Initial Clinical Experience with the Biodegradable Absnow(TM) Device for Percutaneous Closure of Atrial Septal Defect: A 3-Year Follow-Up

OBJECTIVE: We reported the 3-year follow-up results of initial clinical experience with the Absnow(TM) device, a novel biodegradable occluder for percutaneous closure of atrial septal defect (ASD). BACKGROUND: The Absnow(TM) device is a total biodegradable septal occluder with double-disc poly-L-lactic acid (PLLA) framework and PLLA membranes intergraded into the device to ensure its biodegradability, clinical safety, and efficacy. METHODS: Five pediatric patients were enrolled from May to June 2018 in our institution and were followed up for 3 years. A clinical evaluation and transthoracic echocardiography were performed at 24 hr, 1 month, 3 months, 6 months, 12 months, and yearly after implantation. Primary endpoints were a composite clinical success, comprising of clinical closure success and safety at the 36-month follow-up evaluation. Secondary endpoints included technical success, procedure success, closure success, and safety at each of the follow-up visits. RESULTS: The median subject age was 3.6 years (range 3.1–6.5 years). The mean ASD diameter was (13.7 ± 2.9) mm. The median device size was 20 mm (range 14 to 24 mm). Technical and procedure success was achieved in 100% (5/5) of the patients. At 2-year follow-up, 3 of the 5 patients developed new-onset residual shunts and 2 of them reached a moderate degree. At 3-year follow-up, the residual shunt size increased over time in all the 3 patients, and 1 of them had right ventricular enlargement. All of the 5 patients were free from serious adverse events during the 3-year follow-up, with no device embolization, thromboembolization, or reintervention to the target defect. CONCLUSION: This 3-year follow-up result of initial experience with the biodegradable Absnow(TM) device has demonstrated acceptable safety with no procedural complications. Notably, the high rate of residual shunt significantly affected its efficacy. The long-term safety and efficacy of the device should be further evaluated in a large cohort of patients in future studies.