Interventional cardiac catheterisation in congenital heart disease

Fast, automated, real-time 3D passive balloon catheter tracking during MRI-guided cardiac catheterization using orthogonal projection imaging and real-time image-based catheter detection

PURPOSE

MRI-guidance of cardiac catheterization is currently performed using one or multiple 2D imaging planes, which may be suboptimal for catheter navigation, especially in patients with complex anatomies. The purpose of the work was to develop a robust real-time 3D catheter tracking method and 3D visualization strategy for improved MRI-guidance of cardiac catheterization procedures.

METHODS

A fast 3D tracking technique was developed using continuous acquisition of two orthogonal 2D-projection images. Each projection corresponds to a gradient echo stack of slices with only the central k-space lines being collected for each slice. To enhance catheter contrast, a saturation pulse is added ahead of the projection pair. An offline image processing algorithm was developed to identify the 2D coordinates of the balloon in each projection image and to estimate its corresponding 3D coordinates. Post-processing includes background signal suppression using an atlas of background 2D-projection images. 3D visualization of the catheter and anatomy is proposed using three live sagittal, coronal, and axial (MPR) views and 3D rendering. The technique was tested in a subset of a catheterization step in three patients undergoing MRI-guided cardiac catheterization using a passive balloon catheter.

RESULTS

The extraction of the catheter balloon 3D coordinates was successful in all patients and for the majority of time-points (accuracy >96%). This tracking method enabled a novel 3D visualization strategy for passive balloon catheter, providing enhanced anatomical context during catheter navigation.

CONCLUSION

The proposed tracking strategy shows promise for robust tracking of passive balloon catheter and may enable enhanced visualization during MRI-guided cardiac catheterization.

Perioperative care of neonates with critical pulmonary stenosis: Case report

RATIONALE

Summarizing the perioperative nursing experience in the successful treatment of 4 neonates with critical pulmonary stenosis (CPS).

PATIENT CONCERNS

Of the 4 patients, 3 had postnatal shortness of breath and varying degrees of cyanosis, aggravated by crying and noise, and 1 had no obvious shortness of breath and cyanosis. The preoperative auscultation of the precordial region could be heard 3-4/6 systolic murmur; echocardiography was diagnosed as CPS, combined with patent ductus arteriosus, right ventricular dysplasia, and severe tricuspid regurgitation. Four children were treated with prostaglandin 5 ng/(kg-min) to maintain a certain degree of pulmonary blood flow to improve hypoxemia, effectively preventing ductus arteriosus from closure, and the infusion was discontinued 2 hours prior to the operation. Three of the children required ventilator-assisted respiration to relieve severe hypoxia and correct acidosis before surgery.

DIAGNOSIS

Neonatal CPS was diagnosed.

INTERVENTIONS

Four neonates with rapidly developing conditions were admitted to the hospital, a multidisciplinary in-hospital consultation was organized immediately, and a multidisciplinary collaborative team was set up, consisting of medical doctors and nurses from the medical department, the neonatal intensive care unit, cardiovascular medicine, cardiac ultrasound room, anesthesiology department, and radiology and interventional medicine department. The multidisciplinary team evaluated the treatment modality of the children and finally decided to perform percutaneous balloon pulmonary valvuloplasty. The surgical team included specialists from the Department of Cardiovascular Medicine, Department of Interventional Radiology, Cardiac Ultrasound Unit, and Department of Anesthesiology.

OUTCOMES

All 4 neonates were successfully operated and discharged from the hospital. Multidisciplinary follow-up interventions were carried out 1 year after discharge, and the children were in good condition.

LESSONS

The specialty nursing-led multidisciplinary collaboration model significantly improves the professional competence of nurses from various specialties, promotes the integration and development of multispecialty disciplines, and provides better quality services for children, which is the key to improving the success rate of percutaneous balloon pulmonary valvuloplasty in neonates.

Real-time automatic image-based slice tracking of gadolinium-filled balloon wedge catheter during MR-guided cardiac catheterization: A proof-of-concept study

PURPOSE

MR-guided cardiac catheterization procedures currently use passive tracking approaches to follow a gadolinium-filled catheter balloon during catheter navigation. This requires frequent manual tracking and repositioning of the imaging slice during navigation. In this study, a novel framework for automatic real-time catheter tracking during MR-guided cardiac catheterization is presented.

METHODS

The proposed framework includes two imaging modes (Calibration and Runtime). The sequence starts in Calibration mode, in which the 3D catheter coordinates are determined using a stack of 10-20 contiguous saturated slices combined with real-time image processing. The sequence then automatically switches to Runtime mode, where three contiguous slices (acquired with partial saturation), initially centered on the catheter balloon using the Calibration feedback, are acquired continuously. The 3D catheter balloon coordinates are estimated in real time from each Runtime slice stack using image processing. Each Runtime stack is repositioned to maintain the catheter balloon in the central slice based on the prior Runtime feedback. The sequence switches back to Calibration mode if the catheter is not detected. This framework was evaluated in a heart phantom and 3 patients undergoing MR-guided cardiac catheterization. Catheter detection accuracy and rate of catheter visibility were evaluated.

RESULTS

The automatic detection accuracy for the catheter balloon during the Calibration/Runtime mode was 100%/95% in phantom and 100%/97 ± 3% in patients. During Runtime, the catheter was visible in 82% and 98 ± 2% of the real-time measurements in the phantom and patients, respectively.

CONCLUSION

The proposed framework enabled real-time continuous automatic tracking of a gadolinium-filled catheter balloon during MR-guided cardiac catheterization.

Automatic image-based tracking of gadolinium-filled balloon wedge catheters for MRI-guided cardiac catheterization using deep learning

Introduction

Magnetic Resonance Imaging (MRI) is a promising alternative to standard x-ray fluoroscopy for the guidance of cardiac catheterization procedures as it enables soft tissue visualization, avoids ionizing radiation and provides improved hemodynamic data. MRI-guided cardiac catheterization procedures currently require frequent manual tracking of the imaging plane during navigation to follow the tip of a gadolinium-filled balloon wedge catheter, which unnecessarily prolongs and complicates the procedures. Therefore, real-time automatic image-based detection of the catheter balloon has the potential to improve catheter visualization and navigation through automatic slice tracking.

Methods

In this study, an automatic, parameter-free, deep-learning-based post-processing pipeline was developed for real-time detection of the catheter balloon. A U-Net architecture with a ResNet-34 encoder was trained on semi-artificial images for the segmentation of the catheter balloon. Post-processing steps were implemented to guarantee a unique estimate of the catheter tip coordinates. This approach was evaluated retrospectively in 7 patients (6M and 1F, age = 7 ± 5 year) who underwent an MRI-guided right heart catheterization procedure with all images acquired in an orientation unseen during training.

Results

The overall accuracy, specificity and sensitivity of the proposed catheter tracking strategy over all 7 patients were 98.4 ± 2.0%, 99.9 ± 0.2% and 95.4 ± 5.5%, respectively. The computation time of the deep-learning-based segmentation step was ∼10 ms/image, indicating its compatibility with real-time constraints.

Conclusion

Deep-learning-based catheter balloon tracking is feasible, accurate, parameter-free, and compatible with real-time conditions. Online integration of the technique and its evaluation in a larger patient cohort are now warranted to determine its benefit during MRI-guided cardiac catheterization.

Cardiac Catheterisation Interventions in Neonates and Infants Less Than Three Months

Introduction

Pediatric cardiac catheterization interventions become an established way of care for selected patients with congenital heart diseases. Cardiac catheterization for neonates and small infants can be challenging. The indications for diagnostic cardiac catheterization have decreased with the advent of advanced non-invasive imaging modalities.

Patients and method

Between June 2012 and July 2017 patients less than three months who had cardiac catheterization in two centers were reviewed.

Results

During the study period, 174 patients underwent interventional cardiac catheterization,83.3% of them had CHD with two-ventricle circulation and 29 patients (16.7%) had single ventricle pathophysiology. Procedures include diagnostic cath, BAS, balloon pulmonary and aortic valvuloplasty, coarctation angioplasty, and stenting procedures. The vascular access depends upon the type of procedure. All except one had general anesthesia. ICU admission was required on 106 patients (62%). Patients were divided according to the type of cardiac lesion (single versus biventricular pathology) as well as according to the type of intervention (stenting and non-stenting procedures). Comparing these groups revealed that: stent procedures and procedures for patients with single ventricle pathologies were performed at an earlier age, with more contrast, fluoro and procedure time than for non-stent procedures and procedures for patients with biventricular pathologies. Complications include transient arrhythmias in most patients, perforation of the RVOT in one and lower limb hypoperfusion in 12 patients. ICU complications include low cardiac output symptoms (LCOS) in 10 (7%), and sepsis in 8. No intra-procedure mortality. The overall survival was 94%. Ten patients died, with one early and 9 late mortality. 60% of the dead patients had PDA stenting. Reintervention varies according to the patient's diagnosis.

Conclusion

Cardiac catheterization intervention an important modality in the management of neonates and infants with critical CHD. Well planned procedures and team expertise are essential. Stenting procedures and procedures for patients with single ventricles carries higher morbidity and mortality.

Congenital Heart Disease in Low- and Lower-Middle-Income Countries: Current Status and New Opportunities

PURPOSE OF REVIEW

The paper summarises the most recent data on congenital heart disease (CHD) in low- and lower-middle-income countries (LLMICs). In addition, we present an approach to diagnosis, management and interventions in these regions and present innovations, research priorities and opportunities to improve outcomes and develop new programs.

RECENT FINDINGS

The reported birth prevalence of CHD in LLMICs is increasing, with clear evidence of the impact of surgical intervention on the burden of disease. New methods of teaching and training are demonstrating improved outcomes. Local capacity building remains the key. There is a significant gap in epidemiological and outcomes data in CHD in LLMICs. Although the global agenda still does not address the needs of children with CHD adequately, regional initiatives are focusing on quality improvement and context-specific interventions. Future research should focus on epidemiology and the use of innovative thinking and partnerships to provide low-cost, high-impact solutions.

Efficacy of catheter interventions in the early and very early postoperative period after CHD operation

BACKGROUND

Catheter interventions for residual lesions in the early postoperative period after CHD operations are still not established as a reliable treatment option.

METHODS

We retrospectively reviewed our institutional experience of cardiac catheterisations and catheter interventions performed in the early postoperative period. We classified our patients into two groups. The "hyper" acute phase group - operation to cardiac catheterisation of ⩽7 days - and acute phase group - operation to cardiac catheterisation from 7 to 30 days.

RESULTS

Of the 47 patients, catheter interventions were performed in 38 patients (81%). The success rate of the intervention was 96% in the acute phase group and 90% in the "hyper" acute phase group. The overall success rate was 95%. There were two self-limited complications in the acute phase group, but not in the "hyper" acute phase group. There were four cases of catheter interventions performed for a newly reconstructed aortic arch, and those procedures were also safe and effective.

CONCLUSIONS

Cardiac catheterisations and catheter interventions were safe and effective not only in the early postoperative period but also in the very early postoperative period. Catheter interventions for the left-sided heart in the early postoperative period were also safe and effective.

Improved passive catheter tracking with positive contrast for CMR-guided cardiac catheterization using partial saturation (pSAT)

BACKGROUND

Cardiac catheterization is a common procedure in patients with congenital heart disease (CHD). Although cardiovascular magnetic resonance imaging (CMR) represents a promising alternative approach to fluoroscopy guidance, simultaneous high contrast visualization of catheter, soft tissue and the blood pool remains challenging. In this study, a novel passive tracking technique is proposed for enhanced positive contrast visualization of gadolinium-filled balloon catheters using partial saturation (pSAT) magnetization preparation.

METHODS

The proposed pSAT sequence uses a single shot acquisition with balanced steady-state free precession (bSSFP) readout preceded by a partial saturation pre-pulse. This technique was initially evaluated in five healthy subjects. The pSAT sequence was compared to conventional bSSFP images acquired with (SAT) and without (Non-SAT) saturation pre-pulse. Signal-to-noise ratio (SNR) of the catheter balloon, blood and myocardium and the corresponding contrast-to-noise ratio (CNR) are reported. Subjective assessment of image suitability for CMR-guidance and ideal pSAT angle was performed by three cardiologists. The feasibility of the pSAT sequence is demonstrated in two adult patients undergoing CMR-guided cardiac catheterization.

RESULTS

The proposed pSAT approach provided better catheter balloon/blood contrast and catheter balloon/myocardium contrast than conventional Non-SAT sequences. It also resulted in better blood and myocardium SNR than SAT sequences. When averaged over all volunteers, images acquired with a pSAT angle of 20° to 40° enabled simultaneous visualization of the catheter balloon and the cardiovascular anatomy (blood and myocardium) and were found suitable for CMR-guidance in >93% of cases. The pSAT sequence was successfully used in two patients undergoing CMR-guided diagnostic cardiac catheterization.

CONCLUSIONS

The proposed pSAT sequence offers real-time, simultaneous, enhanced contrast visualization of the catheter balloon, soft tissues and blood. This technique provides improved passive tracking capabilities during CMR-guided catheterization in patients.

Monitoring aspirin therapy in children after interventional cardiac catheterization: laboratory measures, dose response, and clinical outcomes

Very few studies have investigated dose response of aspirin and agreement of different platelet function assays in children. One hundred five children were studied at baseline and after interventional cardiac catheterization during aspirin treatment and, in cases of aspirin resistance (AR), after dose increase. Results from arachidonate-induced aggregation (AA) were compared with aggregation induced by ADP, PFA-100 closure times (CTs), urinary 11-dehydro-thromboxane B2 (urinary 11-dhTxB2) levels, and Impact-R % surface coverage. Aspirin at 2-5 mg/kg/day inhibited platelet function in a large majority. While 19 % showed bruising and mild epistaxis, no thrombotic complications were recorded. AR was detected by AA in seven children (6.7 %). After dose increase, the majority showed inhibition by aspirin. Infants had higher urinary 11-dhTxB2 baseline levels; this assay showed some correlation with AA. Both assays manifested high sensitivity and specificity for aspirin while inferior results were found for the other assays. With the PFA-100, 15.2 % of patients were found to have AR, but this corresponded to AR by AA in only one of seven children.

CONCLUSION

While there was poor agreement among assays, AA and urinary 11-dhTxB2 show good specificity for the monitoring of aspirin therapy in children. Aspirin at 2-5 mg/kg inhibits platelet function; AR in children is rare and can be overcome by dose increase.

Pediatric cardiac interventions

The field of pediatric cardiac interventions has witnessed a dramatic increase in the number and type of procedures performed. We review the most common procedures performed in the catheter laboratory. Lesions are divided according to their physiological characteristics into left-to-right shunting lesions (atrial septal defect, patent ductus arteriosus, ventricular septal defect), right-to-left shunting lesions (pulmonary stenosis, pulmonary atresia/intact ventricular septum), right heart obstructive lesions (peripheral arterial pulmonic stenosis, right ventricular outflow tract obstruction), and left heart obstructive lesions (aortic valve stenosis, coarctation of the aorta). In addition, a miscellaneous group of lesions is discussed.

The causes of Charcot-Marie-Tooth disease

Charcot-Marie-Tooth (CMT) disease serves as the summary term for the most frequent forms of inherited peripheral neuropathies that affect motor and sensory nerves. In the last 12 years, 14 genes have been identified that cause different CMT subforms. The genes found initially are predominantly responsible for demyelinating and dysmyelinating neuropathies. Genes affected in axonal and rare forms of CMT have only recently been identified. In this review, we will focus on the currently known genes that are associated with CMT syndromes with regards to their genetics and function.