Evidence from clinical trials on high-risk medical devices in children: a scoping review

BACKGROUND

Meeting increased regulatory requirements for clinical evaluation of medical devices marketed in Europe in accordance with the Medical Device Regulation (EU 2017/745) is challenging, particularly for high-risk devices used in children.

METHODS

Within the CORE-MD project, we performed a scoping review on evidence from clinical trials investigating high-risk paediatric medical devices used in paediatric cardiology, diabetology, orthopaedics and surgery, in patients aged 0-21 years. We searched Medline and Embase from 1st January 2017 to 9th November 2022.

RESULTS

From 1692 records screened, 99 trials were included. Most were multicentre studies performed in North America and Europe that mainly had evaluated medical devices from the specialty of diabetology. Most had enrolled adolescents and 39% of trials included both children and adults. Randomized controlled trials accounted for 38% of the sample. Other frequently used designs were before-after studies (21%) and crossover trials (20%). Included trials were mainly small, with a sample size <100 participants in 64% of the studies. Most frequently assessed outcomes were efficacy and effectiveness as well as safety.

CONCLUSION

Within the assessed sample, clinical trials on high-risk medical devices in children were of various designs, often lacked a concurrent control group, and recruited few infants and young children.

IMPACT

In the assessed sample, clinical trials on high-risk medical devices in children were mainly small, with variable study designs (often without concurrent control), and they mostly enrolled adolescents. We provide a systematic summary of methodologies applied in clinical trials of medical devices in the paediatric population, reflecting obstacles in this research area that make it challenging to conduct adequately powered randomized controlled trials. In view of changing European regulations and related concerns about shortages of high-risk medical devices for children, our findings may assist competent authorities in setting realistic requirements for the evidence level to support device conformity certification.

FAST technique: fast atrial sheath traction technique for device closure of atrial septal defects

Background

Transcatheter closure of atrial septal defects (ASDs) is well-established. However, this procedure can be challenging, requiring multiple attempts and advanced implantation maneuvers.

Materials and methods

From July 2019 to July 2022, patients to whom the fast atrial sheath traction (FAST) technique was applied for ASD device closure were prospectively followed up. The device was rapidly unsheathed in the middle of the left atrium (LA) to let it clamp the ASD from both sides simultaneously. This novel technique was directly applied in patients with absent aortic rims and/or ASD size-to-body weight ratio higher than 0.9 or after failed attempts of standard implantation.

Results

Seventeen patients (64.7% males) were involved with a median age of 9.8 years [interquartile range (IQR), 7.6-15.1] and a median weight of 34 kg (IQR, 22-44). The median ASD size on ultrasound was 19 mm (IQR, 16-22). Five (29.4%) patients had absent aortic rims, and three (17.6%) patients had an ASD size-to-body weight ratio higher than 0.9. The median device size was 22 mm (IQR, 17-24). The median difference between device size and ASD two-dimensional static diameter was 3 mm (IQR, 1-3). All interventions were straightforward without any complications using three different occluder devices. One device was removed before release and upsized to the next size. The median fluoroscopy time was 4.1 min (IQR, 3.6-4.6). All patients were discharged the next postoperative day. On a median follow-up of 13 months (IQR, 8-13), no complications were detected. All patients achieved full clinical recovery with complete shunt closure.

Conclusion

We present a new implantation technique to efficiently close simple and complex ASDs. The FAST technique can be of benefit in overcoming left disc malalignment to the septum in defects with absent aortic rims and in avoiding complex implantation maneuvers and the risks of injuring the pulmonary veins.

Comparative effectiveness of devices for transcatheter closure of atrial septal defects: Systematic review and network meta-analysis

Atrial septal defect is a common congenital heart disease, producing a left-to-right shunt in the atrial septum; the current preferred treatment is transcatheter device closure. The aim is to conduct a systematic review to synthesize information on the comparative effectiveness and safety of atrial septal defect closure devices. The methods used: a comprehensive search of Ovid MEDLINE®, Embase, and Cochrane Central databases was conducted. Studies comparing procedural and follow-up outcomes of atrial septal defect devices were included. Network meta-analyses were conducted to generate direct and indirect evidence for comparative effectiveness and safety outcomes between devices. The results are as follows: Twelve studies met our inclusion criteria and were compared in network meta-analyses. The meta-analyses evaluated contemporary devices: the AMPLATZER Septal Occluder; the GORE CARDIOFORM Septal Occluder; the Figulla Flexible II Occluder; the CeraFlex Septal Occluder; and the HELEX Septal Occluder. These studies represented 3998 patients. The primary safety and efficacy outcomes were device embolization and follow-up residual shunt, respectively. Secondary clinical outcomes included procedural success and major and minor complications. No differences were found between devices in terms of device embolization and secondary clinical outcomes. Follow-up residual shunt was higher with the HELEX Septal Occluder compared with the AMPLATZER Septal Occluder (odds ratio 2.92, 95% confidence interval 1.12-7.61). To conclude: although most outcomes were similar between devices, evidence was largely based on observational low-quality studies. There were inconsistencies in outcome reporting and definitions; this merits future studies, with head-to-head device comparisons and standardization of outcomes.

Cobra-head and other shape-memory abnormalities of nitinol atrial septal occluders: incidence, predisposing factors, and outcomes

BACKGROUND

Shape-memory abnormalities are seen in some nitinol atrial septal occluders. Variably described as cobra-head, tulip, and others, their incidence, mechanisms, clinical impact, and outcome have not been systematically analysed.

METHODS

We retrospectively reviewed all consecutive device closures in the last 6 years for deformations. Type and size of the occluder, deployment technique, size, and angulation/kinking of the delivery sheath were analysed. Procedural success, duration, and other complications were studied.

RESULTS

A total of 112 devices (11.8%) among 950 occluders used in 936 patients showed deformities. Fourteen of 936 received 2 devices. Deformities were transient and self-correcting in 40%. Multivariate analysis showed significant associations with oversized sheaths (p = 0.004), kinked/angulated sheaths (p < 0.001), special deployment techniques (p < 0.001), and twist in the device waist (p = 0.011). Despite more frequent deformities with Figulla (15.6%) and Amplatzer (13.9%) occluders than Cera occluders (6.6%) and larger devices (>24 mm - 14.6%) than smaller devices (less than or equal to 24 mm - 9.7%), they were not significant on multivariate analysis. In vivo manipulations corrected most deformities; nineteen needed in vitro reformations and four needed a change of device. Despite prolongation of the procedure, repeated attempts (mean 2.76 ± 1.7 attempts, with a range from 1 to 9 attempts), and supraventricular tachycardia in two patients, there were no serious adverse effects.

CONCLUSIONS

Deformations were frequent in 11.8% of atrial septal occluders on a targeted search. Oversized and angulated/kinked sheaths, special techniques like pulmonary vein deployment and twist in device waist during procedure predisposed to deformities. While most deformities were corrected with manipulations, removal of the device was infrequently needed and change of device was rarely required. Long procedural time and multiple attempts for deployment did not affect procedural success.

The first described case of late infective endocarditis after implantation of Figulla Flex Ⅱ ASD occluder

Infective endocarditis is one of the complications following the percutaneous occlusion of an atrial septal defect (ASD) with a closure device. To the best of our knowledge, no case reports have been published of infective endocarditis associated with the Figulla Flex Ⅱ ASD occluder (FSO; Occlutech GmbH, Jena, Germany). We present the case of a 50-year-old woman who underwent a transcatheter closure of an ASD with FSO almost 2 years prior to presentation to our institution. Echocardiography showed a mobile vegetation (20 × 10 mm), and her blood culture grew β-hemolytic streptococci. Magnetic resonance imaging revealed acute cerebral infarction. Those findings were diagnosed as late infective endocarditis associated with the ASD closure device. The patient was treated with antibiotics and underwent surgical removal of the FSO, which showed incomplete endothelialization, and surgical repair of ASD. After surgery, the patient made a complete recovery without complications or residual shunts. This case highlights the risk of late infective endocarditis in patients after closure of ASD with an FSO with incomplete endothelialization. <Learning objective: Endothelialization of Figulla Flex Ⅱ ASD occluder (FSO) devices is presumed to be complete within 3 to 6 months. However, some patients have presented with poor endothelialization of the device. In patients who undergo percutaneous atrial septal defect closure with an FSO, delayed endothelialization of the device could be a risk for late infective endocarditis. We suggest the need to be aware of the onset of late infective endocarditis even after 6 months after placement of an FSO.>.

Preliminary Experience With the New Amplatzer™ Trevisio™ Delivery System in Transcatheter Atrial Septal Defect Closures in Children

Objectives: To evaluate safety, efficacy, and technical advantages of Amplatzer™ Trevisio™ intravascular delivery system (ATIDS) in percutaneous atrial septal defect (ASD) closure in children. Background: The Trevisio™ is a novel delivery system designed for accurate and facilitated implantation of Amplatzer™ devices. There are no published clinical reports so far. Methods: During September 2020, 9 children with anatomically challenging ASDs underwent attempted transcatheter closure using ATIDS to deliver Amplatzer™ Septal occluders (ASO). All interventions were performed under general anesthesia, trans-esophageal echocardiography (TOE), and fluoroscopic guidance. Standard safety, immediate, and 60-days outcomes were prospectively assessed. Results: The median age was 8.1 (5.1-16.9) years and the median bodyweight was 30 (18-63) kg. Six patients had isolated secundum-type ASDs with absent anterosuperior rims including one with an aneurysmal septum. Three patients had unclassical defects associated with complex congenital heart anomalies. Eight devices were delivered from the femoral vein and the jugular vein was accessed in one patient with interrupted inferior caval vein and azygos continuation. All implantations were successful. The shape, position, and orientation of the ASO were identical before and after release on TOE and fluoroscopy. There was no device embolization or serious complication following closure. Complete shunt closure was confirmed on follow-up. Conclusions: We report the first clinical experience with ATIDS in transcatheter ASD pediatric closures. Safety and efficacy were witnessed in our case-series. The major advantage of reduced-tension deployment and reliable precision in device positioning is highly beneficial in challenging anatomies and unusual access.