The effect of gastroschisis on experimental diaphragmatic hernia in fetal rabbits

Left congenital diaphragmatic hernia and gastroschisis in a term male infant

A term male infant was born to a healthy 24-year-old mother with antenatally diagnosed liver-up, left congenital diaphragmatic hernia (CDH) and gastroschisis. The infant was stabilised in the neonatal intensive care unit and then underwent primary repair of the CDH via left subcostal incision and silo placement for the gastroschisis. Serial silo reductions were started postoperatively and umbilical flap closure for the gastroschisis was performed on day of life 6. The patient was weaned from respiratory support, started on enteral feeds, and discharged home at 1 month of age. He was weaned from supplemental nasogastric feeds by 6 weeks of age and is currently well and thriving at 11 months of age.

Stereological Lung Parameters After Fetoscopic Abdominal Decompression of Congenital Diaphragmatic Hernia in an Ovine Model: A Pilot Study

Background: Fetoscopic endoluminal tracheal occlusion (FETO) improves lung maturation in severe cases of congenital diaphragmatic hernia (CDH) but it does not ameliorate lung compression by herniated abdominal organs. Surgically opening the fetal abdomen (abdominal decompression [AD]) reduces the intrathoracic pressure by diverting the abdominal organs into the amniotic cavity-a probable causal therapy for lung hypoplasia and pulmonary hypertension in CDH. Open surgical abdominal decompression has been reported: we describe a minimally invasive approach in an ovine model of CDH as a probable fetoscopic intervention. Materials and Methods: Eight fetuses were included, 2 were kept as HEALTHY controls. A CDH (left side, liver down) was created by open fetal surgery at midgestation in 6 fetuses, 2 were taken as CDH controls. Fetoscopic abdominal decompression (fAD) was performed 21 days later in 4 animals. The fetuses were retrieved at the end of gestation and evaluated by lung stereology. Results: fAD led to a near total evacuation of the thoracic cavity in 2 of the 4 animals. Fetuses with CDH had a lower total volume and fraction of alveolar air space, a lower volume fraction of the parenchyma, and an increase of the volume fraction of the alveolar septa and atelectasis, as well as an increased mean thickness of alveolar septa compared with HEALTHY fetuses. Fetuses treated with abdominal decompression showed an improvement of stereological parameters. Conclusions: In spite of relevant limitations (pilot study, small groups, spontaneous closure of the abdominal incision) we were able to demonstrate that abdominal decompression for CDH can be performed by fetoscopy. Our results support the hypothesis of causally improving lung development by abdominal decompression, thus implying increased survival in extreme cases of CDH. A refinement of the fetoscopic techniques and direct comparison to FETO appears warranted.

The impact of iatrogenic gastroschisis on pulmonary maturation in the fetal rabbit models of congenital diaphragmatic hernia

PURPOSE

The aim of this study was to analyze the effect of iatrogenic gastroschisis on pulmonary hypoplasia in fetal rabbits with congenital diaphragmatic hernia (CDH).

MATERIALS AND METHODS

A total of 30 pregnant rabbits received fetal surgery on gestational day 23. A left diaphragmatic hernia was created in one end fetus (DH group) of each rabbit, and the other end fetus of the same rabbit received sham thoracotomy as control (CR group). Another 19 pregnant rabbits underwent partial resection of the diaphragm in both end fetuses on gestational day 23, and then artificial gastroschisis was performed on one end fetus (GS group) on gestational day 26, while the other end remained as control (CGS group). The fetuses were harvested on gestational day 30. The histological and morphometric evaluation of lungs and livers of the end fetuses in each group was conducted.

RESULTS

In the DH group, the lungs were hypoplastic with a decrease in the total lung weight to body weight ratio, and remarkable thickening in alveolar septa. The lung vessels showed significantly thicker arterial walls when compared with those from control fetuses. The pathological finding in the CGS group was similar to that of the DH group. The thickness of the alveolar septa and of the pulmonary arterial walls showed no significant difference among the GS group, DH group and the CGS group. The ratio of liver weight to body weight increased notably in the GS group, DH group and CGS group compared with that in the CR group.

CONCLUSIONS

In the fetal rabbit models of CDH, pulmonary hypoplasia is the most significant pathological feature. Iatrogenic gastroschisis does not improve pulmonary maturation due to the active growth of the liver that herniates into the thoracic cavity.

The effect analysis and comparison between gastroschisis and tracheal ligation on experimental diaphragmatic hernia in fetal rabbits

PURPOSE

The authors analyzed and compared the effects of experimentally induced gastroschisis and tracheal ligation on pulmonary hypoplasia in fetal rabbits with congenital diaphragmatic hernia.

METHODS

Twenty-three pregnant rabbits underwent fetal surgery on gestational day 24 through 27. Left diaphragmatic hernia was created in 1 fetus (DH group) from each rabbit, and a left diaphragmatic hernia with gastroschisis (GS group) or tracheal ligation (TL group) was created in another fetuses. The fetuses were delivered on gestational day 27 through 33. Histologic and morphometric examination of the lungs were performed in each group.

RESULTS

In the DH group, the lungs were hypoplastic with a decrease in lung weight to body weight ratio and an increase in pulmonary arterial wall thickness. The alveolar septae were markedly thickened and diminished alveolar air spaces. In GS and TL groups, the alveolar septae were thickened but narrower than those of the DH group, air spaces were increased, and the pulmonary arterial wall was only slightly thickened.

CONCLUSIONS

Pulmonary hypoplasia seen in newborn rabbits after experimentally induced diaphragmatic hernia is less severe in those rabbits with concurrently made gastroschisis or tracheal ligation. From the histologic viewpoint, the effects of gastroschisis and tracheal ligation on pulmonary hypoplasia in diaphragmatic hernia have no differences.

Bilateral congenital diaphragmatic hernia and gastroschisis in a newborn: can low intrathoracic pressure prevent the pulmonary hypoplasia?

Congenital diaphragmatic hernia (CDH) is associated with high mortality and morbidity due to pulmonary hypoplasia (PH) and persistent pulmonary hypertension (PPH). Bilateral CDH is extremely rare with poor prognosis. It is usually accepted that PH in CDH is due to the herniation of abdominal viscera in the thorax leading to compression of the lung and preventing the normal lung development. On the other hand, some authors suggest that the PH occurs independently from the intrathoracic pressure in foetuses with CDH because of embryologic and genetic factors. We report a case of a newborn with bilateral CDH and gastroschisis born without PH, with favourable outcome. We support the hypothesis that a low intrathoracic pressure in patients with CDH allows an improved lung development.