Bioabsorbable Occluder for Outlet VSD: Safety and Aortic Valve Effects

Transcatheter Bioabsorbable Occluder Closure for Outlet Ventricular Septal Defect: Safety, Effectiveness and Impact on Aortic Valve Function

This study aims to evaluate the efficacy and safety of transcatheter bioabsorbable occluder closure in patients with outlet-type ventricular septal defect (outlet VSD), with a focus on assessing its impact on aortic valve function.

Outflow-type ventricular septal defects (outlet VSDs) represent a challenging subset of congenital heart defects due to their association with progressive aortic valve prolapse and regurgitation. While surgical repair remains the gold standard, no reliable occluder has been available for transcatheter closure of this defect subtype.

The anatomical proximity of outlet VSDs to the aortic valve has historically limited transcatheter interventions. Conventional eccentric metal occluders require strict patient selection, typically being feasible only in cases with small defects and minimal aortic valve prolapse. Moreover, long-term concerns persist regarding metal devices' impact on aortic valve function.

Bioabsorbable occluders have been clinically available for perimembranous VSD closure. Their soft material properties minimize mechanical trauma to the aortic valve, while gradual resorption over time may eliminate permanent device-related complications. However, robust data regarding their efficacy, safety, and long-term impact on aortic valve function in outlet VSDs remain lacking.

This study aims to evaluate the short- and long-term outcomes of bioabsorbable occluder closure in outlet VSD patients, with a focus on defect closure rates and aortic valve function preservation.

Inclusion Criteria:

• Age ≥1 year and weight ≥10 kg
• Outlet VSD without ventricular malalignment
• Maximal defect diameter ≤12mm with subaortic rim ≤1mm and no ≥mild aortic regurgitation by by transthoracic or transesophageal echocardiography
• Written informed consent

Exclusion Criteria:

• Outlet VSD with a fibrous postero-inferior rim
• Concurrent cardiac conditions requiring surgical correction
• Severe pulmonary hypertension (PVR > 5 WU, assessed by right heart catheterization )
• Intracardiac thrombus
• Pregnancy
• Active systemic infection within 1 month