EComment. Personalized annuloplasty rings for mitral valve repair: lessons from the pig model

Abstract

It does make sense to try to develop a method to tailor and manufacture personalized patient-specific annuloplasty rings with regard to preoperative computed tomography (CT)-sizing of a patient's mitral valve annulus [1]. The sizing of mitral annulus area, the knowledge of normal and pathological dynamics of the annulus is essential prior to surgical mitral repair. The dimensions of the mitral annulus vary considerably among individuals [2]. Off-the-shelf rings currently available tend to disregard anatomic variations. Such variability is detected in clinical practice and could be taken into consideration when configuring annuloplasty rings. The authors' idea is to make a 3D-segmentation of the mitral valve and mitral annulus of a patient in systole before surgery. The in vivo study on the animal model has demonstrated that a three-step algorithm consisting of CT-annulus sizing, digital modeling and ring manufacturing, and finally the implantation of such patient-specific devices is feasible. This is quite evident from the article. What only remains is to evaluate the performance of mitral annulus correction using such ring in a patient with mitral valve pathology. We need to answer the question: what is the point of making an annuloplasty using a ring obtained by scanning the pathologically changed annulus of the mitral valve. In this case, the outcome of mitral correction is likely to fail. It is quite obvious that before being implanted in a patient with mitral regurgitation, both the shape and the dimensions of such a ring need to be modified (reduced or downsized) to required values. The authors accept the possibility of modifying annuloplasty rings obtained for an individual by using CT-images of the diseased mitral valve to be corrected. It remains unclear how a solid metal ring can be downsized. However, the authors do not propose any technology for solid ring modification. This device, as attested by clinical practice, is often used in cardiac surgery to compensate for valve tethering and to force coaptation. In conclusion, we would like to congratulate the authors of the article on the innovative method they use to address the issue of developing a person-specific implantable device. Conflict of interest: none declared.