The fate of pulmonary conduits after the Ross procedure: longitudinal analysis of the German-Dutch Ross registry experience

Decellularized Pulmonary Xenograft Matrix PplusN versus Cryopreserved Homograft for RVOT Reconstruction during Ross Procedure in Adults

BACKGROUND

 Decellularized pulmonary homografts are being increasingly adopted for right ventricular outflow tract reconstruction in adult patients undergoing the Ross procedure. Few reports presented Matrix PplusN xenograft (Matrix) in a negative light. The objective of this study was to compare our midterm outcomes of Matrix xenograft versus standard cryopreserved pulmonary homograft (CPHG).

METHODS

 Eighteen patients received Matrix xenograft between January 2012 and June 2016, whereas 66 patients received CPHG. Using nonparametric statistical tests and survival analysis, we compared midterm echocardiographic and clinical outcomes between the groups.

RESULTS

 Except for significant age difference (the Matrix group was significantly older with 57 ± 8 years than the CPHG group, 48 ± 9 years, p = 0.02), the groups were similar in all other baseline characteristics. There were no significant differences in cardiopulmonary bypass times (208.3 ± 32.1 vs. 202.8 ± 34.8) or in cross-clamp times (174 ± 33.9 vs. 184.4 ± 31.1) for Matrix and CPHG, respectively. The Matrix group had significantly inferior freedom from reintervention than the CPHG group with 77.8 versus 98.5% (p = 0.02). Freedom from pulmonary valve regurgitation ≥ 2 was not significantly different between the groups with 82.4 versus 90.5% for Matrix versus CPHG, respectively. After median follow-up of 4.9 years, Matrix xenograft developed significantly higher peak pressure gradients compared with CPHG (20.4 ± 15.5 vs. 12.2 ± 9.0 mm Hg; p = 0.04).

CONCLUSION

 After 5 years of clinical and echocardiographic follow-up, the decellularized Matrix xenograft had inferior freedom from reintervention compared with the standard CPHG. Closer follow-up is necessary to avoid progression of valve failure into right ventricular deterioration.

Pulmonary Homograft vs Handmade Polytetrafluoroethylene-Valved Conduits After the Ross Procedure

BACKGROUND

This study aimed to longitudinally compare expanded polytetrafluoroethylene (ePTFE)-valved conduits vs pulmonary homograft (PH) conduits after right ventricular outflow tract reconstruction in the Ross procedure.

METHODS

Patients undergoing a Ross procedure from June 2004 to December 2021 were identified. Echocardiographic data, catheter-based interventions, or conduit replacements, as well as time to first reintervention or replacement, were comparatively assessed between handmade ePTFE-valved conduits and PH conduits.

RESULTS

A total of 90 patients were identified. The median age and weight were 13.8 years (interquartile range [IQR], 8.08-17.80 years) and 48.3 kg (IQR, 26.8-68.7 kg), respectively. There were 66% (n = 60) ePTFE-valved conduits and 33% (n = 30) PHs. The median size was 22 mm (IQR, 18-24 mm) for ePTFE-valved conduits and 25 mm (IQR, 23-26 mm) for PH conduits (P < .001). Conduit type had no differential effect in the gradient evolution or the odds of presenting with severe regurgitation in the last follow-up echocardiogram. Of the 26 first reinterventions, 81% were catheter-based interventions, without statistically significant differences between the groups (69% PH vs 83% ePTFE). The overall surgical conduit replacement rate was 15% (n = 14), and it was higher in the homograft group (30% vs 8%; P = .008). However, conduit type was not associated with an increased hazard for reintervention or reoperation after adjusting for covariates.

CONCLUSIONS

Right ventricular outflow tract reconstruction using handmade ePTFE-valved conduits after a Ross procedure provides encouraging midterm results, without a differential effect in hemodynamic performance or valve function compared with PH conduits. These results are reassuring about the use of handmade valved conduits in pediatric and young adult patients. Longer follow-up of tricuspid conduits will complement valve competency assessment.

State-of-the-art: Insights from the Ross Registry

The treatment of aortic valve disease in young patients is still a major clinical challenge, as the pre-eminent emphasis is on durability and long-term outcomes beyond 10 to 15 years, sometimes >20 to 30 years. The Ross procedure uses the autologous pulmonary valve as an aortic valve substitute and aims to improve valve durability while avoiding anticoagulation and therefore achieve a sustained long-term result with regard to survival, valve functionality, and quality of life. However, this procedure is technically demanding and only performed at a low frequency. Data investigating the Ross procedure are mostly limited to observational studies from single expert centers, while sufficient randomized data are almost completely lacking. Therefore, to create a clinically relevant database of this therapy, the multicenter Ross Registry was founded in 2001. New patients were included, follow-up of past patients continuously updated, and outcomes regularly reported. Throughout recent years, numerous analyses have been performed to characterize this patient population, surgical techniques, risk factors for morbidity and mortality, and most importantly survival outcomes. Currently, more than 2500 patients are included, and the long-term follow-up has reached >25 years in the very first patients who were included. In the most recent study, 2444 adult patients with a mean age of 44.1 ± 11.7 years were analyzed, and it showed that excellent mid-term survival is maintained after 25 years. In addition, the rate of reintervention was lower than reported in patients with xenografts and anticoagulation-related morbidity lower than reported in patients with mechanical valves. In the absence of robust randomized controlled trials, registry data are very important to monitor outcomes and mirror the quality of current practice. Therefore, the Ross Registry provides a unique and important data base regarding treatment of aortic valve disease in young patients.

Expanded Polytetrafluoroethylene Conduits With Bulging Sinuses and a Fan-Shaped Valve in Right Ventricular Outflow Tract Reconstruction

We developed a handmade expanded polytetrafluoroethylene (ePTFE) pulmonary valvular conduit (PVC) with bulging sinuses and a fan-shaped ePTFE valve for right ventricular outflow tract (RVOT) reconstruction. We aimed to investigate the results of this device in this multicenter study. From 2001 to 2020, 1776 patients underwent RVOT reconstruction using ePTFE PVCs at 65 institutions in Japan. The median age and body weight were 4.1 years (range, 3 days to 67.1 years) and 13.3 (range, 1.8-91.3) kg, respectively. The median PVC size was 18 (range, 8-24) mm. The median Z-value of the ePTFE PVC was 1.1 (range, -3.8 to 5.0). The ePTFE PVC conditions were investigated by cardiac echocardiography and catheterization. The median follow-up period was 3.3 years (range, 0 day to 16.2 years). There were only 9 cases (0.5%) with PVC-related unknown deaths. Reintervention was performed in 283 patients (15.9%), and 190 patients (10.7%) required explantation. Freedom from reintervention and explantation at 5/10 years were 86.7/61.5% and 93.0/69.1%, respectively. At the latest echocardiography, PVC regurgitation grade was better than mild in 88.4% patients. The average peak RVOT gradient was 15.7 ± 15.9 mm Hg at the latest cardiac catheterization. ePTFE PVC infection was detected in only 8 patients (0.5%). Relative stenosis due to somatic growth was the most common cause of PVC explantation. The performance of ePTFE in terms of durability, valvular performance, and the resistance against infection is considerable and may replace conventional prosthetic materials. Further improvement of the ePTFE membrane is essential to prevent valvular dysfunction.

Allografts and xenografts for right ventricular outflow tract reconstruction in Ross patients

OBJECTIVES

Pulmonary allografts (AG) are the gold standard for right ventricular outflow tract (RVOT) reconstruction during the Ross procedure. However, there is limited availability of AG in some countries, and the use of alternative grafts for RVOT reconstruction remains controversial. This study aimed to compare the rates of freedom from RVOT graft dysfunction for AG and diepoxide-treated pericardial xenografts (DPXG).

METHODS

Between 1998 and 2015, 793 adult patients underwent the Ross procedure in our centre. Using propensity score matching, the clinical outcomes and echocardiographic results of AG and DPXG were compared.

RESULTS

Propensity score matching resulted in 2 groups (AG and DPXG) of 122 patients each. No difference was found in early mortality (2.5%) in both groups. The freedom from RVOT graft dysfunction curves were comparable between the AG and DPXG groups (P = 0.186) and the 8-year rates of freedom from graft dysfunction were 91.8% and 82.2%, respectively. The survival rates at 8 years were 90.5% and 90.1%, and the rates of freedom from RVOT reintervention at 8 years were 100% and 96.8% for the AG and DPXG groups, respectively. At discharge and follow-up, transprosthetic gradients were significantly higher in the DPXG group. The rate of the RVOT gradient progression was also higher in the DPXG group than in the AG group (1.80 ± 0.06 vs 1.39 ± 0.04 mmHg/year, P < 0.001).

CONCLUSIONS

There was no difference in freedom from RVOT graft dysfunction by 8 years when using AG and DPXG in adult Ross patients, nor in survival and freedom from RVOT conduit reintervention. Long-term results need further evaluation.

Reconstruction of right ventricular outflow tract stenosis and right ventricular failure after Ross procedure - comprehensive assessment of adult congenital heart disease with four-dimensional imaging: a case report

BACKGROUND

Re-intervention after Ross procedure into the right ventricular outflow tract might be needed in patients in the long term. However, right ventricular outflow tract re-intervention indications are still unclear. Comprehensive assessment of total hemodynamics is needed. A 42-year-old Japanese woman was referred to our hospital for moderately severe pulmonary regurgitation and severe tricuspid regurgitation after a Ross-Konno procedure. Thirteen years after surgery, she developed atrial fibrillation and atrial flutter and complained of dyspnea. Electrophysiological studies showed re-entry circuit around the low voltage area of the lateral wall on the right atrium. Four-dimensional flow magnetic resonance imaging revealed moderate pulmonary regurgitation, severe tricuspid regurgitation, and a dilated right ventricle. Flow energy loss in right ventricle calculated from four-dimensional flow magnetic resonance imaging was five times higher than in normal controls, suggesting an overload of the right-sided heart system. Her left ventricular ejection fraction was almost preserved. Moreover, the total left interventricular pressure difference, which shows diastolic function, revealed that her sucking force in left ventricle was preserved. After the comprehensive assessments, we performed right ventricular outflow tract reconstruction, tricuspid valve annuloplasty, and right-side Maze procedure. A permanent pacemaker with a single atrial lead was implanted 14 days postoperatively. She was discharged 27 days postoperatively. Echocardiography performed 3 months later showed that the size of the dilated right ventricle had significantly reduced.

DISCUSSION

A four-dimensional imaging tool can be useful in the decision of re-operation in patients with complex adult congenital heart disease. The optimal timing of surgery should be considered comprehensively.

Pulmonary homograft dysfunction after the Ross procedure using decellularized homografts-a multicenter study

OBJECTIVES

Pulmonary homograft dysfunction is a limitation after the Ross procedure. Decellularized pulmonary homografts can potentially mitigate this complication. The aim of this study was to examine the incidence, predictors, progression, and morphology of pulmonary homograft dysfunction using data from the Canadian Ross Registry.

METHODS

From 2011 to 2019, 466 consecutive patients (mean age: 47 ± 12 years, 73% male) underwent a Ross procedure using a decellularized cryopreserved pulmonary homograft (SynerGraft SG; CryoKife, Kennesaw, Ga). Pulmonary homograft dysfunction was defined as any of the following: peak pulmonary gradient ≥30 mm Hg, pulmonary regurgitation >2, or pulmonary homograft reintervention. Patients meeting ≥1 of these criteria (n = 30) were compared with the rest of the cohort (n = 436). Median follow-up is 2.2 years (maximum = 8.5 years) and 99% complete (1176 patient-years).

RESULTS

The cumulative incidence of pulmonary homograft dysfunction was 11 ± 2% at 6 years. Pulmonary homograft stenosis was the most frequent presentation (n = 28 patients, 93%). Morphologically, stenosis occurred most often along the conduit (59%). Overall, 4 patients required homograft reintervention. At 6 years, the cumulative incidence of homograft reintervention was 3 ± 1%. The instantaneous risk was greatest in the first year after surgery (3.5%/year) and decreased to <1%/year thereafter. Patient age <45 years was the only independent risk factor associated with pulmonary homograft dysfunction (hazard ratio, 3.1, 95% confidence interval, 1.1-8.6, P = .03).

CONCLUSIONS

The use of decellularized cryopreserved pulmonary homografts results in a low incidence of dysfunction and reintervention after the Ross procedure. The risk is greater in the first postoperative year. Younger age is the only independent risk factor for pulmonary homograft dysfunction.

Pulmonary Valve Function Late After Ross Procedure in 443 Adult Patients

BACKGROUND

Limited data exist on long-term pulmonary valve function after the Ross procedure. This study sought to determine the long-term function of the pulmonary valve in 443 consecutive adult patients who underwent a Ross procedure.

METHODS

All 443 patients who underwent a Ross procedure between November 1992 and March 2018 were reviewed retrospectively. All underwent pulmonary valve replacement using a cryopreserved pulmonary allograft. Freedom from the study's outcomes were calculated using Kaplan Meier survival. Risk factors for valve failure were analyzed using Cox regression.

RESULTS

Mean age at time of operation was 39 years (range: 15-66 years). There was 1 (0.2%, 1 of 443) operative mortality. Nine patients required reintervention on the pulmonary allograft at a mean 6.1 years (range: 1-12 years) after Ross procedure. Patients required pulmonary allograft reintervention for infective endocarditis (n = 4), severe pulmonary stenosis (n = 4), or severe pulmonary regurgitation (n = 1). Freedom from pulmonary allograft reintervention was 98.9% (95% confidence interval [CI] 97.1%-99.6%), 97.7% (95% CI 95.1%-98.9%), 96.6% (95% CI 93.3%-98.3%), and 96.6% (95% CI 93.3%-98.3%) at 5, 10, 15, and 20 years, respectively. Freedom from pulmonary allograft dysfunction (at least moderate pulmonary regurgitation and/or mean systolic gradient ≥ 25 mm Hg and/or reintervention) was 94.5% (95% CI 91.6%-96.4%), 88.1% (95% CI 83.6%-91.4%), 84.9% (95% CI 79.6%-88.9%), and 78.3% (95% CI 69.5%-84.9%) at 5, 10, 15, and 20 years, respectively. No risk factors were identified to influence pulmonary valve durability.

CONCLUSIONS

The pulmonary valve allograft gives excellent long-term function when used in adults undergoing the Ross procedure. Reintervention on the pulmonary valve is rare and significant pulmonary allograft dysfunction is uncommon.

The Ross procedure in adults presenting with bicuspid aortic valve and pure aortic regurgitation: 85% freedom from reoperation at 20 years

OBJECTIVES

The Ross procedure has demonstrated excellent results when performed in patients with aortic stenosis or mixed aortic valve disease [aortic stenosis and aortic regurgitation (AR)]. However, due to its reported risk of late reoperation, it is not recommended under current guidelines for patients presenting with bicuspid aortic valve and pure AR. We have analysed our own results in light of this recommendation.

METHODS

Between 1993 and 2016, 129 consecutive patients with a mean age of 34.7 ± 10.6 years (range 16-64 years) presented with bicuspid aortic valve and pure AR and underwent the Ross procedure. Patients were reviewed annually and had 2nd yearly transthoracic echocardiograms during follow-up. The unit had a liberal reoperation policy where reoperation was performed if patients developed recurrent moderate or greater AR during follow-up.

RESULTS

There was 1 inpatient death, and 3 late deaths over a mean follow-up duration of 9.6 ± 6.8 years. Late survival at 10 and 20 years post-surgery were 99% [95% confidence interval (CI) 94-100] and 95% (95% CI 85-99), respectively. Eleven patients underwent redo aortic valve replacement (AVR) and 4 patients had redo pulmonary valve replacement. Freedom from reoperation for AVR and more-than-mild AR at 10 and 20 years post-surgery were 89% (95% CI 81-94) and 85% (95% CI 74-92), respectively. Having longer aortic cross-clamp (hazard ratio 1.03, 95% CI 1.00-1.06; P = 0.05) and cardiopulmonary bypass times (hazard ratio 1.02, 95% CI 1.00-1.05; P = 0.05), and having a larger preoperative sinotubular junction diameter (hazard ratio 1.15, 95% CI 1.03-1.30; P = 0.02) were significant predictors of having redo AVR or significant AR at follow-up.

CONCLUSIONS

With a 20-year freedom from redo AVR and greater-than-mild residual AR of 85%, the utilization of the Ross procedure in bicuspid aortic valve patients with pure AR should be considered.

Does gender affect the prognosis and risk of complications in patients with congenital heart disease in the modern era?

Gender differences in the outcome of acquired cardiovascular disease are well known, but available literature on the influence of gender in congenital heart disease (CHD) is limited. Registries have provided valuable, albeit at times conflicting data. Higher mortality rates have been reported in older males with CHD, while sudden cardiac death is more prevalent in young males. However, mortality around surgery for CHD is higher in girls compared to boys, likely due to smaller body size. Women are at higher risk of developing pulmonary arterial hypertension, but at lower risk of adverse aortic outcomes, even though they are less likely to receive aortic surgery. Finally, women have a lower risk of presenting with infective endocarditis compared to men. The underlying reasons for gender differences in CHD can be attributed to genetic, hormonal, behavioural and other causes. The aim of the present paper is to provide an overview of available evidence on gender differences in CHD and their impact on outcome.

Aortic Valve Replacement and the Ross Operation in Children and Young Adults

BACKGROUND

There are several options available for aortic valve replacement (AVR), with few comparative reports in the literature. The optimal choice for AVR in each age group is not clear.

OBJECTIVES

The study sought to report and compare outcomes after AVR in the young using data from a national database.

METHODS

AVR procedures were compared after advanced matching, both in pairs and in a 3-way manner, using a Bayesian dynamic survival model.

RESULTS

A total of 1,501 patients who underwent AVR in the United Kingdom between 2000 and 2012 were included. Of these, 47.8% had a Ross procedure, 37.8% a mechanical AVR, 10.9% a bioprosthesis AVR, and 3.5% a homograft AVR, with Ross patients being significantly younger when compared to the other groups. Overall survival at 12 years was 94.6%. In children, the Ross procedure had a 12.7% higher event-free probability (death or any reintervention) at 10 years when compared to mechanical AVR (p = 0.05). We also compared all procedures except the homograft in a matched population of young adults, where the bioprosthesis had the lowest event-free probability of 78.8%, followed by comparable results in mechanical AVR and Ross, with 86.3% and 89.6%, respectively. Younger age was associated with mortality and pulmonary reintervention in the Ross group and with aortic reintervention in the mechanical AVR. Of all 3 options, only the patients undergoing the Ross procedure approached the survival of the general population.

CONCLUSIONS

AVR in the young achieves good results, with the Ross being overall better suited for this age group, especially in children. Although freedom from aortic valve reintervention is superior after the Ross procedure, the need for homograft reinterventions is an issue to take into account. All methods have advantages and limitations, with reinterventions being an issue in the long term for all, more crucially in smaller children.

Pulmonary homograft stenosis in the Ross procedure: Incidence, clinical impact and predictors in long-term follow-up

BACKGROUND

The Ross procedure is used in the treatment of selected patients with aortic valve disease. Pulmonary graft stenosis can appear in the long-term follow-up after the Ross intervention, but the factors involved and its clinical implications are not fully known.

AIM

To describe the incidence, clinical impact and predictors of homograft stenosis and reintervention after the Ross procedure in a prospective series in a tertiary referral hospital.

METHODS

From 1997 to 2009, 107 patients underwent the Ross procedure (mean age: 30±11 years; 69% men; 21 aged<18 years), and were followed for echocardiographic homograft stenosis (peak gradient>36mmHg) and surgical or percutaneous homograft reintervention.

RESULTS

After 15 years of follow-up (median: 11 years), echocardiographic and clinical data were available in 91 (85%) and 104 (98%) patients, respectively: 26/91 (29%) patients developed homograft stenosis; 10/104 (10%) patients underwent 13 homograft reintervention procedures (three patients underwent surgical replacement, three received a percutaneous pulmonary valve and one needed stent implantation). The other three patients underwent two consecutive procedures in follow-up; one died because of a procedure-related myocardial infarction. Rates of survival free from homograft stenosis and reintervention at 1, 5 and 10 years were 96%, 82% and 75% and 99%, 94% and 91%, respectively. Paediatric patients had worse survival free from homograft stenosis (hazard ratio [HR] 3.50, 95% confidence interval [CI]: 1.56-7.90; P=0.002), although there were no significant differences regarding reintervention (HR: 2.01, 95% CI: 0.52-7.78; P=0.31). Younger age of homograft donor was also a stenosis predictor (HR: 0.97, 95% CI: 0.94-0.99; P=0.046).

CONCLUSIONS

The probabilities of homograft stenosis and reintervention 10 years after the Ross procedure were 29% and 10%, respectively; only one patient had a reintervention-related death. Younger donor and recipient age were associated with a higher rate of stenosis.

The Ross procedure: suitable for everyone?

In 1967, Donald Ross transferred the patient's own pulmonary valve into the aortic root. Although results of this technique were encouraging, the Ross procedure did not gain widespread popularity until the late 1980s when surgeons started to implant the pulmonary autograft as a freestanding full root replacement with reimplantation of the coronary arteries. However, frequent dilatation of the pulmonary autograft was observed using the freestanding full root replacement technique. In contrast, the original subcoronary implantation technique and aortic root inclusion technique prevented dilatation in the long-term. Through advancing know-how in aortic root surgery and confidence, the Ross procedure has also been used in combined procedures and complex clinical presentations with good long-term results, which encourage continual use. However, the Ross procedure is a complex operation; careful patient selection and experience of the surgeon are mandatory requirements to achieve satisfactory results.