Objective To assessment of the echogenicity of the ultrasound-guided catheter and its associated delivery system. Methods The study consisted of in vitro characterization experiments and animal studies. In the in vitro phase, the acoustic and mechanical properties of the ultrasound-guided catheter were compared with those of the traditional MPA2 catheter, including parameters such as echo intensity, recognizability, and angle dependence. In the animal experiments, a ventricular septal defect (VSD) model was established in miniature pigs to compare the procedural performance of the ultrasound-guided delivery system versus the conventional system. Evaluation indicators included the time required for the system to cross the VSD, the detection rate of the system within the right ventricle, and the occurrence of intraoperative complications. Results The ultrasound-guided catheter demonstrated a significantly higher mean echo intensity than the MPA2 catheter[ (237.3±1.8) dB vs. (190.9±13.1) dB, P<0.001] and a markedly improved recognizability rate (82.3%±5.6% vs. 26.7±3.2%, P<0.001), along with better angle independence and image quality. In animal experiments, the ultrasound-guided delivery system significantly reduced the time required to cross the VSD (18.5±5.7 min vs. 30.3±4.5 min, P<0.001) and substantially increased the detection rate within the right ventricle (100% vs. 30%). No severe complications occurred in any experimental animal. Conclusion The ultrasound-guided catheter and its corresponding delivery system exhibited superior ultrasound visibility and operational performance in both in vitro and animal experiments, indicating strong potential for clinical application.
Currently, transcatheter intervention is the preferred treatment for patients with anatomically suitable atrial septal defects. However, the use of nickel-titanium alloy occluders in interventional procedures results in lifelong presence of the implant in the body, leading to complications such as metal allergies and arrhythmias in some patients. To overcome the short-term and long-term complications associated with the presence of metal, and to avoid radiation exposure and metal toxicity, this paper reports a case of successful transcatheter closure of atrial septal defect in a pediatric patient with metal allergies using fully biodegradable occlude under ultrasound guidance, achieving excellent results by interventional therapy.