METHODS: This was a single-center, retrospective study. Echocardiographic assessment of the LV geometry, mass, and free wall thickness was performed before stenting and before the arterial switch operation. Patients then underwent the arterial switch operation, and the postoperative outcomes were reviewed.
RESULTS: There were 11 consecutive patients (male, 81.8%; mean age at stenting, 43.11 ± 18.19 days) with TGA-IVS with involuted LV who underwent LV retraining by ductal stenting from July 2013 to December 2017. Retraining by ductus stenting failed in 4 patients (36.3%). Two patients required pulmonary artery banding, and another 2 had an LV mass index of less than 35 g/m2. Patients in the successful group had improved LV mass index from 45.14 ± 17.91 to 81.86 ± 33.11g/m2 (p = 0.023) compared with 34.50 ± 10.47 to 20.50 ± 9.88 g/m2 (p = 0.169) and improved LV geometry after ductal stenting. The failed group was associated with an increased need for extracorporeal support (14.5% vs 50%, p = 0.012). An atrial septal defect-to-interatrial septum length ratio of more than 0.38 was associated with failed LV retraining.
CONCLUSIONS: Ductal stenting is an effective method to retrain the involuted LV in TGA-IVS. A large atrial septal defect (atrial septal defect-to-interatrial septum length ratio >0.38) was associated with poor response to LV retraining.
MATERIALS AND METHODS: This is an observational cohort study and retrospective case assessment, involved twins born at Linkou Chang Gung Memorial Hospital, Taoyuan, Taiwan between 2013 and 2018. DC twins with selective IUGR (sIUGR) were defined as the presence of a birth weight discordance of >25% and a smaller twin with a birth weight below the tenth percentile. PDA was diagnosed using echocardiography between postnatal day 3 and 7. Hs-PDA was defined as PDA plus increased pulmonary circulation, poor systemic perfusion, cardiomegaly, pulmonary edema, or hypotension requiring pharmacotherapeutic intervention.
RESULT: A total of 1187 twins were delivered during the study period, and 53 DC twins with selective IUGR were included in this study. DC twins with PDA have higher rate of preterm birth, lower gestational age of delivery, and lower mean birth weight of both twins compared with DC twins without PDA. In a comparison of the sIUGR twin with the appropriate for gestational age co-twin, both the incidences of PDA (28.30% vs. 7.55%, respectively; P = 0.003) and Hs-PDA (24.53% vs. 5.66%, respectively; P = 0.002) were higher in sIUGR fetuses than in the appropriate for gestational age co-twins. Small gestational age of delivery was the only variable to predict PDA and Hs-PDA [p = 0.002, Odds ratio = 0.57 (0.39-0.82), p = 0.009, Odds ratio = 0.71 (0.55-0.92), respectively].
CONCLUSION: An analysis of dichorionic twins with sIUGR indicated that IUGR increased the risk of PDA and hemodynamically significant PDA.