Fresh Autologous Pericardium to Reconstruct the Pulmonary Valve at the Annulus When Tetralogy of Fallot Requires a Transannular Patch at Midterm

The fate of the fresh autologous pericardium after right ventricular outflow tract reconstruction

Introduction: The autologous pericardium, treated or fresh, is used in reconstructive cardiovascular surgery. We aimed to describe the features of fresh pericardium utilized in right ventricular outflow tract (RVOT) reconstruction, years after the initial surgery.

Methods: This cross-sectional study was performed on 72 patients (65.3% male, mean age =18.68 ± 9.63 y) with a history of RVOT reconstruction with the fresh autologous pericardium who underwent reoperation. During the surgery, a 1 × 1 cm sample was cut from the previous pericardial patch, and hematoxylin and eosin (H & E), Masson’s trichrome, and immunohistochemistry (IHC) staining was conducted. All the stained slides were evaluated,and the descriptive results were explained.

Results: The mean follow-up duration was 13.48 ± 7.38 years. In preoperative evaluations,53 (73.6%) patients exhibited no RVOT dilatation, 17 (23.6%) showed mild RVOT dilatation,and 2 (2.8%) had RVOT aneurysms. The H & E staining revealed no calcification in 80.55%(58/72), mild calcification in 9.72% (7/72), and moderate calcification in 9.72% (7/72) of the total samples. None of the specimens demonstrated a marked calcification. All the samples were positive for CD31, CD34, smooth muscle alpha-actin, and von Willebrand factor in IHC. In Masson’s trichrome staining, on average, 64.74% (±18.61) of the tissue sections contained collagen fibers.

Conclusion: The fresh autologous pericardium, utilized for RVOT reconstruction, showed viability, growth potential, positivity for endothelial cell markers, vascular differentiation,insignificant calcification, and no stenosis at long-term follow-up. We would, therefore, suggest it as a suitable choice for such reconstructive operations. Moreover, its usage during total correction of tetralogy of Fallot could be safe, feasible, and durable.

Long-term performance of untreated fresh autologous pericardium as a valve substitute in pulmonary position

Background:

Pulmonary regurgitation is imminent after transannular patch (TAP). We analyze the long-term performance of untreated autologous pericardium (UAP) as valve substitute at pulmonary position in patients requiring TAP.

Material and Methods:

This cross-sectional study include patients operated between 2007 and 2012 (n = 92). A sample of 19 patients was selected for this study which had a follow-up of more than 3 years. This includes patients with no TAP (n = 4) and with TAP and valve substitute, a monocusp (n = 11) or a tricuspid valve (n = 4) at neopulmonary annulus. Patients underwent echocardiography for assessment of right ventricle function and 18 fluoro-deoxyglucose PET CT scan for measurements of valve substitute at neopulmonary annulus. The target to blood ratio (TBR) of uptake of glucose by monocusp was measured at the cooptation edge of the neopulmonary valve.

Results:

The median age of the patients is 14 (9 – 37). RV function is preserved (TAPSE 18.9 (10.6 – 22.8)) at a mean follow-up of 4 years (3-9). The measurements of monocusp shows a shrinkage in height of the cusp by 35.5% (70% – 1.0%) and length by 7% (-44% - +104%). There was less shrinkage observed in patients below 15 years of age. The TBR of monocusp was 0.945 (0.17 – 3.35) with a strong correlation between the TBR values of aortic valve leaflet and monocusp leaflet of same patient.

Conclusion:

The UAP is functional and successful as a valve substitute at neo pulmonary annulus at long-term follow-up. It has resisted calcification and has shown uptake of glucose in physiological limits.

Risk factors for severe pulmonary regurgitation after repair of tetralogy of Fallot with transannular patch

BACKGROUND

Severe pulmonary regurgitation may result in right ventricular volume overload and decreased right ventricular function. Severe pulmonary regurgitation can be predicted prior to repair of tetralogy of Fallot. The aim of this study was to determine the risk factors for severe pulmonary regurgitation in repaired tetralogy of Fallot with transannular patch.

METHODS

This was a cross-sectional study in 43 patients with repaired tetralogy of Fallot using transannular patch. This study was carried out in Dr. Cipto Mangunkusumo hospital during 2015 to 2018. Participants were followed up for routine examination using echocardiography. We used bivariate and multivariate logistic regression using STATA 12.1 to identify risk factors for severe pulmonary regurgitation in this population.

RESULTS

A total of 43 patients composed of 22 boys and 21 girls with repaired tetralogy of Fallot using transannular patch were enrolled in the study. Median age of participants was 6 years at admission (2.1-18.5 years) and 3.4 years (1-17 years) at repair. Median length of follow-up was 2.1(1-4.3) years. Risk factors associated with severe pulmonary regurgitation after tetralogy of Fallot repair were McGoon ratio > 1.8 (odds ratio = 6.9; 95% confidence interval = 1.6-30) and follow-up duration >1.9 years (odds ratio = 3.6; 95% confidence interval = 0.9-15.2).

CONCLUSION

McGoon ratio > 1.8 and follow-up duration > 1.9 years are associated with severe pulmonary regurgitation after tetralogy of Fallot repair.

Assessment of untreated fresh autologous pericardium as material for construction of heart valve: Result at 5 years

Introduction

Tetralogy of Fallot requiring transannular repair of the right ventricular outflow tract (RVOT) are exposed to free pulmonary insufficiency and hence inevitable right ventricular dysfunction. This study analyzes the function and structure of untreated autologous pericardium monocusp used to create a competent pulmonary valve.

Materials and Methods

This is a retrospective analysis of 52 cases operated between December 2006 and December 2012. Untreated autologous pericardium was used for creating a competent pulmonary valve following a transannular patch. They are followed for functional and structural assessment of the pulmonary valve by echocardiography. Positron emission tomography (PET) with 18 fluorodeoxyglucose was performed in two cases for profiling the pulmonary valve.

Results

Median age was 10.5 years (1-38). The follow-up was complete for 42 (80.76%) patients for 3 years and 25 (48.07%) patients for 5 years. The RVOT gradient was 42 mmHg (16-96) in the year of surgery, which reduced to 26 mmHg (10-58) and pulmonary insufficiency that was present in 8.3% of patients in 1st year was witnessed in 22.7% in the 5th year of follow-up. The monocusp patch was successful in creating a competent valve while maintaining its structure at 3 years; however, it became distorted and retracted at 5 years of follow-up. There was no calcification in any of the patients. PET-computed tomography confirmed the uptake of glucose by monocusp at 1 year of follow-up.

Conclusion

The untreated autologous pericardium functioned well when it was used to create a competent pulmonary valve at short term and midterm. Although it changed in its structure; there was no calcification at 5 years of follow-up.

Assessment of cytocompatibility and mechanical properties of detergent-decellularized ovine pericardial tissue

Background:

Autologous pericardium is widely used for the repair of different sized cardiovascular defects. However, its use is limited especially in redo cardiac surgery. We developed an engineered tissue based on decellularized pericardium reseeded with blood-derived endothelial cells.

Materials and Methods:

Decellularization of ovine pericardium was performed using detergent treatment. Ovine outgrowth blood-derived and green fluorescent protein–labeled endothelial cells were used to reseed the decellularized ovine pericardium on the mesothelial side. The cell adhesion was assessed using fluorescent microscopy up to 15 days of in vitro cultivation. The mechanical properties of the pericardium were evaluated using suturability, burst pressure, and suture retention strength tests.

Results:

After decellularization the pericardial sheets appeared cell-free and repopulation using ovine blood-derived endothelial cells was successful by forming a robust monolayer. Detergent treatment did not affect the extracellular matrix. The thickness of decellularized tissue was similar to native ovine pericardium (285.3 ± 28.2 µm, respective 276.9 ± 23.8 µm, p = 0.48). Decellularized patch showed similar suturability comparable to the native ovine pericardium. Resulted burst pressure was not significantly different (native/decellularized: 312.5 ± 13.6/304.2 ± 16, p = 0.35). The suture retention strength of native pericardium was 638.33 ± 90.2 gr and comparable to decellularized tissue (622.2 ± 89.9 gr, p = 0.76). No differences were observed concerning elongation of native and decellularized pericardium (8.33 ± 1.5 and 8.5 ± 0.84 mm, respectively; p = 0.82).

Conclusion:

Mesothelial surface of decellularized ovine pericardium is suitable for reseeding with ovine blood-derived endothelial cells. The mechanical properties of detergent-treated pericardium were comparable to native tissue.