With increasing data, can guidelines continue to overlook the Ross in adults?

In recent years, there has been increased recognition of sub-optimal outcomes of both biologic and mechanical aortic valve replacements in young adults (<50–60 years of age). Thus, there has been renewed interest in the Ross procedure, which has been shown to outperform both mechanical and biologic aortic valve replacements and restore survival to that of a healthy age-matched population in multiple studies [1]. Despite these excellent results, questions remain around its technical demands and risk of future autograft deterioration, particularly in patients with aortic insufficiency (AI). In this issue of the journal, Oeser and colleagues describe their excellent long-term results following the Ross procedure in young adults (mean patient age 37 years with standard deviation 10 years). In their series, 15 surgeons performed a total of 224 Ross procedures over a 24-year period. Among this group of surgeons, experience with the Ross procedure varied widely with only 2 surgeons having performed >45 cases throughout the study period. Not surprisingly, low-volume surgeons, defined as performing <25 procedures, had a 7.2 times higher odds for a serious adverse event during the perioperative period, compared to high-volume Ross surgeons performing >45 Ross procedures. These volume-dependent outcomes have been replicated in other Ross series and warrant ongoing discussion about how to safely expand access to this operation. Here, the authors report a cumulative incidence of autograft and right ventricular outflow tract reintervention of 21.5% and 5.9% at 20 years, respectively. These rates of reintervention are somewhat higher than reported in other long-term series [2–4], which could be due to the number of low-volume surgeons performing these procedures in this series. This group found that preoperative AI was an important risk factor for future need for autograft reintervention, a concern in other series also [2–4]. More recently, several strategies have been proposed to mitigate the risk for autograft failure in patients with AI. The most widely used approach, known as the inclusion technique, uses the patient’s own aortic root to provide external support of the pulmonary autograft. Two large studies investigating this technique found stable neoaortic root dimensions in nearly all patients undergoing this procedure at 15 years [5, 6]. More recently, a tailored surgical approach based on autograft dimensions in patients undergoing the Ross procedure for AI has been proposed. This technique addresses patient’s individual anatomy and risk factors for autograft dilation, including annular size mismatch, commissural symmetry, and dilation of autograft infundibular muscle [7]. Mid-term results of this technique have been excellent and demonstrated no difference in autograft dilation between patients who underwent the Ross procedure for AI or aortic stenosis [8]. Oeser et al. describe their success with the addition of a dacron support graft to prevent autograft dilation. This technique has also shown promising early results, but we do have concerns that this approach could distort the natural geometry of the autograft or coronaries and result in the degeneration of natural elastic properties of the autograft wall [9]. Furthermore, the normal aortic root undergoes sophisticated changes during the cardiac cycle, which the living autograft replicates. By restricting such motion, valve function may be importantly impaired and lead to early autograft failure from neoaortic insufficiency [10]. Paramount to the success of all of these techniques is strict postoperative blood pressure control, which allows the autograft to adapt to its new haemodynamic environment and avoid early dilation. Oeser and colleagues’ paper is part of a growing body of evidence that supports the safety and excellent long-term survival of the Ross procedure in well-selected recipients, particularly when performed by high-volume surgeons. We hope that these data, along with others, may be considered when future guidelines are devised for young adults requiring aortic valve replacement.