The Resurgence of the Pulmonary Autograft
For young and middle-aged adults requiring aortic valve replacement (AVR), the choice of prosthesis remains a complex clinical dilemma. While mechanical valves offer long-term durability, they necessitate lifelong anticoagulation with its attendant bleeding risks. Conversely, bioprosthetic valves avoid anticoagulation but are prone to structural valve deterioration, particularly in younger, active patients. In this context, the Ross procedure—the replacement of the diseased aortic valve with the patient’s own pulmonary autograft—has seen a significant resurgence.
Originally described by Donald Ross in 1967, the procedure offers several theoretical and clinical advantages: superior hemodynamics, the potential for autograft growth, and the absence of anticoagulation requirements. However, the technical complexity of the procedure, involving a double-valve operation and coronary artery reimplantation, has historically limited its adoption to specialized centers. A new study by Mazine et al., published in the Journal of the American College of Cardiology, provides a timely and critical assessment of how this procedure is currently utilized in North America and how surgical experience directly influences patient survival.
Highlights of the Contemporary Analysis
The study provides several pivotal insights into the current landscape of cardiac surgery in North America:
1. There has been a sevenfold increase in Ross procedure utilization among adults aged 60 and younger between 2017 and 2023, signaling a major shift in surgical preference.
2. A robust and statistically significant volume-outcome relationship exists; centers and surgeons performing more procedures achieve substantially lower operative mortality.
3. The data suggests a critical threshold of approximately 10 Ross procedures per year, beyond which operative mortality stabilizes at lower levels.
4. While overall mortality has improved over the last decade, a slight uptick in 2023 suggests that the expansion of the procedure to lower-volume centers may carry inherent risks.
Study Design and Methodology
The researchers queried the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database, which captures the vast majority of cardiac surgical volume in North America. The study period spanned from 2008 to 2023, focusing on adult patients who underwent the Ross procedure.
To ensure statistical rigor, the team employed modified Poisson regression with generalized estimating equations and robust standard errors. This methodological choice allowed the researchers to account for the clustering of data by both surgical center and year, providing a more accurate picture of the volume-mortality relationship. The primary endpoint was operative mortality, defined as death during the index hospitalization or within 30 days of surgery. The study eventually included 2,268 Ross procedures performed across 194 different centers.
Detailed Findings: Trends and Mortality Data
The Trend Toward Modern Adoption
The utilization of the Ross procedure has followed a non-linear path over the last 15 years. In 2017, the procedure reached a nadir, with only 63 cases reported across North America, representing a mere 0.9% of all AVRs in adults 60 years or younger. However, following several high-profile studies demonstrating superior long-term survival compared to conventional AVR, interest surged. By 2023, the volume reached 531 cases, accounting for 6.7% of AVRs in that demographic.
Volume-Outcome Relationship
The core finding of the study is the dramatic impact of surgical volume on safety. The median number of procedures per center over the 16-year period was remarkably low—just 2 cases. This indicates that while many centers are attempting the Ross procedure, very few are performing it regularly.
Regression-adjusted modeling demonstrated a clear inverse relationship between volume and mortality (P < 0.001). For centers performing only 1 to 2 cases per year, the risk of operative mortality was significantly higher. However, as center volume increased toward 10 cases annually, mortality rates dropped sharply. Beyond the 10-case-per-year mark, the improvements in mortality began to plateau, suggesting that 10 cases represents a reasonable minimum threshold for maintaining surgical proficiency in this complex operation.
The 2023 Mortality Paradox
One of the most striking observations in the data was the fluctuation in mortality rates over time. Operative mortality for the Ross procedure declined from a high of 4.4% in 2008 to a remarkably low 1.0% in 2020. This decline likely reflected the concentration of the procedure in a few highly specialized centers. However, as the procedure became more popular and spread to a larger number of hospitals, the mortality rate rose to 2.5% in 2023. This suggests that the “democratization” of the Ross procedure to lower-volume centers may be diluting the clinical outcomes achieved by expert teams.
Expert Commentary and Clinical Implications
The Ross procedure is often described as the most demanding operation in adult cardiac surgery. Unlike a standard AVR, which involves a single valve and a relatively straightforward suture line, the Ross requires a delicate harvest of the pulmonary valve, precise tailoring of the aortic root, and the implantation of a pulmonary homograft.
The Technical Learning Curve
Experts suggest that the “learning curve” for the Ross procedure is steep. It involves not just the surgeon’s technical skill but also the entire perioperative team’s ability to manage a long bypass time and potential right-sided heart complications. The findings by Mazine et al. support the concept of regionalization—the idea that complex procedures should be concentrated in high-volume “Centers of Excellence.”
Biological Plausibility
The biological advantage of the Ross procedure—using a living autograft that responds to physiological changes—is only realized if the patient survives the initial operation and avoids early autograft failure. Early mortality in low-volume centers is often related to technical issues such as bleeding, myocardial infarction due to coronary reimplantation technicalities, or acute autograft dysfunction. High-volume centers likely benefit from standardized protocols, better intraoperative imaging (TEE), and more experienced anesthesia and intensive care teams.
Conclusions and Future Directions
The Ross procedure is no longer a niche operation; it is becoming a mainstream consideration for young adults with aortic valve disease. However, the data from the STS database serves as a cautionary tale. The significant association between higher surgical volume and lower mortality cannot be ignored by health systems or referring cardiologists.
For clinical practice, these findings suggest that patients considering a Ross procedure should be referred to surgeons and centers that perform at least 10 such cases annually. For the surgical community, the challenge lies in developing training programs that allow new surgeons to gain proficiency without compromising patient safety during the learning curve. As Ross programs continue to develop across North America, adherence to volume-based quality standards will be essential to ensure that the procedure’s long-term benefits are not overshadowed by preventable operative risks.
References
1. Mazine A, Weiss J, Chikwe J, et al. Use of the Ross Procedure in North America: Relation Between Surgical Volume and Operative Mortality. Journal of the American College of Cardiology. 2026;87(8):1012-1025. PMID: 41778950.
2. El-Hamamsy I, Eryigit Z, Stevens LM, et al. Long-term outcomes after autograft versus homograft aortic valve replacement in adults with aortic stenosis: a randomised controlled trial. Lancet. 2010;376(9740):524-531.
3. Romeo JL, Papageorgiou G, Forbess JM, et al. The Ross procedure: a systematic review and meta-analysis. JAMA Cardiology. 2021;6(10):1144-1151.
4. Sievers HH, Stierle U, Charitos EI, et al. A multicentre evaluation of the Ross procedure: 25-year results from the German Ross Registry. European Heart Journal. 2018;39(2):166-174.