**6.4 Congenital diaphragmatic hernia (CDH)**

One in 2500 live infant births may be affected with CDH. It consists of abnormal defect in the fetal diaphragm, resulting in herniation of all or part of abdominal viscera into the thoracic cavity (according to the defect size). Pulmonary hypoplasia and pulmonary hypertension, usually present as a result of abnormal development of the lungs and pulmonary vasculature, this may cause persistent fetal circulation and respiratory failure with increased mortality rate. Despite great improvement in its diagnosis and treatment, infant mortality from isolated CDH still about 20–30%. Poor prognostic indicators by ultrasonography include low lung-to-head ratio, liver herniation into the thoracic cavity, and low total lung volume detected by fetal MRI. Initial experimental studies using sheep models demonstrated that prenatal repair of the diaphragmatic hernia could reverse the pulmonary hypoplasia caused by a surgically created CDH. The first clinical experience in humans likewise involved open fetal surgery. High fetal mortality rate is associated with this approach, because of umbilical vein kinking during reduction of the herniated liver into the fetal abdomen. Therefore, all recent studies consider that minimally invasive methods, taking the upper hand for treatment of CDH, as it stimulates lung growth in utero, while open fetal repair of the diaphragmatic defect was abandoned from the clinical use. Preliminary experimental studies in fetal lambs were promising, demonstrating that fetal tracheal occlusion improved fetal lung growth and reducing the severity of pulmonary hypoplasia. In cases of severe CDH, postnatal mortality appears to be significantly lower with in utero surgical intervention. Studies of fetal endoscopic tracheal occlusion (FETO) performed in cases of severe CDH have demonstrated a significantly higher survival rate compared with control fetuses that did not undergo

**13**

**Figure 3.**

*Principles of Fetal Surgery*

*DOI: http://dx.doi.org/10.5772/intechopen.85883*

FETO. Severe PAH occurred in 47% of fetuses that underwent FETO, but in 89% of patients in the prenatal expectant management group (**Figure 3**) [58, 71, 72]. So, fetal surgeons prefer minimally invasive procedures to avoid large hysterotomy and adequately visualize and access the fetal trachea. In 1997 the first fetal endoscopic (Fetendo) tracheal clipping, was done in human fetus, where maternal laparotomy was done, then 4 trocars was inserted through uterus to access and clip the fetal trachea. For the fear of serious complications of tracheal damage and vocal cord paralysis during clipping, fetoscopic balloon tracheal occlusion technique was introduced, in which no fetal neck dissection and only single uterine port was needed. Fetal endoscopic tracheal occlusion (FETO) is usually performed between 26 and 30 weeks of gestation., A trocar is placed through the maternal abdomen into the amniotic cavity guided by ultrasound, and fetoscope is inserted through the fetal mouth, then advanced into the fetal trachea. Once the carina has been retched, the balloon is inflating with physiologic solution and left just above the carina. The correct position is then checked by ultrasound imaging. In some studies, the tracheal balloon was removed at the time of delivery through ex utero intrapartum therapy. However, balloon removal before birth not only allows for the possibility of vaginal birth, but also was shown to increase pneumocyte cells differentiation type II, with increasing surfactant production. Currently, tracheal occlusion can be reversed in utero, by performing second fetoscopic procedure (typically at 34 weeks of gestation) [73, 74]. A multicenter European series including 210 cases of FETO with severe CDH (liver up and lung-to-head ratio ≤ 1) they reported 48.0% rate of survival to discharge, with 47.1% incidence of premature rupture of membrane. Up to date meta-analysis comparing survival outcome between FETO and a contemporary control group, reported that FETO improves survival compared with standard perinatal care in fetuses with isolated CDH and severe pulmonary hypoplasia (lungto-head ratio ≤ 1). 46.3% of fetuses (Fifty-one of 110) who had undergone FETO survived to discharge, compared with 5.9% (6 of 101) in the control group, giving the FETO group more significant survival chance. However, the true benefits of FETO are difficult to determine because the severity of CDH was not measured uniformly and there was great variability in the postnatal care of these infants. International, randomized controlled studies to evaluate the role of intrauterine fetal surgery in CDH cases with moderate and severe pulmonary hypoplasia is still needed [75].

*Tracheal occlusion in fetus with congenital diaphragmatic hernia (CDH) to increases lung volume, decreases* 

*herniation of abdominal viscera, and improves postnatal lung function.*

### *Principles of Fetal Surgery DOI: http://dx.doi.org/10.5772/intechopen.85883*

*Pediatric Surgery, Flowcharts and Clinical Algorithms*

clinical applications [66–70].

**6.4 Congenital diaphragmatic hernia (CDH)**

prematurity and maternal morbidity [61–65]. In a retrospective review of 54 children evaluated for lower extremity neuro-motor function and short-term ambulatory function following fetal myelomeningocele closure, they concluded that fetal myelomeningocele repair results in better than predicted lower extremity neuro-motor function at birth and short-term ambulatory status. However, these children continue to demonstrate movement incoordination which is characteristic for children with Spina-bifida. In retrospective study evaluated the incidence and clinical implications of the development of cutaneously derived intradural inclusion cysts (ICs) following fetal myelomeningocele closure through parental questionnaire. They concluded that intradural ICs can develop following fetal myelomeningocele repair. ICs long-term complications in these children may include deterioration of bladder function, and loss of lower-extremity function after fetal myelomeningocele closure. Koh et al. 2006 compared urodynamic findings in patients who underwent pre-natal closure of IMM with those of patients who underwent post-natal closure. All prenatally treated patients had lower lumbo-sacral lesions on neurological examination. In comparison, 39% of post-natally treated patients showed lack of sphincter activity at newborn examination, with similar findings noted at 1-year evaluation. Regarding bladder function, all pre-natally treated patients showed detrusor overactivity, compared to 38% of post-natally treated patients, up to 1-year evaluation. They concluded that fetal closure of IMM is associated with a higher incidence of complete denervation of the external urethral sphincter and detrusor over-activity compared to post-natal repair. Open fetal IMM closure has been extensively studied and its benefits to the fetus have been proven. Minimally invasive fetoscopic repair is technically difficult, with high risk of membrane separation and premature rupture of membrane, and its benefits to the fetus have not been proved. Therefore, minimally invasive IMM repair still needs further more studies to confirm its validity for

One in 2500 live infant births may be affected with CDH. It consists of abnormal

defect in the fetal diaphragm, resulting in herniation of all or part of abdominal viscera into the thoracic cavity (according to the defect size). Pulmonary hypoplasia and pulmonary hypertension, usually present as a result of abnormal development of the lungs and pulmonary vasculature, this may cause persistent fetal circulation and respiratory failure with increased mortality rate. Despite great improvement in its diagnosis and treatment, infant mortality from isolated CDH still about 20–30%. Poor prognostic indicators by ultrasonography include low lung-to-head ratio, liver herniation into the thoracic cavity, and low total lung volume detected by fetal MRI. Initial experimental studies using sheep models demonstrated that prenatal repair of the diaphragmatic hernia could reverse the pulmonary hypoplasia caused by a surgically created CDH. The first clinical experience in humans likewise involved open fetal surgery. High fetal mortality rate is associated with this approach, because of umbilical vein kinking during reduction of the herniated liver into the fetal abdomen. Therefore, all recent studies consider that minimally invasive methods, taking the upper hand for treatment of CDH, as it stimulates lung growth in utero, while open fetal repair of the diaphragmatic defect was abandoned from the clinical use. Preliminary experimental studies in fetal lambs were promising, demonstrating that fetal tracheal occlusion improved fetal lung growth and reducing the severity of pulmonary hypoplasia. In cases of severe CDH, postnatal mortality appears to be significantly lower with in utero surgical intervention. Studies of fetal endoscopic tracheal occlusion (FETO) performed in cases of severe CDH have demonstrated a significantly higher survival rate compared with control fetuses that did not undergo

**12**

FETO. Severe PAH occurred in 47% of fetuses that underwent FETO, but in 89% of patients in the prenatal expectant management group (**Figure 3**) [58, 71, 72].

So, fetal surgeons prefer minimally invasive procedures to avoid large hysterotomy and adequately visualize and access the fetal trachea. In 1997 the first fetal endoscopic (Fetendo) tracheal clipping, was done in human fetus, where maternal laparotomy was done, then 4 trocars was inserted through uterus to access and clip the fetal trachea. For the fear of serious complications of tracheal damage and vocal cord paralysis during clipping, fetoscopic balloon tracheal occlusion technique was introduced, in which no fetal neck dissection and only single uterine port was needed. Fetal endoscopic tracheal occlusion (FETO) is usually performed between 26 and 30 weeks of gestation., A trocar is placed through the maternal abdomen into the amniotic cavity guided by ultrasound, and fetoscope is inserted through the fetal mouth, then advanced into the fetal trachea. Once the carina has been retched, the balloon is inflating with physiologic solution and left just above the carina. The correct position is then checked by ultrasound imaging. In some studies, the tracheal balloon was removed at the time of delivery through ex utero intrapartum therapy. However, balloon removal before birth not only allows for the possibility of vaginal birth, but also was shown to increase pneumocyte cells differentiation type II, with increasing surfactant production. Currently, tracheal occlusion can be reversed in utero, by performing second fetoscopic procedure (typically at 34 weeks of gestation) [73, 74]. A multicenter European series including 210 cases of FETO with severe CDH (liver up and lung-to-head ratio ≤ 1) they reported 48.0% rate of survival to discharge, with 47.1% incidence of premature rupture of membrane. Up to date meta-analysis comparing survival outcome between FETO and a contemporary control group, reported that FETO improves survival compared with standard perinatal care in fetuses with isolated CDH and severe pulmonary hypoplasia (lungto-head ratio ≤ 1). 46.3% of fetuses (Fifty-one of 110) who had undergone FETO survived to discharge, compared with 5.9% (6 of 101) in the control group, giving the FETO group more significant survival chance. However, the true benefits of FETO are difficult to determine because the severity of CDH was not measured uniformly and there was great variability in the postnatal care of these infants. International, randomized controlled studies to evaluate the role of intrauterine fetal surgery in CDH cases with moderate and severe pulmonary hypoplasia is still needed [75].

#### **Figure 3.**

*Tracheal occlusion in fetus with congenital diaphragmatic hernia (CDH) to increases lung volume, decreases herniation of abdominal viscera, and improves postnatal lung function.*
