Different methods of neo‐chordal fixation to the papillary muscle: Do they have any influence on the chordal biomechanical characteristics?

Mitral valve repair is undoubtedly the first choice procedure adopted by most surgeons to treat mitral incompetence in patients affected by degenerative, ischemic, and often infective mitral valve disease. Earlier mitral valve repair is recommended by consensus guidelines over replacement in all cases where a reasonable likelihood of valve reconstruction is anticipated. Valve repair consists of several types of gestures carried out on the mitral leaflets to achieve effective valve competence. Mitral valve annuloplasty, obtained by a rigid, semi‐rigid, pliable, complete or incomplete prosthetic or pericardial ring it is mandatory and it must be associated to accomplish a functionally effective result, durable over time. Following several experimental works with chordal substitutes conducted in the late eighties by Frater in New York and David in Toronto, the implantation of polytetrafluoroethylene (PTFE) (W. L. Gore & Association. Inc.) neo‐chordae has proven to be a simple, reproducible and effective surgical procedure, and it is nowadays widely used by most cardiac surgeon as the method of choice to repair incompetent mitral valves. This surgical technique is safe and provides long‐lasting and adequate results, particularly in cases of complex mitral valve disease of various etiology. There are several advantages of PTFE chordal implantation over the traditional techniques to repair a mitral valve. Reproducibility is one of its major benefits. The traditional techniques, to a great extent pioneered by Carpentier, are quite feasible in the cases of simple lesions. The most common mitral valve disease, the posterior leaflet prolapse, can be handled by most surgeons by quadrangular or triangular prolapsing leaflet resection with excellent results. In cases of more complex disease, like anterior leaflet chordal rupture, prolapse of both leaflets, Barlow disease, the repair becomes more demanding, and the traditional techniques, in particular chordal transposition or papillary muscle shortening, require proven surgical skill and are difficult to reproduce. In these cases, the use of PTFE artificial chordae offers an easier way to manage a complex mitral valve repair, very well reproducible and with improved long‐term results. Indead, PTFE neo‐chordae implantation has been in clinical use for more than 20 years and has proven to be a reliable and effective technique for mitral valve repair. Moreover, the new approach to treat the mitral valve disease according to the “Respect rather than Resect” concept, which has further enhanced the outcomes after mitral valve repair by preserving the leaflet's tissue and improving their coaptation, it is largely based on the use of artificial chordae. The technique of PTFE neo‐chordae implantation needs a learning curve to optimize the outcomes of mitral repair. In this regard some crucial technical details must be met, to achieve appropriate valve reconstruction. The attachment of neo‐chordae to the papillary muscle is an important step and is largely discussed in the paper that is the subject of this commentary. Chordal fixing to the valve leaflets is another important surgical detail; it should avoid tears or damage to the leaflet's tissue, at the same time preventing changes in the chordal length due to knot loosening secondary to the peculiar PTFE slippery property. Finally, the optimal height of the neo‐ chordae to gain a perfect leaflets coaptation is a determining factor, and it is obtained by tying knots at the appropriate chordal level by using one of the disparate techniques suggested by many authors. Pre‐measured neo‐chordae (loop technique), also present in the market and ready‐to‐use, have facilitated and propagated mitral repair by using this technique.