Centro de Medicina Fetal Clínic Barcelona


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Congenital diaphragmatic hernia Print
hernia diafragmática congénita
 

What is congenital diaphragmatic hernia?


Congenital diaphragmatic hernia (CDH) is a birth defect occurring because the diaphragm, a flat muscle separating the chest from the abdomen, it is not completely formed. Since there is a whole in this structure, the organs in the abdomen (stomach, bowels, liver) may ascend to the chest, thereby compressing the lungs and preventing their normal development, in a condition called in medicine pulmonary hypoplasia. This problem occurs in about 1 in 2500 pregnancies.
Why does it happen?

The cause of CDH is unknown, and there are no known risk factors. In some cases CDH is part of a more complex disease, for example a chromosomal problem or other malformations, but in more than half of cases it is an isolated defect.
 

Which are the risks involved?


During fetal life, the fetus is not using the lungs to breath and therefore CDH does normally not represent any risk during pregnancy. Immediately after birth, the lungs are needed to breath and obtain oxygen, and if they are too small the infant will develop a severe problem called respiratory insufficiency. The blood vessels of the lungs are also too small and the baby will have problems to circulate blood through the lungs, in a condition defined as pulmonary hypertension. Newborns with CDH require intensive support by neonatologists. Once the respiratory problem is stabilized, a pediatric surgeon will repair the whole in the diaphragm. In some selected cases, the use of extra-corporeal circulation, called ECMO, may be required.
Fetuses with CDH must be born in a tertiary hospital with highly specialized staff and experience in the management of these cases. In spite of a highly advanced healthcare, and even in the best centers in the world, part of these infants will not survive due to the severity of the pulmonary problems. The probability of a good or poor outcome depends critically on the degree of pulmonary hypoplasia, i.e., how small the lungs are. For those cases in which a lower chance of survival is expected, prenatal therapy may be considered to increase the chances for survival with conventional postnatal management.

Which tests are needed to know the prognosis in my case?


To achieve the highest accuracy it is essential that the case is evaluated in a center with experience in the evaluation of fetuses with CDH.
The evaluation follows two steps:
  • to establish whether CDH is an isolated defect or there are other problems
  • to predict the severity of pulmonary hypoplasia and the probabilities for survival with conventional postnatal treatment
This requires several exams and diagnostic tests:
  • High-resolution ultrasound
  • Amniocentesis for the study of fetal karyotype (if not available)
  • Magnetic resonance imaging.
  • Multidisciplinary evaluation and counselling by a team made up of fetal medicine specialists, neonatologists and pediatric surgeons.
Once the workup is completed, the team is able to give a better idea of the prognosis after birth, which will determine the different management options during pregnancy.


Which are the management options?


Once the comprehensive evaluation is completed and after the prognosis is established, parents may opt for three options:
  • Termination of pregnancy, depending on the legal limits on termination.
  • Conventional management alter birth, as defined above.
  • Tratamiento intrauterino mediante oclusión traqueal fetoscópica.

Fetal Endoscopic Tracheal Occlusion (FETO)


The objective of this prenatal therapy is to stimulate pulmonary growth to increase the chances of survival. The treatment is not curative, the lungs will remain small and hypoplastic, and the newborn will require conventional postnatal management as described above. Likewise, since the treatment does not aim to repair the diaphragmatic whole, this will need to be repaired after birth. However, it is thought that prenatal therapy may substantially increase the chances of surviving for a selected group of cases.

As any fetal therapy, the treatment entails some risks for the pregnancy, mainly a risk of delivering earlier, and therefore it is only offered for cases with an estimated probability of survival of 60% or less. Most recent results suggest that the treatment may roughly increase 30 to 40 % the chances for survival with respect to the initial prognosis.

The treatment is based in the occlusion of the trachea (Windpipe: the tube running from the throat down into the lungs). This will result in expansion of the lungs, which is supposed to be the main mechanism to improve respiratory function after birth.

The intervention consists in a fetoscopic treatment (using fetal endoscopy), and therefore it is a minimally invasive therapy. It is performed in an operating room with local or peridural anesthesia and the mother normally remains admitted for about 1-2 days. Through a small incision in the skin (about 3 mm) a tiny fetoscope is inserted and under direct vision the endoscope is advanced through the mouth of the fetus down to the trachea, where a balloon is inflated.  The balloon is left inflated for a period ranging 3 to 6 weeks and then it is removed. The rest of the pregnancy can be managed in a usual way and the fetus can be delivered vaginally.

This treatment is offered in a small number of hospital. The three doctors that initiated this treatment in Europe are working in collaboration and analyze their results in common, according to common protocols and techniques. The treatment is under continuous development and improvement and several aspects are now being refined in the context of European funded research programmes.


What Hospital Clínic Barcelona offers

 
Dr. Gratacós was part of the team of specialists, together with Dr. Deprest (Leuven) and Dr Nicolaides (London), who first implemented the technique that is now the basis for prenatal therapy. Our experience in the evaluation and treatment of congenital diaphragmatic hernia, both prenatally and postnatally, is among the largest in Europe. The Agrupació Sanitaria Clínic-Sant Joan de Deu allows to offer a large group of multidisciplinary staff covering all relevant aspects and guiding all steps from fetal life to the baby’s discharge. The Hospitals count with all relevant medical technology and expertise for the attention of the fetus and neonate with CDH, including ECMO. Patients are supported by our fetal medicine specialized nurses, which provide not only guidance but also emotional support during the whole process. 
nacimiento hernia diafragmaticaNewborn treated with prenatal tracheal occlusion in Hospital Clinic Barcelona.


 
 

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