Safety, effectiveness, and complications of the first-in-human minimally invasive transthoracic ventricular septal defect closure using a bioabsorbable occluder: a cohort study with 12-month follow-up.

Background: Ventricular septal defect (VSD) is one of the most common congenital heart diseases. This study aims to evaluate the clinical value and benefit of transesophageal echocardiography (TEE) in transthoracic minimally invasive closure of VSDs using a completely biodegradable occluders, summarize the main points of surgical procedures, and analyze the follow-up results of short-term and medium-term treatment. Methods: We conducted a retrospective analysis of 24 pediatric cases of VSD, successfully treated with TEE-guided minimally invasive closure using fully biodegradable occluders between June 2019 and June 2022. The preoperative TEE meticulously examined the defect's location, size, and surrounding anatomical relationships, aiding in the selection of appropriate occluders and guiding the entire closure process. All patients were followed up for 1 year. Results: In our cohort, 13 cases were perimembranous inlet VSDs, and 11 involved VSDs with membranous aneurysm formation. The effective shunt size of VSD measured by TEE preoperatively ranged from 2.8 to 4.9 mm, with the defect located 2-6 mm from the aortic valve. Occluders used were 6-8 mm in diameter. All 24 procedures were successful. TEE confirmed that the occluders were tightly fitted at the edges of the VSDs. Twenty-three cases had no residual shunt post-surgery, while one case exhibited a small left-to-right shunt (<1.5 mm) at the occluder's edge. Follow-up was conducted on postoperative day 3, and in months 1, 3, 6, and 12, showing that the occluder's position remained normal in all patients. Except for one child who had a 1.2 mm left-to-right shunt at the edge of the occluder, no residual shunts were observed in the others. The occluder started to degrade from month 6, and the sizes of the left and right occluder discs were significantly smaller compared to those on postoperative day 3 (P=0.003). Conclusions: TEE-guided minimally invasive VSD occlusion using fully biodegradable occluders has the advantages of minimal trauma, high safety, and few complications, with satisfactory recent efficacy, and good prospects for clinical safety applications.