A Single-center Clinical Follow-up Study Of Percutaneous Closure Of Atrial Septal Defect Using Absnow^TM Fully Biodegradable Atrial Septal Occlude

Objective:This study reports on a 3-year follow-up of 10 patients with atrial septal defects who were treated with Absnow ^TMfully biodegradable septal occluders,with a focus on the tolerability,biocompatibility,and efficacy in patients.The aim is to evaluate the short-to-midterm safety and effectiveness of the fully biodegradable septal occluder for treating atrial septal defects in children,and to discuss the degradation and action processes of the occluder in the human body.Methods:We collected all data on children with atrial septal defects who underwent Absnow ^TMcompletely biodegradable atrial septal occluder treatment in our hospital from November 2018 to May 2019 and were followed up for three years.This includes all preoperativee clinical and intraoperative data,as well as clinical indicators(including liver and kidney function,myocardial markers,blood routine and transthoracic echocardiography（TTE）,electrocardiography（ECG）,chest X-ray,and other data obtained immediately after occluder implantation,and at postoperative 1 day,1 month,3months,6 months,1 year,2 years,and 3 years.Results:A total of 10 patients were included in the study,with a male-to-female ratio of3:7.The average age was 5.2（3.0～9.5）years,with an average height of 110.5（94～135）cm and an average weight of 17.7（3.0～29.5）kg.The average defect size was14.1（9.0～23.0）mm,and the average surgical time and radiation exposure time were109（80～160）minutes and 10.9（4.5～23.2）minutes,respectively.The immediate success rate of the surgery was 100%（10/10）.The effective closure rates after immediate postoperative,1 day,1 month,3 months,6 months,1 year,2 years,and 3 years were100%,90%,100%,100%,100%,100%,80%,and 80%,respectively.The severe complication rates after 1 year,2 years,and 3 years were 0%,20%,and 20%,respectively.After surgery,the diameters of the right atrium（RA）and right ventricle（RV）decreased on 1 day,1 month,and 3 months and increased after 2 years and 3 years（P<0.05）.The blood flow velocity of the PV（pulmonary vein）decreased significantly at3 months postoperatively compared to preoperative and 1-day postoperative measurements（P<0.05）.Additionally,at 3 months,6 months,and 1 year postoperatively,the PV blood flow velocity was significantly slower compared to preoperative,1-day postoperative,and 1-month postoperative measurements（P<0.05）.During the 3-year follow-up,there were no specific changes in the electrocardiogram（ECG）results such as newonset atrioventricular block,complete bundle branch block,or ectopic tachycardia compared to pre-operation.Chest X-ray showed reduced pulmonary blood flow 6 months and 1 year after the operation,and the occluder was in good position without any abnormal changes such as displacement or detachment.There was no significant difference in the cardiothoracic ratio between before and 6 months and 1 year after the operation（P>0.05）.WBC increased（P<0.05）and PLT decreased significantly（P<0.05）1day after the operation,but there was no statistical difference in WBC and PLT between before and 3 months,6 months,1 year,2 years,and 3 years after the operation.Hb increased 3 months after the operation compared to 1 day after the operation（P<0.05）,and increased compared to before,1 day,3 months,and 6 months after the operation at 1year and 2 years after the operation（P<0.05）.At 3 years after the operation,Hb was significantly increased compared to before and 1 day after the operation（P<0.05）.N%increased at 1 day,3 months,6 months,2 years,and 3 years after the operation compared to before（P<0.05）.CK-MB decreased 3 years after the operation compared to before（P<0.05）,while there was no statistical difference at other follow-up points compared to before.LDH increased 3 months after the operation compared to before（P<0.05）,and decreased at 6 months,2 years,and 3 years after the operation compared to 3 months after the operation（P<0.05）.LDH decreased at 2 years after the operation compared to 6months after the operation（P<0.05）.Tn I remained at a low level before and after the operation.There was no statistical difference in BUN,ALT,and Scr before and after the operation at each follow-up point（P>0.05）.AST decreased at 2 years and 3 years after the operation compared to 3 months after the operation（P>0.05）.No serious complications such as occluder detachment,high-degree atrioventricular block,refractory headache or migraine,cardiac tamponade,or vascular complications occurred during the 3-year follow-up.However,severe complications（significant residual shunting）occurred in patients 2 and 5 due to occluder degradation and umbrella disc displacement,and they received additional interventional treatment.Conclusion:This study further confirms the short-to-midterm safety and acceptable effectiveness of the Absnow ^TMfully biodegradable atrial septal defect occluder for the trea ^TMent of atrial septal defects during a 3-year follow-up period.However,it should be noted that newly developed residual shunts have a significant impact on its long-term efficacy.Further research and improvement are needed to control the degradation rate of the biodegradable occluder,accelerate its endothelialization,and ensure its tight adherence to the septal structure after implantation.Large-scale multicenter studies are still needed to further evaluate the safety and efficacy of the Absnow ^TMfully biodegradable atrial septal defect occluder.