Mitral valve repair is considered the preferred approach in children with mitral valve disease. In cases where an initial repair fails, a second repair—despite being technically challenging and not always optimal—remains preferable to valve replacement. However, when the valve becomes truly irreparable, replacement becomes the only feasible option.
Three main strategies exist when dealing with an irreparable mitral valve and a small annulus. One option is replacement with a mechanical prosthesis sized between 15 and 17 mm, a strategy historically associated with substantial morbidity and mortality due to the complexities of anticoagulation in infants. An alternative that has gained relevance is the use of the Melody valve in the mitral position (a bovine jugular vein–based, stented bioprosthesis). This option allows staged dilations, postponing anticoagulation and providing a bridge to a definitive prosthesis. Recent cohorts have reported reasonable survival, although freedom from reintervention commonly ranges between 2 and 4 years.
The third option is the use of a pulmonary autograft in the mitral position—the Ross II procedure. The theoretical benefits of this technique include the use of autologous tissue and the potential for somatic growth. However, robust evidence regarding long-term outcomes is still lacking, particularly given the technical complexity of the operation.
This retrospective, single-center study from Fuwai Hospital evaluates the results of the Ross II procedure in infants and young children with congenital mitral valve disease deemed irreparable and lacking appropriately sized mechanical prostheses. The analysis covers the period from 2011 to 2022, with structured clinical and echocardiographic follow-up.
The primary aim of the study was to describe the clinical implications, operative outcomes, and mid-term follow-up after the Ross II procedure. The investigators sought to determine the safety profile of the technique, the functional evolution of the pulmonary autograft implanted in the mitral position, and the incidence of late complications—particularly mitral stenosis (MS) and the need for reintervention. The study also indirectly assessed the growth potential of the pulmonary autograft within the anatomical and dynamic environment of the mitral valve.
A total of 10 consecutive patients were included, all presenting with severe congenital mitral valve disease deemed irreparable and with mitral annuli too small to accommodate mechanical prostheses. The primary endpoint was all-cause mortality (early and late). The secondary endpoint was reoperation for autograft dysfunction. Serial changes in the mean mitral gradient were evaluated to assess autograft performance and potential growth.
The cohort had a median age of 1.8 years and a mitral annulus diameter of 16 mm. Most patients presented with severe mitral stenosis associated with pulmonary hypertension. No in-hospital deaths occurred, although two late deaths were reported: one sudden death in an infant with persistent pulmonary hypertension, and another of unknown cause nine years after the initial procedure. Postoperative recovery was prolonged but acceptable for a complex operation, with median ICU and hospital stays of 11.5 and 24 days, respectively.
During a median follow-up of 36 months, the most frequent complication was late MS, occurring in 80% of patients. Echocardiography showed a marked reduction in mean mitral gradient at discharge, followed by a progressive increase over the subsequent three years, indicating limited growth potential of the autograft. Three patients (30%) required subsequent mechanical mitral valve replacement, with intervals between Ross II and reintervention ranging from 2.2 to 3.5 years. Surgical inspection in one case revealed progressive thickening of the autograft.
Given that the Melody valve is not commercially available in China, the authors conclude that the Ross II may serve as a bridge to definitive mechanical valve replacement at an older age, reducing early-life risks. Nonetheless, the limited capacity for growth and remodeling of the pulmonary autograft in the mitral position remains the main drawback of the technique and leads to a high incidence of late MS and eventual reintervention.
COMMENTARY:
In many situations, clinicians must work with the options available rather than the ones they would ideally choose. Because the Melody valve is not accessible in China, the team at Fuwai Hospital faced a limited therapeutic landscape for children with irreparable mitral valves, leaving the Ross II as the only alternative to mechanical prostheses. The small sample size of this study may seem surprising given the institution of origin. Fuwai Hospital is one of the highest-volume cardiovascular centers in China, with 13 catheterization laboratories and 26 operating rooms. In 2018 alone, the institution performed approximately 46000 catheterizations and 15000 surgical procedures, one-third of which involved congenital heart disease. In 2021, the center reported 3764 congenital cardiac operations. These numbers provide important context: performing only 10 Ross II procedures over a decade suggests two conclusions—an effective pediatric mitral repair program and the rarity of needing mechanical replacement in this population.
The present study offers a valuable contribution by documenting real-world experience with the Ross II in a setting where other suitable prosthetic options are unavailable. It demonstrates the technical feasibility of the procedure and the potential for reasonable early postoperative function. However, significant uncertainty remains regarding the autograft’s capacity for growth. The mechanical forces acting on a valve in the mitral position differ substantially from those in the aortic root, likely explaining the limited growth potential and the frequent development of late mitral stenosis observed in this series.
In summary, the Ross II procedure is still finding its place, particularly in environments where surgical implantation of a Melody valve is feasible. Until broader prosthetic options become universally available, the achievements of the Fuwai team merit recognition from the cardiothoracic community for successfully applying such a demanding procedure with acceptable outcomes.
REFERENCE:
He Q, Lin X, Jiang H, Dou Z, Liu Y, Ma Y, et al. Mid-Term outcomes of the Ross II procedure in infants and young children with irreparable mitral disease. Eur J Cardiothorac Surg. 2025 Oct 23:ezaf359. doi: 10.1093/ejcts/ezaf359. Epub ahead of print. PMID: 41129284.
