Congenital diaphragmatic hernia (CDH) has an incidence of 1:2200 to 1:4000 newborns. The survival rate depends on the extent of the lung hypoplasia and pulmonary hypertension. In case of an observed / expected total fetal lung volume ratio (o/e TFLV) ratio of 25% or lower and herniation of the liver in thorax, the postnatal survival is estimated to be 10-25% or lower. The aim of fetoscopic tracheal balloon occlusion is to positively influence the lung growth in CDH fetuses avoiding the development of lung hypoplasia.

Some complications after sucsessfull FETO before delivery occur because of technical difficulties during the extraction of the balloon from the trachea, leading to asphyxia, worse outcome or neonatal demise. Jani et al. published 10 neonatal deaths from 210 FETO directly related to difficulties with the removal of the intratracheal balloon. The risk of emergent balloon removal was published to be very high (39%-56%).

Our new technique exploits the fetal ability to removal the intratracheal balloon which has been implanted for the treatment of severe CDH before the delivery, avoiding many risks associated with balloon extraction and a second fetoscopy.

The study will be performed on 20 fetuses with severe CDH. Before the FETO the total fetal lung volume ratio (o/e TFLV) will be measured by fetal MRI (magnetic . Only CDH fetuses with 24-32 weeks' gestation with o/e TFLV < 25% or the fetuses with o/e TFLV < 35% and liver herniation will be operated Second fetal MRI should be performed in one week after the FETO. The balloon will be extracted by the fetus itself before the delivery, after puncture with 22 gauge needle under ultrasound guiding, during second fetoscopy or using the EXIT (ex utero intrapartum Treatment). Neonatal follow up 12 months.

Congenital diaphragmatic hernia (CDH) has an incidence of 1:2200 to 1:4000 newborns, depending on whether stillbirths are included or not. 40 % of all CDH cases show associated malformations and chromosomal abnormalities and/or syndromes take place in 10-20%. The survival rate depends on the extent of the lung hypoplasia and pulmonary hypertension. Liver herniation into the thorax, is also a negative predictor of fetal survival. In case of an observed / expected total fetal lung volume ratio (o/e TFLV) ratio of 25% or lower and herniation of the liver in thorax, the postnatal survival is estimated to be 10-25% or lower. The aim of fetoscopic tracheal balloon occlusion is to positively influence the lung growth in CDH fetuses avoiding the development of lung hypoplasia.

A common complication of fetal surgery is the preterm premature rupture of membranes (PPROM) leading to preterm delivery. The next problem occurs because of technical difficulties during the extraction of the balloon from the trachea, leading to asphyxia, worse outcome or neonatal demise. Jani et al. published 10 neonatal deaths from 210 FETO directly related to difficulties with the removal of the intratracheal balloon. The risk of emergent balloon removal was published to be very high (39%-56%).

Our new long tail balloon exploits the fetal ability to removal the intratracheal balloon which has been implanted for the treatment of severe CDH before the delivery, avoiding many risks associated with balloon extraction and a second fetoscopy.

The study will be performed on 20 fetuses with severe CDH with total fetal lung volume ratio (o/e TFLV) < 25% or with o/e TFLV < 35% combined with liver herniation into the thorax. The lung volume will be estimated by fetal MRI. The selected fetuses with severe CDH at 24-32 weeks' gestation will be operated.

Before the Long tail FETO the 0.1 mg/kg Pancuronium, 1 µg/kg Fentanyl® and 0.01 mg/kg atropine will be applicated i.m. to the CDH fetus using 22 gauge needle under ultrasound control. The monofilament 5-0 polypropylene suture of 7 cm will be fixed to the balloon (Goldbal 5, 2,5 ml, BALT Extrusion, Montmorency, France) and the FETO will be performed. The fetoscope (Karl Storz, Tuttlingen, Germany) with a diameter of 1.3 mm will be percutaneously inserted through a sheath into the uterus and then into the fetal trachea. The fetoscope will be removed and the long tail balloon will be inserted under 4-D ultrasound guidance.The position of the balloon and suture will be controlled by fetoscopy and sonography.

Second fetal MRI should be performed in one week after the FETO. The balloon must be extracted before the delivery.

Possibilities of the Long tail extraction:

1. The fetus is able to extract the balloon from the trachea after FETO, by pulling the balloons' long tail, at the end of pregnancy;
2. by fetus itself after balloon puncture with 22 gauge needle under ultrasound guiding;
3. during second fetoscopy;
4. or using the EXIT procedure.

The CDH will be closed with / or without a patch. The follow up examinations will be performed at 6 and 12 months of age the baby.

Inclusion Criteria:

• maternal age of 18-48 years
• severe CDH with MRI measured observed/expected total fetal lung volume (o/e TFLV) < 25% or < 35% in combination with a liver herniation into the thorax.

Exclusion Criteria:

• fetuses with other letal morphological abnormalities
• fetuses with chromosomal abnormalities
• severe maternal illneses

All patients:

only the Nr. of the patient will be available, diagnosis, diaphragmatic hernia left or right, liver herniation, o/e total volume lung ration (%), gestational age at the Operation (long tail FETO), gestational age of the delivery, PPROM (yes/no), APGAR, art. pH, weight.

when summary data are published