Fetal Surgery for Prenatally Diagnosed Malformations
DESCRIPTIONFetal surgery is being investigated for specific congenital abnormalities that are associated with a poor postnatal prognosis. Prenatal surgery typically involves opening the gravid uterus (with a Cesarean surgical incision), surgically correcting the abnormality, and returning the fetus to the uterus and restoring uterine closure. Minimally invasive procedures through single or multiple fetoscopic port incisions are also being developed.
Most fetal anatomic malformations are best managed after birth. However, advances in methods of prenatal diagnosis, particularly prenatal ultrasound, have led to a new understanding of the natural history and physiologic outcomes of certain congenital anomalies. Fetal surgery is the logical extension of these diagnostic advances, related in part to technical advancement in anesthesia, tocolysis, and hysterectomy.
This policy will pertain to fetal surgery performed for the following clinical conditions:
1. Fetal Urinary Tract Obstruction
Although few cases of prenatally diagnosed urinary tract obstruction require prenatal intervention, bilateral obstruction can lead to distention of the urinary bladder and is often associated with serious disease such as pulmonary hypoplasia secondary to oligohydramnios. Therefore, 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 decompression through percutaneous placement of a shunt or stent. Vesico-amniotic shunting bypasses the obstructed urinary tract, permitting fetal urine to flow into the amniotic space. The goals of shunting are to protect the kidneys from increased pressure in the collecting system and to assure adequate amniotic fluid volume for lung development.
2. Congenital Diaphragmatic Hernia (CDH)
CDH results from abnormal development of the diaphragm, which 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 adequately managed postnatally. In contrast, liver herniation into the chest prior to 25 weeks of gestation is associated with a poor prognosis, and these fetuses have been considered candidates for fetal surgery. Temporary tracheal occlusion using a balloon is being evaluated for the treatment of CDH. Occluding the trachea of a fetus prevents the normal efflux of fetal lung fluid, which results in a build-up of secretions in the pulmonary tree and increases the size of the lungs, gradually pushing abdominal viscera out of the chest cavity and back into the abdominal cavity. It is believed that this, in turn, will promote better lung maturation. Advances in imaging have resulted in the ability to detect less severe lesions, which has resulted in a decrease in mortality rates for defects detected during pregnancy. Due to these changes over time, concurrent controls are needed to adequately compare pre- and postnatal approaches.
3. Congenital Cystic Adenomatoid Malformation (CCAM) or Bronchopulmonary Sequestration (BPS)
CCAM and BPS are the two most common congenital cystic lung lesions, and share the characteristic of a segment of lung being replaced by abnormally developing tissue. CCAMs can have connections to the pulmonary tree and contain air, while BPS does not connect to the airway and has blood flow from the aorta rather than the pulmonary circulation. In more severe cases, the malformations can compress adjacent normal lung tissue and distort thoracic structure. CCAM lesions typically increase in size in mid-trimester and then in the third trimester either involute or compress the fetal thorax, resulting in hydrops in the infant and sometimes mirror syndrome (a severe form of pre-eclampsia) in the mother. Mortality is close to 100% when lesions are associated with fetal hydrops (abnormal accumulation of fluid in two or more fetal compartments). These patients may be candidates for prenatal surgical resection of a large mass or placement of a thoraco-amniotic shunt to decompress the lesion.
4. Sacrococcygeal Teratoma
Sacroccoccygeal teratoma (SCT) is both a neoplasm with the power of autonomous growth and a malformation made up of multiple tissues foreign to the region of origin and lacking organ specificity. It is the most common tumor of the newborn and generally carries a good prognosis in infants born at term. However, in utero fetal mortality approaches 100% with large or vascular tumors, which may become larger than the rest of the fetus. In this small subset, SCT is associated with fetal hydrops, which is related to high output heart failure secondary to arteriovenous shunting. In some cases, mothers of fetuses with hydrops can develop mirror syndrome.
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. Myelomeningocele is the most common cause of spina bifida, and depending on the location results in varying degrees of neurologic impairment to the legs and bowel and bladder function, brain malformation (i.e., hindbrain herniation), cognitive impairment, and disorders of cerebrospinal fluid circulation, i.e., 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 the deleterious exposure to the intrauterine environment with the hope of improving neurologic function and decreasing the incidence of other problems related to the condition.
6. Cardiac Malformations
In utero interventions are being investigated for severe narrowing in one of the cardiac outflow tracts (aortic valve or pulmonary valve) that cause progressive damage to the heart in utero. In utero intervention has been proposed for the following lethal cardiac conditions: critical pulmonary stenosis, critical aortic stenosis, and hypoplastic left heart syndrome (HLHS). Critical pulmonary stenosis or atresia with intact ventricular septum is characterized by a very narrow pulmonary valve without a connection between the right and left ventricles. Critical aortic stenosis with impending HLHS is a very narrow aortic valve that develops early during gestation that may result in HLHS. In utero aortic balloon valvuloplasty has been suggested as a way to relieve aortic stenosis in an attempt to preserve left ventricular growth and halt the progression to HLHS. HLHS with intact atrial septum describes the absence of a connection between the left and right atrium. A subset of fetuses with HLHS will present with severe cyanosis and require immediate postnatal intervention to survive. In utero septostomy has been performed in an attempt to improve postnatal survival for this condition.
POLICYFetal surgery is a specialized technique that may require referral to an out-of-network facility.
Vesico-amniotic shunting as a treatment of urinary tract obstruction may be considered medically necessary in fetuses under the following conditions:
Open in utero resection of malformed pulmonary tissue or placement of a thoraco-amniotic shunt may be considered medically necessary under the following conditions:
In utero removal of sacrococcygeal teratoma may be considered medically necessary under the following conditions:
In utero repair of myelomeningocele may be considered medically necessary under the following conditions:
In utero repair of myelomeningocele is considered investigational in the following situations:
Other applications of fetal surgery are considered investigational, including but not limited to, temporary tracheal occlusion as a treatment of congenital diaphragmatic hernia, treatment of congenital heart defects.
POLICY GUIDELINESInvestigative service is defined as the use of any treatment procedure, facility, equipment, drug, device, or supply not yet recognized by certifying boards and/or approving or licensing agencies or published peer review criteria as standard, effective medical practice for the treatment of the condition being treated and as such therefore is not considered medically necessary.
The coverage guidelines outlined in the Medical Policy Manual should not be used in lieu of the Member's specific benefit plan language.
POLICY HISTORY8/2000: Approved by Medical Policy Advisory Committee (MPAC)
5/9/2001: Code Reference section updated, CPT 59899 added
2/14/2002: Investigational definition added
5/1/2002: Type of Service and Place of Service deleted
3/17/2003: Code Reference section updated
3/18/2004: Code Reference section updated, CPT code 59899 deleted
10/13/2004: Code Reference section updated, ICD-9 diagnosis code 75.36 note added, HCPCS S2400, S2401, S2402 added covered codes, non-covered table added, CPT code 59072 added non-covered codes, HCPCS S2403, S2404 added non-covered codes, HCPCS S2409 moved from covered codes to non-covered codes
3/31/2005: Reviewed by MPAC, Description revised to be consistent with BCBSA policy # 4.01.10 and hyperlink added, Temporary tracheal occlusion as a treatment of congenital diaphragmatic hernia changed to investigational, “Candidates for temporary tracheal occlusion are those fetuses with prenatal diagnosis of congenital diaphragmatic hernia, with gestational age of less than 25 weeks at time of diagnosis, and with evidence of liver herniation, and other indicators of poor prognosis, such as a low lung-to-head ratio.” deleted Policy Guidelines, All of the following statements moved from Policy Guidelines section to Policy section: “Fetal surgery is a specialized technique that may require referral to an out-of-network facility. Prior authorization through case management is required.” “Candidates for vesico-amniotic shunting are fetuses with hydronephrosis due to bilateral urinary tract obstruction, evidence of progressive oligohydramnios, and evidence of adequate renal function and with no other lethal abnormalities or chromosomal defects.” “Candidates for fetal surgery for congenital cystic adenomatoid malformation, extralobar pulmonary sequestration or sacrococcygeal teratoma are those fetuses of 32 weeks' gestation or less, with evidence of fetal hydrops, placentomegaly, and/or the beginnings of severe pre-eclampsia (i.e., the maternal mirror syndrome.) (After 32 weeks' gestation, fetal lung maturity is adequate to permit Caesarean section and management of the condition post-natally.)” Sources updated, Code Reference section updated, HCPCS S2400 moved from covered to non-covered, HCPCS S2403 moved from non-covered to covered, this policy change is effective June 1, 2005
9/20/2005: ICD-9 diagnosis code 655.8, 656.7, 658.0 5th digit added
12/19/2006: Policy reviewed, policy unchanged however, prior authorization language removed
12/13/2007: Policy reviewed, congenital heart defects addressed, otherwise unchanged
6/22/2010: Policy description section updated to include detailed descriptions of Fetal Urinary Tract Obstruction, Congenital Diaphragmatic Hernia (CDH), Congenital Cystic Adenomatoid Malformation or Bronchopulmonary Sequestration, Sacrococcygeal Teratoma, Myelomeningocele and Cardiac Malformations. Policy statements were updated to indicate criteria for services to be considered medically necessary. Deleted outdated references from the Sources section. Code reference section updated: CPT codes 655.80, 655.81, 656.70, 656.71,658.00, 658.01 deleted from covered table. CPT codes 642.50-642.54 range, 653.73 and 657.03 added to covered table. Descriptions revised for CPT codes 59897, 655.83, and 656.73.
08/11/2011: Policy statement revised regarding prenatal repair of myelomeningocele, which is now considered medically necessary under specified conditions. Moved S2404 to the Covered Codes table. Added the following ICD-9 codes to the Covered Codes table: 653.70, 655.80, 656.70, and 658.00.
01/18/2012: Policy reviewed; no changes.
04/01/2013: Policy reviewed; no changes.
03/11/2014: Policy reviewed; no changes.
SOURCE(S)Blue Cross & Blue Shield Association Policy # 4.01.10
Hayes Medical Technology Directory
CODE REFERENCEThis may not be a comprehensive list of procedure codes applicable to this policy.
The code(s) listed below are ONLY medically necessary if the procedure is performed according to the "Policy" section of this document.
This may not be a comprehensive list of procedure codes applicable to this policy.