In Utero (Intrauterine) Fetal Surgery for Correction of Malformations DESCRIPTION: In utero (intrauterine) fetal surgery is performed to correct a malformation of a fetus that interferes with organ development and that can have potentially fatal consequences. Intrauterine fetal surgery involves opening of the gravid uterus using a minimally invasive endoscopic technique (single or multiple fetoscopic port incisions) or a traditional cesarean surgical incision to surgically correct a fetal abnormality. Advances in methods of prenatal diagnosis, particularly prenatal ultrasound has led to an understanding of the physiologic outcomes of certain congenital anomalies. Surgical correction of an anatomic malformation in utero remains a highly invasive procedure. At present, there is broad consensus that the potential indications for subjecting mother and fetus to such a high level of risk remain limited to conditions that irreversibly interfere with the development of fetal organs. Fetal surgery requires a multidisciplinary approach (e.g., pediatric surgeons, perinatal obstetricians, sonographers, echocardiographers, neonatologists, intensive care specialists, geneticists, ethicists, neonatal, and obstetric nurses) and must be performed in an appropriate environment for optimum patient care. This guideline addresses fetal surgery performed for the following: Fetal urinary tract obstruction Congenital diaphragmatic hernia Congenital cystic adenomatoid malformation and extralobar pulmonary sequestration Sacrococcygeal teratoma Myelomeningocele (spina bifida) Other neurological conditions. Fetal Urinary Tract Obstruction Few cases of prenatally diagnosed urinary tract obstruction require prenatal intervention. Bilateral obstruction is often associated with serious disease such as pulmonary hypoplasia secondary to oligohydramnios. Fetuses with bilateral obstruction, oligohydramnios, adequate renal function reserve, and no other lethal or chromosomal abnormalities may be candidates for fetal surgery. The most common surgical approach is vesicoamniotic shunting by means of shunt or stent placement. The shunting procedure bypasses the obstructed urinary tract, permitting fetal urine to flow into the amniotic space. Congenital Diaphragmatic Hernia (CDH) CHD is a defect that permits abdominal viscera to enter the chest, frequently resulting in hypoplasia of the lungs. CDH can vary widely in severity, depending on the size of the hernia and the timing of herniation. For example, late herniation after 25 weeks of gestation may be managed postnatally. In contrast, liver herniation into the chest prior to 25 weeks of gestation is associated with a poor prognosis; these fetuses have been considered candidates for fetal surgery. Temporary tracheal occlusion prevents the normal efflux of fetal ling fluid, which in turn enhances positive pressure in the growing lungs, promoting lung growth and ultimately reducing abdominal viscera back into the abdominal cavity. Congenital Cystic Adenomatoid Malformation (CCAM) or Extralobar Pulmonary Sequestration (EPS) CCAM and EPS are the two most common congenital cystic lung lesions. When associated with fetal hydrops before 32 weeks gestation, the survival is poor. These patients may be candidates for prenatal surgical resection of a large mass or placement of a thoraco-aminotic shunt for a large unilocular cystic lesion. Sacrococcygeal Teratoma (SCT) Sacrococcygeal teratoma is both a neoplasm with the power of autonomous growth and a malformation made up of multiple tissues foreign to the region of origin lacking organ specificity. It is the most common tumor of the newborn. Postnatal SCT carries a good prognosis with morbidity and mortality determined largely by extent of local disease and malignant potential. In utero, fetal mortality has approached 100% when SCT is associated with fetal hydrops, which is related to high output heart failure secondary to arteriovenous shunting through the tumor. Intrauterine surgery may result in prenatal resolution of hydrops, healthy long-term survival, and normal development. Myelomeningocele (spina bifida) Myelomeningocele is a neural tube defect in which the spinal cord forms abnormally and is left open, exposing the meninges and neural tube to the intrauterine environment. This exposure may cause secondary trauma to the spinal cord, and depending on the location of the myelomeningocele, results in varying degrees of neurologic impairment to the legs and bowel and bladder function, brain malformation (e.g., hindbrain herniation), and disorders of cerebrospinal fluid circulation (e.g., hydrocephalus requiring placement of a ventriculoperitoneal shunt). Traditional treatment consists of surgical repair after term delivery, primarily to prevent infection and further neurologic dysfunction. Fetal surgical repair to cover the exposed spinal canal has been proposed as a means of preventing exposure to the intrauterine environment with the hope of improving neurologic function and decreasing the incidence of other problems related to the condition. POSITION STATEMENT: NOTE: Refer coverage requests for in utero fetal surgery to the Medical Director for approval. In utero fetal surgery meets the definition of medical necessity for the following conditions: Vesico-amniotic shunting as a treatment of urinary tract obstruction meets the definition of medically necessary in fetuses under the following conditions: Evidence of hydronephrosis due to bilateral urinary tract obstruction; AND Progressive oligohydramnios; AND Adequate renal function; AND No other lethal abnormalities or chromosomal defects. Open in utero resection of malformed pulmonary tissue or placement of a thoraco-amniotic shunt meets the definition of medically necessary under the following conditions: Congenital cystic adenomatoid malformation or bronchopulmonary sequestration is identified; AND The fetus is at 32 weeks’ gestation or less; AND There is evidence of fetal hydrops, placentomegaly, and/or the beginnings of severe pre-eclampsia (i.e., the maternal mirror syndrome) in the mother. In utero removal of sacrococcygeal teratoma meets the definition of medically necessary under the following conditions: The fetus is at 32 weeks’ gestation or less; AND There is evidence of fetal hydrops, placentomegaly, and/or the beginnings of severe pre-eclampsia (i.e., maternal mirror syndrome) in the mother. All other applications of fetal surgery are considered experimental or investigational, including but not limited to the following: Temporary tracheal occlusion as a treatment of congenital diaphragmatic hernia Treatment of congenital heart defects Fetal surgery for myelomeningocele.
Posted on: Sat, 05 Oct 2013 22:19:47 +0000
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