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Techniques of Fetal Intervention

What is fetal intervention?

Fetal intervention is reaching inside the uterus to help a fetus who has a problem. It is surprising new because our ability to detect fetal problems has advanced so rapidly over the last few decades. While many diseases can now be accurately diagnosed before birth by genetic and imaging techniques, only a few require intervention before birth. These are generally simple anatomic problems that cause ongoing damage to the developing fetus and can be corrected using the techniques described below.

All fetal intervention is really maternal-fetal intervention, and the most important consideration in all fetal intervention is the safety of the mother and her reproductive potential. The intervention is designed to benefit the fetus who has a problem, but the mother is an innocent bystander who assumes some risk for the sake of her unborn fetus. In weighing the risks versus the benefits of an intervention, the most important consideration is the mother, her health, her family, and her ability to have other children.

What are the techniques of fetal intervention?

There are three general approaches to fetal intervention, all of which have been developed in the last few decades. The most definitive and most invasive is open fetal surgery.

Open Fetal Surgery

watch video Open Fetal Surgery In open fetal surgery, the mother is anesthetized, an incision is made in the lower abdomen to expose the uterus, the uterus is opened using a special stapling device to prevent bleeding, the surgical repair of the fetus is completed, the uterus followed by the maternal abdominal wall are closed, and the mother awakened.

The magnitude of the surgery is about the same as any intra-abdominal operation like removal of the gall bladder or Cesarean section, except that at the end of the operation the mother is still pregnant.The anesthetic and surgical techniques were worked out in the 1980s and have proven quite safe for mother and fetus. However, this is major surgery which requires hospitalization for 3 to 7 days, requires Cesarean delivery of this and future pregnancies, and often causes preterm labor and preterm delivery. The pregnancy must be closely monitored for preterm labor and drugs to control preterm labor are required.

Fetendo Fetal Surgery

watch video Fetendo “Fetendo” is the name we apply to fetoscopic intervention that was developed in the 1990s to avoid making an incision in the uterus and, hopefully, to minimize preterm labor. The ability to see the fetus through very small endoscopes, which have been available for several decades, were refined to allow surgical manipulation of the fetus with very small instruments guided by direct fetoscopic view on a television monitor.

We called it “Fetendo” because the actual manipulation is much like playing video games. As we developed these techniques, we discovered that the best method of visualizing the fetus in real-time is to use both endoscopic (looking through the telescope), and sonograhic (looking at a cross-sectional images of the fetus) techniques on a separate screens. The combination of image-guided manipulation and sonographically-guided manipulation has proved to be quite powerful in solving a number of fetal problems. Fetendo intervention can be done either through the mother’s skin (percutaneous) or, in some circumstances, requires a small opening in the mother’s abdomen (mini-laparotomy). 

The good part of Fetendo intervention is that it is less invasive than open surgery. It is easier on the mother in terms of postoperative recovery, and causes less trouble with preterm labor. Unfortunately, it has not eliminated the problem of preterm labor and, so, monitoring and drugs are usually still necessary. Fetendo is technically difficult and required the development of many new devices and techniques to allow us to see through the amniotic fluid, maintain the fetal position, and do delicate work within the fetus.

Fetendo has replaced open fetal surgery for some fetal problems but not all. It has proven particularly useful for treating problems with the placenta, like twin-twin transfusion syndrome, and for looking inside the fetus, for example, to place a balloon in the fetal trachea or deal with obstruction of the fetal bladder.

Fetal Image-Guided Surgery (FIGS-IT)

watch video Fetal Image-Guided Surgery FIGS-IT is a term we coined for fetal image-guided surgery for intervention or therapy, and describes the method of manipulating the fetus without either an incision in the uterus or an endoscopic view inside the uterus. The manipulation is done entirely under real-time cross-sectional view provided by the sonogram. This is the same sonogram as is used for diagnostic purposes, but in this case is used to guide instruments.

Like Fetendo, it can be done either through the mother’s skin or, in some cases, with a small opening in the mother’s abdomen.  It can often be done under a regional anesthesia like an epidural or a spinal, or even under local anesthesia. This is the least invasive of the fetal access techniques and, thus, causes the least problem for mother in terms of hospitalization and discomfort. It also causes the least problem with preterm labor. Disappointingly it has not completely eliminated the problem of preterm labor, and so monitoring and drugs are often still necessary. Image-guided intervention was first used for amniocentesis and fetal blood sampling, but now can be used for a variety of fetal manipulations including placement of catheter-shunts in the bladder, abdomen, or chest, radiofrequency ablation to solve problems with anomalous twins, and even for some cardiac manipulation. It is generally not useful for serious structural problems that require surgery. 

It is easiest to think of fetal intervention in terms of invasiveness—open surgery being most invasive; FIGS-IT, least invasive; and Fetendo, in between. It is important to remember that the fetus can be accessed non-invasively through the mother’s circulation. For some problems such as fetal cardiac arrhythmias, medicines and nutrients can be delivered to the fetus by giving them to the mother and letting them cross the placenta naturally. 

EXIT procedure

The EXIT procedure is a type of intervention that occurs at the time of delivery. It is primarily used in cases where the baby's airway requires surgical assistance like CHAOS or with CDH Tracheal Occlusion Surgery

The goal with the EXIT procedure is to provide the baby with a functioning airway so that oxygen can be delivered  to the lungs after the baby is separated from placenta. The EXIT procedure is a planned, specialized delivery involving both the mother and the baby It should only be performed at a hospital that has a team consisting of a pediatric surgeon, obstetrician, anesthesiologist, and neonatologist.The start of the procedure is conducted like a Cesarean section. However, unlike a Cesarean, the mother is put under general anesthesia in order to ensure that the uterus is completely relaxed.

The head of baby is delivered and the pediatric surgeon uses a bronchoscope through the baby’s mouth to look more closely at the airway. Depending on the type of blockage the surgeon may then attempt to pass an endotracheal tube (tube through the baby’s mouth into the trachea) and give breaths to the baby. If this is successful, and oxygen is being delivered to the baby through the tube, the infant is delivered and the umbilical cord cut. If a tube cannot be passed from the mouth through the obstruction, the pediatric surgeon will need to place a tracheostomy tube through the neck directly into the trachea, bypassing the blockage. The surgeon will make an incision in the neck of the baby and place a tube below the level of the airway blockage. Once the tube is placed, and the surgeon is confident that it is functioning and can be used to deliver oxygen to the baby, the infant is delivered. Care of the infant is then provided by the Intensive Care Nursery team.

What will happen after birth?

To provide a functioning airway your baby will likely be delivered via an EXIT procedure. Afterwhich, your baby will be brought to the Intensive Care Nursery for close observation and further assessment. Additional reconstructive surgeries may be required.

Fetal Access

Type of Intervention Description Examples
OPEN SURGERY Hysterotomy
  • CCAM – Lobectomy
  • SCT – Resection
  • MMC – Repair
  • Cervical Teratoma – Resection
  • EXIT
    • Tracheal occlusion
    • Neck tumors
    • CDH (EXIT to ECMO)
    • CCAM (EXIT lobectomy)
FETENDO Fetoscopic Surgery
  • Balloon Occlusion of Trachea (for CDH)
  • Laser Ablation of Vessels (for TTTS)
  • Cord Ligation/Division
  • Cystoscopic Ablation Valves
  • Amniotic Bands Division
FIGS Fetal Image Guided Surgery
  • Amnioreduction/Infusion
  • Fetal Blood Sampling
  • RFA Anomalous Twins
  • Vesico/Pleuro Amniotic Shunts
  • Cord Monopolar Cautery
  • Balloon Dilation Aortic Stenosis
EXIT procedure Planned Specialized Delivery
  • CHAOS
  • Removal of the CDH Tracheal Occlusion Balloon
  • Pulmonary Sequestration
  • CCAM

What is the risk to the mother?

The most important consideration in all fetal intervention is the affect on the mother.  She is, in general, an innocent bystander who chooses to accept some risk to help her fetus. The risk varies with the invasiveness of the procedure. For open surgery, the risk is of general anesthesia and of the abdominal incision, but most important is the consequence of the incision in the uterus itself.  The immediate consequence is preterm labor and the need for monitoring and drugs to control preterm labor.  The longer term consequence is Cesarean delivery in this and subsequent pregnancies. This is because the incision in the uterus in mid-gestation is not the same is that used for elective Cesarean section at term.  The risk of Fetendo procedures is less because the procedure is less invasive. Anesthesia may be regional or local, and an incision in the mother’s abdomen may not be necessary. However, the risk of piercing the uterine muscle and, more importantly, the membranes lining the inside of the uterus remains a problem. There is still the risk of amniotic fluid leaking through the membranes and contributing to preterm labor. Unfortunately, this remains a significant risk and requires monitoring of the amniotic fluid volume, the membranes, and preterm labor. 

The risk of fetal image guided surgery is less than either Fetendo or open fetal surgery. FIGS-IT can usually be done under local or regional anesthesia and usually without the incision in the maternal abdomen. However, the problem with membrane puncture, subsequent leakage, separation of membranes and preterm labor persists. The problem of sealing the membranes remains one of the unsolved problems of fetal intervention.

What can I expect with fetal intervention?

For all fetal intervention, you will undergo careful evaluation and counseling by a multidisciplinary team of physicians, nurses, and social workers.  You will have all the options, risks, and benefits explained honestly and in detail. You will have adequate time to decide whether intervention is the right thing for you and your family. Your decision will always be honored. Since many types of fetal intervention are still novel, the fully informed consent and, indeed, enthusiastic support of the family are essential to every intervention.

For open fetal surgery, you will be admitted to the Obstetrics Floor the night before surgery, and you can expect to stay 3 to 7 days in the hospital for recovery and for monitoring and management of preterm labor. The surgery is performed under general anesthesia and an epidural catheter is placed for 2 to 3 days of postoperative pain control. The most difficult part of the postoperative recovery is often the side effects of the drugs used to manage preterm labor for the first several days. Up to discharge, restricted activity, pills for preterm labor, and intermittent monitoring will be carried out while you are staying at a comfortable outpatient facility (Ronald McDonald House or Koret Family House). Depending on the surgery, you may return home to deliver by Cesarean section at a local institution, or planned delivery at UCSF. The time between the intervention and delivery is a difficult time for many families in terms of family obligations, other children, work, etc. After delivery, the baby will be cared for in the intensive care nursery for days to months, depending on the problem. 

For Fetendo surgery, you will be admitted the night before or perhaps the day of surgery. The procedure is performed in the operating room under regional or, occasionally, general anesthesia. You will recover for 1 to 5 days on the Obstetrics Service while the uterus and fetus are carefully monitored. Drugs to treat preterm labor are sometimes necessary for a short time, and outpatient follow-up sonograms will be necessary for the rest of the pregnancy. In many cases, the family can return home for planned delivery at a local institution or may return to UCSF for delivery and postnatal management. Cesarean section is not necessary.

With fetal image guided surgery, you may be admitted to the hospital for the procedure, or it may be done as an outpatient procedure. In most cases, it is prudent to monitor at least overnight for preterm labor. Drugs to control preterm labor may or may not be necessary. The remainder of the pregnancy will be monitored by sonogram, and delivery may be planned for a local institution or at UCSF. 

Fetal intervention makes the mother an integral part of the fetal management strategy. If you choose fetal intervention, this means a very considerable commitment of time, effort, discomfort, and anxiety from the time of the fetal intervention until birth. This commitment is not appropriate for every family. There may also be a very considerable commitment to a potentially sick infant in the intensive care nursery after birth, but that will be the same whether you choose fetal intervention or standard management after birth without intervention. 

Last Updated: 6/9/2011
Sarah Elizabeth

Sarah Elizabeth

Baby Sarah Elizabeth has a very successful recovery from an SCT which is removed while she is still a fetus.

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Ethne Nerrmana
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