Overview of Ex utero Intrapartum Treatment (EXIT) Procedure
The ex utero intrapartum treatment (EXIT) procedure is a rare and high-risk operation done before birth to help a baby breathe once born. This procedure ensures that the baby can get air to their lungs, while still being connected to the placenta and supported by their mother. It’s typically done for babies in the womb who have problems with their airways or the lower respiratory system (the parts of the body involved in breathing).
The EXIT procedure can involve a variety of specialist techniques, including creating a new airway for the baby, or removing a mass (an abnormal growth). It was successfully done for the first time in the United States in 1990 and has since become a trusted method at specific medical centers for helping babies who have been diagnosed with potentially life-threatening conditions while still in the womb.
The main goal of the procedure is to make sure the baby can breathe during a Caesarean section (a type of surgery used to deliver a baby) before the umbilical cord, which connects the baby to the placenta, is cut. This allows doctors to use the mother’s blood supply to support the baby during the procedure. The most common reason for an EXIT procedure is due to a growth in the neck area. Other reasons may include problems with the baby’s diaphragm or respiratory system, or in rare cases, needing to separate conjoined twins.
In general, the procedure involves making an incision in the mother’s womb and safely delivering the baby’s head, neck, and upper body until the problem area is exposed. The necessary procedure is then done, which can range from a simple intubation to removing the problematic growth. Once the surgery is complete, the baby is safely delivered.
Coordinating the procedure needs teamwork and can require multiple teams of anesthetists, surgical specialists, and necessary nursing and technical staff. As this procedure carries high risks for both mother and baby, early referral to specialized medical centers is crucial. Open discussions with the family and all involved care teams need to happen regularly in these situations.
With medical advances, we’ve become better at diagnosing these conditions before birth, which has led to an increase in EXIT procedures. However, they are still rare and only carried out at specific medical centers.
Anatomy and Physiology of Ex utero Intrapartum Treatment (EXIT) Procedure
To access the uterus, a surgeon has to go through multiple layers within a woman’s body. Firstly, the surgeon must work through the skin and layer of fat to reach the large muscles in the belly (rectus abdominus). In the middle of these muscles, there’s a tough, but bloodless, tissue called aponeurosis. Beyond these muscles is a layer called the parietal peritoneum which directly covers the uterus. Often, especially in women who’ve had previous surgeries like a cesarean section, there may be adhesions which are sort of like scar tissues, involving the peritoneum and other structures inside the belly like the intestines, bladder, etc.
The uterus itself is a muscular organ made up of three layers, from outermost to innermost, they are: the serosa or perimetrium, the myometrium, and the endometrium. Blood flow to the uterus is provided by the uterine arteries and veins that come from the internal iliac vessels. Moreover, these vessels merge with the ovarian vessels coming from the main body artery (abdominal aorta). In some surgeries, like the EXIT procedure performed for a fetal mass, these blood vessels might get injured as the mass can change the normal anatomy, and there’s a need for a larger than usual uterine incision or cut (hysterotomy). Injury to these blood vessels could lead to significant bleeding which could potentially interrupt the surgery. Interestingly, these blood vessels lie quite close to a tube carrying urine from the kidneys to the bladder, called the ureter, which can also potentially get injured during surgery.
Within the uterus, attached usually to the upper wall (superior wall) of the uterus is the placenta – an organ that allows nutrient and oxygen exchange between the mother and the fetus. The position of the placenta is supremely important during an EXIT procedure, as the surgery’s success depends on preserving blood flow through the placenta. Once the uterus’s incision is complete, they reach the water bag or amniotic sac; cutting this open is the final step before delivering the baby.
In neonates (newborns), managing their airways requires specialized knowledge and skills. This is because their body structure is significantly different from adults; for instance, their head is larger compared to their body size resulting in their neck being bent when they’re lying on their back. Also, If their neck is extended too much, it can narrow their airway due to the strain on the soft tissues. The baby’s airway is shaped more like a funnel than an adult’s, with the narrowest part being the circular or somewhat circular cricoid cartilage. Lots of discussions are going on about the exact shape of this cartilage. If the baby has a large mass in the neck or chest area, this could alter and narrow their airway significantly.
The baby’s laryngeal structure (voice box) is situated higher in the neck compared to an adult’s. Also, the different cartilages in the larynx like the epiglottis, arytenoid, corniculate, and cuneiform cartilages are shaped, angled, or sized differently from an adult’s. For example, the epiglottis (a flap that prevents food from going into the windpipe) is longer and curled, covering the glottis (the space between the vocal cords) and angled towards the back of the throat. Furthermore, the baby’s cartilages are more flexible and hence, more prone to external pressure than an adult’s. If they need to place a breathing tube down the baby’s throat (endotracheal intubation), generally, the tube size is chosen based on the baby’s weight, and usually, tube without cuffs (similar to a balloon at the end of the tube) are used.
Why do People Need Ex utero Intrapartum Treatment (EXIT) Procedure
The EXIT procedure, first introduced in 1997, was originally used after a baby’s windpipe was clipped or blocked to treat a severe birth defect known as congenital diaphragmatic hernia. However, with advances in medical technology, the uses for the EXIT procedure have expanded.
The EXIT procedure has sequentially been used to secure the airway during birth for babies with neck masses, to establish a clear pathway for babies who have a condition called Congenital High Airway Obstruction Syndrome (CHAOS), placement of life-support tubing, and in emergency cases, for the separation of conjoined twins.
Conditions that may cause a blockage in a baby’s airway, and may thus require an EXIT procedure, include:
– Neck masses: This occurs when there’s abnormal tissue growth in the neck region.
– CHAOS: A rare birth defect that results in a blockage in the baby’s airway.
– Airway atresia or stenosis: A condition where a baby’s airway is narrowed or blocked.
– Micrognathia: A condition in which the jaw is undersized.
– Removal of a clip or balloon placed in the baby’s windpipe.
The EXIT procedure can also be used to remove certain types of fetal masses that are causing blockages. Conditions that may necessitate this include:
– Neck masses.
– Abnormal masses or malformations within the chest region.
– Sacrococcygeal teratomas: A type of tumor at the base of a baby’s spine.
Furthermore, the EXIT procedure can also be used for Extracorporeal Membrane Oxygenation (ECMO) cannula placement, which is a type of life-support technique. Conditions that may need this are severe heart diseases and diaphragmatic hernias present from birth.
Finally, in extreme conditions, the EXIT procedure can be used to safely separate conjoined twins.
Determining whether an EXIT procedure is necessary can be complex. One way to predict if a baby may need an EXIT procedure is through a measurement known as the tracheoesophageal displacement index (TEDI). This test uses a magnetic resonance imaging (MRI) scan to measure the displacement of the baby’s windpipe and swallowing tube. Studies have shown that a TEDI of over 12 mm, presence of a tumor, excessive amniotic fluid, and a mass diameter of 12 mm or more are reliable indicators that an EXIT procedure may be required. Solid tumors and a missing stomach bubble detected on scan have also been expanded to include as triggers of the need for an EXIT.
When a Person Should Avoid Ex utero Intrapartum Treatment (EXIT) Procedure
Recent studies have identified situations where EXIT (a type of birth procedure) may not be necessary. A comprehensive review found that certain conditions such as lymphatic malformations (a condition that causes fluid-filled sacs to appear in the body), neck masses smaller than 3.5 cm, and any size of fetal neck masses without signs of displacement or compression, are less likely to lead to complications that require anything beyond standard intubation (inserting a tube in the windpipe to aid breathing) after birth. Hence, these situations are generally not considered appropriate for EXIT.
However, depending on the level of confidence and skill of the team handling the resuscitation at birth, a surgeon specializing in airway procedures may still be needed in the delivery room. They would be on standby to carry out a bronchoscopy (a look into the airways using a special device) or tracheostomy (making an incision in the windpipe for breathing) after delivery. There are also certain cases where EXIT is strongly advised against, such as presence of any birth defects that could render the fetus non-viable.
Equipment used for Ex utero Intrapartum Treatment (EXIT) Procedure
When a doctor is performing an EXIT (ex-utero intrapartum treatment) procedure, they must have various necessary equipment ready. This procedure is done while a baby is still inside the mother’s belly, or shortly before delivery. The exact instruments they need can differ depending on the specifics of the treatment. Due to the mother’s open surgical area, tools that are used around the airway need to be kept germ-free to prevent possible infections.
Generally, these are the necessary tools for an EXIT procedure:
- Anesthesia systems for both the mother and baby, along with equipment to monitor the mother’s blood pressure.
- A Foley catheter, which is a thin, flexible tube that’s put into the bladder to help urine flow.
- Two large lines for delivering fluids or medicines into a vein.
- Pre-prepared blood that matches the mother’s type, ready for a possible transfusion.
- Potentially an epidural catheter, which is a pain relieving medicine delivery tube placed near the spine.
- An ultrasound machine with a sterile cover-Basically, this is a tool that uses sound waves to create images of the inside of the body.
- All necessary equipment to perform a Cesarean section, or a delivery through a cut in the mother’s belly and uterus.
- An electrocautery device, which uses electric current to stop bleeding.
- A uterine stapling device, this tool helps in closing wounds.
- Amnioinfusion, or the infusion of fluid into the amniotic cavity, the bag of fluid inside the uterus where the unborn baby develops.
- A space for reviving the baby if necessary.
- An additional operating room nearby that is ready to receive the infant, if needed.
If special procedures are being done such as separating conjoined twins (EXIT-to-separation) or removing certain types of growths or tumours (EXIT-to-resection), additional surgical equipment might be necessary. If a heart-lung machine (ECMO – extracorporeal membrane oxygenation) is needed (EXIT-to-ECMO), a trained team and a special machine are required.
For the procedures involving the baby’s airway (EXIT-to-airway), additional equipment including a paediatric airway cart, paediatric laryngoscopes (tools used to see the voicebox), endotracheal tubes (tubes inserted into the windpipe to help with breathing), and a tracheostomy tray (set of equipment used for making an opening in the windpipe), could be needed.
Who is needed to perform Ex utero Intrapartum Treatment (EXIT) Procedure?
In an ideal situation, a dedicated team of different medical specialists and healthcare staff work together to perform complex medical procedures. Working together under stressful conditions, their teamwork can often mean the difference between success and failure. Each member of the team specializes in different areas of healthcare to best care for mother and baby.
The ‘maternal team’ takes care of the mother. This team includes an ‘obstetric anesthesiologist’, who gives medication to prevent the mother from feeling pain; an ‘obstetrician’, who is a doctor specializing in pregnancy and childbirth; a ‘circulating nurse’, who helps in the operating room with various tasks; and a ‘surgical technician’, who helps the doctors during surgery.
The ‘fetal team’ is focused on caring for the baby. This team includes a ‘neonatal anesthesiologist’, who gives medication to the baby to prevent discomfort; a ‘pediatric surgeon’, a doctor who operates on children; a ‘pediatric otolaryngologist’, a doctor specializing in treating illnesses of the ears, nose and throat in children; a ‘neonatal intensivist’, a doctor who specializes in the care of critically ill newborns; and possibly an ‘ECMO team’, a group of healthcare providers who operate a machine that takes over the functions of the heart and lungs.
There could also be ‘pediatric cardiologists’ or ‘cardiothoracic surgeons’, doctors who treat heart conditions in children, and ‘circulating nurses’ and ‘surgical technicians’ who support the doctors and nurses in their tasks in the operating room.
Preparing for Ex utero Intrapartum Treatment (EXIT) Procedure
If a mother and her unborn baby are suitable for a particular operation known as EXIT (ex utero intrapartum treatment), it’s crucial to get fast access to a medical center that offers this procedure. A detailed pre-birth check-up helps the parents and medical team make the best decision about treatment. Early spotting of conditions that can increase the risk of early birth, such as polyhydramnios (too much amniotic fluid) and hydrops fetalis (the baby developing severe swelling), is key. This procedure is best performed before the mother goes into labor naturally.
Imaging tests are a vital step in preparing for EXIT procedures. It often starts with an ultrasound to get a better understanding of the issues that require the EXIT procedure. Ultrasound can also spot any abnormalities with the placenta, which could complicate the procedure. More advanced ultrasounds and fetal MRIs (a type of imaging test) can provide a clearer picture when the patients reach a high-level care center. For more complex cases, a 3D video of the baby’s windpipe or even a 3D printed model of the airway can be created from MRI scans. In rare instances, doctors may decide to directly examine the baby’s airway using a special tube passed through the placenta.
Thorough preparation of the operating room and the medical teams performing the EXIT operation is essential. The correct equipment should be prepared based on the specific type of EXIT procedure. If possible, a team of seasoned clinicians should be assembled, preferably if they have experience working together and have familiarity with the procedure. A dry run of the procedure is often carried out to ensure smooth execution on the day of the operation. As there could be significant blood loss during the procedure (on average, 1 liter), preparations should be in place for potential blood transfusions.
How is Ex utero Intrapartum Treatment (EXIT) Procedure performed
A surgery called EXIT-to-Airway involves delivering the baby through cesarean section to ensure the baby’s airway is clear, especially in cases where there might be abnormalities like a growth or the baby being one of conjoined twins. In this procedure, the mother is comfortably positioned on the surgical bed, with a slight tilt towards the left to ease pressure on a major vein in her body (vena cava).
The position of the placenta (the organ that supports the baby’s growth in the womb) is confirmed using an ultrasound image before any cuts are made. A sterile ultrasound can be used once more just to be sure of where to make incisions. An incision is then made in the mother’s abdomen, and the top part of the baby, including the head, neck, and torso, are carefully removed from the womb. In some cases, a warm saline solution may be used to prevent the umbilical cord from getting squished.
Then, the doctors ensure the baby is still receiving adequate anesthesia (pain relief), which is achieved through the placenta and delivered via a small tube, if needed. At this stage, opioids and muscle relaxants might be given to the baby, with constant monitoring of the baby’s vital signs.
The next step is ensuring the baby’s airway is clear. The surgeons will try to place a tube down the baby’s windpipe to ensure proper breathing. Various methods and devices can be used depending on the situation, including a stylet (a thin probe), decompressing any fluid-filled masses, or performing partial resections of any solid masses. If the standard approach doesn’t work, the doctors may use a specific technique to feed a tube up through the windpipe from an incision in the throat to secure the airway. If the incision can’t be closed, it might be turned into a tracheostomy (a surgical opening in the neck for breathing).
Once the baby’s airway is secure, further operations like the removal of any mass or separating conjoined twins can be carried out. The current protocol sets about 90 minutes for this whole process. The baby is then given oxygen and the umbilical cord is clipped. Following this, the baby is handed over to a specialized team for further care and monitoring.
In all this, communication between the doctor and surgeon is key, ensuring a smooth transition from the procedure to the routine tasks following a baby’s birth. After the surgery, the focus is on preventing heavy bleeding in the mother. The surgical site is then closed, and depending on her condition, the mother is moved to the intensive care unit or the maternity ward for recovery.
Possible Complications of Ex utero Intrapartum Treatment (EXIT) Procedure
When a woman goes through a process known as EXIT (Ex-Utero Intrapartum Treatment) during childbirth, she might face certain complications. The main risk is heavy bleeding, which can be caused by an overly relaxed uterus, a larger than normal cut in the uterus, and a high chance of injuring the placenta, the organ that provides oxygen and nutrients to the baby. Even though these risks exist, studies have shown that only 6% of mothers need a blood transfusion during the procedure.
There’s also a higher chance of infection at the surgical site compared to normal Cesarean delivery (15% vs 2%). This is because the EXIT procedure takes longer. Some people used to think this procedure could lead to fertility issues or complications in future pregnancies, but recent studies have not backed this up.
The baby might also face some risks during EXIT. One is heart problems, which could happen if the mother gets too much anesthetic, her blood pressure drops leading to less blood flow to the placenta, the placenta gets injured, or the umbilical cord gets compressed. Other risks include damage to nerves or blood vessels, bleeding, and infection when the mass is removed. The most serious risks are being unable to secure the baby’s airway and fetal demise. However, the actual rates of these complications are not well documented in medical literature.
What Else Should I Know About Ex utero Intrapartum Treatment (EXIT) Procedure?
The EXIT procedure, while not widely known or common, is often a lifesaver for newborn babies needing help with their airways at birth. This method has greatly reduced the death rates related to issues with the upper airway, head and neck lumps, heart and lung abnormalities, and other specific birth defects. This has been achieved thanks to proper exams before the baby is born, a well-prepared medical team, and careful surgical methods.
However, it’s important to note that the EXIT procedure does carry some risks for both the mother and baby. Despite these risks, the chances of having a healthy baby usually make the procedure worth it.