgitation (MR). This method uses a transseptal approach and is based on the creation of a double orifice mitral valve by suturing of the middle scallops of the mitral valve’s leaflets. Aim. The aim of the study was to assess the effectiveness of MC method in treating patients with severe MR. We analysed MR severity, patient’s clinical condition evaluated by New York Heart Association (NYHA) functional class, and the function of the left ventricle evaluated by Left Ventricle Ejection Fraction (LVEF). Methods. A retrospective single-centre study with patients hospitalised at the Department of Cardiology and Internal Medicine in Bydgoszcz. All diagnosed with severe MR and treated by performing MC procedure in the time period from August 2010 to December 2014. The following data from medical history (NYHA class) and echocardiography examinations (MR severity and LVEF) were analysed in three time points: before, right after the procedure, and after the follow-up period (four weeks since discharge). Results. The studied group consisted of 11 patients — 8 male, 3 female, aged 64.4 ( ± 10.2) years, treated with MC. All of the three analysed parameters improved relevantly as a result of the evaluated procedure. The percentage of patients classified as NYHA class III/IV presents as follows: 90% before the procedure, 55% after MC implantation (ns), and 44% after the follow-up period (p = 0.01). All patients suffered from severe-to-moderate (3+) and severe (4+) MR before the procedure. After implantation only 9% (ns) were still classified with 3+/4+ MR, and after the follow-up this percentage reached 18% (p = 0.0005). We observed relevant changes of LVEF. The average LVEF at baseline was 27.9 ± 2%, which increased to 29.6 ± 2% (ns) after the MC implantation and 34 ± 7% (p = 0.02) after the follow-up. Conclusion. MC therapy is effective in patients with severe symptomatic MR with congestive heart failure and decreased LVEF. It reduces MR severity both acutely and after the follow-up period and improves NYHA class and LVEF.

Recognition of Fibrotic Infarct Density by the Pattern of Local Systolic-Diastolic Myocardial Electrical Impedance

Myocardial electrical impedance is a biophysical property of the heart that is influenced by the intrinsic structural characteristics of the tissue. Therefore, the structural derangements elicited in a chronic myocardial infarction should cause specific changes in the local systolic-diastolic myocardial impedance, but this is not known. This study aimed to characterize the local changes of systolic-diastolic myocardial impedance in a healed myocardial infarction model. Six pigs were successfully submitted to 150 min of left anterior descending (LAD) coronary artery occlusion followed by reperfusion. 4 weeks later, myocardial impedance spectroscopy (1–1000 kHz) was measured at different infarction sites. The electrocardiogram, left ventricular (LV) pressure, LV dP/dt, and aortic blood flow (ABF) were also recorded. A total of 59 LV tissue samples were obtained and histopathological studies were performed to quantify the percentage of fibrosis. Samples were categorized as normal myocardium (<10% fibrosis), heterogeneous scar (10–50%) and dense scar (>50%). Resistivity of normal myocardium depicted phasic changes during the cardiac cycle and its amplitude markedly decreased in dense scar (18 ± 2 Ω·cm vs. 10 ± 1 Ω·cm, at 41 kHz; P < 0.001, respectively). The mean phasic resistivity decreased progressively from normal to heterogeneous and dense scar regions (285 ± 10 Ω·cm, 225 ± 25 Ω·cm, and 162 ± 6 Ω·cm, at 41 kHz; P < 0.001 respectively). Moreover, myocardial resistivity and phase angle correlated significantly with the degree of local fibrosis (resistivity: r = 0.86 at 1 kHz, P < 0.001; phase angle: r = 0.84 at 41 kHz, P < 0.001). Myocardial infarcted regions with greater fibrotic content show lower mean impedance values and more depressed systolic-diastolic dynamic impedance changes. In conclusion, this study reveals that differences in the degree of myocardial fibrosis can be detected in vivo by local measurement of phasic systolic-diastolic bioimpedance spectrum. Once this new bioimpedance method could be used via a catheter-based device, it would be of potential clinical applicability for the recognition of fibrotic tissue to guide the ablation of atrial or ventricular arrhythmias.