Is a significant 6-8 mm Ventricular Septal Defect (VSD) with left to right shunt indicated for device closure, and what are the alternatives if a device or delivery system is not available?

VSD Device Closure for 6-8 mm Defect with Left-to-Right Shunt

A 6-8 mm VSD with significant left-to-right shunt is indicated for closure when hemodynamic criteria are met (Qp:Qs ≥1.5:1 with evidence of left ventricular volume overload), and surgical closure is the preferred method, though device closure may be considered for muscular VSDs in specific anatomic situations. 1

Primary Indication Assessment

The most critical determination is whether your patient meets hemodynamic thresholds for closure:

Class I Indication (Strongest Recommendation)

• Closure is definitively indicated when Qp:Qs ≥1.5:1 with evidence of left ventricular volume overload, PA systolic pressure <50% systemic, and pulmonary vascular resistance <1/3 systemic. 1
• An alternative Class I threshold is Qp:Qs ≥2.0 with clinical evidence of LV volume overload. 1

Class IIa Indication (Reasonable to Proceed)

• Closure is reasonable when Qp:Qs >1.5:1 with PA pressure <2/3 systemic and PVR <2/3 systemic, particularly if LV systolic or diastolic dysfunction is present. 1

Surgical vs. Device Closure Decision Algorithm

Surgical Closure (Standard Approach)

• All VSD closures should be performed by surgeons with training and expertise in congenital heart disease. 1
• Surgical patch closure (typically Dacron or Gore-Tex) is the standard approach for perimembranous VSDs, which represent the majority of cases. 1

Device Closure Considerations

• Device closure of muscular VSDs may be considered (Class IIb) when the defect is remote from the tricuspid valve and aorta, especially with severe left-sided chamber enlargement or pulmonary hypertension. 1
• The 2008 ACC/AHA guidelines specifically note that device closure is appropriate for residual defects after prior surgical attempts, restrictive VSDs with significant shunts, or iatrogenic defects post-aortic valve replacement. 1

When Device Closure is NOT Available: Surgical Alternatives

If device closure is unavailable or contraindicated, proceed with:

• Standard surgical patch closure via cardiopulmonary bypass using synthetic material (Dacron or polytetrafluoroethylene). 1
• Intraoperative transesophageal echocardiography is essential to identify additional muscular VSDs that may only manifest after closure of the dominant defect. 1

Critical Contraindications to Any Closure

VSD closure should NOT be performed when: 1

• PA systolic pressure >2/3 systemic
• Pulmonary vascular resistance >2/3 systemic
• Net right-to-left shunt is present (Eisenmenger physiology)

These patients have severe irreversible pulmonary arterial hypertension, and closure will cause acute right ventricular failure and death. 1

Special Clinical Scenarios Favoring Closure

Beyond hemodynamic criteria, closure is indicated for:

• History of infective endocarditis caused by the VSD (Class I indication). 1
• Worsening aortic regurgitation caused by perimembranous or supracristal VSD (Class IIa for surgical closure). 1

Device-Specific Evidence for 6-8 mm VSDs

Research data supports device closure for this size range:

• A 10-year retrospective study showed 97% successful device implantation in adult VSDs with median size 6 mm, with 71% immediate complete closure and marked symptom improvement in 64% of symptomatic patients. 2
• Amplatzer Duct Occluder II devices have been successfully used for perimembranous VSDs up to 6 mm with no atrioventricular block during mean 2.5-year follow-up. 3
• However, the evidence notes that device closure is technically more challenging for perimembranous defects near cardiac valves compared to muscular defects. 2, 4

Critical Pitfalls to Avoid

• Do not underestimate defect size: Underestimation led to treatment failure and death in one surgical series using intraoperative devices. 5
• Assess for multiple VSDs: Additional muscular defects may only become apparent after closure of the dominant defect. 1
• Monitor for complete heart block: This complication can occur months after device closure, particularly with perimembranous defects, requiring permanent pacemaker placement. 3, 6
• Exclude aortic valve prolapse: Small VSDs with aortic valve involvement may develop progressive aortic regurgitation requiring intervention. 1

Follow-Up Requirements

• Patients undergoing device closure require follow-up every 1-2 years at an Adult Congenital Heart Disease (ACHD) center. 1
• Those with residual shunts, heart failure, PAH, or valvular complications require annual ACHD center evaluation. 1