Quantitative Evaluation of Right Ventricular Workload Based on the Stroke Work Index in Patients after Right Ventricular Outflow Tract Reconstruction

The evaluation of right ventricular workload is sometimes complicated in patients after right ventricular outflow tract reconstruction (RVOTR) because both stenotic and regurgitation lesions are involved. In this study, we modified the right ventricular stroke work index (RVSWI) and evaluated the relationship between the modified RVSWI (mRVSWI) and patient prognosis after RVOTR.We enrolled 69 patients who underwent RVOTR (the RVOTR group), including those who needed early reoperation (early reoperation subgroup) and those who did not (follow-up subgroup), and 13 age-matched control participants (control group). Based on the catheterization results 1 year after RVOTR, we compared the mRVSWI between these groups. Additionally, we evaluated the influence of the mRVSWI on the reoperation avoidance rate and survival.The mRVSWI in the RVOTR group was significantly greater than that in the control group (17.7 ± 8.6 vs. 11.0 ± 2.7 g·m/m2, p = 0.008). The mRVSWI in the early reoperation subgroup was significantly greater than that in the follow-up subgroup (32.5 ± 11.1 vs. 15.8 ± 6.0 g·m/m2, p < 0.0001). In the follow-up subgroup, patients with an mRVSWI higher than the upper limit of normal (16.4 g·m/m2) had a greater rate of reoperation than did the other patients (p = 0.0013). One patient died suddenly, and her mRVSWI was consistently high throughout her life.We established the mRVSWI as an index that integrates the pressure and volume load on the right ventricle. Our results indicate the utility of the mRVSWI for predicting patient prognosis after RVOTR.

Ex vivo evaluation of 3 different right ventricular outflow tract substitutes

OBJECTIVES

The Ross procedure represents an excellent treatment option in younger patients with aortic stenosis but is limited by poor availability of homografts. In this study, we investigated the hydrodynamic performance of 3 different types of right ventricular outflow tract replacement with pericardium or synthetic material.

METHODS

Three different types of valved conduits were constructed using pericardium and/or synthetic material (Group PEPE: pericardial cusps and pericardial conduit, Group PEPR: pericardial cusps and Dacron conduit, Group PRPR: expanded polytetrafluoroethylene cusps and Dacron conduit). The conduits were designed according to the Ozaki method. Their hydrodynamic performance (effective orifice area, mean pressure gradient and leakage volume) were evaluated in a mock circulation loop at different hydrodynamic conditions.

RESULTS

Hydrodynamic assessment showed significantly larger effective orifice area of PEPE and PEPR compared to PRPR under all conditions and there were no significant differences between PEPE and PEPR [for condition 2: PEPE 2.43 (2.35-2.54) cm2, PEPR: 2.42 (2.4-2.5) cm2, PRPR: 2.08 (1.97-2.21) cm2, adjusted pairwise comparisons: PEPE versus PEPR: P = 0.80, PEPE versus PRPR: P  < 0.001, PEPR versus PRPR: P  < 0.001]. Mean pressure gradient was significantly lower for PEPE and PEPR compared with PRPR, whereas no significant differences were seen between PEPE and PEPR. Leakage volume was significantly lower for PEPE and PEPR compared with PRPR under all conditions while leakage was similar between PEPE and PEPR.

CONCLUSIONS

Pulmonary graft reconstruction with pericardium cusps showed superior hydrodynamic performance compared with polytetrafluoroethylene cusps. Our results suggest that it could be considered as an alternative substitute for right ventricular outflow tract replacement during the Ross procedure.

Valved Conduits for Right Ventricular Outflow Tract Reconstruction: A Review of Current Technologies and Future Directions

The need for right ventricular outflow tract reconstruction is common and growing in congenital heart surgery given expanding indications for the repair of congenital as well as acquired heart disease. Various valved conduit options currently exist including homografts, xenograft pulmonary valved conduits (Contegra™), and porcine valved conduits. The major limitation for all conduits is implant durability, which requires reoperation. Currently, cryopreserved homografts are often used given their superiority shown in long-term data. Significant limitations remain in the cost and availability of the graft, particularly for smaller sizes. Contegra conduits are available in a variety of sizes. Nonetheless, the data regarding long-term durability are less robust and studies comparing durability with homografts have been conflicting. Additionally, there is concern for increased rates of late endocarditis in this conduit. Porcine valved conduits offer a reliable option but are limited by structural valve degeneration associated with all types of bioprosthetic heart valve replacements. New developments in the field of tissue engineering have produced promising bio-restorative valved conduits that may overcome many of the limitations of previous conduit technologies. These remain in the early stages of clinical testing. This review summarizes the clinical data surrounding the conduits used most commonly in clinical practice today and explores emerging technologies that may bring us closer to developing the ideal conduit.

20-Year follow-up and comparison of valved conduits used for right ventricular outflow tract reconstruction: single-centre, propensity score match analysis

OBJECTIVES

Surgical repair of complex congenital heart defects with hypoplasia or atresia of the right ventricular outflow tract (RVOT) may require pulmonary valve implantation or replacement during the primary repair or reoperation. The purpose of this study is to evaluate the outcomes of cryopreserved homografts, bovine jugular vein conduits and decellularized Matrix P Plus N conduits in patients undergoing RVOT reconstruction at a single centre.

METHODS

Retrospective, single-centre review of 173 patients with 199 conduits undergoing right ventricle-to-pulmonary artery reconstruction with valved conduit from 2002 to 2022.

RESULTS

A total of 199 conduits were implanted in 173 patients (62.8% male), with a mean age of 8.97 ± 8.5 years. The following 3 types of conduits were used: homografts 129 (64.8%), bovine jugular vein conduits 45 (22.7%) and Matrix P Plus N 25 (12.5%). During the mean follow-up duration of 8.6 ± 5.8 years, there were 20 deaths, 35 conduit reoperations and 44 catheter reinterventions. Overall survival, reoperation-free and catheter reintervention-free survival at 20 years were 83%, 67.8% and 65.6%, respectively. Multivariable Cox analysis identified younger patient age, smaller conduit size, low patient weight and primary diagnosis of common arterial trunk as risk factors for reoperation and catheter reintervention.

CONCLUSIONS

Long-term outcomes of reconstruction of the RVOT using homografts, bovine jugular vein and Matrix P Plus N conduits were acceptable. The reoperation rate for conduit dysfunction did not differ significantly among groups. Over time, the need for conduit replacement was higher in smaller conduits and in patients with common arterial trunk diagnosis.

Medium-term outcomes of bovine jugular valved conduits for right ventricular outflow tract reconstruction in children: a retrospective cohort study from China

Background

Bovine jugular valved conduit (BJVC) has been reported as an optional material for right ventricular outflow tract (RVOT) reconstruction in patients with complex congenital heart disease (CHD). It showed comparable or even better performance than homograft. However, the durability of BJVC is still very poor in infants and children. Herein, we retrospectively analyzed and evaluated the mid-term results of RVOT reconstruction by using bovine jugular vein valved conduits (Balance BJVCs) in CHD patients, with a special focus on the functional status of the conduits.

Methods

Pediatric patients undergoing RVOT reconstruction using Balance BJVC in Guangzhou Women and Children's Medical Center from January 2018 to December 2020 were enrolled in this study. The demographic information, cardiac anatomical abnormalities, preoperative hemodynamic characteristics, surgical details, postoperative outcomes, and follow-up data of the patients were reviewed retrospectively.

Results

Ninety-four patients were enrolled in this study. The median age at implantation was 22 months (range, 2-168 months), the median weight was 10.8 kg (range, 3.8-40.0 kg); 34 children (36.2%) were younger than 1 year. The most common disease in these children was pulmonary atresia with ventricular septal defect (PA/VSD) (66/94, 70.2%). The patients were followed up for a median of 43.5 months (range, 6-60 months). Late mortality occurred in 4 (4.3%). Cumulatively, conduit dysfunction at different levels occurred in 31 (33%), conduit failure in 9 (9.6%), 6 patients underwent reoperation for conduit replacement, 5 (5.3%) developed infective endocarditis (IE) within 24 months (range, 12-36 months) after the surgery. Five-year survival rate is 95.7%. The free of conduit dysfunction rates at 1, 3, and 5 years was 91.4%, 68.5%, and 50.4%, respectively. In addition, the rates of patients who were free of conduit failure at 1, 3, and 5 years were 100%, 88.9%, and 88.9%, respectively.

Conclusions

Despite the high risk of BJVC dysfunction, approximately 90% of children are free from conduit failure at 5 years after conduit implantation through aggressive transcatheter intervention without increasing the incidence of IE. Thus, BJVC remains a useful alternative material for RVOT reconstruction in patients with complex CHD.

Clinical outcomes of handmade polytetrafluoroethylene trileaflet-valved conduit used for pulmonary valve replacement

OBJECTIVES

To mitigate the shortage of homograft sources, the use of handmade trileaflet expanded polytetrafluoroethylene valves in pulmonary valve replacement has shown excellent results from multicentre studies conducted in Japan. However, world-wide data outside Japan are relatively insufficient. This study presents the long-term results of a single surgeon's use of flipped-back trileaflet method in a 10-year case series.

METHODS

We have developed an efficient way to make a trileaflet-valved conduit utilizing flipped-back method for pulmonary valve replacement and have employed the technique since 2011. Retrospective data were studied between October 2010 and January 2020. Echocardiography, electrocardiogram, Pro-Brain Natriuretic Peptide and Magnetic Resonance Imaging data were analysed.

RESULTS

Fifty-five patients were reviewed and median follow-up duration was 2.9 years. The majority of diagnoses was Tetralogy of Fallot (n = 41), and these patients subsequently underwent secondary pulmonary valve replacement at a median age of 15.6 years. Survival was 92.7% with the longest follow-up period being 10 years. There was no need for reoperation, and freedom from reintervention was 98.0% at 10 years. There were 4 deaths (3 in-hospital and 1 outpatient). One patient eventually received transcatheter pulmonary valve implantation. Postoperative echocardiography showed mild or less pulmonary stenosis and pulmonary regurgitation degree in 92.2% and 92.0% of patients, respectively. Comparable magnetic resonance imaging data (n = 25) showed significant reduction in right ventricular volumes but not in ejection fractions.

CONCLUSIONS

Our series showed satisfactory long-term function of handmade flipped-back trileaflet-valved conduit used in our patients. The simple design is efficiently reproducible without complex fabrication process.

Handmade tri-leaflet ePTFE conduits versus homografts for right ventricular outflow tract reconstruction

BACKGROUND

This study aimed to investigate the performance of handmade tri-leaflet expanded polytetrafluoroethylene (ePTFE) conduits in the absence of a suitable homograft.

METHODS

Patients who underwent right ventricular outflow tract reconstruction with tri-leaflet ePTFE conduits or homografts between December 2016 and August 2020 were included. The primary endpoint was the incidence of moderate or severe conduit stenosis (≥ 36 mmHg) and/or moderate or severe insufficiency. The secondary endpoint was the incidence of severe conduit stenosis (≥ 64 mmHg) and/or severe insufficiency.

RESULTS

There were 102 patients in the ePTFE group and 52 patients in the homograft group. The median age was younger [34.5 (interquartile range: 20.8-62.8) vs. 60.0 (interquartile range: 39.3-81.0) months, P = 0.001] and the median weight was lower [13.5 (10.0-19.0) vs. 17.8 (13.6-25.8) kg, P = 0.003] in the ePTFE group. The conduit size was smaller (17.9 ± 2.2 vs. 20.5 ± 3.0 mm, P < 0.001) and the conduit Z score was lower (1.48 ± 1.04 vs. 1.83 ± 1.05, P = 0.048) in the ePTFE group. There was no significant difference in the primary endpoints (log rank, P = 0.33) and secondary endpoints (log rank, P = 0.35). Multivariate analysis identified lower weight at surgery [P = 0.01; hazard ratio: 0.75; 95% confidence interval (CI) 0.59-0.94] and homograft conduit use (P = 0.04; hazard ratio: 8.43; 95% CI 1.14-62.29) to be risk factors for moderate or severe conduit insufficiency. No risk factors were found for moderate or severe conduit stenosis or conduit dysfunction on multivariate analysis.

CONCLUSION

Handmade tri-leaflet ePTFE conduits showed acceptable early and midterm outcomes in the absence of a suitable homograft, but a longer follow-up is needed.

Mid-term outcomes of Contegra implantation for the reconstruction of the right ventricular outflow tract to proximal branch pulmonary arteries: Japan multicentre study

OBJECTIVES

To reveal the mid-term outcomes of Contegra implantation for the reconstruction of the right ventricular outflow tract to proximal branch pulmonary arteries in a multicentre study.

METHODS

Between April 2013 and December 2019, 178 Contegra conduits were implanted at 5 Japanese institutes. The median age and body weight at operation were 16 months (25th-75th percentile: 8-32) and 8.3 kg (6.4-10.6). Sixteen patients were neonates (9.0%). Selected conduit sizes were 12 mm in 28 patients (15.7%), 14 mm in 67 patients (37.6%), 16 mm in 66 patients (37.1%), 18 mm in 5 patients (2.8%) and <12 mm in 12 patients (6.7%). Fifty-six grafts (31.4%) were ring supported. Proximal branch pulmonary arteries were concomitantly augmented in 85 patients (47.5%). Follow-up was completed in all patients and the median follow-up period was 3.1 years (1.3-5.1).

RESULTS

The overall, conduit explantation-free and conduit infection-free survival rates at 5 years were 91.3%, 71.0% and 83.7%, respectively. Infection (P = 0.009) and common arterial trunk (P = 0.024) were risk factors for explantation. Conduit durability was shorter in smaller one (P < 0.001). Catheter interventions (for conduit to proximal branch pulmonary artery)-free survival rates at 5 years was 52.9%; however, need for catheter interventions was not a risk factor for conduit explantation.

CONCLUSIONS

Mid-term outcomes of reconstruction of the right ventricular outflow tract to the proximal branch pulmonary arteries with Contegra were acceptable. The need for explantation over time was higher in smaller conduits. Conduit infection was a strong risk factor for conduit explantation. Frequently and repeated catheter interventions effectively extended the conduit durability.

Alternative techniques of right ventricular outflow tract reconstruction for surgical repair of truncus arteriosus

OBJECTIVES

This study aimed to evaluate the outcomes and feasibility of different techniques of reconstruction of the right ventricular outflow tract (RVOT) in surgical repair of truncus arteriosus.

METHODS

We retrospectively reviewed all consecutive patients with truncus arteriosus who underwent successful surgical repair in our centre between 1994 and 2017. We analysed late results according to the type of RVOT repair.

RESULTS

We collected data from 29 survivors after truncus arteriosus repair. Six (20%) of them were affected by DiGeorge syndrome. The RVOT reconstruction was achieved using a valved conduit in 58.6%, while a direct right ventricle-pulmonary artery (RV-PA) anastomosis, with or without the interposition of the left atrial appendage, was performed in the remaining. At a median follow-up time of 7.9 years (interquartile range 1.8-13.1), 6 patients (3 affected by DiGeorge syndrome) died. Between the 2 groups, there were no differences in terms of the late mortality and onset of adverse events. However, the use of a conduit seemed more prone to reintervention and onset of adverse events.

CONCLUSIONS

Different RVOT reconstruction techniques are safe and have similar late outcomes. However, use of a direct RV-PA anastomosis and left atrial appendage interposition may reduce the need for reoperation in the long term.

Right ventricular outflow tract reconstruction with the Labcor® stentless valved pulmonary conduit

OBJECTIVES

The right ventricular outflow tract reconstruction is a common necessity in congenital cardiac surgery. As homograft availability is limited, alternatives need to be evaluated. The Labcor® conduit consists of a porcine tricomposite valve assembled inside a bovine pericardium tube. This study presents intermediate-term results for its utilization for right ventricular outflow tract reconstruction.

METHODS

Labcor conduits were implanted in 53 patients (February 2009-July 2016). We analysed perioperative data, freedom from conduit failure and risk factors for conduit dysfunction.

RESULTS

The most common diagnosis was Tetralogy of Fallot (n = 20, 37.7%). The median age at surgery was 10.0 [interquartile range (IQR) 4.9-14.3] years. Pulmonary artery plasty (n = 37, 69.8%) and augmentation of the right ventricular outflow tract (n = 16, 30.2%) were often part of the procedure. The median conduit size was 21 (range 11-25) mm. There was no in-hospital death. The median follow-up after surgery was 4.6 (IQR 3.4-5.6) years. Fourteen patients (27.5%) developed conduit failure with stenosis being the main cause. Freedom from conduit failure was 98.0% at 2 and 80.5% at 5 years. The median longevity of the conduit was 7.4 years (95% confidence interval 5.1-9.8 years). Younger age and smaller conduit size were related to conduit failure.

CONCLUSIONS

Utilization of the Labcor conduit revealed acceptable intermediate-term results. The conduit appeared to be functioning sufficiently well within the first 5 years in the majority of patients. The higher rate of failure concerning smaller conduits might be associated with somatic outgrowth; however, conduit degeneration as common and long-term outcome still needs to be evaluated.

Single-centre 20-year experience with repair of truncus arteriosus

OBJECTIVES

We analysed a large series of truncus arteriosus repairs with a focus on early and late outcomes.

METHODS

Ninety-seven consecutive patients who underwent truncus arteriosus repair (1997-2017) were included retrospectively. Univariable analysis for mortality and reintervention was performed.

RESULTS

The early mortality rate decreased from 45% (1997-2007; 14/31) to 4.5% (2008-2017; 3/66) (P = 0.001). Repair beyond the neonatal period (P = 0.03) and direct connection for right ventricular outflow tract reconstruction (P = 0.001) were associated with early death by univariable analysis. Overall survival was 68 ± 6.0% at 15 years; a majority of the deaths (90%; 9/10) occurred within the first year after repair. Freedom from the first and second conduit reoperations at 10 years was 22.9% and 89%, respectively. Freedom from truncal valve (TrV) reoperation was 83.9% at 15 years. Initial TrV insufficiency ≥ moderate was associated with a TrV reoperation (P = 0.008) with freedom from TrV reoperation in this subgroup of 58.3% at 10 years. Freedom from TrV reoperation for quadricuspid and tricuspid TrVs was 66.8% and 93.8% at 10 years with 100% for bicuspid TrVs at 8 years. At the last follow-up, 98.5% (69/70) were in New York Heart Association functional class I-II.

CONCLUSIONS

In the current era, truncus arteriosus can be repaired with a low early mortality rate and a good long-term outcome. A significant reintervention burden still persists. Direct connection is associated with early mortality.

Histopathologic Analysis of Explanted Polytetrafluoroethylene-Valved Pulmonary Conduits

The expanded polytetrafluoroethylene (ePTFE)-valved conduits as alternative material for right ventricular outflow reconstruction provides satisfactory long-term outcomes. The purpose of this study was to investigate degenerative changes in failed conduits through histopathologic analysis of the explanted specimens. All leaflets of explanted conduits were observed macroscopically, and their longitudinal sections were examined microscopically. Three typical findings, that is, calcification of the leaflet, neointimal proliferation, and proteinaceous infiltration into the leaflet, were evaluated quantitatively by measuring their degree and appearance probability. A total of 15 leaflets from 5 failed conduits (group F) and 12 leaflets from 5 nonfailed conduits (group non-F) were included. The median duration of implantation was 7.6 years (5.3-10.9 years) in group F and 1.3 years (0.7-3.9 years) in group non-F (P = 0.003). In group F, calcification tended to occur in the middle and upper third of the leaflet, causing stiffening, distortion, and exophytic concretion of the leaflet, and mean neointimal thickness on inflow and outflow surfaces were 0.33 ± 0.02 mm and 0.22 ± 0.01 mm, respectively. There was a moderately strong correlation between appearance probability of calcification in group F and that of proteinaceous infiltration in group non-F (correlation coefficient 0.67, P < 0.001). Proteinaceous infiltration into the leaflet was presumed be responsible for future calcification of the leaflet and subsequent stenotic conduit failure. Modification of the ePTFE material to prevent proteinaceous infiltration may contribute to improving the durability of ePTFE-valved conduit.

Outcomes of Prosthetic Valved Conduits for Right Ventricular Outflow Tract Reconstruction

There are limited data regarding the implantation of prosthetic valved conduits for right outflow tract reconstruction in pediatric patients in China. A retrospective review of 128 patients undergoing conduits implantation with a median follow-up of 33.3 months (range, 3.3 months to 10.1 years) was performed between 2009 and 2018. Multivariate Cox regression model was used to analyze the risk factors for mortality, reintervention and endocarditis. Freedom from reintervention and endocarditis were plotted using the Kaplan-Meier curve. Hospital mortality was 7.8%, and the late mortality was 3.1%. Patient survival at 1, 5 and 10 years was 92.2%, 87.1% and 84.3%, respectively. Freedom from reintervention at 1 and 5 years was 94.1% and 60.9%. Small size conduit (p = 0.019) and previous palliation (p < 0.001) were predictive of reintervention. Ten conduits developed endocarditis at a median of 4.8 years after implantation. Freedom from endocarditis at 1, 5 and 10 years was 99.1%, 93.0% and 58.0%, respectively. Diffuse stenosis of the conduit (p = 0.003) was an independent risk factor for late endocarditis. Both bovine jugular venous conduits and bovine pericardial prosthetic conduits are associated with acceptable outcomes. Reintervention remains high in patients who have smaller size conduit and undergo previous palliation. It is plausible that the suboptimal flow may be one of major mechanisms involved in the development of late endocarditis.

Pulmonary valve replacement after right ventricular outflow tract reconstruction with homograft vs Contegra®: a case control comparison of mortality and morbidity

Background

Repair of congenital heart defects involving the right ventricular outflow tract may require the implantation of a right ventricle to pulmonary artery conduit. This conduit is likely to be replaced during childhood. This study compares the operative outcomes of the replacement procedure of Contegra® and homografts in pulmonary position.

Methods

From 1999 to 2016, 82 children underwent 87 right ventricle to pulmonary artery conduit replacements (60 Contegra® and 27 homografts). Demographics, operative and clinical data were obtained through a retrospective review of the medical records. The two groups were matched for comparison using propensity score matching. All the procedures were performed by the same team of surgeons.

Results

No statistically significant difference was observed between the two groups when considering the operative data for anesthesia, surgery, cardiopulmonary bypass and aortic clamping durations. A peroperative complication rate of 13.47% and 15.36% in Contegra® and homograft replacement groups respectively (p value = 0.758) was observed. There was no difference regarding the blood loss and fluid input. No statistically significant difference was observed between the two groups for the post-operative morbidity. We considered the Pediatric Risk of Mortality (PRISM) score, the day of extubation, the day of withdrawal of inotropic drugs, the length of the intensive care unit stay and the length of hospital stay. The overall mortality is 2.3% but there is no statistically significant difference between the two groups.

Conclusion

Right ventricle to pulmonary artery conduit replacement procedure can be achieved with a low surgical morbidity or mortality, not influenced by the type of conduit that is replaced. Therefore, the choice between homograft or Contegra® for right ventricle to pulmonary artery reconstruction should not be influenced by the future surgical risk during the replacement procedure.

Trial registration

NCT03048071. Registered 9 February 2017 (retrospectively registered).

The Initial Glimpse at Long-term Outcomes Following the Repair of Truncus Arteriosus

The article by Naimo and colleagues (outcomes of truncus arteriosus repair in children: 35 years of experience from a single center) provides the initial glimpse at long-term outcomes following truncus arteriosus repair. Although survival has improved over the past decade, the morbidity resulting from subsequent re-operations now comprises a significant area for improvement in the ensuing decade.

A simple modification to fix the commissural pillar during right ventricular outflow tract reconstruction during the arterial switch operation

A simplified technique to fix the commissural pillar of the pulmonary valve at the time of right ventricular outflow tract reconstruction during the arterial switch operation is presented.