Recommendations of the British Paediatric Cardiac Association for therapeutic cardiac catheterisation in congenital cardiac disease

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.

Complicaciones relacionadas con el cateterismo cardíaco pediátrico y cardiopatías congénitas

INTRODUCTION

Congenital heart diseases are the most common congenital abnormalities in newborns with a prevalence of 1%. Therapeutic and diagnostic cardiac catheterization has revolutionized the treatment of these diseases; however, it can be associated with complications.

OBJECTIVE

To describe the incidence and type of complications associated with pediatric cardiac catheterization in a reference center for congenital heart defects.

METHODOLOGY

Retrospective observational study, with analytical intention based on records of cardiac catheterization performed on patients with congenital and acquired heart disease.

RESULTS

2,688 records were included for nine consecutive years. 53.9% were men, 21.3% with ages between 2 and 5 years and 20.3% between 6 months and 2 years. 63.5% of the procedures were elective. The prevalence of complications in the first 24 hours after catheterization was 6.7% (4.2% minor and 2.4% major). Early death occurred in 0.8% of the procedures. Factors associated with complications were age at catheterization <28 days (OR 2.18, 95% CI [1.28-3.70]), precatheter oxygen saturation <79% (OR 2.15, 95% CI [1.02-4.53]), use of pre-catheter inotropics (OR 3.00, 95% CI [1.68-5.33]). The variables included in the model explain 38% of the variance of post-cardiac catheterization complications in patients younger than 18 years.

DISCUSSION

Cardiac catheterization is associated with major and minor complications including death. The associated factors were less than 28 days, lower oxygen saturation and use of pre-catheter inotropics.

Towards the definition of Institutional diagnostic reference levels in paediatric interventional cardiology procedures in Greece

This study aimed to evaluate paediatric radiation doses in a dedicated cardiology hospital, with the objective of characterising patterns in dose variation. The ultimate purpose was to define Local (Institutional) Diagnostic Reference Levels (LDRLs) for different types of paediatric cardiac interventional procedures (IC), according to patient age. From a total of 710 cases performed during three consecutive years, by operators with more than 15 years of experience, the age was noted in only 477 IC procedures. The median values obtained for Fluoroscopy Time (FT), Number of Frames (N) and Kerma Area Product (P_KA) by age range were 5.8 min, 1322 and 2.0 Gy.cm² for <1 y; 6.5 min, 1403 and 3.0 Gy.cm² for 1 to <5 y; 5.9 min, 950 and 7.0 Gy.cm² for 5 to <10 y; 5.7 min, 940 and 14.0 Gy.cm² for 10 to <16 y, respectively. A large range of patient dose data is observed, depending greatly on procedure type and patient age. In all age groups the range of median FT, N and P_KA values was 3.1-15.8 min, 579-1779 and 1.0-20.8 Gy.cm² respectively. Consequently, the definition of LDRLs presents challenges mainly due to the multiple clinical and technical factors affecting the outcome. On the other hand the lack of paediatric IC DRLs makes the identification of good practices more difficult. A consensus is needed on IC procedures nomenclature and grouping in order to allow a common assessment and comparison of doses.

The International Atomic Energy Agency action plan on radiation protection of patients and staff in interventional procedures: Achieving change in practice

INTRODUCTION

The International Atomic Energy Agency (IAEA) organized the 3rd international conference on radiation protection (RP) of patients in December 2017. This paper presents the conclusions on the interventional procedures (IP) session.

MATERIAL AND METHODS

The IAEA conference was conducted as a series of plenary sessions followed by various thematic sessions. "Radiation protection of patients and staff in interventional procedures" session keynote speakers presented information on: 1) Risk management of skin injuries, 2) Occupational radiation risks and 3) RP for paediatric patients. Then, a summary of the session-related papers was presented by a rapporteur, followed by an open question-and-answer discussion.

RESULTS

Sixty-seven percent (67%) of papers came from Europe. Forty-four percent (44%) were patient studies, 44% were occupational and 12% were combined studies. Occupational studies were mostly on eye lens dosimetry. The rest were on scattered radiation measurements and dose tracking. The majority of patient studies related to patient exposure with only one study on paediatric patients. Automatic patient dose reporting is considered as a first step for dose optimization. Despite efforts, paediatric IP radiation dose data are still scarce. The keynote speakers outlined recent achievements but also challenges in the field. Forecasting technology, task-specific targeted education from educators familiar with the clinical situation, more accurate estimation of lens doses and improved identification of high-risk professional groups are some of the areas they focused on.

CONCLUSIONS

Manufacturers play an important role in making patients safer. Low dose technologies are still expensive and manufacturers should make these affordable in less resourced countries. Automatic patient dose reporting and real-time skin dose map are important for dose optimization. Clinical audit and better QA processes together with more studies on the impact of lens opacities in clinical practice and on paediatric patients are needed.

Recommendations for the configuration of a cardiac catheterisation laboratory for the treatment of children with CHD

A modern catheter laboratory for the treatment of children with CHD should be in close proximity to the paediatric ICU, operating theatres, and imaging facilities. Space requirements and equipment for an up-to-date catheter laboratory are discussed. The document was endorsed by the council of the Association of European Paediatric and Congenital Cardiologists.

Landmark lecture on interventional cardiology: interventional cardiac catheterisation for CHD: the past, present, and the future

CHD affects millions of patients worldwide. Interventional therapies for CHD goes back to the mid-1960s when Bill Rashkind performed balloon atrial septostomy on a cyanotic baby with transposition of the great vessels. This was followed by development of balloon catheters to perform balloon valvuloplasties and angioplasties in the early to late 1980s. Although King and Mills performed the first transcatheter closure of secundum atrial septal defect in the mid-1970s, this procedure was better realised in the mid-1990s. More intracardiac defect closures were performed in the late 1990s and early 2000. This brings us to the current era of percutaneous valve implantation as developed by Bonhoeffer. In this paper, we will discuss the past, present, and future of interventional cardiac catheterisation for CHD patients.

Patient radiation doses in paediatric interventional cardiology procedures: a review

A large number of investigations into the radiation doses from x-ray guided interventional cardiology procedures in children have been carried out in recent years. A review was conducted of these studies, gathering data on kerma area product (P KA), fluoroscopic screening time (FT), air kerma, and estimates of effective dose and organ doses. The majority of studies focus on P KA and FT with no estimation of dose to the patient. A greater than ten-fold variation in average P KA was found between different studies, even where data were stratified by patient age or weight. Typical values of P KA were 0.6-10 Gy · cm2 (<1 year/10 kg), 1.5-30 Gy · cm2 (1-5 years), 2-40 Gy · cm2 (5-10 years), 5-100 Gy · cm2 (10-16 years) and 10-200 Gy · cm2 (>16 years). P KA was lowest for heart biopsy (0.3-10 Gy · cm2 for all ages combined) and atrial septostomy (0.4-4.0 Gy · cm2), and highest for pulmonary artery angioplasty (1.5-35 Gy · cm2) and right ventricular outflow tract dilatation (139 Gy · cm2). Most estimates of patient dose were in the form of effective dose (typically 3-15 mSv) which is of limited usefulness in individualised risk assessment. Few studies estimated organ doses. Despite advances in radiation protection, recent publications have reported surprisingly large doses, as represented by P KA and air kerma. There is little indication of a fall in these dose indicators over the last 15 years. Nor is there much suggestion of a fall in doses associated with the use of flat panel detectors, as opposed to image intensifiers. An assessment of the impact of radiation dose in the context of overall patient outcome is required.

Adult congenital heart disease interventions: recommendations from a joint working group of the British Congenital Cardiac Association, British Cardiovascular Intervention Society, and the British Cardiovascular Society

In order to optimise care of the adult patients with complex congenital heart disease, there is a need to develop recommendations for interventions. This document is the work of representatives of the three relevant societies and provides recommendations for institutions and operators performing cardiac interventions in these patients.

Complications of pediatric cardiac catheterization and system of catheterization laboratories minimizing complications--a Japanese multicenter survey

BACKGROUND

Pediatric cardiac catheterization is sometimes associated with serious complications. However, there are no data regarding the organization of pediatric cardiac catheterization laboratories to minimize complications.

OBJECTIVES

The aim of this study was to determine the current organization of pediatric cardiac catheterization laboratories with regard to patient safety in Japan.

METHODS AND RESULTS

We sent questionnaires to 105 institutions and obtained data from 82. Major complications requiring surgical therapy or death occurred in 22 institutes (27%). The incidence of major complications did not relate to the number of procedures performed. The procedures were performed without written informed consent in 21% of all institutions. The time to inform about the procedures was within 30 min in 43 institutes (52%). A pre-procedure meeting was held in 56 institutions (68%). The anesthetist attended the diagnostic procedures in 23% and the therapeutic procedures in 53%. The drugs and defibrillator for resuscitation were available in almost all institutions, but a pacemaker was not in 23 institutions (28%). The procedures were performed under the "back-up" of cardiovascular surgeons in 38 institutions (46%).

CONCLUSION

There are still large numbers of institutions in Japan, which need much improvement in the organization of pediatric cardiac catheterization laboratories as an aspect of patient safety.

The Role of Cardiac Catheterization in Adult Congenital Heart Disease

The role of heart catheterization continues to evolve as the sophistication of cardiac MRI and CT improves and the breadth of interventional catheter techniques widens. This analysis is approached from four perspectives: (1) planning of the procedure, including information required, potential pitfalls, and equipment; (2) performance of the procedure, including sample run, coronary arteriography, chamber angiography, and angiography of selected lesions; (3) current role of heart catheterization, considering the impact of echo, MRI, and CT on indications for catheterization procedures and current interventional procedures; and (4) new and emerging interventions and speculation as to the future role of diagnostic heart catheterization in patients who have adult congenital heart disease.

Incidents and complications during pediatric cardiac catheterization

BACKGROUND

Cardiac catheterization has revolutionized the management of pediatric cardiac disease. There has been little information on adverse events during these cases from an anesthesia viewpoint. The aim of this audit was to determine the incident rate during pediatric cardiac catheterization as contemporaneously reported by the anesthetist and to identify both the types of events and which procedures had the highest risk.

METHODS

Since 1993, data have been collected prospectively on an audit form for every anesthetic given in our institution, and in-theatre events were recorded on this form. We have reviewed the data collected on pediatric cardiac catheterizations over a period of 9 years.

RESULTS

A total of 4454 cardiac catheterizations were recorded. The overall incidence of events was 9.3%. Cardiac catheterization with occlusion of a patent ductus arteriosus (PDA) or a secundum atrial septal defect (ASD) had the lowest event rate at 4.2%. The figure for cardiac catheterization with other therapeutic interventions was 11.6 and 9.3% for solely diagnostic cardiac catheterization. The event rate in infants under the age of 1 year was 13.9% compared with 6.7% for those children over the age of 1 year. Of the 253 reports from cardiac catheterizations that could be analyzed further, there were 91 major complications including four deaths, 72 minor complications and 90 other incidents.

CONCLUSIONS

Adverse events occur more commonly during cardiac catheterization than during pediatric anesthesia in general. Cases with highest risk are those in the under 1 year olds and those including a therapeutic intervention other than PDA or ASD occlusion.

Complications of paediatric interventional catheterisation: an analysis of risk factors

OBJECTIVES

To identify predictive factors of complications occurring during paediatric interventional catheterisation.

BACKGROUND

Interventional paediatric catheterisation is still burdened by a substantial risk. Risk factors, however, have rarely been investigated.

METHODS

We analysed prospectively 1,022 interventional procedures performed over a period of 8 years, excluding 260 procedures for atrial septostomy. We considered several patient-related variables, specifically age, weight, and gender, type of procedure, times required for fluoroscopy and the overall procedure, technical challenge, and the severity of the clinical condition. We also analysed variables linked to the environment, specifically the date of the examination, whether the operator remained in training, the novelty of the material, any breakdown in the installation, and errors made by the operator. We classified complications as those without clinical consequence, those which proved lethal, those requiring cardiopulmonary resuscitation, elective or emergency surgery, hospitalisation in the intensive care unit, and those leading to recatheterisation.

RESULTS

Our average incidence of complications was 4.1 per cent, which did not change significantly during the period of study. Of the patients, 4 died, 7 needed urgent surgery, 5 elective surgery, 3 hospitalisation in intensive care unit, and 8 recatheterisation. Independent risk factors for complications were technical challenge, critical clinical condition, operator in training, operator error, and breakdown of the installation. Young age was not associated with a higher risk of complications. Patients in whom no cause for complication could be found, either related to their own features or the environment, had a risk of complication of 1.4 per cent (95 per cent confidence intervals from 0.7 to 2.5 per cent).

CONCLUSIONS

Our data show that variables relating either to the patient or the environment of catheterisation are associated with an increased risk of procedural complications. Knowledge of the risk factors can improve the odds of paediatric interventional catheterisation.

Interventional cardiac catheterisation in congenital heart disease

As a result of recent technological advances, more types of congenital heart disease are amenable to treatment in the cardiac catheter laboratory than ever before.1 Improved imaging techniques allow for better selection of patients, and the development of a wide range of devices specifically for use in children means that many patients can avoid surgery altogether, while those with complex congenital heart disease may require fewer or less complex surgical procedures.2 This allows for a quicker recovery and a shorter hospital stay, and gives many patients an improved quality of life in the short to medium term. However, the long term outcome for many of the newer forms of intervention is still unknown.

Proposals for future training in interventional paediatric cardiology

Training in all medical disciplines is currently undergoing a major overhaul. There is a move away from the old concept of training as an apprentice, towards more structured programmes of training. Proposals have recently been made to shorten higher specialist training to 3-4 years, thus producing "generalist" consultants to meet the growing need for service. Advanced subspeciality training can then be undertaken by those with the ability, and desire, to do so following the core training. In the near future, therefore, subspeciality training will need to meet the needs of those undertaking core training, and those wishing to develop a higher degree of expertise. It will have to be focused, to allow skills appropriate to the future practice to be undertaken as a consultant to be developed efficiently. We propose a new scheme for training in interventional paediatric cardiology as a template for subspeciality training. The scheme proposes training at three levels. The first level, basic training, is required of all trainees. Training for the intermediate level will be required for those proposing to carry out diagnostic cardiac catheterisation and basic intervention. Training at the advanced level will be needed by those who wish to carry out a wide range of interventional procedures. A curriculum is proposed for each level, detailing skills that must be attained. Attendance at procedures needs to be driven by the educational needs of the trainee, rather than the requirements of the service. Objective methods are suggested to allow assessment of competence. These should supersede log-books, which document only procedural numbers. Training may be needed for the trainers to ensure that teaching and assessment achieve agreed standards of excellence.

Maternal infant bonding enhanced after atrial septostomy in cyanotic neonates in a general hospital

Seventeen newborns in a general hospital had a successful atrial septostomy when indicated. Mostly done at the bedside under echocardiographical guidance, the successful introduction of this procedure enabled the infants to remain with mother to facilitate feeding and bonding prior to elective transfer to a children's hospital for corrective surgery.

BACKGROUND

Atrial septostomy is a well-recognised intervention in the newborn to facilitate atrial mixing in transposition of the great arteries (TGA) or to decompress an atrium where the connecting AV valve is absent or stenosed, e.g. tricuspid atresia (TA).

AIMS

To review the outcome of this procedure in a general hospital with appropriate neonatal and cardiological facilities.

METHODS

Retrospective review over an 11-year period.

RESULTS

Seventeen inborn infants had successful atrial septostomies, 11 with TGA and 6 with TA. All done under general anaesthesia, 15 were performed in the newborn nurseries, under echocardiographic guidance, and 2 in the catheter laboratory. No complications occurred. Eleven had a prenatal diagnosis made. All infants were able to be subsequently nursed by their mothers, affording prime time facilitating feeding and bonding. They were electively transferred to a children's hospital for corrective surgery.

CONCLUSIONS

Atrial septostomy can be safely performed in a general hospital with appropriate neonatal and cardiological expertise. Such intervention allows for elective transfer of the infant for corrective surgery, allowing the infant and mother to be initially cared for at the one hospital, thereby facilitating maternal contact, feeding and bonding, doing away with the added stress of emergency transfer.