Extreme Airway Difficulty During EXIT in Severe Fetal Agnathia: Failed Conventional Intubation and Successful Emergency Tracheostomy-A Case Report.

Background: Severe mandibular hypoplasia, particularly agnathia, is a rare congenital condition that may cause critical neonatal airway obstruction. The Ex Utero Intrapartum Treatment (EXIT) procedure allows airway control while maintaining uteroplacental circulation; overall airway establishment success rates for EXIT exceed 90%, yet conventional endotracheal intubation fails in a meaningful subset of cases with extreme anatomic distortion, necessitating surgical airway access. In the most severe forms of agnathia, primary tracheostomy under placental support may represent the most appropriate airway strategy from the outset. Case Presentation: A 36-year-old gravida 5 para 4 woman was referred after prenatal ultrasound detected severe fetal facial abnormalities. Serial imaging demonstrated progressive micrognathia evolving toward agnathia. Prenatal ultrasound demonstrated a markedly abnormal inferior facial angle (IFA) of 11° (normal mean 65° ± 16°) and a fetal nasomental angle of 92.87° (normal approximately 147°), indicating profound mandibular hypoplasia. Fetal MRI performed at 35 weeks and 3 days confirmed these findings, demonstrating an IFA of 40° and a nasomental angle of 116°, both below normal thresholds. The pregnancy was complicated by severe polyhydramnios. Fetal magnetic resonance imaging confirmed near-complete absence of the mandible with glossoptosis and severe narrowing of the oropharynx and hypopharynx, while the distal trachea and bronchi appeared normal. Because of the anticipated risk of airway obstruction, a multidisciplinary team planned an EXIT-to-airway procedure at late preterm gestation. The mother underwent general anesthesia with rapid sequence induction using propofol and suxamethonium. Uterine relaxation was achieved via inhaled sevoflurane at 1.2 MAC and nitroglycerin infusion at 0.5 mcg/kg/min. Fetal heart rate was continuously monitored using a pulse oximeter applied to the fetal foot after partial delivery. During the procedure, attempts at airway establishment using video laryngoscopy and rigid bronchoscopy failed due to the inability to identify a recognizable epiglottis or glottic opening. The decision to proceed with emergency tracheostomy was made after three unsuccessful video laryngoscopy attempts, during which the airway appeared completely obliterated with no visible laryngeal inlet. Mask ventilation was also ineffective because of absent mandibular support and severe upper airway obstruction. An emergency tracheostomy was, therefore, performed while uteroplacental circulation was maintained, resulting in successful ventilation and stabilization of the neonate. Conclusion: This case highlights the limitations of conventional intubation during EXIT in fetuses with extreme mandibular deficiency. Detailed prenatal imaging is essential for anticipating airway challenges. In cases with complete upper airway obliteration, planned primary tracheostomy under placental support should be considered the primary airway strategy rather than a rescue measure.