Feasibility and short-term outcomes of transcatheter closure of moderate-to-large perimembranous ventricular septal defects in children using bioabsorbable occluders: a prospective case series

Objectives: Transcatheter closure has become an important treatment modality for perimembranous ventricular septal defects (pmVSDs). However, conventional metallic occluders carry the risk of long-term complications. Fully bioabsorbable occluders offer a potential solution, yet their application in children with moderate-to-large pmVSDs remains under-reported. This study evaluated the feasibility and 1-year outcomes of transthoracic, transesophageal echocardiography (TEE)-guided implantation of a bioabsorbable occluder via a small subxiphoid incision in children with moderate-to-large pmVSDs. Methods: Children aged ≥1 year with moderate-to-large pmVSDs (defined as left ventricular defect diameter exceeding one-third of the aortic root diameter) who underwent TEE-guided transthoracic device closure using a bioabsorbable occluder between July 2024 and January 2025 were prospectively enrolled. Baseline characteristics, procedural data, and follow-up outcomes at 1, 3, 6, and 12 months were collected. The primary endpoints were technical success, valvular function, conduction disturbance, and occluder degradation. Results: Five children (mean age 2.4 ± 1.7 years; mean weight 12.6 ± 4.6 kg; mean defect diameter 8.8 ± 2.6 mm) were included. All implants were successful (technical success 100%). One patient with a multi-fenestrated defect had a 2 mm residual shunt immediately post-procedure, which resolved by 6 months. At 1 year, no patient developed new-onset or worsening aortic regurgitation (AR) or tricuspid regurgitation (TR), and none had complete atrioventricular block (cAVB). Quantitative echocardiographic analysis showed that occluder disc area decreased substantially at 1 year, indicating progressive absorption. Conclusions: TEE-guided transthoracic closure of moderate-to-large pmVSDs using a bioabsorbable occluder appears feasible in selected children. One-year follow-up data suggest favorable preservation of valvular and conduction function, with progressive occluder degradation. This approach may offer a minimally invasive alternative to surgery for this challenging population, although larger studies are warranted.