Abstract
Background
To reconstruct the right ventricular outflow tract (RVOT) during the Ross procedure, various types of conduits are used. However, their application is often limited due to donor availability. A polytetrafluoroethylene (PTFE) valved conduit can be considered a viable alternative.
Methods
This study summarizes 17 years of experience with RVOT reconstruction via polytetrafluoroethylene (PTFE)-valved conduits in adult patients who underwent the Ross procedure. To collect data, an extensive search of our clinic’s medical database was conducted. Follow-up data were collected either via phone calls or during in-person visits.
Results
Between 2007 and 2018, 20 adult patients (> 18 years old) who underwent RVOT reconstruction with PTFE valved conduits were retrospectively analysed. The mean patient age was 39.8 ± 14.3 years, and the mean follow-up period was 9.9 ± 3.5 years. Echocardiography was used to assess conduit function during follow-up. There was one early death and one late death. The mean conduit size was 25.3 ± 1.5 mm, and the mean peak RVOT gradient was 23.3 ± 11.7 mmHg. Mild or less regurgitation was observed in 7 patients (35%), moderate - in 2 patients (10%), with no cases of severe regurgitation observed. Freedom from conduit dysfunction at the latest follow-up was 90%. Conduit replacement was successfully performed in one patient.
Conclusions
For RVOT reconstruction in adult patients undergoing the Ross procedure, a PTFE valved conduit is a feasible alternative without compromising surgical outcomes.
Trial registration
Retrospectively registered.
Supplementary Information
The online version contains supplementary material available at 10.1186/s13019-026-03878-4.
Keywords: Adult, Ross operation, Right ventricular outflow tract reconstruction, Polytetrafluoroethylene
Introduction
The Ross procedure has been established as a viable alternative for young patients, offering physiologically optimal hemodynamics and excellent long-term outcomes. Cryopreserved or decellularized pulmonary homografts remain among the most widely used conduits for right ventricular outflow tract (RVOT) reconstruction in the Ross procedure, demonstrating high rates of freedom from reoperation [1, 2]. However, limited donor availability, stringent storage requirements, and ethical restrictions in certain countries significantly hinder their widespread use. Consequently, developing alternative RVOT reconstruction techniques remains a surgical priority.
Polytetrafluoroethylene (PTFE) valved conduits are already widely employed in congenital heart defect repair in children [3–5], yet their application in adults remains understudied. In this retrospective study, we present long-term outcomes of RVOT reconstruction via PTFE valved conduits in adult patients undergoing the Ross procedure.
Methods
Patients
We retrospectively analysed consecutive adult patients (> 18 years) who underwent RVOT reconstruction with PTFE valved conduits during the Ross procedure between 2007 and 2018. From an initial cohort of 32 eligible procedures, we excluded redo operations and pediatric cases (< 18 years), yielding 20 patients for the final analysis. All primary procedures were performed by a single surgeon. The baseline demographic and clinical characteristics are detailed in Table 1.
Table 1.
Demographic and baseline characteristics
| Variables | Values |
|---|---|
| Number of patients | 20 |
| Age (years), mean ± SD | 39.8 ± 14.3 |
| Sex, n (%) | |
| Male | 12 (60) |
| Female | 8 (40) |
| Body mass index (kg/m2), mean ± SD | 23.4 ± 5.5 |
| Body surface area (m2), mean ± SD | 1.69 ± 0.38 |
| NYHA functional class, n (%) | |
| II class | 12 (60) |
| III class | 8 (40) |
| Aortic valve disease aetiology, n (%) | |
| Congenital | 11 (55) |
| Degenerative | 4 (20) |
| Endocarditis | 1 (5) |
| Rheumatic | 4 (20) |
NYHA – New York Heart Association, SD – standard deviation
Study endpoints and follow-up
The primary endpoint was reoperation on the PTFE conduit, indicated by severe conduit stenosis, moderate-to-severe conduit regurgitation (≥ grade 2), clinical symptoms caused by conduit stenosis/regurgitation, and right ventricular dysfunction or progressive tricuspid regurgitation secondary to conduit pathology. The secondary endpoints included all-cause mortality, major adverse cardiac and cerebrovascular event (MACCE) rate, echocardiographic assessment of PTFE-conduit function and autograft reinterventions.
After discharge, patients were followed up through in-person visits. In cases where in-person monitoring was not possible, follow-up was conducted via telephone calls or email correspondence. The patient follow-up rate was 100%, and no patients were lost to follow-up. The mean follow-up period was 9.9 ± 3.5 years. Echocardiography at the last follow-up was performed for all patients.
Conduit features
The “EvRos-MI” pulmonary valve prosthesis was fabricated as a complete valved conduit via a standardized manufacturing protocol with specialized surgical templates. Three paired leaflet-sinus units were precision-formed from PTFE material (0.1 mm thickness for leaflets and 0.4 mm for sinuses) and meticulously assembled to create a trileaflet architecture with anatomically shaped sinuses. The construct incorporates separate linear PTFE prostheses that form both ventriculo-arterial and sinotubular junctions (Fig. 1).
Fig. 1.
Polytetrafluoroethylene-valved conduit «EvRos-MI»
For optimal hemostasis, all suture lines were sealed with biocompatible surgical adhesive. The prosthesis was industrially manufactured under strict quality control protocols by the JSC Research and Production Enterprise “MedEng” (CardiaMed, Penza, Russian Federation).
Operative technique
All procedures were performed via standard median sternotomy with cardiopulmonary bypass established through aorta-bicaval cannulation under moderate hypothermia (28–32 °C). Following aortic cross-clamping and antegrade cardioplegia delivery, the pulmonary autograft was harvested and reimplanted in the aortic position. For RVOT reconstruction, individually sized PTFE conduits (mean diameter 25.3 ± 1.5 mm) were selected from available prosthesis dimensions. To optimize myocardial protection, RVOT reconstruction was performed during reperfusion after aortic unclamping in 80% of the patients (n = 16). Both proximal (ventricular) and distal (pulmonary) anastomoses were constructed via a continuous 5–0 PTFE running suture technique. The concomitant procedures included mitral valve repair (5%), tricuspid valve repair (10%), coronary artery bypass grafting (5%) and septal myectomy (15%). More detailed operative data are presented in Table 2.
Table 2.
Operative characteristics
| Variables | Values |
|---|---|
| Conduit size (mm), n (%) | |
| 22 | 1 (5) |
| 23 | 2 (10) |
| 24 | 1 (5) |
| 25 | 9 (45) |
| 27 | 7 (35) |
| Cardiopulmonary bypass time (min), mean ± SD | 199.3 ± 63.4 |
| Aortic cross clamp time (min), mean ± SD | 149.7 ± 36.3 |
| Additional interventions, n (%) | |
| Mitral valve repair | 1 (5) |
| Tricuspid valve repair | 2 (10) |
| CABG | 1 (5) |
| Septal myectomy | 3 (15) |
CABG – coronary artery bypass grafting, SD – standard deviation
Statistical analysis
Categorical variables are presented as counts and percentages, whereas continuous variables are expressed as the means ± standard deviations (SDs) for normally distributed data or medians (interquartile ranges) for nonnormally distributed data. The differences between the preoperative and postoperative data were assessed for statistical significance via paired Student’s t test, the Wilcoxon signed-rank test for paired data, or Fisher’s exact test if the expected frequency was < 5. Survival, freedom from autograft reintervention, and freedom from PTFE-conduit dysfunction were estimated via the Kaplan‒Meier method, and the results are reported with 95% confidence intervals (CIs). To analyse risk factors associated with late mortality, freedom from autograft reintervention and freedom from PTFE-conduit dysfunction, we reviewed the preoperative and intraoperative variables and used univariable Cox proportional hazard regression models to calculate hazard ratios (HRs) and 95% CI. P values < 0.05 were considered statistically significant. Stata/MP for Windows, version 13.0 (StataCorp LLC, College Station, TX, USA), was used for the statistical analyses.
Results
The hospital mortality rate in the study was 5% (1 patient), with a single early death resulting from low cardiac output syndrome secondary to myocardial infarction requiring prolonged extra corporeal membrane oxygenation (ECMO) support, unrelated to conduit pathology. During the follow-up period, one case of late mortality occurred due to COVID-19-associated pulmonary thromboembolism. No cases of myocardial infarction, stroke, or thromboembolic complications were observed during the follow-up period.
Echocardiographic evaluation at the final follow-up revealed a mean peak RVOT gradient of 23.3 ± 11.7 mmHg across the cohort.
The assessment of conduit regurgitation was performed using standard quantitative and qualitative echocardiographic criteria. Patients without conduit insufficiency were excluded from the final analysis. Conduit function assessment revealed mild or less regurgitation in 35% of patients (n=7) and moderate regurgitation in 10% (n=2), with no instances of severe regurgitation. Severe conduit stenosis was identified in 10% of the patients (n=2), including one patient who underwent reoperation at two years postprocedure (Fig. 2). Reoperation was indicated by significant stenosis at the distal anastomotic site between the PTFE conduit and pulmonary artery bifurcation. Intraoperatively, the PTFE valve leaflets were found to be functionally intact, although complete conduit explantation was required for pulmonary artery repair. The right ventricular outflow tract was reconstructed again using a new PTFE conduit. Five years following this intervention, the same patient developed severe stenosis of the replacement PTFE conduit with extensive calcification of both wall and valve structures, ultimately necessitating homograft replacement (Fig 3). A second patient with a peak gradient of 58 mmHg is currently awaiting surgical intervention.
Fig. 2.
Kaplan-Meier curve of freedom from PTFE conduit dysfunction. PTFE – Polytetrafluoroethylene
Fig. 3.
PTFE graft after surgical removal. a - superior (en face) view demonstrating calcification of both the conduit wall and the leaflets; b - the conduit has been opened longitudinally, revealing calcific deposits within the leaflets
Echocardiographic data at discharge and the latest follow-up are presented in Table 3.
Table 3.
Follow-up echocardiogram results
| Echocardiographic characteristics | At discharge | At last follow-up |
|---|---|---|
| RVOT gradient (mmHg), mean ± SD | ||
| Peak | 14.6 ± 7.5 | 23.3 ± 11.7 |
| Mean | 9.2 ± 6.0 | 12.3 ± 6.9 |
| Conduit regurgitation, n (%) | ||
| Mild\less | 3 (15) | 7 (35) |
| Moderate | 0 | 0 |
| Severe | 0 | 2 (10) |
| RV FAC (%) mean ± SD | 46.8 ± 7.0 | 43.6 ± 5.3 |
FAC – fractional area change, RV – right ventricular, RVOT – right ventricular outflow tract, SD – standard deviation
Notably, no patients developed right ventricular dysfunction or clinically significant tricuspid regurgitation during follow-up. Univariable analysis failed to identify significant predictors of conduit dysfunction (Supplementary Table 1).
The autograft reintervention rate was 15% (n = 3), comprising one case of sinus of Valsalva fistula repaired with a MemoPart™ occluder device (Shanghai Shape Memory Alloy Co., Ltd.) and two cases of fibrotic neoaortic valve degeneration leading to severe aortic insufficiency, both of which were treated with mechanical valve replacement (Fig. 4).
Fig. 4.
Kaplan-Meier curve of freedom from Autograft dysfunction
Discussion
At present, a wide variety of materials are available for the reconstruction of the RVOT, including cryopreserved aortic and pulmonary homografts, various xenografts, biological heart valves, and, more recently, polymer materials. Given this diversity, surgeons must select the optimal conduit for each patient. Durability is a key criterion prioritized by patients, as a longer-lasting conduit reduces the risk of reoperation. The advantages and disadvantages of the most commonly used conduits are well documented in numerous studies [6–8].
Results from the largest meta-analysis evaluating outcomes after the Ross procedure in adult patients, published by Serena Sibilio, aggregated data from 19,155 patients across 63 studies. The estimated all-cause mortality rate at mean follow-up was 5.9%. Among all included studies, 29 (N = 7,024) provided data on the rate of pulmonary reintervention, and 30 studies (N = 7,600) reported data on aortic reintervention. The pooled rates of reintervention on the pulmonary and aortic valves were 3.42% (95% CI: 2.67%–4.25%; I² = 63.79%) and 5.75% (95% CI: 4.41%–7.25%; I² = 84.23%), respectively [9].
Based on our experience with the Ross procedure, we believe that cryopreserved pulmonary homografts remain a reliable choice for RVOT reconstruction [8]. However, their preparation, storage requirements, and limited donor availability often restrict their consistent use. These limitations underscore the need to explore alternative materials.
The use of PTFE for creating valved synthetic prostheses is not entirely novel. Synthetic valves were first introduced for congenital heart disease in the 20th century [3]. However, reports on PTFE conduit implantation in adults remain scarce. One of the few studies by Carlos E. Diaz-Castrillon et al. compared PTFE conduits and homografts in 60 Ross procedure patients, including 14 adults [10]. They reported no increased hazard ratio for conduit reintervention (HR, 0.87; 95% CI, 0.20–2.75; P = 0.85). Our study evaluated adult Ross patients with PTFE valved conduits and demonstrated favourable hemodynamics (mean peak gradient: 23.3 ± 11.7 mmHg) and valve competency (35% had mild or less regurgitation, with no severe cases). Freedom from PTFE dysfunction at the latest follow-up was 90%.
An important consideration is the potential for repeat endovascular interventions. A number of authors suggest that PTFE conduits may be amenable to stenting or balloon dilation [11]. However, to date, no specific data have been presented that detail the technical aspects or outcomes of endovascular interventions in such conduits. Notably, none of our patients, including pediatric patients, required transcatheter interventions on pulmonary-position PTFE conduits. Continued follow-up may reveal further insights into endovascular approaches.
Durability remains a critical factor. Yasunobu Hayabuchi et al. used multidetector-row computed tomography (MDCT) to assess calcification in 66 PTFE grafts, including 32 RVOT prostheses. Calcification was detected in 26 of 32 cases (81%) [12]. Histopathologic analysis of explanted PTFE-valved conduits revealed a significant correlation between calcification and proteinaceous infiltration (correlation coefficient: 0.67, P < 0.001) [13]. Modifying the material to prevent protein infiltration could improve prosthesis longevity.
PTFE conduits have undergone iterative technological refinements, with contemporary iterations now incorporating anatomically optimized designs featuring sinus of Valsalva bulges and geometrically enhanced fan-shaped valve leaflets. Longitudinal outcome data demonstrate differential performance on the basis of conduit diameter: small-caliber conduits (8–16 mm) exhibited 92.3% and 76.1% freedom from reintervention at 5- and 10-year follow-up intervals, respectively, whereas larger diameter prostheses (18–24 mm) demonstrated superior durability, with 99.6% and 95.1% freedom from intervention over equivalent timeframes [14]. Although current manufacturing specifications predominantly target pediatric applications, these robust hemodynamic performance metrics suggest significant translational potential for adult-adapted configurations while maintaining valvular competence and flow dynamics.
Limitations
This study has several important limitations that warrant consideration. First, the retrospective single-center design inherently limits the generalizability of our findings. Second, while our follow-up duration was substantial, the relatively small cohort size may reduce the statistical power to detect clinically significant differences. This sample size limitation precluded meaningful comparative analyses with alternative conduit types, a critical gap that will be addressed in our ongoing prospective multicenter study.
Conclusion
Our findings demonstrate that PTFE valved conduits represent a hemodynamically competent and durable option for RVOT reconstruction in adult Ross procedures. The observed outcomes, including favourable transconduit gradients (23.3 ± 11.7 mmHg) and excellent freedom from dysfunction (90%), suggest comparable performance to conventional alternatives.
Supplementary Information
Acknowledgements
Not applicable.
Abbreviations
- CABG
Coronary artery bypass grafting
- FAC
Fractional area change
- MACCE
Major adverse cardiac and cerebrovascular event
- RVOT
Right ventricular outflow tract
- SD
Standard deviation
- PTFE
Polytetrafluoroethylene
Author contributions
RK and AB-P designed the study, collected the data, and wrote the main text of the paper. AA and RS performed a systematic analysis of the collected data. DA, ID and ER conducted the final analysis of the work and implemented the concluding revisions.
Funding
Not applicable.
Data availability
All data generated or analysed during this study are included in this published article.
Declarations
Ethics approval and consent to participate
The study was approved by the Internal Ethics Committee on December 16, 2016 (Meeting Protocol No. 44).
Consent for publication
Not applicable.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
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Associated Data
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Data Citations
Supplementary Materials
Data Availability Statement
All data generated or analysed during this study are included in this published article.