The average age of patients with rheumatic mitral valve disease in China is 40–55 years old(10). The first choice for these patients' treatment in most centers is mitral valve replacement. However, the risk of anticoagulation/bleeding of mechanical valves and early bioprosthetic valves deterioration in young patients(11) affects the patients’ long-term survival and quality of life. Thus, a feasible and effective mitral valve repair for young rheumatic valve patients is required.
Asian countries such as Thailand, India, Vietnam, and Malaysia have shown good therapeutic effects in rheumatic mitral valve repair(12). They use a pericardial patch for anterior or posterior mitral valve extension to repair the rheumatic mitral valve(13) and the Peeling technique for both leaflets(14). However, the pathology of the Chinese rheumatic heart disease population is different. Patients in Asian countries such as Thailand, India, Vietnam, and Malaysia are younger, and the main population is adolescents. The valve is usually not yet mature. In the meanwhile, Chinese patients are normally in their 50s/60s(15). The size of the leaflet is normal and the coaptation area is sufficient therefore does not require widening. Furthermore, after a thorough peeling in both leaflets, in order to acquire better leaflet morphology and coaptation height, require a down-sized annulus ring. For Chinese rheumatic patients, we do not recommend using a small ring, due to the normal size of the leaflet and adequate coaptation height. A down-sized ring will bring no benefit to mean transvalvular pressure gradients and end-diastolic peak flow velocity. So as to remain an actual-sized annulus, additional leaflet extension is necessary. All procedures performed simultaneously are complicated and highly increase the risk of repair failure. We only perform the Peeling technique in the anterior leaflet to remove fibrous plaque that affects coaptation. The posterior leaflet is thickened and fixed and does not play a key role in the opening of the mitral valve.
Another important aspect of the mitral valve structure is the subvalvular apparatus. The Score procedure introduced by Meng and colleagues is a simple operation and with reliable effects and easy to promote(16). This procedure had shown many encouraging clinical outcomes in severe rheumatic mitral stenosis(17, 18). On the basis of this procedure, we further focus on subvalvular apparatus. Modified release technique separates the shortened chordal (preserve the paracommissural chordal), performs papillary muscle dissection for fused papillary muscle and chordal fenestration under the coaptation area. This technique ensures the maintenance of mitral valve structure to ensure the best preload state of the left ventricle. On the other hand, leaflet and subvalvular apparatus were removed during valve replacement, causing left heart function was also lost. This is one of the important reasons why the long-term survival rate after valve replacement is less satisfactory(9).
In recent years, whether mitral valve repair or replacement is better in rheumatic heart patients remains debatable(19, 20). There might be a few possible reasons: (1) rheumatic mitral valve disease has more complicated pathological changes in the valve, annulus, and subvalvular apparatus; (2) surgeon skills and experience matter in valve repair; (3) the potential failure of valve repair and tendency of valve replacement in mixed rheumatic lesion; (4) durability of mitral valve repair in rheumatic patients. Our modified release technique, according to the pathological change of adult rheumatic valve patients, peeling in the anterior leaflet, separating the shortened chordal and chordal fenestration are feasible and received acceptable mid & long-term results. Echo showed lower mean transvalvular pressure gradients and end-diastolic peak flow velocity. These changes are important in relieving patients valve-related symptoms and the durability of valve repair.