The Effect of the Superior Cavopulmonary Anastomosis on Ventricular Remodeling in Infants with Single Ventricle

Safety and feasibility of adjunct autologous cord blood stem cell therapy during the Norwood heart operation

BACKGROUND

We conducted this phase I, open-label safety and feasibility trial of autologous cord blood (CB) stem cell (CBSC) therapy via a novel blood cardioplegia-based intracoronary infusion technique during the Norwood procedure in neonates with an antenatal diagnosis of hypoplastic left heart syndrome (HLHS). CBSC therapy may support early cardiac remodeling with enhancement of right ventricle (RV) function during the critical interstage period.

METHODS

Clinical grade CB mononucleated cells (CBMNCs) were processed to NetCord-FACT International Standards. To maximize yield, CBSCs were not isolated from CBMNCs. CBMNCs were stored at 4 °C (no cryopreservation) for use within 3 days and delivered after each cardioplegia dose (4 × 15 mL).

RESULTS

Of 16 patients with antenatal diagnosis, 13 were recruited; of these 13 patients, 3 were not treated due to placental abruption (n = 1) or conditions delaying the Norwood for >4 days (n = 2) and 10 received 644.9 ± 134 × 106 CBMNCs, representing 1.5 ± 1.1 × 106 (CD34+) CBSCs. Interstage mortality was 30% (n = 3; on days 7, 25, and 62). None of the 36 serious adverse events (53% linked to 3 deaths) were related to CBMNC therapy. Cardiac magnetic resonance imaging before stage 2 (n = 5) found an RV mass index comparable to that in an exact-matched historical cohort (n = 22), with a mean RV ejection fraction of 66.2 ± 4.5% and mean indexed stroke volume of 47.4 ± 6.2 mL/m2 versus 53.5 ± 11.6% and 37.2 ± 10.3 mL/m2, respectively. All 7 survivors completed stage 2 and are alive with normal RV function (6 with ≤mild and 1 with moderate tricuspid regurgitation).

CONCLUSIONS

This trial demonstrated that autologous CBMNCs delivered in large numbers without prior cryopreservation via a novel intracoronary infusion technique at cardioplegic arrest during Norwood palliation on days 2 to 3 of life is feasible and safe.

Pulmonary artery banding and venous bidirectional cava-pulmonary shunt for two-stage arterial switch procedure in late referral of patients with transposition of the great arteries and intact ventricular septum: midterm results

OBJECTIVE

Two-stage arterial switch operation and left ventricle retraining are necessary for the patients with left ventricle dysfunction and transposition of great vessels with intact ventricular septum (TGA-IVS) who are referred late.

MATERIAL AND METHODS

Forty-seven patients with the diagnosis of TGA-IVS and left ventricle dysfunction who underwent arterial switch operation in our centre between July 2013 and August 2017 were analysed retrospectively. The inclusion criteria for left ventricle retraining were patients older than 2 months of age at presentation, having an echocardiographic left ventricle mass index of less than 35 g/m², and having an echocardiographic "banana-shaped" left ventricle geometric appearance. The patients were divided into two groups: pulmonary artery banding and Blalock Taussig shunt were performed as the initial surgical procedure for later arterial switch operation in Group I (n = 19) and pulmonary artery banding and bidirectional cava-pulmonary shunt in Group 2 (n = 28).

RESULTS

The average age was found to be 122.3 ± 45.6 days in Group I and 145.9 ± 37.2 days in Group II. There was no statistically significant difference (p = 0.232 versus p = 0.373) between the average left ventricle mass index of the two groups neither before the first stage nor the second stage (26.6 ± 4.8 g/m² versus 25.0 ± 4.9 g/m² and 70.5 ± 12 g/m² versus 673.8 ± 12.0 g/m², respectively). The average time interval for the left ventricle to retrain was 97.7 ± 42.9 days for Group I and 117.3 ± 40.3 days for Group II, significantly lower in Group I (p = 0.027). The time spent in ICU, length of the period during which inotropic support was required, and the duration of hospital stay were significantly higher in Group I (p<0.001, p < 0.001, and p < 0.00, respectively).

CONCLUSION

Pulmonary artery banding and bidirectional cava-pulmonary shunt can be performed as a safe and effective alternative to pulmonary artery banding and arterial Blalock Taussig shunt for patients with TGA-IVS in whom arterial switch operation is needed beyond the neonatal period. This approach involves a shorter hospital stay and fewer post-operative complications.