Early results of neopulmonary valve creation technique using right atrial appendage tissue.

INTRODUCTION: Various valve repair techniques have been described for prevention of pulmonary insufficiency (PI) during right ventricular outflow tract (RVOT) reconstruction with transannular patch. Herein, we present the early results of an alternative technique of neopulmonary valve reconstruction using right atrial appendage (RAA) tissue. METHODS: Between October 2019 and December 2019, 12 patients with tetralogy of fallot (TOF) (n = 10), TOF-absent pulmonary valve (n = 1) and intact ventricular septum-pulmonary atresia (n = 1) underwent RVOT reconstruction with neopulmonary valve that was created using RAA tissue. Median age and weight of patients were 9.9 months (5 months-14 years) and 9.8 kg (6.2-47), respectively. RESULTS: No mortality or major events developed. Postoperative echocardiography revealed none/trace PI in 11 patients and mild PI in 1 patient. Median right ventricle/left ventricle ratio was 0.46 (0.35-0.65) and RVOT gradient was 20 mm Hg (0-30). Median cardiopulmonary bypass and aortic clamping times were 121 minutes (81-178) and 94 minutes (59-138), respectively. Operative times revealed statistically significant learning curve pattern in terms of cardiopulmonary bypass (r2 = .568; P = .005) and aortic clamping times (r2 = .635; P = .002). Median ventilation time, intensive care unit stay, and the length of hospital stay were 6 hours (2-48), 1 days (1-5), and 7 days (4-10), respectively. Longer perfusion time was not correlated with postoperative times. At median 6 months, echocardiography showed none/trivial PI in 11 patients and mild PI in one patient. CONCLUSION: Early results showed that neopulmonary valve reconstruction using the RAA tissue may provide a reasonable alternative for RVOT reconstruction with transannular patch. But long-term results are needed.

Pericardial Patch Exclusion Technique for Left Atrial Appendage Closure.

We describe a technique of left atrial appendage occlusion that consists of autologous pericardial patch closure of the left atrial appendage orifice from within the left atrium. This pericardial patch exclusion technique has little added risk of bleeding, can be performed through sternotomy or right minithoracotomy, and can be used in re-operative situations.

Cardiac atrial appendage stem cells engraft and differentiate into cardiomyocytes in vivo: A new tool for cardiac repair after MI.

BACKGROUND: This study assessed whether autologous transplantation of cardiac atrial appendage stem cells (CASCs) preserves cardiac function after myocardial infarction (MI) in a minipig model. METHODS AND RESULTS: CASCs were isolated from right atrial appendages of Göttingen minipigs based on high aldehyde dehydrogenase activity and expanded. MI was induced by a 2h snare ligation of the left anterior descending coronary artery. Upon reperfusion, CASCs were intramyocardially injected under NOGA guidance (MI-CASC, n=10). Non-transplanted pigs (MI, n=8) received sham treatment. 3D electromechanical mapping (EMM) and cardiac MRI were performed to assess left ventricular (LV) function. MI pigs developed LV dilatation at 2 months (2M), while in the MI-CASC group volumes remained stable. Global LV ejection fraction decreased by 16 ± 8% in MI animals vs 3 ± 10% in MI-CASC animals and regional wall thickening in border areas was better preserved in the MI-CASC group. EMM showed decreased viability and wall motion in the LV for both groups POST-MI, whereas at 2M these parameters only improved in the MI-CASC. Substantial cell retention was accompanied by cardiomyogenic differentiation in 98±1% of the transplanted CASCs, which functionally integrated. Second harmonic generation microscopy confirmed the formation of mature sarcomeres in transplanted CASCs. Absence of cardiac arrhythmias indicated the safety of CASC transplantation. CONCLUSION: CASCs preserve cardiac function by extensive engraftment and cardiomyogenic differentiation. Our data indicate the enormous potential of CASCs in myocardial repair.

Surgical management of the left superior vena cava draining into the left atrium: a novel off-pump technique using the left atrial appendage.

The left superior vena cava is the most common congenital venous anomaly in the chest; however, its drainage into the left atrium is exceptional. The aim of the paper is to describe our novel technique to connect the left superior vena cava to the right cavities using the left atrial appendage, without cardiopulmonary bypass.

A new direction for cardiac regeneration therapy: application of synergistically acting epicardium-derived cells and cardiomyocyte progenitor cells.

BACKGROUND: Adult human epicardium-derived cells (EPDCs), transplanted into the infarcted heart, are known to improve cardiac function, mainly through paracrine protection of the surrounding tissue. We hypothesized that this effect might be further improved if these supportive EPDCs were combined with cells that could possibly supply the ischemic heart with new cardiomyocytes. Therefore, we transplanted EPDCs together with cardiomyocyte progenitor cells that can generate mature cardiomyocytes in vitro. METHODS AND RESULTS: EPDCs and cardiomyocyte progenitor cells were isolated from human adult atrial appendages, expanded in culture, and transplanted separately or together into the infarcted mouse myocardium (total cell number, 4x10(5)). Cardiac function was determined 6 weeks later (9.4T MRI). Coculturing increased proliferation rate and production of several growth factors, indicating a mutual effect. Cotransplantation resulted in further improvement of cardiac function compared with single cell-type recipients (P<0.05), which themselves demonstrated better function than vehicle-injected controls (P<0.05). However, in contrast to our hypothesis, no graft-derived cardiomyocytes were observed within the 6-week survival, supporting that not only EPDCs but also cardiomyocyte progenitor cells acted in a paracrine manner. Because injected cell number and degree of engraftment were similar between groups, the additional functional improvement in the cotransplantation group cannot be explained by an increased amount of secreted factors but rather by an altered type of secretion. CONCLUSIONS: EPDCs and cardiomyocyte progenitor cells synergistically improve cardiac function after myocardial infarction, probably instigated by complementary paracrine actions. Our results demonstrate for the first time that synergistically acting cells hold great promise for future clinical regeneration therapy.