Discussion

Presenter: Dr Marc W. Gerdisch Moderator: Dr Tirone E. David Dr Hans-Joachim Schäfers (Saar, Germany). First, my congratulations for this presentation and the excellent clinical results. Also, my thanks for giving me the chance to review the manuscript in advance. As background, we need to keep in mind that, in isolated bicuspid repair for aortic regurgitation, the presence of annular dilatation is important, and the use of an annuloplasty, as well as creation of a symmetric postoperative valve configurations, are important prerequisites for durable valve function. In interpreting your results, we need to keep in mind that these were predominantly or primarily aortic patients, because all 70 underwent aortic surgery, and you have a multicenter study. The common denominator really is the annuloplasty device. Let's keep in mind mean crossclamp time was 145 minutes and pacemaker rate was 4%, which is, in my mind, a bit on the high side. The 3 reoperations that you mentioned were apparently related to abrasion of cusp tissue in 1 patient and ring dehiscence in the other 2, and this needs to be kept in mind when judging the effect of the annuloplasty result. The interpretation is not facilitated by the heterogeneity of valves. You use the Sievers classification to describe it, which I don't find very helpful. Maybe the de Kerchove classification from symmetric to very asymmetric would be helpful. Three of your patients were classified with type 2 Sievers, which is a unicuspid valve. Mean aortic regurgitation (AR) was only 2.4. The majority of patients apparently had lesser degrees of AR preoperatively, and the heterogeneous operations as you described. In trying to bring a little more clarity in judging the effect of the annuloplasty and the operation, in how many instances was symptomatic AR the indication for surgery? And could you state preoperative annular diameters? Another interesting question with these annuloplasty devices, which tend to be a little on the small side, but gradients are apparently good, have these gradients remained stable over time? I would like to thank the Society for the privilege of discussing the papers, and also my compliments and thanks to you for this honest report. In my mind, further experience, more follow-up, and a more homogeneous cohort will be needed to judge the risk-benefit ratio of this annuloplasty. Maybe you can clarify a few of these aspects. Dr Marc W. Gerdisch (Indianapolis, Ind). Thank you, Dr Schäfers, for taking the time to review the paper and asking these very important questions, which, to be honest, I had considered myself and lead up to this thought, in part, because in your own literature you reflect on some of these issues. I'll try to be as brief as possible. I do think classification with respect to asymmetry would be more accurate for assessing efficacy of the repair. Our data collection up to that point wasn't quite as robust as perhaps it should've been, although now it is. We have a much more detailed methodology for collecting data, which we need to prepare going forward. The intention of the paper was to show the robust response amongst surgeons, talented surgeons admittedly, adopting the technology and then performing repairs. With respect to the severity of congestive heart failure symptoms, I can't give you a breakdown. I would just offer that the mean value shows an improvement in the overall incidence of congestive heart failure. With respect to asymmetry, it's important to notice, and you did mention that we had some Sievers 2, and that we treated intermediate type 1 as well. We have an aggressive approach to repair in this cohort, meaning asymmetry was considered a factor, but in general all valves were approached with a plan to repair, and in fact, they were repaired. When we look for example at your experience, 15 years, 150 patients with remodeling and superb outcomes, you also point out that most of those patients approximate a 180 configuration. There are not many of patients with diverse anatomy. So, the driving thought was first, could we take surgeons that do valve repair in general and expand their capability? Could they repair more valves, and more complex anatomy? In centers of excellence like yours or perhaps Dr David's---and Dr David has a recent commentary saying that the reimplantation model has been incredibly successful but largely in normal leaflets and is now just being expanded to more complex leaflet morphology. Still, when we think about the overall experience as Dr David showed earlier today, 465 patients over 30 years in the busiest reimplantation center, perhaps in the world, there's something missing for most surgeons, right? There are many surgeons who are encountering anatomy that either they've never addressed before or perhaps they're not comfortable even with simple anatomy. So, the goals here were twofold: to expand applicability for surgeons who are already comfortable with aortic valve repair to do more complex repairs and then to also expand opportunity for surgeons and patients who are in the operating room with simple anatomy that might otherwise not be repaired. This experience provides insight that the early outcomes are like those seen in centers of excellence, including with diverse anatomy. We know, for example, a large root, a lot of leaflet work, and bicuspid anatomy, all contributed to earlier failures in the David operation. Chen showed that nicely. We can debate whether it is true for everybody, but the question is whether there is a way for us to standardize the experience for the surgeon, drive the anatomy more toward a 180 configuration safely, and then address the leaflets with the techniques that you've established, to achieve repair in most cases. Could it be the same kind of process we went through over several decades with mitral valve repair? We've perhaps accelerated it little bit for aortic valve repair. Now, time will tell as you mentioned, and we do have to delineate in detail symmetrical versus asymmetrical. With respect to complex anatomies, some patients we have converted for intermediates to tricuspid of bicuspid, and all of it will be published over time. But, again, the goal here was not to say this is the only way to repair a valve. It was to demonstrate this is a way to repair a valve that can be standardized, that can be performed in 15 different centers with results that are acceptable, and appropriate for aortic valve repair.