VSD and mitral regurgitation: why closure alone is often sufficient

The dilemma of mitral regurgitation during VSD closure

Facing a large ventricular septal defect (VSD), the pediatric cardiac surgeon frequently encounters mitral valve annulus dilation induced by volume overload, generating concomitant mitral regurgitation (MR). The central question remains: is the simple suppression of the shunt sufficient to correct this functional MR, or is mitral valvuloplasty imperative to avoid long-term degradation?

To clarify this decision-making knot, this retrospective study analyzed 30 patients presenting with at least moderate MI, selected from a cohort of 1524 VSD closures performed between 2004 and 2024. The studied population consists of particularly young infants, with a median age of 5.4 months and a weight of 5.6 kg at the time of surgery. The specific objective was to evaluate the impact of the surgical procedure on mitral valve-related events and the serial evolution of its function over a median follow-up of 6.7 years.

The study is based on the hypothesis that while isolated VSD closure reduces functional MI in the majority of cases, structural valve abnormalities (notably Carpentier type IIIa) and preoperative severity constitute major risk factors for progression toward valve replacement surgery.

Methodology: analysis of a surgical cohort over two decades

This retrospective study focused on a global cohort of 1524 patients who underwent ventricular septal defect (VSD) closure between 2004 and 2024. The authors selected 30 patients presenting with preoperative mitral regurgitation (MR) qualified as moderate or severe. At the time of the procedure, the median age of the subjects was 5.4 months with a median weight of 5.6 kg.

Patients were divided into two distinct groups according to the surgical strategy adopted:

• Isolated VSD closure group (n=14): including 13 patients with moderate MI and 1 patient with severe MI.
• Combined surgery group (n=16): combining VSD closure with concomitant mitral valvuloplasty, including 12 patients with moderate MR and 4 patients with severe MR.

The primary endpoint was the occurrence of long-term mitral valve-related events, while the secondary endpoint focused on the serial evolution of valvular function. Median follow-up extended over 6.7 years. Risk analysis specifically integrated preoperative MI severity and Carpentier's structural classification (notably type IIIa) as predictive variables for regurgitation progression and the need for reoperation.

Evolution of mitral regurgitation after VSD closure

In a cohort of 1524 patients who underwent ventricular septal defect (VSD) closure between 2004 and 2024, 30 presented with moderate or severe preoperative mitral regurgitation (MR). The median age at the time of surgery was 5.4 months with a median weight of 5.6 kg. Patients were followed over a median period of 6.7 years.

Comparison of clinical outcomes by group

The study distinguishes between two surgical approaches: VSD closure alone (n=14) and closure combined with concomitant mitral valvuloplasty (n=16).

Tracking parameters	Fermeture CIV seule (n=14)	Closure + Valvuloplasty (n=16)
Preoperative MI (Moderate / Severe)	13 / 1	12 / 4
MI at follow-up (≤ Mild)	12	10
Moderate MI follow-up	1	3
Follow-up (Severe)	0	2
Reoperation (Valve replacement)	0	3

In the "VSD alone" group, almost all patients (12 out of 13 evaluable) saw their MR reduced to a mild stage or lower, without any need for reintervention. Conversely, the group that underwent valvuloplasty showed more heterogeneous results, with three cases of subsequent mitral valve replacement.

Freedom of reoperation and risk factors

The overall rate of freedom from reoperation for the entire cohort is as follows:

• At 1 year: 96.3%
• At 5 years: 87.3%
• At 10 years: 87.3%

Data analysis identifies two critical predictors of mitral regurgitation progression and surgical failure. Initial MR severity and the presence of a Carpentier type IIIa structural abnormality constitute the main risk factors for long-term reoperation. These results suggest that while VSD closure alone effectively resolves functional MR related to volume overload, structural (organic) involvement exposes the patient to a risk of initial repair failure.

Clinical analysis and impact on patient management

The data from this 20-year cohort provide crucial insight into the surgical dilemma surrounding mitral regurgitation (MR) associated with a VSD. The results demonstrate that for the majority of patients presenting with moderate MR, isolated shunt closure is sufficient to restore valvular competence. This finding clinically confirms that pediatric functional MR is primarily a volume overload pathology: once ventricular volume is normalized, the mitral annulus retracts and the regurgitation resolves.

However, the study identifies a clear risk threshold: structural MR, and particularly Carpentier type IIIa, does not follow this trajectory of spontaneous resolution. These patients present a significantly higher risk of regurgitation progression and reoperation. The fact that three patients in the valvuloplasty group ultimately required valve replacement serves as a reminder of the technical complexity and the limitations of organic repairs in infants.

Although the overall cohort is large (1524 patients), the main limitation lies in the small size of the subgroup presenting with moderate to severe MR (n=30), which may limit the statistical power of the predictive factors. Nevertheless, the implication for the surgeon is immediate: moderate MR on a normal valve can be observed after VSD closure, while a structural abnormality or severe preoperative MR requires an aggressive mitral repair strategy from the initial intervention.

Summary of results

This 20-year retrospective study shows that isolated VSD closure resolves functional mitral regurgitation (MR) in the majority of cases, with regression to minimal leakage in 12 out of 14 patients. Conversely, structural MR, particularly Carpentier type IIIa, presents a high risk of progression, showing a freedom from reoperation rate of 87.3% at 10 years and sometimes requiring mitral valve replacement (3 cases observed).

In concrete terms, for the practitioner:

• Distinguish the origin of the leak: a purely functional moderate MI, linked to dilatation by volume overload, is generally corrected by simple VSD closure without concomitant mitral procedure.
• Identify structural abnormalities: the presence of Carpentier type IIIa MR or marked preoperative severity should prompt you to consider immediate valvuloplasty or, at the very least, rigorous postoperative echocardiographic follow-up.
• Adjust your advice to families: if the mitral apparatus is structurally affected, the risk of long-term reintervention remains significant, unlike purely functional forms where the prognosis after VSD closure is excellent.

Surgical management of a ventricular septal defect (VSD) is sometimes accompanied by significant mitral regurgitation (MR). The dilemma for the cardiac surgeon is then to determine whether correction of the VSD alone will suffice to resolve the MR by reducing volume overload, or whether concomitant mitral valvuloplasty is imperative. The study aimed to evaluate the long-term results of these two strategies to refine clinical decision-making.

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