**2. Prenatal**

Maternal-fetal medicine and intrauterine intervention in defects of the fetus, or unborn child, emerged and has evolved as a result of the technical advancements in medicine. The scope of these specialties is encouraging and promises advanced interventions with improved results. The refinement of ultrasound has made a great contribution to the field [1]. The use of ultrasound to visualize the fetus in its environment created a great interest to be able to identify malformations that could be corrected through intrauterine intervention. The most important antecedents of fetal surgery date back to the early 1960s, when Liley devised a technique for fetal transfusion [2]. In 1965, Adamson reported the first fetal surgery in humans, using a hysterotomy [3]. In this research line, experiments were carried out on lamb and monkey fetuses to perfect instruments and techniques, evaluate the results in these models and study their feasibility and reproducibility in humans.

a successful postgraduate project in neonatal surgery has been developed at the Universidad Nacional Autónoma de México, which is already being replicated in other institutions in

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145

Congenital hydronephrosis was the first condition to attract attention within the scope of prenatal interventions, especially in bladder outlet obstructions due to urethral valves [4]. Congenital obstruction of the lower urinary tract (bladder neck) comprises a set of conditions of which atresias and posterior urethral valve obstructions are representative. With an approximate incidence of 2.2 per 10,000 live births, it results in oligohydramnios, pulmonary hypoplasia and irreparable renal damage, with 45% mortality. The role of prenatal obstetric ultrasound is crucial as the defect can be detected in 85% of the cases. Ultrasonographic features suggestive of lower urinary tract obstruction are an enlarged fetal bladder and dilated proximal urethra with or without associated hydronephrosis. It has been observed that when the anomaly is present before 25 weeks of gestation and secondary oligohydramnios prevails for more than 14 days, this malformation is associated with neonatal mortality > 90%. The canalicular phase of lung development, crucial to the development of the human lung, occurs during 14–25 weeks of gestation. Morris et al. demonstrated that prenatal intervention to treat bladder obstruction by hydronephrosis using percutaneous or open bladder shunt by a vesico-amniotic shunt increases overall survival in neonates affected by this abnormality,

Sacrococcygeal teratoma is the most common tumor in the newborn. This neoplasm arises between the base of the spine and the rectum and protrudes from inside of the pelvis outwards. The tumor is more frequent in females than in males (3:1), with an incidence of 1 per 40,000 births. The presentation may be grossly frank and is seen at birth. Type 1 has the best prognosis, as the tumor is predominantly external with a small pre-sacral component (**Figure 1**). The tumor corresponding to type 4 is invasive, deforming the pelvis and part of the abdomen. The risk of malignancy depends on two factors: the site and extent of the tumor and age at the time of diagnosis. The prenatal appearance of the sacrococcygeal teratoma on ultrasound is of a mixed solid lesion with a cystic component that arises from the sacrum, with hyperechogenic zones corresponding to calcifications. Recently, ultrafast fetal nuclear magnetic resonance imaging has been used to assess the vascular component of these neoplasms, as there is risk of fetal intrauterine hemorrhage with secondary anemia, hemodynamic decompensation due to the formation of arteriovenous fistulas, hydramnios, hydrops fetalis, placentomegaly and eventually, in severe cases, intrauterine death. The effect of the mass of a sacrococcygeal teratoma has been related to uterine distension, dystocia and tumor

rupture at birth, as well as causing mirror syndrome and severe hypertensive states.

The hemodynamic effect of the coccygeal sacrum tumor can be evaluated with echocardiographic study, measuring the relationship between ventricular outflow and the diameter of the vena cava, descending aorta and umbilical vein. A poor prognosis is related to

Mexico and other Latin American countries.

however, the studies published in this regard are few [6].

**2.1. Obstructive uropathy**

**2.2. Sacrococcygeal teratoma**

The modern history of fetal surgery began at the University of California, San Francisco, with Michael Harrison. He first conceived his interest in intrauterine intervention for the treatment of congenital diaphragmatic hernia when he was an intern at Massachusetts General Hospital. Harrison's work continues today and is a valuable resource in the field [1–3]. In 1982, Harrison noted that diaphragmatic hernia, congenital hydronephrosis and hydrocephalus were defects which could be susceptible to prenatal treatment, as they were simple structural defects that prevented the normal fetal development of the structures involved. In that same year, the first open fetal surgery was performed at 21 weeks of gestation on a fetus with congenital hydronephrosis, which consisted of performing a hysterotomy to expose the lower abdomen of the fetus and place a double pigtail catheter to communicate the bladder with the amniotic cavity to promote the free flow of urine, thus relieving the obstruction causing the hydronephrosis [4]. The intervention was successful, and pregnancy continued for 14 weeks after intervention; however, at birth, the kidneys already showed irreversible damage, and it was clear that intervention had to be at an earlier stage of intrauterine life [5].

Neonatal surgery was not well known as a separate specialty of general pediatric surgery but has a history dating back to 1955 when P. Rickham, a pediatric surgeon from Switzerland, started a newborn surgery program in the city of Liverpool. Rickham's program began the systematization of neonatal care, especially for congenital anomalies. It was to be hoped that, having established a program of neonatal surgery, it would be recognized as a specialty. In spite of his prestige and worldwide fame, the specialty was not yet established. He published two editions of his classic book Neonatal Surgery, where in addition to the classically studied congenital defects, he narrated his experience operating on children with neurological conditions such as congenital hydrocephalus associated, or not, with pituitary-spinal malformations and musculoskeletal disorders such as club foot.

Neonatal surgery in the last third of the twentieth century has made remarkable advances in diagnostic resources. Postoperative management development has been especially important, with the implementation of ventilators and intravenous nutrition. In Mexico (specifically in the unit where the authors work), after years of managing hundreds of malformed newborns, a successful postgraduate project in neonatal surgery has been developed at the Universidad Nacional Autónoma de México, which is already being replicated in other institutions in Mexico and other Latin American countries.

#### **2.1. Obstructive uropathy**

**2. Prenatal**

144 Selected Topics in Neonatal Care

feasibility and reproducibility in humans.

lier stage of intrauterine life [5].

tions and musculoskeletal disorders such as club foot.

Maternal-fetal medicine and intrauterine intervention in defects of the fetus, or unborn child, emerged and has evolved as a result of the technical advancements in medicine. The scope of these specialties is encouraging and promises advanced interventions with improved results. The refinement of ultrasound has made a great contribution to the field [1]. The use of ultrasound to visualize the fetus in its environment created a great interest to be able to identify malformations that could be corrected through intrauterine intervention. The most important antecedents of fetal surgery date back to the early 1960s, when Liley devised a technique for fetal transfusion [2]. In 1965, Adamson reported the first fetal surgery in humans, using a hysterotomy [3]. In this research line, experiments were carried out on lamb and monkey fetuses to perfect instruments and techniques, evaluate the results in these models and study their

The modern history of fetal surgery began at the University of California, San Francisco, with Michael Harrison. He first conceived his interest in intrauterine intervention for the treatment of congenital diaphragmatic hernia when he was an intern at Massachusetts General Hospital. Harrison's work continues today and is a valuable resource in the field [1–3]. In 1982, Harrison noted that diaphragmatic hernia, congenital hydronephrosis and hydrocephalus were defects which could be susceptible to prenatal treatment, as they were simple structural defects that prevented the normal fetal development of the structures involved. In that same year, the first open fetal surgery was performed at 21 weeks of gestation on a fetus with congenital hydronephrosis, which consisted of performing a hysterotomy to expose the lower abdomen of the fetus and place a double pigtail catheter to communicate the bladder with the amniotic cavity to promote the free flow of urine, thus relieving the obstruction causing the hydronephrosis [4]. The intervention was successful, and pregnancy continued for 14 weeks after intervention; however, at birth, the kidneys already showed irreversible damage, and it was clear that intervention had to be at an ear-

Neonatal surgery was not well known as a separate specialty of general pediatric surgery but has a history dating back to 1955 when P. Rickham, a pediatric surgeon from Switzerland, started a newborn surgery program in the city of Liverpool. Rickham's program began the systematization of neonatal care, especially for congenital anomalies. It was to be hoped that, having established a program of neonatal surgery, it would be recognized as a specialty. In spite of his prestige and worldwide fame, the specialty was not yet established. He published two editions of his classic book Neonatal Surgery, where in addition to the classically studied congenital defects, he narrated his experience operating on children with neurological conditions such as congenital hydrocephalus associated, or not, with pituitary-spinal malforma-

Neonatal surgery in the last third of the twentieth century has made remarkable advances in diagnostic resources. Postoperative management development has been especially important, with the implementation of ventilators and intravenous nutrition. In Mexico (specifically in the unit where the authors work), after years of managing hundreds of malformed newborns, Congenital hydronephrosis was the first condition to attract attention within the scope of prenatal interventions, especially in bladder outlet obstructions due to urethral valves [4]. Congenital obstruction of the lower urinary tract (bladder neck) comprises a set of conditions of which atresias and posterior urethral valve obstructions are representative. With an approximate incidence of 2.2 per 10,000 live births, it results in oligohydramnios, pulmonary hypoplasia and irreparable renal damage, with 45% mortality. The role of prenatal obstetric ultrasound is crucial as the defect can be detected in 85% of the cases. Ultrasonographic features suggestive of lower urinary tract obstruction are an enlarged fetal bladder and dilated proximal urethra with or without associated hydronephrosis. It has been observed that when the anomaly is present before 25 weeks of gestation and secondary oligohydramnios prevails for more than 14 days, this malformation is associated with neonatal mortality > 90%. The canalicular phase of lung development, crucial to the development of the human lung, occurs during 14–25 weeks of gestation. Morris et al. demonstrated that prenatal intervention to treat bladder obstruction by hydronephrosis using percutaneous or open bladder shunt by a vesico-amniotic shunt increases overall survival in neonates affected by this abnormality, however, the studies published in this regard are few [6].

#### **2.2. Sacrococcygeal teratoma**

Sacrococcygeal teratoma is the most common tumor in the newborn. This neoplasm arises between the base of the spine and the rectum and protrudes from inside of the pelvis outwards. The tumor is more frequent in females than in males (3:1), with an incidence of 1 per 40,000 births. The presentation may be grossly frank and is seen at birth. Type 1 has the best prognosis, as the tumor is predominantly external with a small pre-sacral component (**Figure 1**). The tumor corresponding to type 4 is invasive, deforming the pelvis and part of the abdomen. The risk of malignancy depends on two factors: the site and extent of the tumor and age at the time of diagnosis. The prenatal appearance of the sacrococcygeal teratoma on ultrasound is of a mixed solid lesion with a cystic component that arises from the sacrum, with hyperechogenic zones corresponding to calcifications. Recently, ultrafast fetal nuclear magnetic resonance imaging has been used to assess the vascular component of these neoplasms, as there is risk of fetal intrauterine hemorrhage with secondary anemia, hemodynamic decompensation due to the formation of arteriovenous fistulas, hydramnios, hydrops fetalis, placentomegaly and eventually, in severe cases, intrauterine death. The effect of the mass of a sacrococcygeal teratoma has been related to uterine distension, dystocia and tumor rupture at birth, as well as causing mirror syndrome and severe hypertensive states.

The hemodynamic effect of the coccygeal sacrum tumor can be evaluated with echocardiographic study, measuring the relationship between ventricular outflow and the diameter of the vena cava, descending aorta and umbilical vein. A poor prognosis is related to

Arnold-Chiari malformation.This anomaly is a generally congenital disease, consisting of an anatomical alteration of the base of the skull, which produces herniation of the cerebellum and brainstem through the foramen magnum to the cervical canal. This anomaly ultimately causes abnormal circulation of cerebrospinal fluid, culminating with hydrocephalus, central apnea, stridor and swallowing disorders. The embryonic pathophysiology of the defect is due to the combination of two strands or the two-hit model. The first effect consists of failure in the formation and closure of the neural tube, with an open defect, which exposes the neural elements to amniotic fluid (the second effect). It is important to note that in experimental models with fetal lambs, where an open neural defect was created and immediately surgically covered, effects on the lower extremities and on urinary continence and bowel movements were not observed. On the other hand, fetuses of lambs who underwent surgical repair of the myelomeningocele after 4 weeks of having experimentally created the defect showed good outcome after fetal intervention, urinary continence was maintained and preserved the neuromuscular function of their limbs, Which supports the hypothesis that prenatal intervention prevents neurological and associated confusion. Adzick in 2011 in a randomized clinical

Pre- and Postnatal Surgery, Most Common Conditions, Diagnosis and Treatment

http://dx.doi.org/10.5772/intechopen.69219

147

Congenital pulmonary malformations have been divided for their study into those related to the bronchial tree: agenesis, aplasia and pulmonary hypoplasia and those of pulmonary parenchyma: congenital lung cystic adenomatoid disease, pulmonary sequestration, lobar emphysema and bronchogenic cyst. The high definition and quality provided by current sonographic studies have achieved better prenatal identification of the fetal lung lesions in the majority of cases detected on routine ultrasound between 18 and 20 weeks of gestation. These malformations have an incidence from 1 per 10,000 to 1 per 35,000 pregnancies. Sonographic study provides information on variables such as volume, location, arterial blood supply and venous drainage and consistency of the adenomatoid malformation, which can vary widely

Adenomatoid malformation, consisting of small cysts, generally grows unpredictably and causes compression on surrounding structures, as well as an effect of mass on the mediastinum, esophagus and lungs, causing pulmonary hypoplasia, obstruction of the vena cava, cardiac insufficiency, hydrops fetalis and polyhydramnios. As one method to identify serious cases, several investigators have proposed predictive indices and measures such as the cystic volume ratio (CVR), obtained by dividing the volume of the cystic lesion (length X width X height X 0.52) by the circumference of the head. In a retrospective study by Crombleholme, it was concluded that a CVR greater than 1.6 was associated with a 75% chance of developing hydrops fetalis, which justified prenatal intervention [7, 9]. In cases with a better prognosis, EXIT therapy is recommended, with resection of the mass before birth. Postnatal stabilization and thoracotomy are also acceptable. Macrocystic lesions may be prenatally decompressed by thoracentesis with a single needle or with drainage guided by amniotic thoracic ultrasound. At this time, microcystic lesions are not candidates for drainage and will require

trial [8].

fetal surgery [10].

**2.4. Pulmonary cystic adenomatoid malformation**

from solid (microcystic) to frankly cystic (macrocystic) [7].

**Figure 1.** A giant sacrococcygeal teratoma in a newborn patient.

disproportionate tumor size (more than 150 cm per week is a very poor prognosis), high vascularity, predominantly solid component, placentomegaly, heart failure and concomitant maternal complications. The main objective of prenatal care is to identify the most reliable predictor of poor prognosis in fetuses with sacrococcygeal teratoma. The gestational age at the time of decompensation will determine the type of intervention; if it occurs after the 27th or 28th week of gestation, an emergency cesarean section or EXIT procedure (ex utero intrapartum treatment) will be chosen. If the hemodynamic imbalance is identified before week 27 in the cases of teratoma classes 1 and 2, open maternal-fetal surgery and partial resection of the tumor followed by definitive surgical intervention at birth should be chosen. There are other procedures that consist of disrupting tumor vascularity with dissimilar results, such as thermoregulation, radiofrequency ablation, alcohol sclerosis or laser ablation. The complications or side effects of these methods can result in extensive pelvic muscle damage, hemorrhage, nerve injury and hip dislocation [7].

#### **2.3. Myelomeningocele**

Within the congenital anomalies of the central nervous system, myelomeningocele is the most common variety of spina bifida and consists of the extrusion of the spinal tissue into a sac (meninges) occupied by cerebrospinal fluid. Its frequency is about 3.4 per 10,000 live births. Mortality is 10%, and survivors show varying degrees of disability depending on the height of the neural damage, including paralysis of the lower extremities and bladder and bowel dysfunction. In addition to exhibiting the anatomical neurological abnormalities characteristic of Arnold-Chiari malformation.This anomaly is a generally congenital disease, consisting of an anatomical alteration of the base of the skull, which produces herniation of the cerebellum and brainstem through the foramen magnum to the cervical canal. This anomaly ultimately causes abnormal circulation of cerebrospinal fluid, culminating with hydrocephalus, central apnea, stridor and swallowing disorders. The embryonic pathophysiology of the defect is due to the combination of two strands or the two-hit model. The first effect consists of failure in the formation and closure of the neural tube, with an open defect, which exposes the neural elements to amniotic fluid (the second effect). It is important to note that in experimental models with fetal lambs, where an open neural defect was created and immediately surgically covered, effects on the lower extremities and on urinary continence and bowel movements were not observed. On the other hand, fetuses of lambs who underwent surgical repair of the myelomeningocele after 4 weeks of having experimentally created the defect showed good outcome after fetal intervention, urinary continence was maintained and preserved the neuromuscular function of their limbs, Which supports the hypothesis that prenatal intervention prevents neurological and associated confusion. Adzick in 2011 in a randomized clinical trial [8].

#### **2.4. Pulmonary cystic adenomatoid malformation**

disproportionate tumor size (more than 150 cm per week is a very poor prognosis), high vascularity, predominantly solid component, placentomegaly, heart failure and concomitant maternal complications. The main objective of prenatal care is to identify the most reliable predictor of poor prognosis in fetuses with sacrococcygeal teratoma. The gestational age at the time of decompensation will determine the type of intervention; if it occurs after the 27th or 28th week of gestation, an emergency cesarean section or EXIT procedure (ex utero intrapartum treatment) will be chosen. If the hemodynamic imbalance is identified before week 27 in the cases of teratoma classes 1 and 2, open maternal-fetal surgery and partial resection of the tumor followed by definitive surgical intervention at birth should be chosen. There are other procedures that consist of disrupting tumor vascularity with dissimilar results, such as thermoregulation, radiofrequency ablation, alcohol sclerosis or laser ablation. The complications or side effects of these methods can result in extensive pelvic

Within the congenital anomalies of the central nervous system, myelomeningocele is the most common variety of spina bifida and consists of the extrusion of the spinal tissue into a sac (meninges) occupied by cerebrospinal fluid. Its frequency is about 3.4 per 10,000 live births. Mortality is 10%, and survivors show varying degrees of disability depending on the height of the neural damage, including paralysis of the lower extremities and bladder and bowel dysfunction. In addition to exhibiting the anatomical neurological abnormalities characteristic of

muscle damage, hemorrhage, nerve injury and hip dislocation [7].

**Figure 1.** A giant sacrococcygeal teratoma in a newborn patient.

**2.3. Myelomeningocele**

146 Selected Topics in Neonatal Care

Congenital pulmonary malformations have been divided for their study into those related to the bronchial tree: agenesis, aplasia and pulmonary hypoplasia and those of pulmonary parenchyma: congenital lung cystic adenomatoid disease, pulmonary sequestration, lobar emphysema and bronchogenic cyst. The high definition and quality provided by current sonographic studies have achieved better prenatal identification of the fetal lung lesions in the majority of cases detected on routine ultrasound between 18 and 20 weeks of gestation. These malformations have an incidence from 1 per 10,000 to 1 per 35,000 pregnancies. Sonographic study provides information on variables such as volume, location, arterial blood supply and venous drainage and consistency of the adenomatoid malformation, which can vary widely from solid (microcystic) to frankly cystic (macrocystic) [7].

Adenomatoid malformation, consisting of small cysts, generally grows unpredictably and causes compression on surrounding structures, as well as an effect of mass on the mediastinum, esophagus and lungs, causing pulmonary hypoplasia, obstruction of the vena cava, cardiac insufficiency, hydrops fetalis and polyhydramnios. As one method to identify serious cases, several investigators have proposed predictive indices and measures such as the cystic volume ratio (CVR), obtained by dividing the volume of the cystic lesion (length X width X height X 0.52) by the circumference of the head. In a retrospective study by Crombleholme, it was concluded that a CVR greater than 1.6 was associated with a 75% chance of developing hydrops fetalis, which justified prenatal intervention [7, 9]. In cases with a better prognosis, EXIT therapy is recommended, with resection of the mass before birth. Postnatal stabilization and thoracotomy are also acceptable. Macrocystic lesions may be prenatally decompressed by thoracentesis with a single needle or with drainage guided by amniotic thoracic ultrasound. At this time, microcystic lesions are not candidates for drainage and will require fetal surgery [10].
