Ex-utero intrapartum treatment in the Indian scenario: Anesthetic challenges and positioning.

Ex-utero intrapartum treatment (EXIT) is performed for fetuses diagnosed with large neck masses. A case report of a fetus diagnosed with a large cystic hygroma and cord around the neck who was delivered by EXIT is presented. The airway challenges and optimal positioning is discussed.

INTRODUCTION

The advent of antenatal ultrasound has allowed the diagnosis of conditions like large neck masses affecting the fetus which can compromise the airway after delivery. Fetal magnetic resonance imaging (MRI) has helped in better delineation and planning for perinatal intervention which will improve the survival of these babies.[1] Ex-utero intra partum treatment (EXIT) is a procedure conducted for a fetus diagnosed with compromised airway. By this procedure the airway can be secured while the fetus is on utero-placental circulation and hypoxia can be prevented.[2] There are many indications for EXIT but the commonest indication is for a fetus with compromised airway. The diagnosis of congenital high airway obstruction syndrome (CHAOS), lesions in the mouth and neck compressing the trachea is a definite indication for EXIT.[34] Detailed planning and execution is essential for this procedure to be successful.

This procedure has been extensively described in literature and this is one of first few case reports from India. We present our experience with EXIT procedure and the challenges and the optimal positioning of the mother, fetus and anesthesiologist which helped us in securing the airway.

CASE REPORT

A 29-year-old multi-gravida was referred to our hospital with an antenatal diagnosis of a large cystic hygroma diagnosed at 38 weeks of gestation. Fetal MRI revealed a large multiseptated cystic mass (measuring 12 × 8 cm) involving both sides of the neck with compression over the trachea [Figure 1]. Hence a difficulty in securing the airway was anticipated and EXIT procedure was planned. The parents were counseled and informed written consent was obtained. A multispecialty team comprising of obstetricians, anesthesiologists, pediatric surgeons, neonatologists, and radiologists were involved in planning and executing the procedure. Under general anesthesia elective Cesarean section was performed. Two teams of anesthesiologists were present, one for the mother and the other for the fetus. Apart from the routine monitoring, radial artery cannulation was done for invasive blood pressure monitoring. Patient was positioned in the supine position with left lateral tilt to prevent compression on the aorta. The legs were slightly abducted in order to allow easy access to the fetus for intubation. General anesthesia was commenced and maintained with higher concentration of isoflurane (for complete uterine relaxation), oxygen, nitrous oxide, and muscle relaxants. Before skin incision, ultrasound was done to locate the placental edge which revealed two loops of umbilical cord around the fetal neck. After skin and uterine incision, the fetal head and neck with the mass was delivered [Figure 2]. Warm Ringer lactate was infused into the uterine cavity to maintain the uterine volume. Fetal heart rate was monitored with an ultrasound probe and manually by umbilical cord pulsation. Initial attempts at intubation failed. Ultrasound-guided aspiration of the cyst was done but since most of the cysts were microcystic, adequate decompression could not be obtained. The neck was delivered up to the sternal notch [Figure 3] and then intubated. Intubation could be accomplished in 3 minutes and 47 seconds and airway was secured with a 3-mm ID oral endotracheal tube and then ventilated with 100% oxygen. There was no fetal bradycardia and cord was clamped and handed over to the neonatologist for further resuscitation. Isoflurane was stopped and oxytocin 20 units in 500 ml Ringer Lactate solution was administered. Hemostasis was achieved and patient was extubated at the end of surgery. The neonate was taken up for definitive surgery after 4 hours of stabilization in the NICU. The lesion was excised and elective tracheostomy was done due to tracheomalacia. Second sitting of excision was done after 4 months and tracheostomy has been decannulated.

Figure 1

Fetal MRI showing large multiseptated cystic mass compressing trachea

Figure 2

Fetal head and mass delivered — intubation attempts failed

Figure 3

Fetus delivered up to sternal notch — successful intubation

DISCUSSION

EXIT was initially described to remove the tracheal clip which was utilized to PLUG in fetuses with CDH (congenital diaphragmatic hernia).[5] By this procedure, the fetus is maintained on utero-placental circulation without hypoxia to the neonate. Later it was expanded to other procedures such as intubation for fetuses with large neck masses. The EXIT procedure maximizes the chance of survival for theses fetuses with large neck masses. Martino et al., had described respiratory distress in their five cases with antenatal detection of cervical teratoma. Two of them were planned for EXIT but lost one baby due to difficulty in intubation as the baby was delivered via naturalis due to preterm delivery.[6]

Our patient had a large neck mass compressing the trachea and successful intubation could be performed because of EXIT.

The Philadelphia group has explained the procedure of EXIT in great detail and the procedure was performed as advised.[7] On reviewing the literature, mother has been positioned either in supine with left uterine displacement,[78] modified lithotomy,[9] or lithotomy.[10] Murphy DJ et al.[9] had positioned the mother in the modified lithotomy position for better access during intubation of the fetus. Considering the technical difficulties for the obstetrician to deliver the fetal head in lithotomy position on one hand and easy accessibility it would offer for the intubation of the fetus on the other hand, we decided to position the mother supine with left tilt and lower limbs abducted for the anesthesiologist to stand in between the patient's legs for better access to the fetal airway [Table 1]. The ideal positioning of the fetus before intubation has been to deliver the head and neck upto thorax.[7] In our patient, the fetal head with the neck mass was not delivered upto the thorax because of the two twists of the cord around the neck. As the positioning was sub-optimal, initial attempts of intubation failed. Delivering the head and neck up to the sternal notch facilitated the proper alignment of the oro-pharyngo-laryngeal axes and successful intubation. It would be ideal to unwind the umbilical cord while the fetus is still in the relaxed uterus, but unwinding the tight loop could lead to undue traction on the cord compromising the fetal circulation.

Table 1

Optimal position of the mother, anesthesiologist, and fetus for intubation during EXIT

The uterus should be relaxed in order to maintain placental circulation. A uterine stapler minimizes blood loss and this is essential if a longer procedure is planned. Due to non-availability of staplers and as we had planned only for intubation we could perform hysterotomy without staplers and the blood loss was approximately 400 ml. Mother was not transfused.

EXIT has a definite role in fetuses diagnosed with large neck masses where airway compromise is suspected. Optimal positioning of the mother, obstetrician, anesthesiologists, and fetus is of paramount importance for successful and safe EXIT, especially in fetus with cord around the neck. Thus, EXIT can be safely performed in Indian set up, with adequate planning and execution.