DESCRIPTION
Prenatal surgery typically involves opening the gravid uterus (with a Cesarean surgical incision), to correct the abnormality, then return the fetus to the uterus and restore the uterine closure. Minimally invasive procedures through a single or multiple fetoscopic port incisions are also being developed.
This policy addresses fetal surgery performed for the following clinical conditions:
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.
Congenital Cystic Adenomatoid Malformation (CCAM) or Broncopulmonary 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 individuals may be candidates for prenatal surgical resection of a large mass or placement of a thoraco-amniotic shunt to decompress the lesion.
Sacrococcygeal Teratoma
Sacroccoccygeal teratoma (SCT) 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.
Myelomeningocele
Myelomeningocele is a type of spina bifida that occurs at the end of the fourth week of fetal development in approximately one in every 1000 pregnancies the United States each year. The diagnosis of myelomeningocele is determined with measurement of maternal serum alpha-fetoprotein levels, the use of amniocentesis, and high-resolution ultrasonography.
Myelomeningocele occurs when the spinal cord rather than closing remains open exposing the meninges and neural tube to the intrauterine environment. The neural tube gives rise to the brain, spinal cord, and other neural tissue of the central nervous system. This neural tube defect results in varying degrees of deformities and functional disabilities (e.g., spine, limbs, bladder, bowel, sexual dysfunction, learning disabilities and neurologic deformities). Although the exact cause of the neurologic deficits is unknown, possible cause is attributed to either the primary defect in closure of the neural tube or secondary injury to exposed neural tissue throughout gestation by amniotic fluid and mechanical trauma.
Congenital Diaphragmatic Hernia
Congenital diaphragmatic hernia results from abnormal development of the diaphragm, which permits abdominal viscera to enter the chest, frequently resulting in hypoplasia of the lungs. Congenital diaphragmatic hernia can vary widely in severity, depending on the size of the hernia and the timing of herniation. Currently, temporary tracheal occlusion using a balloon is being investigated for the treatment of congenital diaphragmatic hernia. 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 will promote better lung maturation.
Cardiac Malformations
In utero interventions are currently 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.
POLICY
Vesico-amniotic shunting for the treatment of urinary tract obstruction in fetuses is considered medically necessary if the medical appropriateness criteria are met. (See Medical Appropriateness below.)
Open in utero resection for the treatment of malformed pulmonary tissue or placement of a thoraco-amniotic shunt is considered medically necessary if the medical appropriateness criteria are met. (See Medical Appropriateness below.)
In utero removal for the treatment of sacrococcygeal teratoma is considered medically necessary if the medical appropriateness criteria are met. (See Medical Appropriateness below.)
In utero repair for the treatment of myelomeningocele is considered medically necessary if the medical appropriateness criteria are met. (See Medical Appropriateness below.)
In utero repair for the treatment of myelomeningocele, including but not limited to, the following: fetal anomaly unrelated to myelomeningocele, severe kypohosis, risk of preterm birth (e.g., short cervix or previous preterm birth), maternal body mass index of 35 or more is considered investigational.
Other applications of fetal surgery, including but not limited to, the following: temporary tracheal occlusion as a treatment of congenital diaphragmatic hernia and treatment of congenital heart defects is considered investigational.
MEDICAL APPROPRIATENESS
Fetal surgeries for prenatally diagnosed malformations are considered medically appropriate for ANY ONE of the following:
Vesico-amniotic shunting for the treatment of urinary tract obstruction in fetuses if ALL of the following criteria are met:
Evidence of hydronephrosis due to bilateral urinary tract obstruction
Progressive oligohydramnios
Adequate renal function
No other lethal abnormalities or chromosomal defects
Open in utero resection for the treatment of malformed pulmonary tissue or placement of a thoraco-amniotic shunt if ALL of the following criteria are met:
Congenital cystic adenomatoid malformation or bronchopulmonary sequestration is identified
The fetus is at 32 weeks’ gestation or less
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 for the treatment of sacrococcygeal teratoma if ALL of the following criteria are met:
The fetus is at 32 weeks’ gestation or less
There is evidence of fetal hydrops, placentomegaly, and/or the beginnings of severe pre-eclampsia (i.e., maternal mirror syndrome) in the mother
In utero repair for the treatment of myelomeningocele if ALL of the following criteria are met:
The fetus is at less than 26 weeks’ gestation
Myelomeningocele is present with an upper boundary located between T1 and S1 with evidence of hindbrain herniation
IMPORTANT REMINDER
We develop Medical Policies to provide guidance to Members and Providers. This Medical Policy relates only to the services or supplies described in it. The existence of a Medical Policy is not an authorization, certification, explanation of benefits or a contract for the service (or supply) that is referenced in the Medical Policy. For a determination of the benefits that a Member is entitled to receive under his or her health plan, the Member's health plan must be reviewed. If there is a conflict between the Medical Policy and a health plan, the express terms of the health plan will govern.
ADDITIONAL INFORMATION
There is a lack of published evidence based studies and randomized controlled trials to demonstrate that fetal tracheal occlusion and aortic valvuloplasty provide improved health outcomes. For these and other applications of fetal surgery that are currently considered investigational, additional studies are needed to identify appropriate candidates and to evaluate longer term outcomes compared with postnatal management.
SOURCES
Adzick, N. S., Thom, E. A., Spong, C. Y., Brock, J. W., Burrows, P. K., Johnson, M. P., et al. (2011). A randomized trial of prenatal versus postnatal repair of myelomeningocele. The New England Journal of Medicine, 364 (11), 993-1004. (Level 1 Evidence - Independent study)
American College of Obstetricians and Gynecologists. (2005, November). Maternal decisions making, ethics, and the law. Retrieved April 1, 2011 from http://www.acog.org/from_home/publications/ethics/co321.pdf.
American College of Obstetricians and Gynecologists. (2008). ACOG practice bulletin. Neural tube defects. Retrieved December 15, 2010 from http://www.acog.org/publications/educational_bulletins/pb044.cfm.
BlueCross BlueShield Association, Medical Policy Reference Manual. (3:2011) Fetal surgery for prenatally diagnosed malformations. (4.01.10). Retrieved May 12, 2011 BlueWeb. (26 articles and/or guidelines reviewed)
Dhaulakhandi, D. B., Rohilla, S., & Rattan, K. N. (2010). Neural tube defects: review of experimental evidence on stem cell therapy and newer treatment options. Fetal Diagnosis and Therapy, 28 (2), 72-78.
Fayoux, P., Hosana, G., Devisme, L., Deprest, J., Jani, J., Vaast, P. et al. (2010). Neonatal tracheal changes following in utero fetoscopic balloon tracheal occlusion in severe congenital diaphragmatic hernia. Journal of Pediatric Surgery, 45 (4), 687-692.
Hirose, S., & Farmer, D. L. (2009). Fetal surgery for myelomeningocele. Clinics in Perinatology, 36 (2), 431-438.
Mayer, S., Weisser, M., Till, H., Grafe, G., & Gever, C. (2010). Congenital myelomeningocele - Do we have to change our management? Cerebrospinal Fluid Research, 7 (17), 1-7.
McEljinney, D. B., Marshall, A. C., Wilkins-Haug, L. E., Brown, D. W., Benson, C. B., Silva, V., et al. (2009). Predictors of technical success and postnatal biventricular outcome after in utero aortic valvuloplasty for aortic stenosis with evolving hypoplastic left heart syndrome. Circulation, 120 (15), 1482-1490.
MOMS. (2010, May). Management of myelomeningocele study. Retrieved December 13, 2010 from http://www.spinabifidamoms.com/english/pdf/brochure.pdf.
National Guideline Clearinghouse. (2008). Neural tube defects. Retrieved December 13, 2010 from http://www.guidelines.gov.
National Institute of Neurological Disorders and Stroke. National Institutes of Health. (2009, December). NINDS spina bifida information page. Retrieved December 13, 2010 from http://www.ninds.nih.gov/health_and_medical/disorders/spina_bifida.htm.
Poretti, A., Anheier, T., Zimmermann, R., Boltshauser, E., & Swiss Pediatric Surveillance Unit (SPSU). (2008). Neural tube defects in Switzerland from 2001 to 2007: Are periconceptual folic acid recommendations being followed? Swiss Medical Weekly, 138 (41-42), 608-613. (Level 3 Evidence - Independent study)
Sutton, L. N. (2008). Fetal surgery for neural tube defects. Best Practice & Research. Clinical Obstetrics & Gynaecology, 22 (1), 175-188.
The Pluto Collaborative Study Group, Kilby, M., Khan, K., Morris, K., Daniels, J., Gray, R., et al. (2007). PLUTO trial protocol: Percutaneous shunting for lower urinary tract obstruction randomised controlled trial. British Journal of Obstetrics and Gynaecology, 114 (7), 904-905, e1-4. (Level 1 Evidence - Independent study)
ORIGINAL EFFECTIVE DATE: 7/14/2007
MOST RECENT REVIEW DATE: 6/24/2011
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Policies included in the Medical Policy Manual are not intended to certify coverage availability. They are medical determinations about a particular technology, service, drug, etc. While a policy or technology may be medically necessary, it could be excluded in a member's benefit plan. Please check with the appropriate claims department to determine if the service in question is a covered service under a particular benefit plan. Use of the Medical Policy Manual is not intended to replace independent medical judgment for treatment of individuals. The content on this Web site is not intended to be a substitute for professional medical advice in any way. Always seek the advice of your physician or other qualified health care provider if you have questions regarding a medical condition or treatment.
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