Outcome of Right Ventricle to Pulmonary Artery Conduit for Biventricular Repair

Performance and Failure of Right Ventricle to Pulmonary Artery Conduit in Congenital Heart Disease

Surgical implantation of a right ventricle to pulmonary artery (RV-PA) conduit is an important component of congenital heart disease (CHD) surgery, but with limited durability, leading to re-intervention. The present single-center, retrospective, cohort study reports the results of surgically implanted RV-PA conduits in a consecutive series of children and adults with CHD. Patients with CHD referred for RV-PA conduit surgical implantation (from October 1997 to January 2022) were included. The primary outcome was conduit failure, defined as a peak gradient above 64 mm Hg, severe regurgitation, or the need for conduit-related interventions. Longitudinal echocardiographic studies were available for mixed-effects linear regression analysis. A total of 252 patients were initially included; 149 patients were eligible for follow-up data collection. After a median follow-up time of 49 months, the primary study end point occurred in 44 (29%) patients. A multivariable Cox regression model identified adult age (>18 years) at implantation and pulmonary homograft implantation as protective factors (hazard ratio 0.11, 95% confidence interval [CI] 0.02 to 0.47 and hazard ratio 0.34, 95% CI 0.16 to 0.74, respectively). Fever within 7 days of surgical conduit implantation was a risk factor for early (within 24 months) failure (odds ratio 4.29, 95% CI 1.41 to 13.01). Long-term use of oral anticoagulants was independently associated with slower progression of peak echocardiographic gradient across the conduits (mixed-effects linear regression p = 0.027). In patients with CHD, the rate of failure of surgically implanted RV-PA conduits is higher in children and after nonhomograft conduit implantation. Early fever after surgery is a strong risk factor for early failure. Long-term anticoagulation seems to exert a protective effect.

Outcomes after Biventricular Repair Using a Conduit between the Right Ventricle and Pulmonary Artery in Infancy

Background

This study investigated the outcomes of biventricular repair using right ventricle to pulmonary artery (RV-PA) conduit placement in patients aged <1 year.

Methods

Patients aged <1 year who underwent biventricular repair using an RV-PA conduit between 2011 and 2020 were included in this study. The outcomes of interest were death from any cause, conduit reintervention, and conduit dysfunction (peak velocity of ≥3.5 m/sec or moderate or severe regurgitation).

Results

In total, 141 patients were enrolled. The median age at initial conduit implantation was 6 months. The median conduit diameter z-score was 1.3. The overall 5-year survival rate was 89.6%. In the multivariable analysis, younger age (p=0.006) and longer cardiopulmonary bypass time (p=0.001) were risk factors for overall mortality. During follow-up, 61 patients required conduit reintervention, and conduit dysfunction occurred in 68 patients. The 5-year freedom from conduit reintervention and dysfunction rates were 52.9% and 45.9%, respectively. In the multivariable analysis, a smaller conduit z-score (p<0.001) was a shared risk factor for both conduit reintervention and dysfunction. Analysis of variance demonstrated a nonlinear relationship between the conduit z-score and conduit reintervention or dysfunction. The hazard ratio was lowest in patients with a conduit z-score of 1.3 for reintervention and a conduit z-score of 1.4 for dysfunction.

Conclusion

RV-PA conduit placement can be safely performed in infants. A significant number of patients required conduit reintervention and had conduit dysfunction. A slightly oversized conduit with a z-score of 1.3 may reduce the risk of conduit reintervention or dysfunction.

Early Outcome of Simplified Standardized Trileaflet Polytetrafluoroethylene Valved Conduit Placement

Background

Use of the expanded polytetrafluoroethylene (ePTFE) valved conduit in the pulmonary position during the correction of congenital heart defects has significantly increased in popularity over the last decade due to its promising conduit longevity. We describe the standardized process to create and implant a trileaflet ePTFE pulmonary conduit along with the early outcomes of such procedures at our institute.

Methods

Records of 100 consecutive patients who underwent ePTFE valved conduit placement using our technique from April 2018 through February 2022 were retrospectively analyzed. The function of the conduit was evaluated by transthoracic echocardiography.

Results

The mean age of the patients was 28 ± 13.2 years old at the time of the operation. The conduit diameters ranged from 16 to 24 mm (mean 23.0 ± 1.9 mm). Conduit placement was utilized for pulmonary valve replacement in 68 patients, conduit change in 25 patients, and as a part of total repair in 7 patients. There were 2 in-hospital conduit-unrelated deaths from multi-organ dysfunction and pulmonary hypertensive crisis. From the postoperative echocardiography, the average peak pressure gradient across the conduit was 18.6 ± 9.0 mm Hg, and the conduit regurgitation was graded as none or trace in 81 patients, mild in 17 patients, and moderate in 2 patients. At 589 days of median follow-up, there was no conduit reoperation. Follow-up imaging of 60 available patients at a median time of 511 days did not show a significant change in conduit function.

Conclusions

Our standardized ePTFE valved conduit creation and placement demonstrated satisfactory clinical and echocardiographic outcomes.

Decellularized bovine jugular vein and hand-sewn ePTFE valved conduit for right ventricular outflow tract reconstruction in children undergoing Ross procedure

Background

The Ross procedure is recommended as an optimal aortic valve replacement (AVR) in children and young adults due to several advantages. Nevertheless, multiple reconstructions of the right ventricular outflow tract (RVOT) with new valve conduits have caused some concern regarding the durability of the Ross AVR. Decellularized bovine jugular vein conduit (BJVC) (DP-BJVC) and hand-sewn expanded polytetrafluoroethylene valved conduits (ePTFE VC) are widely employed to reconstruct the RVOT with satisfactory long-term outcomes. However, few studies have compared the safety and efficacy between the two valve conduits. We aimed to evaluate the early outcomes and report our single center experience in the application of these conduits.

Methods

Twenty-two pediatric patients (aged &lt; 18 years) who underwent Ross procedures with DP-BJVC and ePTFE VC in our center between 1 June, 2017 and 31 January, 2022 were enrolled. The Kaplan–Meier method was used to evaluate survival, freedom from RVOT reintervention, and freedom from RVOT graft dysfunction. Mixed-effects analysis with the Geisser–Greenhouse correction and Sidak's multiple comparisons test for post-hoc analysis was employed to compare the peak gradient across the conduit at varying follow-ups.

Results

All patients were followed up in full. The total early survival rate was 90.9%; two patients in the DP-BJVC group died. There was no significant difference in early mortality, cross-clamp time (p = 0.212), in-hospital stay (p = 0.469), and RVOT graft thrombosis or endocarditis between the two groups. There was similarly no significant difference between Kaplan–Meier freedom from RVOT graft dysfunction curve (P = 0.131). The transprosthetic gradient gradually increased over time in both groups and was significantly higher in the DP-BJVC group at follow-up (P &lt; 0.05).

Conclusions

Both conduits show excellent early and midterm outcomes for RVOT reconstruction in the Ross procedure. We suggest that DP-BJVC is more suitable for infants, and ePTFE conduit is more suitable for older children who require larger conduits.

Hand-Made Polytetrafluoroethylene Tricuspid-Valved Conduit for Surgical Reconstruction of the Right Ventricular Outflow Tract in a Child With Truncus Arteriosus

Although a new right ventricle outflow can be introduced during pulmonary artery reconstruction, it is a suboptimal option as the valved conduits that mimic the natural right ventricular outflow do not grow, and a surgical conduit replacement cannot be averted. This study reported the implementation of hand-made polytetrafluoroethylene (PTFE) tricuspid-valved conduits to rebuild the right ventricular outflow tract in toddlers with truncus arteriosus and risk factors for earlier conduit explant. Herein, we described a case report of a 9-month-old toddler diagnosed in November 2021 with truncus arteriosus type I with ventricular septal defect (VSD) and severe pulmonary arterial hypertension, who has been successfully discharged 20-days postoperative surgical reconstruction with good bi-ventricular functions. Hand-made PTFE tricuspid-valved conduits are efficient in the reconstruction process of the right ventricular outflow tract in children with truncus arteriosus. The conduits are cheap, easily available, and lack potential sensitization.

Pre- and Postprocedure Imaging of Transcatheter Pulmonary Valve Implantation

Transcatheter pulmonary valve replacement (TPVR) is a minimally invasive procedure for treatment of right ventricular outflow tract (RVOT) dysfunction in surgically repaired congenital heart diseases. TPVR is performed in these patients to avoid the high risk and complexity of repeat surgeries. Several TPVR devices are now available to be placed in the right ventricle (RV) to pulmonary artery (PA) conduit, native RVOT, or surgical bioprosthetic valves. Imaging is used before TPVR to determine patient eligibility and optimal timing, which is critical to avoid irreversible RV dilatation and failure. Imaging is also required for evaluation of contraindications, particularly proximity of the RVOT to the left main coronary artery and its branches. Cross-sectional imaging provides details of the complex anatomy in which the TPVR device will be positioned and measurements of the RVOT, RV-PA conduit, or PA. Echocardiography is the first-line imaging modality for evaluation of the RVOT or conduit to determine the need for intervention, although its utility is limited by the complex RVOT morphology and altered anatomy after surgery. CT and MRI provide complementary information for TPVR, including patient eligibility, assessment of contraindications, and key measurements of the RVOT and PA, which are necessary for procedure planning. TPVR, performed using a cardiac catheterization procedure, includes a sizing step in which a balloon is expanded in the RVOT, which also allows assessment of the risk for extrinsic coronary artery compression. Follow-up imaging with CT and MRI is used for evaluation of postprocedure remodeling and valve function and to monitor complications. ^©RSNA, 2022 Online supplemental material is available for this article.

Individualized right ventricular outflow tract reconstruction using autologous pulmonary tissue in situ for the treatment of pulmonary atresia with ventricular septum defect

OBJECTIVE

The study aims to evaluate the feasibility and effectiveness of an individualized procedure for right ventricular outflow tract (RVOT) reconstruction in pulmonary atresia with ventricular septal defect (PA-VSD).

METHODS

RVOT was reconstructed using autologous pulmonary artery tissue preserved in situ as the posterior wall and a bovine jugular vein patch (BJVP) as the anterior wall in patients with PA-VSD (observation group). The size of the BJVP made from a bovine jugular vein conduit (BJVC) was individually calculated using a formula based on the child's weight and the size of the autologous pulmonary artery (the diameter of BJVC DB⁢J⁢V⁢C = Dt⁢h⁢e⁢o⁢r⁢e⁢t⁢i⁢c⁢a⁢l-W⁢z^-4π). Its effect was then compared with the conventional modified Rastelli procedure based on the BJVC (control group).

RESULTS

A total of 22 patients that underwent the new procedure were simultaneously compared with the 25 patients in the control group. No deaths occurred in both groups. Notably, there were no significant differences in mechanical ventilation, ICU and postoperative residence, cardiopulmonary bypass, and aortic cross-clamp time. In the follow-up, which spanned for 8-12 years (mean 9.2 years), only four cases with moderate regurgitation were noted in the observation group without obstruction. In the control group, two patients had a conduit replacement. Three patients suffered from anastomotic stenosis, which was corrected by balloon dilatation.

CONCLUSION

Individualized RVOT reconstruction with autologous pulmonary tissue preserved in situ as the posterior wall is adequate for treating PA-VSD.

Application of Homograft Valved Conduit in Cardiac Surgery

Valved conduits often correct the blood flow of congenital heart disease by connecting the right ventricle to the pulmonary artery (RV-PA). The homograft valved conduit was invented in the 1960s, but its wide application is limited due to the lack of effective sterilization and preservation methods. Modern cryopreservation prolongs the preservation time of homograft valved conduit, which makes it become the most important treatment at present, and is widely used in Ross and other operations. However, homograft valved conduit has limited biocompatibility and durability and lacks any additional growth capacity. Therefore, decellularized valved conduit has been proposed as an effective improved method, which can reduce immune response and calcification, and has potential growth ability. In addition, as a possible substitute, commercial xenograft valved conduit has certain advantages in clinical application, and tissue engineering artificial valved conduit needs to be further studied.

Time-related risk of pulmonary conduit re-replacement: a Congenital Heart Surgeons' Society Study

BACKGROUND

Patients receiving a right ventricle-to-pulmonary artery conduit in infancy will require successive procedures or replacements, each with variable longevity. We sought to identify factors associated with time-related risk of a subsequent surgical replacement (PC3) or transcatheter pulmonary valve insertion (TPVI) after a second surgically-placed PC (PC2).

METHODS

From 2002 to 2016, 630 patients from 29 Congenital Heart Surgeons' Society member institutions survived to discharge after initial valved PC insertion (PC1) at age < 2 years. Of those, 355 had undergone surgical replacement (PC2) of that initial conduit. Competing risk methodology and multiphase parametric hazard analyses were used to identify factors associated with time-related risk of PC3 or TPVI.

RESULTS

Of 355 PC2 patients (median follow-up of 5.3 years), 65 underwent PC3 and 41 TPVI. Factors at PC2 associated with increased time-related risk of PC3 were smaller PC2 Z score (Hazard Ratio [HR] 1.6, p<0.001), concomitant aortic valve intervention (HR 7.6, p=0.009), aortic allograft (HR 2.2, p=0.008), younger age (HR 1.4, p<0.001), and larger Z score of PC1 (HR 1.2, p=0.04). Factors at PC2 associated with increased time-related risk of TPVI were aortic allograft (HR: 3.3, p=0.006), porcine unstented conduit (HR 4.7, p<0.001), and older age (HR 2.3, p=0.01).

CONCLUSIONS

Aortic allograft as PC2 was associated with increased time-related risk of both PC3 and TPVI. Surgeons may reduce risk of these subsequent procedures by not selecting an aortic homograft at PC2, and by oversizing the conduit when anatomically feasible.

Transposition of the Great Arteries, Ventricular Septal Defect, and Pulmonary Stenosis: Modified REV versus Rastelli

The objective of this study was to evaluate and compare the results of the modified réparation à l'ètage ventriculaire (REV) and the Rastelli operation for the treatment of transposition of the great arteries (TGA), ventricular septal defect (VSD), and pulmonary stenosis (PS). Records of 38 patients who underwent the modified REV (n = 16) or the Rastelli operation (n = 22) for the treatment of TGA, VSD, and PS between 2010 and 2019 were reviewed. The median age was 2.2 years (range 0.6-8.0 years) and the median weight was 11.3 kg (range 6.4-22.0 kg). No in-hospital death occurred and there were 4 early reoperations (two in each group). Overall survival at 10 years was 97.4% (100% in Modified REV group and 95.5% in Rastelli group, P = 0.39). Freedom from left ventricular outflow tract (LVOT) reoperation was 100% in both groups. Freedom from right ventricular outflow tract (RVOT) reoperation was 100% in Modified REV group and 75.4% in Rastelli group (P = 0.073). Event-free survival was 100% in Modified REV group and 72.0% in Rastelli group (P = 0.048). The most recent echocardiography showed that LVOT peak gradient was less than 10 mmHg in all patients. In Modified REV group, 30.8% of patients (4/13) had either RVOT obstruction (RVOT peak gradient more than 40 mmHg) or moderate or severe pulmonary insufficiency, while conduit stenosis (peak gradient more than 40 mmHg) was found in 25.0% of patients (3/12) in Rastelli group. The modified REV and the Rastelli operation provide satisfactory early results, as well as long-term survival and LVOT performance. However, the modified REV has better RVOT performance.

Outcomes Following Heterotopic Placement of Right Ventricle to Pulmonary Artery Conduits

BACKGROUND

We sought to evaluate the outcomes following right ventricle to pulmonary artery (RV-PA) conduit placement in pediatric patients, excluding those with a RV-PA conduit for the Ross procedure which is associated with improved conduit durability, partly related to its orthotopic position.

METHODS

Outcomes for 119 patients who underwent RV-PA conduit placement at a single institution from January 2004 to December 2016 were reviewed. Primary outcome measures were reintervention-free survival (RFS) and overall survival. Survival analyses were performed using the Kaplan-Meier method, and risk factors associated with reintervention were evaluated.

RESULTS

The median age at the time of conduit placement was 6 months (interquartile range, IQR: 1-14), and the median length of follow-up was 63 months (range: 0-156). During follow-up, 39 patients required conduit-related reintervention, while 6 patients died perioperatively with an overall survival of 90% at 10 years. Among the remaining 113 patients, the RFS at one, five, and ten years was 91% (84%-95%), 72% (60%-80%), and 33% (16%-50%), respectively. The median time to conduit replacement in the series was 43.5 months (IQR: 19.3-76.2). The use of a pulmonary homograft was associated with improved RFS (P = .03), and this was particularly pronounced in comparison with aortic homografts in neonates. Infection was the indication for replacement in only one patient.

CONCLUSIONS

The majority of the conduits placed during the neonatal period required conduit replacement before the age of five years. Endocarditis was not a common indication for replacement. In neonates and infants, we prefer pulmonary homografts for most indications.

Longevity of Large Aortic Allograft Conduits in Tetralogy With Major Aortopulmonary Collaterals

BACKGROUND

Appropriate conduit selection for right ventricle (RV)-to-pulmonary artery (PA) connection has been extensively studied, with older implantation age, pulmonary (vs aortic) homografts, and true sizing associated with increased longevity. Notably, patients with PA arborization abnormalities (ie, major aortopulmonary collateral arteries [MAPCAs]) are reported to require earlier and more frequent conduit interventions. We aim to understand the behavior of large-diameter aortic homografts in patients with MAPCAs, which are programmatically utilized at our institution.

METHODS

This is a single-center retrospective cohort study including all children less than 12 years of age who underwent RV-PA connection using an aortic homograft greater than or equal to 16 mm diameter between 2002 and 2019, with a primary outcome of freedom from any RV-PA reintervention and a secondary outcome of freedom from surgical reintervention. Patients were grouped by absolute and indexed conduit sizes for further analysis.

RESULTS

A total of 336 conduits were followed for a median of 3.0 years; transcatheter (n = 30) or surgical (n = 35) reintervention was performed on 64 conduits. Estimated freedom from reintervention and surgical replacement was 84% and 90% at 5 years. Younger age and smaller absolute conduit size were associated with earlier reintervention, but conduit Z-score (median 3.5) was not associated with outcome.

CONCLUSIONS

The programmatic use of oversized aortic homograft RV-PA conduits in the surgical repair of MAPCAs provides a focused experience that demonstrates similar longevity to reported best alternatives. Secondarily, conduit oversizing may improve durability and enables an increased likelihood of nonoperative reintervention.

Long-term results of large-calibre expanded polytetrafluoroethylene-valved conduits with bulging sinuses

OBJECTIVES

In Japan, homograft and bovine jugular vein are available in very limited institutions for the reconstruction of the right ventricular outflow tract, and handmade expanded polytetrafluoroethylene (ePTFE)-valved conduits have been widely used instead. This study aimed to clarify the long-term outcomes and the durability of the ePTFE-valved conduits purely by narrowing down to those with large sizes to eliminate the influence of the body growth.

METHODS

Between January 2002 and December 2015, patients who underwent right ventricular outflow tract reconstruction in 34 Japanese institutions using ePTFE-valved conduits with a diameter of ≥18 mm were included. All the valved conduits were made in the authors' institution and delivered to each participating institution.

RESULTS

Overall, 502 patients were included. Early mortality was 1.4% and not related to conduit failure. The overall survival rate was 98.2% at 5 years and 96.6% at 10 years. Freedom from conduit explantation was 99.5% at 5 years and 89.0% at 10 years. Three patients (0.13 per 100 patient-years) developed infective endocarditis of the conduit, and only 1 patient required conduit removal. Pulmonary insufficiency was mild or less in 480 (96%) patients, and conduit stenosis was mild or less in 436 (88%) patients at the latest follow-up.

CONCLUSIONS

By narrowing the analyses down to only ePTFE conduits with a large size, satisfactory long-term outcomes of these conduits with a fan-shaped valve and bulging sinuses were shown. These conduits would be among the optimal choices for right ventricular outflow tract reconstruction.

Right Ventricle to Pulmonary Artery Conduit With Tricuspid Expanded Polytetrafluoroethylene Valves

BACKGROUND

Excellent outcomes of right ventricle to pulmonary artery conduits with expanded polytetrafluoroethylene (ePTFE) valves have been reported. The purpose of this study was to evaluate the outcomes of the different material conduits with tricuspid ePTFE valves.

METHODS

Forty-one consecutive patients who received right ventricle to pulmonary artery conduit with tricuspid ePTFE valves for biventricular repair between April 2004 and December 2016 were studied. The conduits made of autologous pericardial roll or xenograft roll were used in 22 patients (group P) and the conduits made of ePTFE tube were used in 19 patients (group G). The conduit reoperation and the conduit dysfunction were analyzed.

RESULTS

During the median follow-up of 5.8 years, no death related to the conduit was observed. There were four reoperations (three in group P and one in group G). Freedom from conduit reoperation at 5 years was 100% in both groups (P = .30). Freedom from more than moderate conduit stenosis at 5 years after operation was not significantly different between groups (46.9% in group P vs 76.3% in group G, P = .23) even though the group G conduits were significantly smaller and freedom from more than moderate conduit regurgitation at 5 years was significantly better in group G (63.3% in group P vs 94.1% in group G, P = .04).

CONCLUSIONS

The conduit with ePTFE valves in the ePTFE tubes had better conduit function compared with the conduit with autologous pericardial or xenograft roll, especially in terms of conduit regurgitation.

The Role of Novel Transcatheter Procedures in Patients With Congenital Heart Disease

The development of percutaneous structural interventions in patients with acquired heart disease is happening at an exponential rate, and some of this technology is being used to treat patients with congenital heart disease. This review describes the pathophysiology of valvular abnormalities specific to congenital heart disease and discusses the application of structural procedures in this population. Although the overall experience has been encouraging, especially in high-risk patients, this article will highlight the reasons that a cautious approach to adoption of this technology is necessary in these patients.