Based on Carpentier’s classification and principles, the techniques for mitral valve repair continue to evolve. We herein report our experience with the morpho-functional echocardiographic analysis of single mitral leaflets, as different anatomic features, even if conflicting, may coexist not only in the two leaflets, but in the same leaflet as well. A classification is proposed, based on the length (normal, short, or long) and mobility (normal, restricted, or excessive) of mitral leaflets. The surgical techniques adopted for mitral valve repair are the direct consequence of this analysis.
Mitral valve repair is the procedure of choice to correct mitral regurgitation. However, some dangerous complications, correlated to the surgical technique, can occur in the operating theatre, at the end of the procedure. The most frequent is the systolic anterior motion. Due to a systolic dislocation of the anterior leaflet toward the outflow tract, it causes both obstruction of the outflow tract and mitral regurgitation. Often it is due to excess of catecholamines or to reduced filling of the left ventricle, but sometimes needs further surgical maneuvers, focused on moving posteriorly the coaptation line. It can be obtained by shortening the posterior leaflet or increasing the size of the ring or applying an Alfieri stitch to limit the movements of the anterior leaflet. Another complication, often underdiagnosed and potentially lethal, is the injury of the circumflex artery that happens at the level of the anterolateral commissure or P1 zone. Two mechanisms are involved. The first one is direct injury of the artery by a stitch (roughly 25% of the patients present a distance artery-annulus<3 mm). The second one the distortion of the artery, attracted toward the annulus by a misplaced stitch. The attraction causes kinking with stenosis of different degrees till functional occlusion. However, the artery has to be far from the annulus and the atrial tissue has to be stiff and resistant, as after an infective process, to move the CX toward the annulus without tearing. Positioning the stitches very close to the mitral leaflets in the dangerous area is the only prevention to the complication. The treatment in the operating theatre is partial or total removal/re-implantation of the annular sutures or coronary artery bypass grafting to the circumflex area. If the injury is demonstrated only after a coronary angiography, percutaneous revascularization can be attempted before further surgical treatment.
The chordae tendinae connect the papillary muscles to the mitral valve. While the first-order chordae serve to secure the leaflets to maintain valve closure and prevent mitral valve prolapse, the second-order chordae are believed that they play a role in maintaining normal LV size and geometry. The papillary muscles, from where the chordae tendinae originate, function as shock absorbers that compensate for the geometric changes of the left ventricular wall. The second-order chordae connect the PMs to both trigons under tension. The tension distributed towards the second-order chordae has been demonstrate to be more than three-fold that in the first-order counterpart. Cutting the second-order chordae puts all the tension on the first-order chordae, that can go closer to their rupture point. However, it has been experimentally demonstrated that the tension where the first-order chordae break is 6.8 N, by far higher than the maximal tension reached, that is 0.4 N. Even if the clinical reports have been favorable, the importance of cutting the second-order chordae to recover curvature of the anterior leaflet and increasing the coaptation length between the mitral leaflet has been slowly absorbed by the surgical world. Nevertheless, there are progressive demonstrations that chordal tethering affects the anterior leaflet not only in secondary, but also in primary mitral regurgitation, having a not negligeable role in the long-term outcome of mitral repair.
Background and aim of the study. Wrapping of the ascending aorta (AA), isolated or associated with aortoplasty, has never been completely accepted. Some complications, as folding of the aortic wall, compression of the vasa vasorum and changes in the flow pattern, with consequent dilatation of the proximal arch, have been described. We used fresh autologous pericardium (FAP), so far never reported, to wrap the AA, with the aim to stabilize its size when moderately dilated, maintaining the preoperative dimension or limiting the reduction to a few mm. Material and Methods. From 2015 to 2019, 10 patients, who were operated on for valve or coronary surgery or both, underwent wrapping of the AA with FAP. Mean age was 69±7 years and ESII 3.5±1.7. Four patients had moderately impaired ejection fraction (35-49%). Results. There was no early or late mortality. One patient was reoperated on after 48 months for severe mitral regurgitation. At a follow up of 53±14 months, a transthoracic echocardiogram showed that the AA size reduced slightly but significantly, from 45.2±2.0 to 42.5±4.1 mm, p=0.03. The diameter of the proximal arch remained unchanged, from 37.1±1.6 to 36.3±2.9 mm, p=0.20. Conclusions. In presence of moderately dilated AA wrapping can be a reasonable option. The use of FAP stabilizes the size of the aorta after a follow up of 53 months. Maintaining a size similar to the preoperative one avoids the complications related to the procedure.
Resection or exclusion of scars following a myocardial infarction on the LAD territory started even before the beginning of the modern era of cardiac surgery. Many techniques were developed, but there is still confusion on who did what. The original techniques underwent modifications that brought to a variety of apparently new procedures that, however, were only a “revisitation” of what described before. In some case old techniques were reproposed and renamed, without giving credit to the surgeon that was the original designer. Herein we try to describe which are the seminal procedures and some of the most important modifications, respecting however the merit of who first communicated the procedure to the scientific world.
The meta-analysis by Di Tommaso et al demonstrated as elderly patients with mitral regurgitation (MR) undergoing mitral valve repair (MVr) had lower short-term mortality and higher long-term survival with respect to patients undergoing mitral valve replacement (MVR). The benefit of repair is such, that initial surgical strategy is advisable in the elderly even in case of mild symptoms if compared with conservative management. However, even if repair can be performed in presence of some specific etiologies, as degenerative MR or secondary MR, there are always cases where a replacement can be an acceptable solution compared to a repair with uncertain future, regardless of our believes and our technical ability. In this subset of patients, the literature does not show any improvement in outcome of transcatheter mitral repair. Mitral valve repair has to be always done, but look at the etiologies and to the consequences that what is done today can cause tomorrow.
Mitral valve (MV) repair for mitral regurgitation (MR) due to posterior leaflet (PL) prolapse is achieved nowadays with a great success rate and a good survival, similar, in certain subgroups. In this paper, Sakaguchi et al describe their results in two groups of patients with PL prolapse. Some patients underwent resection (resection group) and others chordal replacement with/out limited resection (respect group). Results were similar in terms of survival and MR recurrence. Our goal is to eliminate, as much as possible, MR when a patient with degenerative MR is operated on. Reduction of the mitral orifice and consequently an increase of the transmitral gradient is the rule. MV repair for degenerative MR provides great results, but there is not a single surgical technique. A close evaluation of the anatomical findings will allow us to choose the best strategy for the individual patient. An open mind is the most important characteristic that a surgeon should have to repair a prolapsing PL without residual regurgitation and dangerous gradients.
Large studies demonstrated that moderate or severe patient-prosthesis mismatch (PPM) occurs in 44.2% to 65% of patients undergoing aortic valve replacement. If there is general agreement that patients with PPM have worse outcome than patients without, it is difficult to understand how to prevent this dangerous complication. The formula used to calculate the effective orifice area (EOA) of an implanted aortic prosthesis has many weak points that produce inconsistent results using the same prosthetic valve (type and size). The observed EOA (3 to 6 months postoperatively) of a #23 biological prosthesis can range from 0.9 to 3.5 cm², making PPM prevention impossible using projected EOA, where only the mean value is reported (1.83 cm² for the same #23 biological prosthesis). An EACTS-STS-AATS Valve Labelling Task Force has been established to suggest the manufacturers to present essential information on valvular prosthesis characteristics in standardized Valve Charts. For valves used in the aortic position, Valve Charts should include a standardized PPM chart to assess the probability of PPM after implantation. This will not solve completely the conundrum of prevention, but most likely it will be a step ahead.