Compared fate of small-diameter Contegras® and homografts in the pulmonary position

A Novel Model for Xenograft Right Ventricle to Pulmonary Artery Conduit

The last 40 years have shown dramatic improvement in outcomes for neonatal cardiac surgery for a spectrum of congenital heart disease diagnoses. With more patients surviving into adulthood, the long-term impact of initial management strategies of these patients has come into focus. This is particularly true for patients with pediatric heart valve disease. Many patients born with right ventricular to pulmonary artery (RVPA) discontinuity require placement of a valved conduit in the neonatal period. Valved conduit options are limited in this patient population due to patient size and inability to respond to somatic growth. Genetically engineered porcine (GEP) donors may offer a xenograft conduit alternative that can grow with the patient. We have developed a model utilizing GEP donor RVPA conduits placed in infantile nonhuman primate (NHP) recipients. Our recipient is maintained on single-drug immunosuppression and demonstrates no evidence of pulmonary valve insufficiency or stenosis during short-term follow-up. Further studies and long-term outcomes are necessary to determine the utility of this technology in human application.

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.

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.

Subcoronary Ross/Ross-Konno operation in children and young adults: initial single-centre experience

OBJECTIVES

We sought to evaluate the outcome after modified subcoronary Ross/Ross-Konno operation in children and young adults.

METHODS

Between January 2013 and January 2019, a total of 50 patients with median age of 6.3 years (range 0.02-36.5 years, 58% males), including 10 infants (20%), received modified subcoronary Ross/Ross-Konno operation at our institution. Survival, morbidity, reinterventions, aortic valve function and aortic root dimensions were analysed.

RESULTS

At a median follow-up of 31.2 months (range 14.4-51 months), there were 1 early death and 1 late death, both in the infant group. The overall survival at 5 years after the operation was 95%. Two patients needed aortic valve replacement, 11 and 15 months after their Ross operation. At 5 years, freedoms from reoperation on the autograft and on the right ventricle to pulmonary artery conduit were 94% and 97%, respectively. Freedom from aortic valve regurgitation greater than mild was 97% at 5 years. Median dimensions of the aortic root at all levels remained in normal range at last visit. Forty-four patients (95%) were in New York Heart Association class I with normal left ventricular function.

CONCLUSIONS

The initial experience with the subcoronary Ross/Ross-Konno operation in children and young adults showed excellent outcome. The mortality and morbidity among infants remain significant. The described technique is reproducible and might be advantageous in situations when prosthetic supporting techniques interfere with somatic growth.

Twenty-Year Experience with Truncus Arteriosus Repair: Changes in Risk Factors in the Current Era

Although the clinical outcomes of truncus arteriosus (TA) repair have been improving, few data are available on long-term outcomes after truncus arteriosus repair in the current era. This study evaluated long-term outcome after repair of TA. Fifty-one patients underwent total correction from April 1982 to June 2018. Since 2003, perioperative strategy has changed to minimal priming volume, modified ultrafiltration, and early total repair (n = 26). Mortality and reoperation rates were analyzed before and after 2003. There were 8 hospital deaths after initial operation, all before 1997. During the mean follow-up of 9.8 years, there were 2 deaths. The Kaplan-Meier estimate of survival among all hospital survivors was 94.7% at 5 years and 88.0% at 20 years. A significant independent risk factor for early mortality was operation before 2003 (Hazard ratio (HR) 9.710, p = 0.041) and REV operation (HR 8.000, p = 0.028). Freedom from reoperation for conduit change and TV repair were 88.3% and 41% at 1 and 5 years, and 96.2% and 85.4% at 1 and 5 years, respectively. After 2003, younger age and conduit choice were risk factors for conduit-related reoperation. Initial preoperative TV regurgitation was independent risk factor for sequential TV repair. Patients with TA can undergo total repair of TA with excellent results, especially in current era. Most of the patients require conduit-related reoperations. Younger age and the methods of RVOT reconstruction were risk factors for conduit-related reoperations. TV repair is necessary in limited patients, and initial regurgitation was a risk factor.

Right Ventricular Outflow Tract Reconstruction in Infant Truncus Arteriosus: A 37-year Experience

BACKGROUND

Multiple conduits for right ventricular outflow tract reconstruction exist, although the ideal conduit that maximizes outcomes remains controversial. We evaluated long-term outcomes and compared conduits for right ventricular outflow tract reconstruction in children with truncus arteriosus.

METHODS

Records of patients who underwent truncus arteriosus repair at our institution between 1981 and 2018 were retrospectively reviewed. Primary outcomes included survival and freedom from catheter reintervention or reoperation. Secondary analyses evaluated the effect of comorbidity, operation era, conduit type, and conduit size.

RESULTS

One hundred patients met inclusion criteria. Median follow-up time was 15.6 years (interquartile range, 5.3-22.2). Actuarial survival at 30 days, 5 years, 10 years, and 15 years was 85%, 72%, 72%, and 68%, respectively. Early mortality was associated with concomitant interrupted aortic arch (hazard ratio, 5.4; 95% confidence interval, 1.7-17.4; P = .005). Median time to surgical reoperation was 4.6 years (interquartile range, 2.9-6.8; n = 58). Right ventricle to pulmonary artery continuity was established with an aortic homograft (n = 14), pulmonary homograft (n = 41), or bovine jugular vein conduit (n = 36) in most cases. Multivariate analysis revealed longer freedom from reoperation with the bovine jugular vein conduit compared with the aortic homograft (hazard ratio, 3.1; 95% confidence interval, 1.3-7.7; P = .02) with no difference compared with the pulmonary homograft. Larger conduit size was associated with longer freedom from reoperation (hazard ratio, 0.7; 95% confidence interval, 0.6-0.9; P < .001).

CONCLUSIONS

The bovine jugular vein conduit is a favorable conduit for right ventricular outflow tract reconstruction in patients with truncus arteriosus. Concomitant interrupted aortic arch is a risk factor for early mortality.

Small-sized conduits in the right ventricular outflow tract in young children: bicuspidalized homografts are a good alternative to standard conduits

OBJECTIVES

Downsizing a homograft (HG) through bicuspidalization has been used for more than 2 decades to overcome the shortage of small-sized conduits for reconstruction of the right ventricular outflow tract (RVOT) in young children. Our goal was to investigate the durability of bicuspidalized HGs compared with other small HGs.

METHODS

A retrospective analysis of 93 conduits ≤20 mm, implanted over 23 years, was performed. The end-points were survival, structural valve degeneration and conduit replacement. The conduits comprised 40 pulmonary HGs, 12 aortic HGs, 17 bicuspidalized HGs and 24 xenografts.

RESULTS

The median age, mean conduit diameter and z-value at implantation were 1.4 (interquartile range 0.3-3) years, 16.5 ± 2.7 mm and 2.8 ± 1.3, respectively. Valve position was heterotopic in 59 patients and orthotopic in 34 patients. At a mean follow-up period of 7.6 ± 5.9 years, the hospital survival rate was 89%. Freedom from explant at 5 and 10 years was 83 ± 5% and 52 ± 6%, respectively. Freedom from structural valve degeneration was 79 ± 5% at 5 years and 47 ± 6% at 10 years [68 ± 8% for pulmonary HG, 42 ± 16% for bicuspidalized HG, 31 ± 15% for aortic HG and 20 ± 9% for xenografts (log rank P < 0.001)]. Multivariable analysis indicated an increased risk for structural valve degeneration with smaller conduit size (hazard ratio 0.79, 95% confidence interval 0.67-0.94; P < 0.008), extra-anatomic position (hazard ratio 2.71, 95% confidence interval 1.33-5.50; P = 0.006) and the use of xenografts compared with non-downsized pulmonary HGs (hazard ratio 4.90, 95% confidence interval 2.23-10.76; P < 0.001).

CONCLUSIONS

Appropriately sized pulmonary HGs remain the most durable option for a right ventricular outflow tract conduit in young children. However, when a small pulmonary HG is unavailable, bicuspidalization offers a valid alternative, preferable to xenograft conduits, at mid-term follow-up.

Contegra versus pulmonary homograft for right ventricular outflow tract reconstruction in newborns

OBJECTIVES

Pulmonary homografts are standard alternatives to right ventricular outflow tract reconstruction in congenital heart surgery. Unfortunately, shortage and conduit failure by early calcifications and shrinking are observed for small-sized homografts in younger patients. In neonates, Contegra® 12 mm (Medtronic Inc., Minneapolis, Minnesota, United States of America) could be a valuable alternative, but conflicting evidence exists. There is no published study considering only newborns with heterogeneous pathologies. We retrospectively compared the outcomes of these two conduits in this challenging population.

METHODS

Patients who underwent a right ventricular outflow tract reconstruction between January 1992 and December 2014 at the Hôpital Universitaire des Enfants Reine Fabiola were included. We retrospectively collected and analysed demographic, echocardiographic, surgical, and follow-up data.

RESULTS

Of the 53 newborns who benefited from a right ventricular outflow tract reconstruction during the considered period, 30 received a Contegra 12 mm (mean age 15 ± 8 days), and 23 a small (9-14 mm) pulmonary homograft (mean age 10 ± 7 days). Overall mortality was 16.6% with Contegra versus 17.4% in the pulmonary homograft group (p = 0.98 log-rank). Operative morbidity and early re-operation for conduit failure were not significantly different between the two groups. Mean follow-up in this study is 121 ± 74 months. Survival free from re-operation was not different between the two groups (p = 0.15). Multivariable analysis showed that weight and significant early gradient were factors associated with anticipated conduit failure.

CONCLUSIONS

Contegra 12 mm is a valid alternative to small pulmonary homografts in a newborn patient population.

TRIAL REGISTRATION

NCT03348397.

Right ventricular outflow tract obstruction: a quest for ideal management

Management of right ventricular outflow tract obstruction has undergone much change over the last century. Techniques described in the literature include anatomical repairs and the use of various patches, conduits, and innovative grafts. However, many of these approaches require reoperations or catheter-based interventions, leading to increased morbidity, mortality, and cost. The search for the ideal long-lasting conduit continues and there are new techniques on the horizon, using genetic engineering and nanotechnology. This review discusses the evolution of various techniques for repair of right ventricular outflow tract obstruction, past and current conduits, as well as ongoing research.

Ross-Konno Procedure in Children: Midterm Results

The aim of this study was to analyze the midterm results following the Ross-Konno procedure in children. Between 1999 and 2008, 29 patients with complex left ventricular outflow tract obstruction underwent the Ross-Konno procedure. There were 12 (41%) infants (group A) and 17 (59%) older patients (group B). The median age at operation was 3.3 years (range, 6 days to 16 years). At 7 years of follow-up, survival was 96% (1 late death), with no differences between groups A and B. Freedom from aortic regurgitation ≥ mild was 81%, with no differences between groups A and B. No residual gradient was noted in the left ventricular outflow tract in either group. Freedom from mitral regurgitation ≥ mild was 100% in group B and 41% in group A ( P = .0029). The mitral regurgitation was associated with morphological abnormalities of the mitral valve and with development of endocardial fibroelastosis after failed intervention during the newborn period. Freedom from reoperation was 73% in group B and 24% in group A ( P = .0093). All patients are now in sinus rhythm, and 43% are without medication. With the technical aspects of this procedure well accomplished, mortality is low, and the functional outcome is encouraging. At midterm follow-up, there was no residual or recurrent outflow tract obstruction and an excellent function of the neoaortic valve. The higher incidence of mitral regurgitation in infants, which was associated with morphological abnormalities of mitral valve and development of endocardial fibroelastosis, is worrisome.

Ten-year experience with handmade trileaflet polytetrafluoroethylene valved conduit used for pulmonary reconstruction

OBJECTIVE

The objective of this study was to investigate the results of handmade polytetrafluoroethylene trileaflet conduits implanted in the pulmonary position since 1997.

METHODS

One hundred thirty-nine patients underwent pulmonary reconstruction with a polytetrafluoroethylene conduit. Conduit function was investigated by means of review of serial echocardiographic studies.

RESULTS

Mean age and body weight were 12.7 +/- 12.0 years and 30.9 +/- 20.6 kg. Mean size of the conduit was 21.0 +/- 3.8 mm (12-28 mm). The z score of the conduit was +0.5 +/- 0.8 for patients older than 15 years (n = 43), +1.2 +/- 0.7 for patients 5 to 15 years old (n = 48), and +2.4 +/- 0.5 for patients younger than 5 years (n = 48). Conduits were used for the Ross procedure in 21 patients and for repair of complex congenital heart disease in 118 patients. There were 3 (2.2%) in-hospital deaths and 1 late death. Four patients required conduit explantation because of pulmonary artery distortion at a distal anastomotic site (interval, 1.2 years), infection of the polytetrafluoroethylene valve (interval, 1.6 years), midportion angulation of the conduit (interval, 4.9 years), and conduit compression by the ascending aorta (interval, 5.4 years). Estimated freedom from conduit explantation was 88.0% +/- 6.8%, and pulmonary insufficiency was less than or equal to mild in 75.0% at 10 years. All valves maintained their motion, and the mean estimated pressure gradient across the conduit was 19.6 +/- 11.9 mm Hg at 5 years and appeared to reach a plateau thereafter. The pressure gradient across the conduit was 14.2 +/- 8.0 mm Hg at 3 years (P = .0127) and 18.1 +/- 7.5 mm Hg at 7 years (P = .0208).

CONCLUSIONS

Polytetrafluoroethylene conduits represent a valid option and reliable alternative to homograft and xenograft implantation for pulmonary reconstruction.