The use of human amniotic fluid stem cells as an adjunct to promote pulmonary development in a rabbit model for congenital diaphragmatic hernia.

Objective: This study aimed to evaluate the potential benefit of intra-tracheal injection of human amniotic fluid stem cells (hAFSC) on pulmonary development combined with TO in a rabbit model for CDH.

Methods: In time-mated pregnant does a left diaphragmatic defect was created at d23 (term = 31). At d28, previously operated fetuses were assigned to either TO and injection with 70 μL of phosphate buffered saline (PBS) or 1.

Alveolarization genes modulated by fetal tracheal occlusion in the rabbit model for congenital diaphragmatic hernia: a randomized study.

Background: The mechanisms by which tracheal occlusion (TO) improves alveolarization in congenital diaphragmatic hernia (CDH) are incompletely understood. Therefore transcriptional and histological effects of TO on alveolarization were studied in the rabbit model for CDH. The question of the best normalization strategy for gene expression analysis was also addressed.

Signaling molecules in the fetal rabbit model for congenital diaphragmatic hernia.

Rationale And Objectives: Little is known about molecular changes in lungs of fetal rabbits with surgically induced diaphragmatic hernia (DH). Therefore, we examined in this model gene expressions of pivotal molecules for the developing lung.

Methods: At day 23 of gestation, DH was created in 12 fetuses from 4 does.

A longer tracheal occlusion period results in increased lung growth in the nitrofen rat model.

Objective: Prenatal tracheal occlusion (TO) promotes lung growth and is applied clinically in fetuses with severe congenital diaphragmatic hernia. Limited data are available regarding the effect of duration of TO on lung development. Our objective was to evaluate the effects of long (2 and 2.

Morphologic changes and methodological issues in the rabbit experimental model for diaphragmatic hernia.

Fetal lung development may be impaired by some congenital anomalies or in utero events. Animal models are used to understand the pathophysiology of these diseases and explore therapeutic strategies. Our group has an interest in the prenatal management of congenital diaphragmatic hernia (CDH).

Antenatal fetal VEGF therapy to promote pulmonary maturation in a preterm rabbit model.

Aim: To assess the effects of fetal tracheal administration of VEGF on pulmonary maturation in a preterm rabbit model.

Methods: On day 26 (term=31days), fetal rabbits received recombinant rat VEGF (30microg in 70microL normal saline) or placebo (normal saline 70microL) intratracheally, with or without subsequent tracheal occlusion. Non-operated littermates served as internal controls.

Albumin as an adjunct to tracheal occlusion in fetal rats with congenital diaphragmatic hernia: a placebo-controlled study.

Objective: We sought to investigate effects of intratracheal albumin injection prior to tracheal occlusion (TO) on lung proliferation in fetal rats with nitrofen-induced congenital diaphragmatic hernia.

Study Design: On embryonic day 19, nitrofen-exposed fetuses underwent TO, TO and 50 microL of either intratracheal albumin 20% or saline, or remained untouched. Main outcome at embryonic day 21.

The effect of maternal betamethasone and fetal tracheal occlusion on pulmonary vascular morphometry in fetal rabbits with surgically induced diaphragmatic hernia: a placebo controlled morphologic study.

Objectives: We studied the vascular effects of betamethasone (BM) and/or tracheal occlusion (TO) in fetal rabbits with surgically induced congenital diaphragmatic hernia (CDH).

Methods: At day 23 (pseudoglandular phase; term = 31 d), 54 ovarian-end fetuses from 27 does underwent induction of CDH. Thirteen did receive either 0.

The effect of fetal tracheal occlusion on lung tissue mechanics and tissue composition.

Fetal tracheal occlusion (TO) is currently used to treat severe cases of congenital diaphragmatic hernia (DH). Clinical and experimental studies suggest an improved postnatal outcome, but lung tissue mechanics after TO have not been studied. We determined the effect of TO on mechanical impedance and lung tissue components in a rabbit model for DH.

Effects of betamethasone on peripheral arterial development in term fetal rabbit.

Glucocorticoids are given antenatally to promote pulmonary epithelial maturation and prevent respiratory distress syndrome in premature newborns. In contrast to airway changes, effects on vessels are less documented. We hypothesized that antenatal betamethasone (BM) administration promotes vascular development.

Effects of maternal retinoic acid administration in a congenital diaphragmatic hernia rabbit model.

Maternal retinoid administration has beneficial effects on lung development in the nitrofen rodent toxic model of congenital diaphragmatic hernia (DH). We wanted to investigate the effects in a surgical model, where the retinoid signaling pathway is not primarily disrupted by the toxic agent. We created DH in fetal rabbits at day 23 of gestation, administrated to the does all trans-retinoic acid (ATRA) or vehicle (VHC) intramuscularly for 8 consecutive days and harvested normal and operated (DH) fetuses at 31 d (n = 7 in each group).

Effect of maternal administration of betamethasone on peripheral arterial development in fetal rabbit lungs.

Objectives: Glucocorticoids promote lung maturation and reduce the incidence of respiratory distress syndrome in premature newborns. We hypothesized that betamethasone (BM), which is known to induce thinning of the alveolar walls, would also thin the arterial media and adventitia of intra-parenchymatic vessels in developing rabbit lungs.

Study Design: 112 fetuses from 21 time-mated, pregnant, giant white rabbits received maternal injections of BM at either 0.

T2 quantifications of lungs in the fetal lamb with experimentally-induced congenital diaphragmatic hernia.

Objective: As an aid to evaluate lung hypoplasia, we investigated the difference between T2 value in fetal lungs of lambs with surgically-induced left-sided diaphragmatic hernia (DH) and gestational age (GA)-matched control littermates (normal [NL]).

Methods: Lungs were divided into two groups: DH (n = 4) and NL (n = 6). DH was induced at 65-75 days GA (term = 145 days).

Fetoscopic surgery: encouraged by clinical experience and boosted by instrument innovation.

Today, modern ultrasound equipment and the wide implementation of screening programmes allow the timely diagnosis of many congenital anomalies. For some of these, fetal surgery may be a life-saving option. In Europe, open fetal surgery became poorly accepted because of its invasiveness and the high incidence of postoperative premature labour and rupture of the fetal membranes.

Ultrasound-guided injection and occlusion of the trachea in fetal sheep.

Objectives: To access the fetal sheep trachea by ultrasound-guided transthoracic injection in order to deliver gene therapy vectors or occlude the trachea with a detachable balloon.

Methods: Fetal sheep were operated on at a mean gestational age of 102 (range, 81-116) days (term = 145 days). Under ultrasound guidance, either a 20-G spinal (for vector delivery) or a 16-G Kellett (for placement of an occlusive balloon) needle was inserted via the fetal thorax into the fetal trachea.

Accuracy of magnetic resonance imaging for measuring fetal sheep lungs and other organs.

Objective: Lung volume measurement by fetal magnetic resonance imaging (fetMRI) has been used to predict survival of fetuses with isolated congenital diaphragmatic hernia (CDH). So far, the accuracy and precision of fetMRI for volumetry of either the normal or hypoplastic developing lung has not been formally studied.

Methods: A total of nine sheep carrying 14 fetuses underwent fetMRI under general anesthesia at a mean of 118 days' gestational age (term = 145 days).

Pulmonary vascular effects of sildenafil on the development of chronic pulmonary hypertension in the ovine fetus.

We investigated the pulmonary vascular effects of prophylactic use of sildenafil, a specific phosphodiesterase-5 inhibitor, in late-gestation fetal lambs with chronic pulmonary hypertension. Fetal lambs were operated on at 129 +/- 1 days gestation (term = 147 days). Ductus arteriosus (DA) was compressed for 8 days to cause chronic pulmonary hypertension.

Pulmonary circulation of fetal sheep with lung hyperplasia following tracheal occlusion.

Objectives: To determine the alteration of blood flow velocity profile in the pulmonary arteries (PAs) of fetal sheep after tracheal occlusion (TO).

Methods: Doppler ultrasound investigations of the PAs, the pulmonary trunk and the ductus arteriosus were performed weekly in nine ewes (gestational age 92-98 days, term 145 days) with singleton pregnancies after TO (n = 5) and in control fetuses (n = 4). Histological examinations with morphometry of pulmonary arterial vessels and of airways were performed in both groups.

Effect of tracheal occlusion on peripheric pulmonary vessel muscularization in a fetal rabbit model for congenital diaphragmatic hernia.

Objective: This study was undertaken to evaluate the effects on peripheric pulmonary vessel muscularization by tracheal occlusion (TO) performed at different gestational ages in fetal rabbits with surgically induced diaphragmatic hernia.

Study Design: In 23 New Zealand white does, both ovarian end fetuses underwent surgical creation of diaphragmatic hernia at 23 days of gestation (pseudoglandular phase). At 26, 27, or 28 days 1 fetus underwent TO, the contralateral one underwent a sham operation for a total of 46 fetuses.

Pulmonary vascular morphology in a fetal rabbit model for congenital diaphragmatic hernia.

Background/purpose: Although the pulmonary vascular abnormalities in congenital diaphragmatic hernia (CDH) are described from a morphologic point of view, the treatment of pulmonary hypertension (PH) remains one of the main unsolved problems in clinical daily practice. For this reason, detailed studies in well-validated animal models could still be of significance in our understanding of the pathogenesis of CDH.

Methods: In does of 23 days' gestational age (GA), 39 fetuses underwent creation of diaphragmatic hernia (DH) and 15 fetuses a sham thoracotomy (SHAM).