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.
Study Type
OBSERVATIONAL
Enrollment
50
Transcatheter closure of outlet ventricular septal defects using a bioabsorbable occluder (Shape Memory Alloy Ltd, Shanghai, China). Implantation is performed via femoral/transthoracic approach under echocardiographic guidance following standard interventional protocols.
The First Affiliated Hospital of Guangxi Medical University
Nanning, Guangxi, China
Number of participants with procedural success
1. Occluder in correct anatomical position 2. Absence of major adverse events (all-cause mortality, all stroke, myocardial infarction, or re-hospitalization for device/procedure-related causes) 3) Residual shunt ≤ 2 mm and aortic regurgitation ≤ trace evaluated by transthoracic or transesophageal echocardiography
Time frame: 12 months
Number of participants with technical success
Absence of mortality, correct positioning of the occluder into the proper anatomical location， aortic regurgitation≤ trace by transthoracic or transesophageal echocardiography
Time frame: Intraprocedural
Number of participants with major adverse events
All-cause mortality, all stroke, myocardial infarction, re-hospitalization for device or procedure-related causes
Time frame: 12/24/60 months
Closure Efficacy
1）Successful closure: Rate of successful VSD closure (residual shunt ≤2 mm) assessed by transthoracic or transesophageal echocardiography. 2\) Complete closure: Rate of complete closure (no residual shunt) assessed by transthoracic or transesophageal echocardiography.
Time frame: Intraprocedural, 72 hours post procedure, 1/3/6/12/24/60 months
Aortic regurgitation severity
Aortic regurgitation severity measured by transthoracic and/or transesophageal echocardiography. Assessment of aortic regurgitation severity according to current recommendations for valvular heart disease.
Time frame: Baseline, Intraprocedural, 72 hours post procedure, 1/3/6/12/24/60 months
Pulmonary regurgitation severity
Pulmonary regurgitation severity measured by transthoracic and/or transesophageal echocardiography. Assessment of pulmonary regurgitation severity according to current recommendations for valvular heart disease.
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Time frame: Baseline, Intraprocedural, 72 hours post procedure, 1/3/6/12/24/60 months
Left ventricular outflow tract (LVOT) velocity and pressure gradient
Peak LVOT velocity (m/s) and maximum instantaneous pressure gradient (mmHg) measured by continuous-wave Doppler (CWD) echocardiography, using the simplified Bernoulli equation (ΔP = 4v²).
Time frame: Baseline, Intraprocedural, 72 hours post procedure, 1/3/6/12/24/60 months
Right ventricular outflow tract （RVOT）velocity and pressure gradient
Peak LVOT velocity (m/s) and maximum instantaneous pressure gradient (mmHg) measured by continuous-wave Doppler (CWD) echocardiography, using the simplified Bernoulli equation (ΔP = 4v²).
Time frame: Baseline, Intraprocedural, 72 hours post procedure, 1/3/6/12/24/60 months
Disc area quantification
Left and right disc areas are measured by transthoracic echocardiography (TTE) planimetry in parasternal short-axis (PSAX), apical long-axis (ALAX), and apical 5-chamber (A5C) views using QLAB 3DQ Advanced software (Philips). The mean disc area is derived from the average of three orthogonal transthoracic echocardiography measurements.
Time frame: 72 hours post procedure, 1/3/6/12/24/60 months