The surgical delicacy of personalized, lifelong care: commentary on early results from the CAVIAAR study

The aortic root and the valve within it are complex structures affected by varied pathologies and treated with a variety of techniques to address the many mechanisms of dysfunction. In Cleveland, Lars Svensson teaches the use of the mnemonic CLASS (Commissures, Leaflets, Annulus, Sinuses and Sinutubular junction) to aid in the structured assessment of the aortic root and aortic valve particularly when considering aortic valve repair [1]. Patients with aortic root aneurysm, and especially those with aortic valve regurgitation, require attention to and possible correction of each of these components. Drs Magdi Yacoub and Tirone David pioneered many of the techniques used to treat the aortic root and helped to develop our understanding of the anatomical and physiological properties of the complex [2, 3]. One criticism of the Yacoub remodelling technique is a lack of stabilization of the annulus [4]. The reimplantation technique described by David stabilizes the annulus as the graft is secured to the left ventricular outflow tract below the aortic valve, but loss of dynamic annulus function may ensue. Lansac’s technique with the use of an expansile external ring annuloplasty appears to address both of these shortcomings with 4–9% systolic expansion, as demonstrated by Holubec and colleagues [5]. This is the technique studied as part of the CAVIAAR study described in the recent publication by Lansac and colleagues [6]. We congratulate the authors for performing a prospective study examining outcomes of patients undergoing aortic root replacement using Lansac’s remodelling plus ring technique (REPAIR) compared to a mechanical valve composite graft (REPLACE). Although there was no difference in the primary endpoint (composite of mortality, reoperation, thromboembolic or major bleeding events, endocarditis or operating site infections, pacemaker implantation or heart failure) at 4 years, there may be some advantages to the REPAIR versus REPLACE strategy. The described technique of aortic remodelling was performed safely and demonstrated superior outcomes in terms of valve-related death and bleeding complications at 4 years. Given the difficulties with analysing such longitudinal data, it was promising to see the authors included an analysis of end-diastolic diameter as a reasonable surrogate for successful operation and positive remodelling. The cardiovascular surgical community has learned to perform elective operations, in a very safe fashion with ever-decreasing operative mortality [7]. The multicentre design of this study abates the potential concern of superb outcomes being limited to a singular expert surgeon. The valve-sparing techniques are reproducible with appropriate training. As medical care and the safety of elective root surgery has improved, cardiovascular specialists are tasked with providing lifelong solutions for the patient who presents with aortic root disease who is now typically expected to live beyond one or two decades from the time of surgery. The key task for the future is finessing techniques that improve longer-term outcomes for our patients, without compromising safety or quality of life. Ultimately, we treat patients rather than disease and therefore functional outcomes such as exercise capacity and quality-of-life measures may become more important guides in the shared decision-making process. The maintenance of systolic expansibility of the annulus may prove to be an important element of success for many of these young patients. Considering the classically described 1.2–2.6 events per 100 patient-years risk of haemorrhagic event with mechanical valves and the high risk (20–50% depending on patient age) of reoperation in patients with a biological valve over a lifetime, valve-sparing root procedures are particularly attractive, but not limited to, the younger cohort [8, 9] The 2 groups were not entirely equivalent with a third of patients who underwent REPAIR with a bicuspid valve, while this was true in 55% of the REPLACE group. There were no differences in Marfan syndrome between groups, but rates were low at <5% in each. This study reiterates the aforementioned haemorrhagic complication concerns associated with replacement, with 8.8% of patients in the REPLACE group having a haemorrhagic complication in the postoperative follow-up period compared to 0% in the REPAIR group. There was no difference in reoperative rates, although the 4 years of follow-up is likely inadequate to address this question. The study could not proceed as a randomized trial due to recruitment issues stemming from patient and referring physician bias about avoiding anticoagulation. This highlights real-world difficulties with such studies and the importance of shared decision-making in the selection of therapy. Modern patients are more knowledgeable of their choices. Safe surgery is the minimum expectation and one must deliberate the lifelong care of the aorta and the patient when offering the optimal treatment option. Considering this, we must establish outcomes of valve-sparing surgery not just in 4, 8 or 12 years, but 20 years and beyond. These early results from the CAVIAAR study are outstanding, and begin to validate the superior role for valve-sparing root replacement with the modified remodelling plus annuloplasty technique over mechanical valve replacement. We look forward to learning from future longer-term studies of this cohort. The journey of discovery for which technique is optimal for which patient taking into consideration disease-specific details such as the presence of a bicuspid valve versus a tricuspid valve, other comorbid conditions such as the presence of a syndromic connective tissue disorder, as well as operator experience and outcomes should all be considered while we move towards more personalized care for aortic valve and root disease. Conflict of interest: Dr Eric E. Roselli speaks and serves as a consultant and investigator for Artivion, Cook, Edwards Lifesciences, W.L. Gore, Medtronic and Terumo Aortic.