Surgical Indications for Subaortic VSD with Right Coronary Cusp Prolapse
Surgery should be performed promptly when right coronary cusp (RCC) prolapse is detected in subaortic VSD, regardless of the presence or severity of aortic regurgitation, to prevent life-threatening complications including progressive aortic regurgitation, infective endocarditis, and aneurysm rupture. 1
Immediate Surgical Indications
Presence of RCC Prolapse Alone
The European Society of Cardiology recommends surgical closure for closed (aneurysmal) perimembranous VSD to prevent life-threatening complications even in asymptomatic patients. 1 This applies when RCC prolapse is identified, as the prolapse itself represents a high-risk anatomic deformity.
The American College of Cardiology specifically recommends surgery for patients with VSD-associated prolapse of an aortic valve cusp causing progressive aortic regurgitation. 1
When Any Degree of Aortic Regurgitation Exists
Surgical closure is reasonable when worsening aortic regurgitation is caused by the VSD, regardless of hemodynamic significance. 2 This represents a Class IIa recommendation from the 2018 ACC/AHA guidelines.
Research demonstrates that among patients with mild AR and RCC prolapse, small patch closure improves AR in 79% of cases (15 of 19 patients), whereas direct closure shows significantly worse outcomes. 3
Hemodynamic Indications (Standard VSD Criteria Still Apply)
Mandatory Surgery
- Qp:Qs ≥2.0 with clinical evidence of LV volume overload 2
- Qp:Qs ≥1.5 with evidence of LV systolic or diastolic failure 2
- PA systolic pressure <50% of systemic pressure AND pulmonary vascular resistance <1/3 systemic resistance when Qp:Qs ≥1.5 2
Additional High-Risk Features
- History of infective endocarditis (13.7% of patients with perimembranous VSD experience bacterial endocarditis, representing a 6-fold increased risk) 1
- Progressive LV enlargement on serial echocardiography 4
Timing Considerations Based on Age and Defect Size
Early Intervention Preferred
Subaortic VSDs ≥5mm should be closed as early as possible to prevent development of aortic cusp prolapse and AR. 5 Research shows that at 5,10, and 15 years of age, the prevalence of aortic cusp prolapse reaches 30%, 64%, and 83% respectively in conservatively managed patients. 5
Children operated before age 5 years with clinical AR show better outcomes: 50% become regurgitant-free and 25% have only trivial AR postoperatively. 4
For children older than 5 years with clinical AR, 57% become regurgitant-free but outcomes are less favorable than earlier intervention. 4
Small Defects (<5mm) Without Prolapse
- Conservative management is acceptable for asymptomatic patients with small perimembranous VSDs <5mm who have not yet developed cusp prolapse. 5
- However, once RCC prolapse develops, even with small defects, surgery is indicated to prevent progression. 6
Absolute Contraindications to Surgery
Severe Pulmonary Vascular Disease
VSD closure should not be performed when PA systolic pressure exceeds 2/3 systemic AND pulmonary vascular resistance exceeds 2/3 systemic. 2, 7
Surgery is contraindicated in Eisenmenger syndrome with exercise-induced desaturation and net right-to-left shunt. 2, 1
Mortality approaches 100% in patients with non-reactive pulmonary vascular disease who undergo closure. 7
Critical Diagnostic Requirements Before Surgery
Echocardiographic Assessment Must Document
- Location, number, and size of VSD 1
- Presence and extent of aneurysmal tissue 1
- Aortic valve morphology and degree of prolapse (specifically which cusp is affected) 1
- Severity of aortic regurgitation using color Doppler 1
- LV volume overload and systolic/diastolic function 1
- Pulmonary artery pressure estimation 1
Cardiac Catheterization Indications
- Required when pulmonary hypertension is suspected to assess operability 2
- Useful when noninvasive data are inconclusive regarding hemodynamics 2
Surgical Technique Considerations
Patch Closure Preferred Over Direct Closure
Small patch closure is significantly safer and more reliable in improving mild AR compared to direct closure (p<0.05). 3
Direct closure in patients with mild preoperative AR results in AR aggravation in 17% (2 of 12 patients) requiring reoperation. 3
Patch closure diminishes AR in 79% of patients with mild preoperative AR versus only 33% with direct closure. 3
Concomitant Aortic Valve Procedures
- Aortic valvuloplasty should be performed when significant cusp deformity or moderate-to-severe AR exists. 4, 6
- Valve replacement is reserved for severe AI in adults where repair is not feasible. 8
Common Pitfalls to Avoid
Do not delay surgery waiting for AR to become "severe enough" - once RCC prolapse develops, progressive valve damage is inevitable and early intervention prevents irreversible cusp deformity. 1, 5
Do not assume small VSDs are safe to observe - defects ≥5mm have nearly universal development of cusp prolapse by adolescence. 5
Do not proceed with surgery in cardiogenic shock within 72 hours - mechanical circulatory support should stabilize the patient first, as immediate surgery carries 100% mortality. 7
Do not underestimate infective endocarditis risk - this occurs in up to 2 per 1000 patient-years even with small residual VSDs. 7