Outcomes of Repair of Congenital Aortic Valve Lesions Using Autologous Pericardium vs Porcine Intestinal Submucosa

Outcomes of aortic valve repair in children stratified by complexity: Which outcome for which lesion?

OBJECTIVE

Aortic valvuloplasty frequency has significantly increased over the past 15 years. Surgical repair varies in complexity depending on valvular lesions. Our aim is to report results on the whole spectrum of aortic valvuloplasty techniques.

METHODS

All children who consecutively underwent aortic valvuloplasty for aortic stenosis and/or aortic insufficiency between January 2006 and December 2020 at Necker Sick Children's Hospital (Paris, France) were included in a retrospective cohort study. Aortic valvuloplasty techniques were classified into 3 difficulty levels: (1) simple repair, corresponding to commissurotomy and/or shaving in aortic stenosis (AS) in neonates (group 1) and children >1 month (group 2); (2) intermediate-complexity repair, corresponding to commissuroplasty, leaflet resuspension, and fenestration closure in aortic insufficiency (leaflet prolapse in connective tissue disease, isolated leaflet prolapse and Laubry-Pezzi groups); and (3) complex repair requiring a pericardial patch to restore a functional aortic valve in mixed aortic valve disease (bicuspidization with neocommissure and cusp extension groups).

RESULTS

During the study period, 324 children underwent aortic valvuloplasty. Survival and freedom from aortic valve reintervention at 10 years were, respectively, 86.1% and 50.9% in neonates with AS, 95.2% and 71.7% in children >1 month with AS, 93.8% and 79.5% in leaflet prolapse in connective tissue disease, 97.7% and 91.9% in isolated leaflet prolapse, 100% and 88% in those with Laubry-Pezzi syndrome, 97.4% and 84.8% in bicuspidization with neocommissure, and 100% and 54.2% in the cusp extension.

CONCLUSIONS

Durability of aortic valvuloplasty techniques is satisfactory and offers the possibility to delay the Ross procedure, regardless of the lesion's complexity.

Aortic valve repair in neonates, infants and children: a systematic review, meta-analysis and microsimulation study

OBJECTIVES

To support clinical decision-making in children with aortic valve disease, by compiling the available evidence on outcome after paediatric aortic valve repair (AVr).

METHODS

A systematic review of literature reporting clinical outcome after paediatric AVr (mean age at surgery <18 years) published between 1 January 1990 and 23 December 2021 was conducted. Early event risks, late event rates and time-to-event data were pooled. A microsimulation model was employed to simulate the lives of individual children, infants and neonates following AVr.

RESULTS

Forty-one publications were included, encompassing 2 623 patients with 17 217 patient-years of follow-up (median follow-up: 7.3 years; range: 1.0-14.4 years). Pooled mean age during repair for aortic stenosis in children (<18 years), infants (<1 year) or neonates (<30 days) was 5.2 ± 3.9 years, 35 ± 137 days and 11 ± 6 days, respectively. Pooled early mortality after stenosis repair in children, infants and neonates, respectively, was 3.5% (95% confidence interval: 1.9-6.5%), 7.4% (4.2-13.0%) and 10.7% (6.8-16.9%). Pooled late reintervention rate after stenosis repair in children, infants and neonates, respectively, was 3.31%/year (1.66-6.63%/year), 6.84%/year (3.95-11.83%/year) and 6.32%/year (3.04-13.15%/year); endocarditis 0.07%/year (0.03-0.21%/year), 0.23%/year (0.07-0.71%/year) and 0.49%/year (0.18-1.29%/year); and valve thrombosis 0.05%/year (0.01-0.26%/year), 0.15%/year (0.04-0.53%/year) and 0.19%/year (0.05-0.77%/year). Microsimulation-based mean life expectancy in the first 20 years for children, infants and neonates with aortic stenosis, respectively, was 18.4 years (95% credible interval: 18.1-18.7 years; relative survival compared to the matched general population: 92.2%), 16.8 years (16.5-17.0 years; relative survival: 84.2%) and 15.9 years (14.8-17.0 years; relative survival: 80.1%). Microsimulation-based 20-year risk of reintervention in children, infants and neonates, respectively, was 75.2% (72.9-77.2%), 53.8% (51.9-55.7%) and 50.8% (47.0-57.6%).

CONCLUSIONS

Long-term outcomes after paediatric AVr for stenosis are satisfactory and dependent on age at surgery. Despite a high hazard of reintervention for valve dysfunction and slightly impaired survival relative to the general population, AVr is associated with low valve-related event occurrences and should be considered in children with aortic valve disease.

Degassing a Decellularized Scaffold Enhances Wound Healing and Reduces Fibrosis during Tracheal Defect Reconstruction: A Preliminary Animal Study

Few efforts have been made regarding the optimization of porcine small intestinal submucosa (SIS) to improve its biocompatibility. This study aims to evaluate the effect of SIS degassing on the promotion of cell attachment and wound healing. The degassed SIS was evaluated in vitro and in vivo, compared with the nondegassed SIS control. In the cell sheet reattachment model, the reattached cell sheet coverage was significantly higher in the degassed SIS group than in the nondegassed group. Cell sheet viability was also significantly higher in the SIS group than in the control group. In vivo studies showed that the tracheal defect repaired by the degassed SIS patch showed enhanced healing and reductions in fibrosis and luminal stenosis compared to the nondegassed SIS control group, with the thickness of the transplanted grafts in the degassed SIS group significantly lower than those in the control group (346.82 ± 28.02 µm vs. 771.29 ± 20.41 µm, p < 0.05). Degassing the SIS mesh significantly promoted cell sheet attachment and wound healing by reducing luminal fibrosis and stenosis compared to the nondegassed control SIS. The results suggest that the degassing processing might be a simple and effective way to improve the biocompatibility of SIS.

Small intestinal submucosa-derived extracellular matrix as a heterotopic scaffold for cardiovascular applications

Structural cardiac lesions are often surgically repaired using prosthetic patches, which can be biological or synthetic. In the current clinical scenario, biological patches derived from the decellularization of a xenogeneic scaffold are gaining more interest as they maintain the natural architecture of the extracellular matrix (ECM) after the removal of the native cells and remnants. Once implanted in the host, these patches can induce tissue regeneration and repair, encouraging angiogenesis, migration, proliferation, and host cell differentiation. Lastly, decellularized xenogeneic patches undergo cell repopulation, thus reducing host immuno-mediated response against the graft and preventing device failure. Porcine small intestinal submucosa (pSIS) showed such properties in alternative clinical scenarios. Specifically, the US FDA approved its use in humans for urogenital procedures such as hernia repair, cystoplasties, ureteral reconstructions, stress incontinence, Peyronie's disease, penile chordee, and even urethral reconstruction for hypospadias and strictures. In addition, it has also been successfully used for skeletal muscle tissue reconstruction in young patients. However, for cardiovascular applications, the results are controversial. In this study, we aimed to validate our decellularization protocol for SIS, which is based on the use of Tergitol 15 S 9, by comparing it to our previous and efficient method (Triton X 100), which is not more available in the market. For both treatments, we evaluated the preservation of the ECM ultrastructure, biomechanical features, biocompatibility, and final bioinductive capabilities. The overall analysis shows that the SIS tissue is macroscopically distinguishable into two regions, one smooth and one wrinkle, equivalent to the ultrastructure and biochemical and proteomic profile. Furthermore, Tergitol 15 S 9 treatment does not modify tissue biomechanics, resulting in comparable to the native one and confirming the superior preservation of the collagen fibers. In summary, the present study showed that the SIS decellularized with Tergitol 15 S 9 guarantees higher performances, compared to the Triton X 100 method, in all the explored fields and for both SIS regions: smooth and wrinkle.