The Ross procedure in adults: which patients, which disease?

Outcomes of the Ross procedure in patients older versus younger than 50 years old

OBJECTIVES

The Ross procedure is traditionally considered for young adult patients with aortic valve disease. This study compares long-term outcomes of patients undergoing the Ross procedure who are ≥50 and <50-years old.

METHODS

Data were collected from 225 patients undergoing Ross procedure at a single centre from 1994 to 2019. Patients were categorized into younger (<50-years old; n = 156) and older (≥50-years old; n = 69) cohorts. Baseline demographics clinical outcomes were compared.

RESULTS

The mean age was 36 ± 8.1 and 55 ± 4.2 years in the younger and older cohort, respectively. Both groups were predominantly male (58.5% vs 69.6%; P = 0.59). The younger group had a higher rate of aortic insufficiency (51% vs 26.1%; P < 0.01), and bicuspid aortic valve (81.4% vs 58.0%; P < 0.01). Aortic stenosis was more prevalent in the older cohort (25.6% vs 58.0%; P < 0.01). Operative mortality was acceptable in both groups (1.3% vs 4.3%; P = 0.15). Survival up to 10 years was not statistically different between 2 groups (96.2% vs 91.3% P = 0.16), whereas survival up to 15 years for younger patients was significantly higher (94.9% vs 85.5%; P = 0.03). After non-cardiac related deaths were excluded, survival up to 15 years (98.7% vs 91.3%; P = 0.02) was significantly lower than younger patients. In both groups, survival after the Ross procedure was similar to the age- and sex-matched US population.

CONCLUSIONS

Survival up to 10 years after Ross procedure were similar, but up to 15 years was significantly higher in younger patients. The Ross procedure restored patients from both groups to expected survival. Our results suggest that at experienced centres, the Ross procedure is a safe and reasonable option for patients who are 50 years and older.

New insights into the hemodynamics of pulmonary homograft patients under stress echocardiography: The contribution of pressure recovery

BACKGROUND

The importance of pulmonary artery pressure recovery (PR) in patients with Ross procedures in whom a homograft substitutes the resected pulmonary valve, is unknown. The aim of the study was to evaluate the occurrence and extent of PR in the pulmonary artery in 65 asymptomatic patients with pulmonary homograft after Ross surgery during rest and exercise.

METHODS

Stress echocardiography was performed in 65 pulmonary homograft patients and 31 controls with native pulmonary valves up to 75 W. Right ventricular systolic pressure (RVSP), transvalvular flow, mean pressure gradient (Pmean ), valve resistance, and RV stroke work were determined in the exercise (max. 75 W) and recovery phases in increments of 25 W each.

RESULTS

Pulmonary homografts demonstrated significantly elevated Pmean compared to controls at all stages. When considering pressure recovery (absolute and relative PR at rest 3.8 ± 1.8 mm Hg, 42.6 ± 7.2%, respectively) and transvalvular energy loss (EL; at rest 4.5 ± 4.3 mm Hg) the homograft hemodynamics reached the level of controls. In a subgroup of patients with tricuspid regurgitation, resting RVSP was the same in homograft patients and controls (21.3 ± 6.1 vs. 20.4 ± 6.3, p = .62), despite significant different Pmax values.

CONCLUSIONS

Ross patients with pulmonary homograft showed systematically increased hemodynamic parameters compared to normal pulmonary valves. These differences were abolished when PR was considered for homograft patients. The equality of RVSP values at rest in both groups shows non-invasive evidence for PR in the pulmonary system after homograft implantation. Therefore, PR appears to be an important measure in calculating the actual hemodynamics in pulmonary homografts.

Physical and Mental Recovery after Aortic Valve Surgery in Non-Elderly Patients: Native Valve-Preserving Surgery vs. Prosthetic Valve Replacement

Background: Exercise capacity and patient-reported outcomes are increasingly considered crucial following aortic valve (AV) surgery in non-elderly adults. We aimed to prospectively evaluate the effect of native valve preservation compared with prosthetic valve replacement. Methods: From October 2017 to August 2020, 100 consecutive non-elderly patients undergoing surgery for severe AV disease were included. Exercise capacity and patient-reported outcomes were evaluated upon admission, and 3 months and 1 year postoperatively. Results: In total, 72 patients underwent native valve-preserving procedures (AV repair or Ross procedure, NV group), and 28 patients, prosthetic valve replacement (PV group). Native valve preservation was associated with an increased risk of reoperation (weighted hazard ratio: 10.57 (95% CI: 1.24-90.01), p = 0.031). The estimated average treatment effect on six-minute walking distance in NV patients at 1 year was positive, but not significant (35.64 m; 95% CI: -17.03-88.30, adj. p = 0.554). The postoperative physical and mental quality of life was comparable in both groups. Peak oxygen consumption and work rate were better at all assessment time points in NV patients. Marked longitudinal improvements in walking distance (NV, +47 m (adj. p < 0.001); PV, +25 m (adj. p = 0.004)) and physical (NV, +7 points (adj. p = 0.023); PV, +10 points (adj. p = 0.005)) and mental quality of life (NV, +7 points (adj. p < 0.001); PV, +5 points (adj. p = 0.058)) from the preoperative period to the 1-year follow-up were observed. At 1 year, there was a tendency of more NV patients reaching reference values of walking distance. Conclusions: Despite the increased risk of reoperation, physical and mental performance markedly improved after native valve-preserving surgery and was comparable to that after prosthetic aortic valve replacement.

Structural dysregulation of the pulmonary autograft was associated with a greater density of p16INK4A-vascular smooth muscle cells

The present study tested the hypothesis that a senescent phenotype of vascular smooth muscle cells (VSMCs) may represent the seminal event linked to maladaptive pulmonary autograft remodeling of a small number of patients that underwent the Ross procedure. The diameter of the pulmonary autograft (47±4 mm) of three male patients was significantly greater compared to the pulmonary artery (26±1 mm) excised from bicuspid aortic valve (BAV) patients. The pulmonary autograft was associated with a neointimal region and the adjacent medial region was significantly thinner compared to the pulmonary artery of BAV patients. Structural dysregulation was evident as elastin content of the medial region was significantly reduced in the pulmonary autograft compared to the pulmonary artery of BAV patients. By contrast, collagen content of the medial region of the pulmonary autograft and the pulmonary artery of BAV patients was not significantly different. Reduced medial elastin content of the pulmonary autograft was associated with increased protein levels of matrix metalloproteinase-9. The latter phenotype was not attributed to a robust inflammatory response as the percentage of Mac-2⁽⁺⁾-infiltrating monocytes/macrophages was similar between groups. A senescent phenotype was identified as protein levels of the cell cycle inhibitor p27^kip1 were upregulated and the density of p16^INK4A/non-muscle myosin IIB⁽⁺⁾-VSMCs was significantly greater in the pulmonary autograft compared to the pulmonary artery of BAV patients. Thus, senescent VSMCs may represent the predominant cellular source of increased matrix metalloproteinase-9 protein expression translating to maladaptive pulmonary autograft remodeling characterized by elastin degradation, medial thinning and neointimal formation.

Ross Procedure in Neonate and Infant Populations: A Meta-Analysis Review

Objective

This study aims to perform a meta-analysis of early and late outcomes of the Ross/Ross-Konno procedures in neonates/infants.

Methods

A meta-analysis was performed in accordance with PRISMA guidelines. We used Ovid versions of MEDLINE/PubMed for relevant studies and included those that reported Ross/Ross-Konno operations in neonates/infants and at least one of the predetermined clinical outcomes. I2 and double arcsine methods assessed the heterogeneity between pooled estimates. We used a random-effect model to account for heterogeneity with MetaXL. We calculated point estimates of a pooled estimates along with its 95% CI.

Results

587 neonate/infant patients were included with median age of 87.5 days old. The follow-up range was five days to 23 years. Early mortality reported in 25 studies with pooled estimates of 18.3% (95% CI: 13.6%-23.5%). Estimates ranged from 0% to 50% with relatively substantial heterogeneity ( P = .01, I2 = 48.6%). Late mortality reported in 22 studies with pooled incidence of 9.7% (95% CI: 5.9%-14.3%). Estimates ranged from 0% to 53% with relatively substantial heterogeneity ( P = .01, I2 = 46.1%). Autograft reintervention reported in 18 studies with pooled estimate of 19.2% (95% CI: 7.3%-34.5%). Estimates ranged from 0% to 81.8% with high heterogeneity ( P < .001, I2 = 90.5%). Right ventricle-to-pulmonary artery conduit reintervention reported in 16 studies with pooled estimates of 32.0% (95% CI: 20.9%-44.12%). Estimates ranged from 0% to 92.3% with high heterogeneity ( P < .001, I2 = 75.9%).

Conclusions

The data suggest that the Ross/Ross-Konno procedure in neonates/infants still carries significant risk of early/late mortality and autograft/conduit reintervention. The high variability of results among centers confirms the need for surgical expertise and good patient selection. Prospective multicenter studies are warranted to investigate the rate of autograft reintervention and the impact on long-term survival in this specific population.

Outcomes of Redo Operations after Ross procedure

BACKGROUND

The Ross procedure is not commonly performed, owing to the procedural complexity and the risk of autograft and/or homograft reoperation. This study examined outcomes of patients undergoing Ross reinterventions at a dedicated Ross center.

METHODS

We retrospectively reviewed 225 consecutive patients who underwent a Ross procedure between 1994 and 2019. Index and redo operation characteristics and outcomes were compared between patients with and those without redo operations. Multivariate analysis was used to identify independent predictors of Ross-related reinterventions. Survival was estimated with Kaplan-Meier analysis.

RESULTS

Sixty-six patients (29.3%) required redo Ross surgery, 41 patients (18.2%) underwent autograft reoperation only, 8 patients (3.6%) had a homograft reintervention, and 17 patients (7.6%) had both autograft and homograft reoperations (12 as a combined procedure and 5 as sequential procedures). The mean time to reintervention was 11 ± 6 years for autograft reoperations and 12 ± 7 years for homograft reoperations. Patients who underwent Ross-related reinterventions were younger (mean, 38 ± 11 years vs 43 ± 11 years; P < .01) and had a higher rate of New York Heart Association class III/IV (56% vs 38%; P = .02) at the index Ross procedure. Most patients undergoing autograft reintervention had aortic insufficiency and/or aneurysm (98.2%; 57 of 58). The primary reason for homograft reintervention was pulmonary stenosis (92%; 23 of 25). The operative mortality of Ross reintervention was 1.5% (1 of 66). Survival at 15 years was similar in patients who required a redo operation and those who did not (91.2% vs 93.9%; P = .23).

CONCLUSIONS

Ross reinterventions can be performed safely and maintain patients at the normal life expectancy restored by the index Ross procedure up to 15 years at experienced centers.

The Ross procedure is the optimal solution for young adults with unrepairable aortic valve disease

While aortic valve repair remains the ideal intervention to restore normal valvular function, the optimal aortic valve substitute for patients with a non-repairable aortic valve remains an ongoing subject for debate. In particular, younger patients with a non-repairable valve represent a unique challenge because of their active lifestyle and long life expectancy, which carries a higher cumulative risk of prosthesis-related complications. The Ross procedure, unlike prosthetic or homograft aortic valve replacement (AVR), provides an expected survival equivalent to that of the age and gender-matched general population. Contemporary data has shown that the Ross procedure can be performed safely in centers with expertise, and is associated with improved valvular durability, hemodynamics and quality of life.

The Ross procedure in children: a systematic review

Background

The Ross procedure involves autograft transplantation of the native pulmonary valve into the aortic position and reconstruction of the right ventricular outflow tract (RVOT) with a homograft. The operation offers the advantages of a native valve with excellent hemodynamic performance, the avoidance of anticoagulation, and growth potential. Conversely, the operation is technically demanding and imposes the risk of turning single-valve disease into double-valve disease. This systematic review reports outcomes of pediatric patients undergoing the Ross procedure.

Methods

An electronic search identified studies reporting outcomes on pediatric patients (mean age <18 years, max age <21 years) undergoing the Ross procedure. Long-term outcomes, including early mortality, late mortality, sudden unexpected unexplained death, reoperation due to failure of the pulmonary autograft or RVOT reconstruction, thromboembolic events, bleeding events, and endocarditis-related complications, were evaluated.

Results

Upon review of 2,035 publications, 30 studies and 3,156 pediatric patients were included. Patients had a median age of 9.5 years and median follow-up period of 5.7 years. Early mortality rates varied from 0.0 to 17.0% and were increased in the neonatal population. Late mortality rates were much lower (0.04-1.83%/year). Reoperation due to pulmonary autograft failure occurred at rates of 0.37-2.81%/year and reoperation due to RVOT reconstruction failure was required at rates of 0.34-4.76%/year. Thromboembolic, bleeding, and endocarditis events were reported to occur at rates of 0.00-0.58, 0.00-0.39, and 0.00-1.68%/year, respectively.

Conclusions

The Ross operation offers a durable aortic valve replacement (AVR) option in the pediatric population that offers favorable survival, excellent hemodynamics, growth potential, decreased risk of complications, and avoidance of anticoagulation. Larger multi-institutional registries focusing on pediatric patients are necessary to provide more robust evidence to further support use of the Ross procedure in this population.

Distinct Expression of Nonmuscle Myosin IIB in Pulmonary Arteries of Patients With Aortic Stenosis vs Insufficiency Undergoing a Ross Procedure

BACKGROUND

Clinical studies have revealed a greater risk of pulmonary autograft dilation after the Ross procedure in patients with preoperative aortic insufficiency (AI). The present study examined whether the morphologic, biomechanical, and cellular properties of the pulmonary artery (PA) from patients with AI were phenotypically different compared with patients diagnosed with aortic stenosis (AS).

METHODS

PA segments were harvested from patients undergoing the Ross procedure for AS (n = 16) and AI (n = 6). Preoperative aortic annulus was significantly larger (P < 0.05) in patients with AI (28.5 ± 1.8 mm) vs AS (22.8 ± 1.2 mm). Morphologic, biomechanical, and cellular phenotypes of the PA were analyzed.

RESULTS

Collagen and elastin content in the media of the PA wall were similar in patients with AS and AI. Elastic modulus and energy loss of the PA were not significantly different between the groups. In the media of the PA, expression of a panel of vascular smooth muscle cell-specific proteins were similar in patients with AS and AI. In contrast, nonmuscle myosin IIB protein levels in the PA of AS patients were significantly higher compared with AI patients, and immunofluorescence identified staining in α-smooth muscle actin-positive vascular smooth muscle cells.

CONCLUSIONS

Despite similar morphological and biomechanical properties, the disparate expression of nonmuscle myosin IIB protein distinguishes the PA of patients with AI from patients with AS. The biological role in vascular smooth muscle cells and the potential contribution of nonmuscle myosin IIB to pulmonary autograft dilation in a subset of AI patients after the Ross procedure remain to be determined.

Outcomes and Quality of Life After Ross Reintervention: Would You Make the Same Choice Again?

BACKGROUND

The Ross procedure was introduced as a long-term if not definitive solution for aortic pathology. However, the rate of reoperation is not negligible.

METHODS

This single-center prospective study assessed the general outcome of Ross reoperation and patients' perceived quality of life compared with 2 control groups (Ross non-reoperation and mechanical aortic valve replacement). Patient's preference regarding the choice between mechanical aortic valve and Ross procedure was investigated in a subgroup that could theoretically have been directed to either of the 2 procedures.

RESULTS

Between 2005 and 2017, 64 consecutive patients underwent reoperation after Ross. Median age was 31 years. Median freedom from reoperation after the Ross procedure was 136 months. An autograft reoperation was required in 49, and 25 had homograft failure. No in-hospital death was recorded. Mean follow-up was 77 months (range, 6-164 months). Quality of life was assessed with the 36-Item Short Form Health Survey questionnaire. The Ross reoperation group showed a lower score involving psychological concerns compared with the other groups. In the reoperated-on patients group, 52 had adequate aortic annulus dimensions to receive a prosthetic valve instead of a Ross procedure. When asked whether they would make the same choice, only 31% confirmed the preference.

CONCLUSIONS

Reoperations after Ross procedure have low mortality and morbidity. Long-term follow-up showed a high quality of life, even after reoperations. However, owing to psychological concerns after the redo operation, when choosing a Ross procedure, it is our duty to thoroughly explain to patients that a high level of disillusion is predictable in case of reoperations.

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.

Valve performance classification in 630 subcoronary Ross patients over 22 years

OBJECTIVE

To define the function of the "Ross valves" and its clinical meaning in a practical valve performance classification as part of the outcome analysis.

METHODS

From 1994 to 2017, 630 consecutive patients underwent the subcoronary Ross procedure at our institution. The valve performance classification combines hemodynamics, symptoms, and management criteria. Median follow-up was 12.5 years (maximum 22.3 years, 7404 patient-years, 99.4% completeness).

RESULTS

The mean age of the patients was 44.7 ± 11.9 years. Hospital deaths was 0.3% (n = 2). Twenty years after the operation survival was 73.1% (95% confidence interval [CI], 65.4%-81.6%) and statistically not different from the age- and gender-matched general population; freedom from reoperation was 85.9% (95% CI, 80.2%-92.0%; 0.6% per patient-year), 89.8% (95% CI, 84.3%-95.7%) for autograft, and 91.0% (95% CI, 86.3%-96.0%) for homograft. Preoperative annulus diameter, aortic regurgitation, annulus reinforcement, sinotubular junction reinforcement, and bicuspid aortic valve type were no significant risk factors for reoperation. At 20 years the probability of a patient being in valve performance class I to IV was 5%, 74%, 19%, and 1%, respectively. Time to reoperation was not different in bicuspid and tricuspid aortic valves; preoperative aortic stenosis tended to have better outcome of autograft function.

CONCLUSIONS

These up to 22 years data show that the subcoronary Ross procedure continues to provide an excellent tissue aortic valve replacement. The suggested valve performance classification emerged as a practical concept for outcome analysis with the probability of 79% being in the favorable class I or II at 20 years.