The art and craft of valve-sparing aortic root surgery

Valve-sparing surgery of the aortic root (VSRR) has become the treatment of choice for patients with aortic root aneurysm and a structurally normal valve [1]. The procedure can be performed with excellent long-term results and very low mortality. By now, several groups have shown that this is also true for patients with bicuspid aortic valves (BAV) and those that present with significant aortic regurgitation (AR) [2]. Nevertheless, in a recent analysis of the STS database with >8000 patients undergoing primary, elective aortic root replacement without the need for circulatory arrest, only 19% of patients received a VSRR [3]. But even in centres of excellence not all patients that present with this pathology undergo VSRR. Epidemiological data can help to estimate the bias. In a large series from Hanover, Germany, 8.6% of VSRR procedures were performed in patients with BAV [4]. The prevalence of BAV is 1–2% in the general population. In most series, 25–45% of BAV patients develop aortic dilatation >45mm. Although in the majority of BAV patients, 60–70%, aneurysm formation occurs in the ascending and not so much the aortic root, it becomes clear that many more BAV patients with aortic root aneurysm undergo a Bentall procedure than VSRR. And this is not necessarily a bad thing. It just shows that excellent results in this patient population are possible but patient selection seems an important contributing factor. The AVIATOR study group recently published their results on patients with heritable thoracic aortic disease comprising data from several centers of excellence [5]. The authors report 22% of AR ≥ 2 after 10 years. While this in line with previously reported results in patients with Marfan syndrome, it is sobering to note that the median time to develop AR ≥ 2 was <3 years. It seems that the art of performing this operation lies within the ability to know which patient will have a good result for the foreseeable future and who will soon come back and require reoperation. Unfortunately, not all of us are artists. While Dr. Schäfers has enabled countless patients to live a normal life by sparing their aortic valve during surgery for aortic root aneurysm, his contributions to the field go far beyond the individual patient. Over the past 25 years, Dr. Schäfers has developed a surgical technique that is not only effective but also reproducible by many surgeons around the world. His technique relies on parameters that can be measured in a standardized way and provides guidance for the operating surgeon whether to continue or abandon a valve-sparing procedure. There are very few instances in medicine where ‘eyeballing’ provides better outcomes than measuring defined parameters. This has been shown time and again. There is a plethora of examples; the very recent RENOVATE-COMPLEX-PCI trial has shown that intravascular imaging-guided revascularization is more effective than revascularization based on angiography alone [6]. In the current study [7], Dr. Schäfers and his group have shown that observing certain cut-offs with regard to geometric as well as effective height not only results in a competent valve after surgery but also informs long-term prognosis of the valve. The need to repair all 3 cusps resulted in a worse outcome compared to patients where only 1 or 2 of the cusps had to be repaired. This is a timely reminder that there are limits to long-term success of this procedure. The fact that annuloplasty was only mildly protective regarding the development of significant AR in the long term cannot be easily explained and does not correlate with results of other groups using a remodelling approach [8]. Importantly, with this study, the group has shown that the degree of preoperative AR in patients with aortic root aneurysm and tricuspid valves is not a predictor of recurrent AR when observing their ‘rules of engagement’. Dr. Schäfers turned art into craft. This is his legacy. And it will pervade the field of reconstructive aortic valve surgery for decades to come.