Do pulmonary autografts provide better outcomes than mechanical valves? A prospective randomized trial

Ross Procedure Versus Mechanical Versus Bioprosthetic Aortic Valve Replacement: A Network Meta-Analysis

Background The Ross operation appears to restore normal survival in young and middle-aged adults with aortic valve disease. However, there are limited data comparing it with conventional aortic valve replacement. Herein, we compared outcomes of the Ross procedure with mechanical and bioprosthetic aortic valve replacement (M-AVR and B-AVR, respectively). Methods and Results MEDLINE and EMBASE were searched through March 2022 to identify randomized controlled trials and propensity score-matched studies that investigated outcomes of patients aged ≥16 years undergoing the Ross procedure, M-AVR, or B-AVR. The systematic literature search identified 2 randomized controlled trials and 8 propensity score-matched studies involving a total of 4812 patients (Ross: n=1991; M-AVR: n=2019; and B-AVR: n=802). All-cause mortality was significantly lower in the Ross procedure group compared with M-AVR (hazard ratio [HR] [95% CI], 0.58 [0.35-0.97]; P=0.035) and B-AVR (HR [95% CI], 0.32 [0.18-0.59]; P<0.001) groups. The reintervention rate was lower after the Ross procedure and M-AVR compared with B-AVR, whereas it was higher after the Ross procedure compared with M-AVR. Major bleeding rate was lower after the Ross procedure compared with M-AVR. Long-term stroke rate was lower following the Ross procedure compared with M-AVR and B-AVR. The rate of endocarditis was also lower after the Ross procedure compared with B-AVR. Conclusions Improved long-term outcomes of the Ross procedure are demonstrated compared with conventional M-AVR and B-AVR options. These results highlight a need to enhance the recognition of the Ross procedure and revisit current guidelines on the optimal valve substitute for young and middle-aged patients.

Perioperative and long-term outcomes of Ross versus mechanical aortic valve replacement

Background

The ideal aortic valve replacement strategy in young‐ and middle‐aged adults remains up for debate. Clinical practice guidelines recommend mechanical prostheses for most patients less than 50 years of age undergoing aortic valve replacement. However, risks of major hemorrhage and thromboembolism associated with long‐term anticoagulation may make the pulmonary autograft technique, or Ross procedure, a preferred approach in select patients.

Methods

Data were retrospectively collected for patients 18–50 years of age who underwent either the Ross procedure or mechanical aortic valve replacement (mAVR) between January 2000 and December 2016 at a single institution. Propensity score matching was performed and yielded 32 well‐matched pairs from a total of 216 eligible patients.

Results

Demographic and preoperative characteristics were similar between the two groups. Median follow‐up was 7.3 and 6.9 years for Ross and mAVR, respectively. There were no early mortalities in either group and no statistically significant differences were observed with respect to perioperative outcomes or complications. Major hemorrhage and stroke events were significantly more frequent in the mAVR population (p < .01). Overall survival (p = .93), freedom from reintervention and valve dysfunction free survival (p = .91) were equivalent.

Conclusions

In this mid‐term propensity score‐matched analysis, the Ross procedure offers similar perioperative outcomes, freedom from reintervention or valve dysfunction as well as overall survival compared to traditional mAVR but without the morbidity associated with long‐term anticoagulation. At specialized centers with sufficient expertize, the Ross procedure should be strongly considered in select patients requiring aortic valve replacement.

State-of-the-art: Insights from the Ross Registry

The treatment of aortic valve disease in young patients is still a major clinical challenge, as the pre-eminent emphasis is on durability and long-term outcomes beyond 10 to 15 years, sometimes >20 to 30 years. The Ross procedure uses the autologous pulmonary valve as an aortic valve substitute and aims to improve valve durability while avoiding anticoagulation and therefore achieve a sustained long-term result with regard to survival, valve functionality, and quality of life. However, this procedure is technically demanding and only performed at a low frequency. Data investigating the Ross procedure are mostly limited to observational studies from single expert centers, while sufficient randomized data are almost completely lacking. Therefore, to create a clinically relevant database of this therapy, the multicenter Ross Registry was founded in 2001. New patients were included, follow-up of past patients continuously updated, and outcomes regularly reported. Throughout recent years, numerous analyses have been performed to characterize this patient population, surgical techniques, risk factors for morbidity and mortality, and most importantly survival outcomes. Currently, more than 2500 patients are included, and the long-term follow-up has reached >25 years in the very first patients who were included. In the most recent study, 2444 adult patients with a mean age of 44.1 ± 11.7 years were analyzed, and it showed that excellent mid-term survival is maintained after 25 years. In addition, the rate of reintervention was lower than reported in patients with xenografts and anticoagulation-related morbidity lower than reported in patients with mechanical valves. In the absence of robust randomized controlled trials, registry data are very important to monitor outcomes and mirror the quality of current practice. Therefore, the Ross Registry provides a unique and important data base regarding treatment of aortic valve disease in young patients.

Ross Procedure vs Mechanical Aortic Valve Replacement in Adults: A Systematic Review and Meta-analysis

Importance

The ideal aortic valve substitute in young and middle-aged adults remains unknown.

Objective

To compare long-term outcomes between the Ross procedure and mechanical aortic valve replacement in adults.

Data Sources

The Ovid versions of MEDLINE and EMBASE classic (January 1, 1967, to April 26, 2018; search performed on April 27, 2018) were screened for relevant studies using the following text word search in the title or abstract: ("Ross" OR "autograft") AND ("aortic" OR "mechanical").

Study Selection

All randomized clinical trials and observational studies comparing the Ross procedure to the use of mechanical prostheses in adults undergoing aortic valve replacement were included. Studies were included if they reported any of the prespecified primary or secondary outcomes. Studies were excluded if no clinical outcomes were reported or if data were published only as an abstract. Citations were screened in duplicate by 2 of the authors, and disagreements regarding inclusion were reconciled via consensus.

Data Extraction and Synthesis

This meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Meta-analysis of Observational Studies in Epidemiology guidelines. Data were independently abstracted by 3 reviewers and pooled using a random-effects model.

Main Outcomes and Measures

The prespecified primary outcome was all-cause mortality.

Results

The search identified 2919 reports, of which 18 studies (3516 patients) met inclusion criteria, including 1 randomized clinical trial and 17 observational studies, with a median average follow-up of 5.8 (interquartile range, 3.4-9.2) years. Analysis of the primary outcome showed a 46% lower all-cause mortality in patients undergoing the Ross procedure compared with mechanical aortic valve replacement (incidence rate ratio [IRR], 0.54; 95% CI, 0.35-0.82; P = .004; I2 = 28%). The Ross procedure was also associated with lower rates of stroke (IRR, 0.26; 95% CI, 0.09-0.80; P = .02; I2 = 8%) and major bleeding (IRR, 0.17; 95% CI, 0.07-0.40; P < .001; I2 = 0%) but higher rates of reintervention (IRR, 1.76; 95% CI, 1.16-2.65; P = .007; I2 = 0%).

Conclusions and Relevance

Data from primarily observational studies suggest that the Ross procedure is associated with lower all-cause mortality compared with mechanical aortic valve replacement. These findings highlight the need for a large, prospective randomized clinical trial comparing long-term outcomes between these 2 interventions.

Ross Procedure: How to Do It and How to Teach It

Prosthesis choice for aortic valve replacement (AVR) in children is frequently compromised by unavailability of prostheses in very small sizes, the lack of prosthetic valve growth, and risks associated with long-term anticoagulation. The Ross procedure with pulmonary valve autograft offers several advantages for pediatric and adult patients. We describe our current Ross AVR technique including replacement of the ascending aorta with a prosthetic graft. The procedure shown in the video involves an adult-sized male with a bicuspid aortic valve, mixed aortic stenosis and insufficiency, and a dilated ascending aorta.

Long-term results after aortic root replacement using self-assembled valve composite grafts in patients with small aortic annulus

OBJECTIVES

The study was aimed to evaluate operative and long-term results after complete root replacement using self-assembled valve composite grafts in patients with a small aortic annulus.

METHODS

Among 547 consecutive patients who received the Bentall procedure between 2000 and 2012, a total of 29 patients (61 ± 10; range 42-79 years) had an annulus of ≤20 mm (mean 19.0 ± 0.9). Patients with a native aortic valve (22) suffered from stenosis, insufficiency or mixed defect in 10, 10 and 2 cases, respectively. Among the remaining 7 patients with an artificial aortic valve, there were 3 symptomatic prosthesis-patient mismatches, 3 valve prosthesis deteriorations (1 structural and 2 none-structural) and 1 paravalvular leak. Indication for aortic root replacement was true or false aneurysm, porcelain aorta and intraoperative aortic wall injury in 17, 6 and 6 patients, respectively.

RESULTS

The composite graft for complete aortic root replacement was assembled using a mechanical (26) or biological (3) valve prosthesis placed inside a vascular graft with a median size of 24 (range 22-26) mm. The margin of the tube beneath the valve was anastomosed to the aortic annulus, and coronary ostia were implanted in the usual manner. The mean transvalvular gradient at discharge was 10.8 ± 3.9 mmHg and remained virtually unchanged at the follow-up completed for all patients. Early mortality was 0. During the mean follow-up of 95.8 ± 43.7 months, 2 patients died (54 and 146 months after surgery) due to pulmonary embolism and myocardial infarction, respectively.

CONCLUSIONS

In patients with a small aortic annulus who need complete aortic root replacement, an oversizing of the valve can be easily achieved using modified, self-assembled composite grafts. Offering excellent haemodynamic characteristics, these grafts lead to prevention of prosthesis-patient mismatch and result in very good and durable functional and clinical results.

The Ross-Konno procedure as reoperative treatment in a young adult with congenital aortic stenosis

Mechanical and biological prostheses are valid options when aortic valve replacement is necessary. The Ross procedure is also an alternative solution, especially for young patients. We describe the case of a young patient with congenital aortic stenosis and bicuspid aortic valve who presented with dyspnea on exertion. An open commissurotomy was performed, and within 8 months the patient developed recurrent symptoms of severe aortic stenosis. He underwent redo sternotomy and a Ross-Konno procedure with an uneventful recovery.

Mid-Term Clinical Results Using a Tissue-Engineered Pulmonary Valve to Reconstruct the Right Ventricular Outflow Tract During the Ross Procedure

BACKGROUND

The Ross procedure is mainly limited by the durability of the valve prostheses used to reconstruct the right ventricular outflow tract. This study was performed to collect prospective safety and effectiveness data of the Ross procedure using a tissue-engineered heart valve to reconstruct the right ventricular outflow tract.

METHODS

Between May 2000 and February 2003, 23 patients received tissue-engineered heart valves. Two to four weeks before the Ross operation, a piece of forearm or saphenous vein was harvested to isolate, characterize, and expand endothelial cells. A pulmonary allograft (n = 11) or xenograft (n = 12) was decellularized, coated with fibronectin, and seeded with autologous vascular endothelial cells, using a specially developed bioreactor. Follow-up was performed by clinical evaluation, transthoracic echocardiography, magnetic resonance imaging, and multislice computed tomography.

RESULTS

The patient mean age was 44.0 +/- 13.7 years. Cell seeding density was 1.1 x 10(5) +/- 0.5 x 10(5) cells/cm2, with a viability of 90.2% +/- 8.9%. All patients survived the operation. One patient died during follow-up, and 1 patient required reoperation. All surviving patients are currently in New York Heart Association functional class I. Transthoracic echocardiographic evaluation of the tissue-engineered heart valve showed a mean flow velocity of 0.9 +/- 0.4 m/s at 5 years. Multislice computed tomography showed no calcification up to 5 years postoperatively.

CONCLUSIONS

Tissue-engineered heart valves showed excellent hemodynamic performance during mid-term follow-up. Decellularization of heart valves and seeding with autologous vascular endothelial cells may prevent tissue degeneration and improve valve durability.

Is the Ross procedure as good as we thought it would be?

For patients requiring intervention because of progressive disease of the aortic valve, the perfect palliation will provide a valve that produces normal dynamics of flow, will not require anti-coagulation, will grow with the patient, and have long term durability. Current surgical interventions include aortic valvoplasty, or replacement with either a mechanical or tissue prosthesis. Options for tissue valves include insertion of a pulmonary autograft in the Ross procedure, a cadaveric homograft, or porcine or bovine xenograft valves. The optimal option is still debated.