Unexpected presentation of a type IV laryngo-tracheo-oesophageal cleft: Anaesthetic implications of a rare case.

Laryngo-tracheo-oesophageal cleft (LTEC) is a congenital midline defect of the posterior larynx and trachea and the anterior wall of the oesophagus. Existence of these clefts may not be apparent during pre-operative evaluation. We present a rare case of a neonate initially scheduled for tracheo-oesophageal fistula repair. Unexplained air leak in spite of placement of size 4.0 mm endotracheal tube in a 2.5 kg neonate triggered extensive intra-operative evaluation of the airway anatomy via flexible and rigid bronchoscope. A type IV LTEC with an unusual anatomy was identified that was considered surgically irreparable. This case also highlights the need for a team approach and preparedness of anaesthesiologists for a difficult airway while managing such cases. Maintenance of high degree suspicion is warranted.

INTRODUCTION

Laryngo-tracheo-oesophageal cleft (LTEC) is a congenital midline defect of the posterior larynx and trachea and the anterior wall of the oesophagus. It is a rare disorder occurring in <1% of the population.[1] Laryngeal clefts occur with varying degree of severity. There have been multiple classification systems. A simple and clinically applicable is that proposed by Benjamin and Inglis that divides the clefts into four types based on function.[2] Type I involves inter-arytenoid musculature, type II involves the cricoid only, type III involves the proximal larynx, trachea and oesophagus and type IV LTEC extend into the thoracic trachea and may extend down to the carina. We report an unexpected presentation of a type IV LTEC in a neonate.

CASE REPORT

A 2.5 kg baby boy was born to a 22 year old mother of para 1 and gravida 1 via caesarean section. He showed poor respiratory effort at delivery that improved after resuscitation. APGAR scores were 2 at 1 min, 7 at 5 min and 10 at 10 min. Excessive oral secretions and an inability to pass orogastric tube beyond 10 cm was noted. He was transferred to our facility with a preliminary diagnosis of tracheo-oesophageal fistula (TOF).

Patient was scheduled for a TOF repair. Pre-operatively, child was breathing spontaneously and was stable on room air. Following induction with propofol and sevoflurane, patient was intubated with a size 3.0 mm uncuffed endotracheal tube (ETT). Monitoring included 3-lead electrocardiography, non-invasive blood pressure, pulse oximetry (SpO2), end-tidal carbon dioxide (EtCO2) and inspired/expired concentrations of sevoflurane using Phillips IntelliVue® and Masimo® for SpO2. Adequacy of placement of ETT was confirmed with appearance of EtCO2, but a large leak was noted. The leak persisted in spite of advancement to a size 3.5 mm and then 4.0 mm uncuffed ETT. In collaboration with the paediatric surgical team, a fibreoptic bronchoscopy (FOB) was performed through the ETT to evaluate its placement and positioning. An abnormal looking airway was seen at this time. Due to inability to ventilate adequately via FOB and the presence of an abnormal airway, the ETT was removed and a rigid bronchoscopy was performed by the surgical team. A posterior LTEC [Figure 1] was seen which appeared to extend down distally to what was thought to be a carina. During rigid bronchoscopy, ventilation and oxygenation was maintained via intermittent positive pressure manual ventilation with mixture of oxygen and sevoflurane using high flows. Visual evaluations of chest raise and fall along with presence of EtCO2 guided adequacy of ventilation. Intermittent bolus of fentanyl was used for analgesia. During the entire procedure, SpO2 was maintained between 95% and 100%. Neuromuscular blockers (NMBs) were avoided anticipating the need for spontaneous ventilation in the event of difficult positive pressure ventilation. A constant communication was maintained with the surgical team along with having FOB and laryngeal mask airway (LMA) in the room as back up measures for intubation and ventilation.

Figure 1

Rigid bronchoscopic view of the laryngotracheo-oesophageal cleft showing three openings: Right anterior (RA), left anterior (LA) and posterior (P). The right main stem (RA) can be seen with disrupted tracheal rings. Left main stem (LA) is visualized as a tiny opening, the anatomy of which was confirmed after injection of contrast and subsequent visualization of bronchial anatomy by fluoroscopy. Oesophageal opening (P) on the posterior aspect was confirmed following visualization of stomach rugae by flexible bronchoscopy

Three openings were seen at the distal end of the cleft located at right anterior (RA), left anterior (LA) and posterior (P) aspect [Figure 1]. The opening on the RA had some disrupted tracheal rings that led to right main. On passing the scope down the posterior opening, stomach was visualised suggesting that this was the oesophageal opening. The LA opening was too small for the camera. Fluoroscopy with contrast injected using a 4 Fr catheter revealed the LA lumen leading to the left lung. Final diagnosis was a type IV LTEC with aberrant left main bronchus and distal oesophageal fistula connecting to the entire area [Video 1]. Surgery was abandoned and patient was taken to neonatal intensive care unit intubated with a size 4.0 mm ETT. Further work-up of patient including ultrasound revealed mild hydronephrosis of left kidney and possible tethered spinal cord. An echocardiogram revealed a small patent ductus arteriosus (PDA) and patent foramen ovale. Unfortunately, the complex malformation was deemed irreparable and patient discharged home with palliative care.

Video available online at http://www.ijaweb.org/article.asp?issn=0019-5049;year=2014;volume=58;issue=6;spage=746;epage=748;aulast=Dwarakanath

DISCUSSION

Congenital laryngeal clefts and LTEC are rare developmental disorders of the upper airway accounting for 0.3–0.5% of all congenital anomalies of the larynx.[1] Development of larynx begins with a groove in the foregut at approximately 4th week of gestation. By 5th week, the laryngotracheal groove is transformed into laryngotracheal diverticulum that grows parallel to foregut. Tracheo-oesophageal fold then form to create the laryngotracheal septum, which separates the diverticulum from the foregut. The laryngotracheal septum develops in a caudal to rostral direction. By the seventh gestational week, the trachea and oesophagus are largely separated. It is postulated that a compromise in the blood supply or fusion of the tracheo-oesophageal septum results in an LTEC.[1]

During review of anaesthesia literature, most of the cases including our own, presented to the operating room for repair of TOF.[3] Although a nonspecific finding of polyhydramnios and prematurity has been associated with LTEC, there are no pathognomonic prenatal findings associated with LTEC.[4] In our case, in addition to polyhydramnios and prematurity, mother had pre-eclampsia. Symptoms associated with LTEC depend on the severity of the cleft and includes hoarse or husky voice, feeding difficulties, increased secretions, choking, stridor, aspiration, pneumonia, and cyanotic episodes. Major clefts (types III and IV) may be associated with stridor and/or respiratory distress. Types III and IV LTEC often require airway intervention soon after birth along with difficulties in maintaining an intubated airway.[4]

The extent or the existence of clefts may not always be apparent during pre-operative evaluation. Although the incidence of severe LTEC is rare, anaesthesiologists may need to maintain an index of suspicion and be ready for existence of an abnormal airway, especially in patients undergoing TOF repair. The operating room should be ready with appropriate size laryngoscopes and bronchoscopes. It is important to incorporate a team approach during management of the airway including paediatric surgeon, otolaryngologist, neonatal intensive care specialist, and nursing staff. Successful management of these patients entails experience in airway assessment, maintenance of airway and adequacy of ventilation. In our case, inability to maintain adequate ventilation with a size 4.0 ETT raised a suspicion of abnormal airway which was confirmed with a flexible FOB. A rigid bronchoscope was then performed for detailed examination of the airway with the involvement of ear-nose-throat specialist team. Critical factors in maintaining oxygenation and ventilation include visual evaluation of chest raise and fall, avoiding NMB, monitoring of EtCO2 and SpO2. Total intravenous anaesthesia should be considered if delivery of inhalation agents is deemed inadequate. Other options for airway evaluation are placement of LMA to allow FOB or intermittent apnoeic ventilation. Deliberate endobronchial placement of ETT guided by FOB can be considered which can help with oxygenation, avoid gastric insufflation and still allow evaluation of airway via bronchoscope.

Type IV LTEC has a high mortality rate. Roth et al. reported mortality rate ranging from around 43% for types I, II and III to 93% for type IV.[5] Surgical repair has been described for type IV LTEC in the ENT and paediatric surgical literature through an anterior sternotomy approach or transthoracic approach with possible need to use cardiopulmonary bypass.[267] In our case, the LTEC was associated with a vestigial left main bronchus along with disrupted rings on right side. Surgical repair was considered beyond the capability of our expertise.

Other anomalies associated with our case were a small PDA with patent foramen ovale, hydronephrosis of the left kidney and a low-lying spinal cord suspicious for a tethered cord. LTEC have been described in two syndromes: Optiz-Frias (G syndrome) and Pallister-Hall syndrome.[8] Laryngeal clefts have also been found in patients with VATER association. A left-sided pulmonary agenesis has been reported in the literature.[49] Our case did not fit any known syndrome but did have a vestigial left main bronchus with normal development of both lungs. A review of the literature did not reveal any reports of a similar presentation.

CONCLUSION

We share our experience of an unusual and unexpected presentation of a case of LTEC. Clinical diagnosis may not be apparent prior to presentation to the operating room and hence poses special challenges to the anaesthesiologists while managing the airway.