Comparison of homografts and bovine jugular vein conduits in the pulmonary position in patients <20 years of age

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.

Matched comparison of decellularized homografts and bovine jugular vein conduits for pulmonary valve replacement in congenital heart disease

For decades, bovine jugular vein conduits (BJV) and classic cryopreserved homografts have been the two most widely used options for pulmonary valve replacement (PVR) in congenital heart disease. More recently, decellularized pulmonary homografts (DPH) have provided an alternative avenue for PVR. Matched comparison of patients who received DPH for PVR with patients who received bovine jugular vein conduits (BJV) considering patient age group, type of heart defect, and previous procedures. 319 DPH patients were matched to 319 BJV patients; the mean age of BJV patients was 15.3 (SD 9.5) years versus 19.1 (12.4) years in DPH patients (p = 0.001). The mean conduit diameter was 24.5 (3.5) mm for DPH and 20.3 (2.5) mm for BJV (p < 0.001). There was no difference in survival rates between the two groups after 10 years (97.0 vs. 98.1%, p = 0.45). The rate of freedom from endocarditis was significantly lower for BJV patients (87.1 vs. 96.5%, p = 0.006). Freedom from explantation was significantly lower for BJV at 10 years (81.7 vs. 95.5%, p = 0.001) as well as freedom from any significant degeneration at 10 years (39.6 vs. 65.4%, p < 0.001). 140 Patients, matched for age, heart defect type, prior procedures, and conduit sizes of 20-22 mm (± 2 mm), were compared separately; mean age BJV 8.7 (4.9) and DPH 9.5 (7.3) years (p = n.s.). DPH showed 20% higher freedom from explantation and degeneration in this subgroup (p = 0.232). Decellularized pulmonary homografts exhibit superior 10-year results to bovine jugular vein conduits in PVR.

Long-term outcomes of tetralogy of Fallot repair: A 30-year experience with 960 patients

OBJECTIVE

This study evaluates the long-term results of tetralogy of Fallot repair and assesses the risk factors for adverse outcomes.

METHODS

This retrospective study included 960 patients who underwent transatrial transpulmonary tetralogy of Fallot repair between 1990 and 2020.

RESULTS

A transannular patch was placed in 722 patients, and pulmonary valve preservation was achieved in 233 patients. The median age at tetralogy of Fallot repair was 9.4 (interquartile range, 6.2-14.2) months. The median follow-up duration was 10.6 (interquartile range, 5.4-16.3) years. There were 8 early deaths (0.8%) and 20 late deaths (2.1%). Genetic syndrome and pulmonary valve annulus Z score less than -3 were risk factors for mortality. The survival was 97.7% (95% confidence interval, 96.4-98.5) and 94.5% (95% confidence interval, 90.9-96.7) at 10 and 30 years, respectively. Freedom from any reoperation was 86.4% (95% confidence interval, 83.6-88.7) and 65.4% (95% confidence interval, 59.8-70.4) at 10 and 20 years, respectively. Postoperative right ventricular outflow tract peak gradient of 25 mm Hg or greater correlated with reoperation. Propensity score-matched analysis demonstrated that freedom from pulmonary valve replacement at 15 years was higher in the pulmonary valve preservation group compared with the transannular patch group (98.2% vs 78.4%, P = .004). Freedom from reoperation for right ventricular outflow tract obstruction at 15 years was lower in the pulmonary valve preservation group compared with the transannular patch group (P = .006).

CONCLUSIONS

The long-term outcomes of tetralogy of Fallot repair are excellent. A postoperative right ventricular outflow tract peak gradient less than 25 mm Hg appears to be optimal to prevent reoperation. If the pulmonary valve size is suitable, pulmonary valve preservation reduces the risk of pulmonary valve replacement, yet increases the reoperation rate for right ventricular outflow tract obstruction.

Association between postoperative exposure to fine particulate matter and patency of the right ventricle-pulmonary artery conduit

BACKGROUND

Ambient air pollution is a leading risk factor for cardiovascular diseases. No study has investigated the association between exposure to fine particulate matter <2.5 μm in aerodynamic diameter (PM2.5) and the prognosis of patients undergoing surgery for the right ventricle-pulmonary artery (RV-PA) conduit.

METHODS

From 2013 to 2020, patients with six complicated congenital heart defects who had undergone surgery for the RV-PA conduit were selected. Four conduit materials were used: bovine jugular vein graft (BJV), pulmonary homograft (PHG), aortic homograft (AHG), and handmade tri-leaflet expanded polytetrafluoroethylene (ePTFE) conduit. Telephone interviews were used to confirm the postoperative address of patients. The monthly average PM2.5 concentration was obtained from the ChinaHighPM2.5 dataset using the place of residence of patients. By comparing findings of echocardiography undertaken before patients' return to their residence and during re-examination, we defined an increase in the trans-conduit peak velocity of ≥1.5 m/s as the study endpoint.

RESULTS

We enrolled 232 patients. Compared with BJV conduits, homografts (AHGs and PHGs) (0.052 (95 % CI = 0.005-0.558), P = 0.015) and ePTFE conduits (0.009 (95 % CI = 0.002-0.054), P < 0.001) were protective factors. The cumulative monthly PM2.5 concentration (10 μg/m3) was a risk factor (1.014 (95 % CI = 1.001-1.026), P = 0.028). Winter experience was a risk factor (1.971 (95 % CI: 1.021-3.804), P = 0.043). In the subgroup analysis, Spearman correlation analysis indicated BJV conduits (r = 0.680, P < 0.001), PHGs (r = 0.559, P = 0.020), and AHGs (r = 0.745, P = 0.021) had medium-to-high positive correlations between the cumulative PM2.5 concentration and change in the conduit velocity. For ePTFE, the correlation was weak and not significant (r = 0.222, P = 0.073).

CONCLUSIONS

Postoperative exposure to PM2.5 affects the patency of biologic prosthetic conduits (especially xenografts). The increase in the velocity of the ePTFE conduit is not associated with PM2.5 exposure, and is a suitable material for patients living in areas with high pollutant concentrations.

Pulmonary valve reconstruction for acquired pulmonary regurgitation in patients with treated congenital heart disease

OBJECTIVES

Pulmonary valve regurgitation is a common problem after relief of right ventricular outflow tract (RVOT) obstruction with a transannular patch. Pulmonary valve replacement with a homograft or xenograft is the routine treatment. Longevity of biological valves and the availability of homografts are limited. Alternatives to restore RVOT competence are evaluated. The goal of this study was to present intermediate-term results for pulmonary valve reconstruction (PVr) in patients with severe regurgitation.

METHODS

PVr was performed in 24 patients (August 2006‒July 2018). We analysed perioperative data, pre- and postoperative cardiac magnetic resonance (CMR) imaging studies, freedom from valve replacement and risk factors for pulmonary valve dysfunction.

RESULTS

The underlying diagnoses were tetralogy of Fallot (n = 18, 75%), pulmonary stenosis (n = 5, 20.8%) and the double outlet right ventricle post banding procedure (n = 1, 4.2%). The median age was 21.5 (14.8-23.7) years. Main (n = 9, 37.5%) and branch pulmonary artery procedures (n = 6, 25%) and surgery of the RVOT (n = 16, 30.2%) were often part of the reconstruction. The median follow-up after the operation was 8.0 (4.7-9.7) years. Freedom from valve failure was 96% at 2 and 90% at 5 years. The mean longevity of the reconstructive surgery was 9.9 years (95% confidence interval: 8.8-11.1 years). CMR before and 6 months after surgery showed a reduction in the regurgitation fraction [41% (33-55) vs 20% (18-27) P = 0.00] and of the indexed right ventricular end-diastolic volume [156 ml/m2 (149-175) vs 116 ml/m2 (100-143), P = 0.004]. Peak velocity across the pulmonary valve (determined by CMR) half a year after surgery was 2.0, unchanged.

CONCLUSIONS

PVr can be achieved with acceptable intermediate-term results and may delay pulmonary valve replacement.

Pediatric pulmonary valve replacements: Clinical challenges and emerging technologies

Congenital heart diseases (CHDs) frequently impact the right ventricular outflow tract, resulting in a significant incidence of pulmonary valve replacement in the pediatric population. While contemporary pediatric pulmonary valve replacements (PPVRs) allow satisfactory patient survival, their biocompatibility and durability remain suboptimal and repeat operations are commonplace, especially for very young patients. This places enormous physical, financial, and psychological burdens on patients and their parents, highlighting an urgent clinical need for better PPVRs. An important reason for the clinical failure of PPVRs is biofouling, which instigates various adverse biological responses such as thrombosis and infection, promoting research into various antifouling chemistries that may find utility in PPVR materials. Another significant contributor is the inevitability of somatic growth in pediatric patients, causing structural discrepancies between the patient and PPVR, stimulating the development of various growth-accommodating heart valve prototypes. This review offers an interdisciplinary perspective on these challenges by exploring clinical experiences, physiological understandings, and bioengineering technologies that may contribute to device development. It thus aims to provide an insight into the design requirements of next-generation PPVRs to advance clinical outcomes and promote patient quality of life.

Past, present, and future options for right ventricular outflow tract reconstruction

The pulmonary valve is the most frequently replaced cardiac valve in congenital heart diseases. Whether the valve alone or part of the right ventricular outflow tract have to be repaired or replaced depends on the specific pathological anatomy of the malformation. Once the decision to replace the pulmonary valve has been made, two options are available: the isolated transcatheter pulmonary valve replacement and the surgical implantation of a prosthetic valve either isolated or in combination with a procedure on the right ventricular outflow tract. In this paper, we will focus on the different past and present surgical options and present a new concept called "endogenous tissue restoration," a promising alternative to the hitherto existing implants. From a general point of view, neither the transcatheter nor the surgical valvular implants are magic bullets in the arsenal for the management of valvular diseases. Smaller valves have to be frequently replaced because of outgrowth of the patients, larger tissue valves may present late structural valve deterioration, while xenograft and homograft conduits may calcify and therefore become narrowed within unpredictable incidence and interval following implantation. Based on long-term research efforts combining the knowledge of supramolecular chemistry, electrospinning, and regenerative medicine, endogenous tissue restoration has emerged most recently as a promising option to create long-term functioning implants. This technology is appealing because following resorption of the polymer scaffold and timely replacement through autologous tissue, no foreign material remain at all in the cardiovascular system. Proof-of-concept studies as well as small first-in-man series have been completed and have demonstrated favorable anatomic and hemodynamic results, comparable to currently available implants in the short term. Based on the initial experience, important modifications to improve the pulmonary valve function have been initiated.

The Ross Procedure in Children: Defining the Optimal Age

BACKGROUND

It has been proposed that delaying the Ross procedure to later in childhood, allowing autograft stabilisation and placement of a larger pulmonary conduit, may improve outcomes. However, the effect of age at the time of Ross procedure on outcomes remains unclear.

METHODS

All patients who underwent the Ross procedure between 1995 and 2018 were included in the study. Patients were divided into four groups: infants, age 1 to 5 years, age 5 to 10 years and age 10 to 18 years.

RESULTS

A total of 140 patients underwent the Ross procedure in the study period. Early mortality was 23.3% (7/30) for infants compared to 0% for older children (p<0.001). Survival at 15 years was significantly lower in infants (76.3%±9.9%), compared to children aged 1 to 5 years (90.9%±20.1%), 5 to 10 years (94%±13.3%), and 10 to 18 years (86.7%±10.0%), p=0.01. Freedom from autograft reoperation at 15 years was significantly lower in infants (58.4%±16.2%), compared to children aged 1 to 5 years (77.1%±14.9%), 5 to 10 years (84.2%±6.0%) and 10 to 18 years (87.8%±9.0%), p=0.01. Overall freedom from reoperation at 15 years was 13.0%±6.0% for infants, 24.2%±9.0% for children aged 1 to 5 years, 46.7%±15.8% for children aged 5 to 10 years, and 78.4%±10.4%, p<0.001.

CONCLUSIONS

The Ross procedure performed after 10 years of age appears to be associated with improved freedom from reoperation, primarily due to a reduction in reoperation on the pulmonary conduit.

Ross Procedure in the era of Handmade-Valved Conduits for Right Ventricular Outflow Tract Reconstruction in Children: Short-Term Surgical Outcomes

Objective

Ross procedure is considered as the “gold standard” for aortic valve replacement, but the conduits used for right ventricular outflow tract (RVOT) reconstruction, such as homografts and bovine jugular vein (BJV) conduits, are of limited availability in China. Handmade expanded polytetrafluoroethylene-valved conduits (HVCs) have been used recently as the alternative for RVOT reconstruction, but their specific experience in Ross procedure is limited in the literature.

Methods

This was a retrospective review of 27 children who underwent Ross procedure in our center from January 2018 to January 2022.

Results

Mean age at surgery was 8.0 ± 3.8 years. During the study period, BJV conduits were used for RVOT reconstruction in 6 patients (22%), and HVCs were used in 21 patients (78%). Median conduit size was 20 mm (range, 16–24 mm), and mean conduit Z-score was +0.8 ± 0.9. Median time for cardiopulmonary bypass was 158 min (range, 109–275 min), and mean time for aortic crossclamping was 110 ± 21 min. There was no early mortality. During a median follow-up time of 1.4 years (range, 0.1–3.7 years), 3 patients (11%) with BJV conduits had peak conduit velocity of &gt; 3.5 m/s; 3 patients (11%) with HVCs developed moderate conduit insufficiency; no patients had more than moderate conduit insufficiency. Three patients with BJV conduits had 5 reinterventions, and all received conduit replacement with HVCs.

Conclusion

HVC is an appealing alternative to BJV conduit for RVOT construction for children undergoing Ross procedure, with favorable short-term outcomes.