Successful management of subglottic stenosis in pregnancy

Abstract

Evaluation and management of subglottic stenosis in pregnancy is challenging. It often is not only a multidisciplinary approach between obstetricians, otolaryngologists (ENT surgeons) and anesthesiologists, but also requires a thorough understanding of possible foreseen complications by the patient as well. Hence, whenever we are presented with a challenging case requiring multidisciplinary approach involving team of physicians from different specialties, it is routine practice to huddle regarding the preoperative, intraoperative and postoperative management and care. We present a case of a 37-year-old woman with a known history of idiopathic subglottic stenosis, 16 weeks’ pregnant, G4P1, with a surgical history significant for two previous subglottic dilations in the past and who now presented with an audible stridor and shortness of breath on activity. We highlighted the unique challenges encountered and the corresponding management adopted. This is a case of successful management of symptomatic worsening of subglottic stenosis managed during pregnancy.

Background

Subglottic stenosis is defined as the narrowing of the airway in the region below the vocal folds¹ and may be congenital or secondary to systemic conditions including Wegener’s granulomatosis, sarcoidosis, gastro-oesophageal reflux disease (GORD), prolonged intubation or prior tracheostomy. Idiopathic subglottic stenosis (ISS), a diagnosis of exclusion,² is rarely encountered during pregnancy and therefore little guidance is available to those managing parturient with this condition as most of the existing literature is based on a few case reports. Written informed consent was obtained from the patient to publish this case.

Case presentation

We report the successful management of a 37 year-old gravida 4 para 1 woman at 16 weeks’ gestation with a known medical history of ISS presenting with gradual worsening of audible stridor and shortness of breath on exertion. Obstetric history was remarkable for one prior caesarean delivery and two miscarriages.

She was evaluated by a rheumatologist as the subglottic stenosis was initially considered to be autoimmune and was on methylprednisolone with mild improvement in symptoms initially. However, the diagnosis of idiopathic aetiology was established over the course of years due to multiple negative workups to rule out auto immune pathology. She underwent subglottic dilations twice over the course of 2 years with temporary improvement that lasted for 4–5 months. Other significant surgical history was gastric fundoplication for severe GORD, which was now well controlled.

Flexible nasopharyngoscopy performed, as an outpatient, had revealed subglottic stenosis of 2.5 mm in diameter. Airway examination revealed a Mallampati Score of 3, mouth opening of 4 cm, thyromental distance of 4 cm and full cervical range of motion. An audible tracheal bruit was auscultated as well as an inspiratory stridor was present, though the patient was able to lie flat without significant distress. Her otolaryngologist considered it a life-threatening state that needed urgent surgery due to her worsening symptoms and precious pregnancy. After discussion with patient’s obstetrician, decision was made to proceed with surgery during second trimester of pregnancy.

Treatment

The patient was offered various surgical options such as cryotherapy, endoscopic radial laser incisions and balloon dilations along with an awake temporary tracheostomy for airway protection. Detailed risks of aspiration especially with a history of reflux disease increased during pregnancy along with difficult airway was explained when the patient refused an awake tracheostomy as a backup.

Given the success of previous two balloon dilation procedures and the less invasiveness nature compared with others, the decision was made to proceed with balloon dilation for symptomatic relief keeping in mind the high-risk nature during the precious pregnancy.

Following administration of aspiration prophylaxis which included 30 mL of sodium citrate, standard American Society of Anesthesiology (ASA) monitoring was initiated as well as continuous fetal heart rate monitoring. The patient was preoxygenated in the left lateral position followed by induction of anaesthesia with 2 mg midazolam, 150 mcg fentanyl and 150 mg of propofol, 50 mg of rocuronium was given after successful mask ventilation. Propofol and remifentanil infusions were then started at 120 mcg/kg/min and 0.15 mcg/kg/min, respectively. Laryngotracheal administration of 160 mg of lidocaine 4% preceded transtracheal jet ventilation with a 14 gauge needle.

Suspension laryngoscopy revealed significant scarring of the subglottic region with narrowing estimated to be 2.5 mm (figure 1) and a diagnostic bronchoscope could not be passed through the lumen. A surgical incision was made using micro laryngeal scissors at the 12‘o clock and 15‘o clock in the trachea. Successive Jackson laryngeal dilators were passed (20–38 Fr) followed by 12 mm and 15 mm balloons sequentially deployed in the subglottis and inflated for 1 min. Following dilation, a 7.0 endotracheal tube (ETT) could easily be inserted into the trachea without complication. The improvement to Myer-Cotton grade 1 from pre procedure grade 3 is the highlight of the case.

Figure 1.

Intraoperative laryngoscopy view of subglottic region before (A) during (B) balloon dilation and after (C) balloon dilation.

Following this, muscle relaxant was reversed with administration of glycopyrrolate 0.8 mg and neostigmine 5 mg, the patient was successfully extubated in the operating room. She was then transferred to post anaesthesia care unit in stable condition. She was evaluated by the obstetrician with a bedside ultrasound which revealed a single fetus with good fetal movements and normal fetal heart rate (table 1).

Table 1.

Summary of intraoperative challenges and corresponding management

Challenges	Management
High aspiration risk during pregnancy	Sodium citrate was given in addition to standard antiemetic regimen
Anticipated difficult airway, surgical manipulation and chance of bleeding due to increased vascularity
	Preoperative consent for tracheostomy in case of an emergency
Changes in cardiopulmonary physiology during pregnancy	Preoxygenation in left lateral position
Risk of laryngospasm in the setting of increased bleeding secondary to increased vascularity and mucosal congestion	Laryngotracheal topicalisation with 4% lidocaine
Airway manipulation—preference of anesthetic– oxygenation–ventilation technique to avoid interference with surgical field	Total intravenous anaesthesia with remifentanil and propofol infusion Intermittent jet ventilation
Increased fire risk in the setting of airway manipulation	Use laryngeal scissors and balloon dilators instead of lasers and electrocautery
Significant scarring of the subglottic region with very narrow lumen (2.5 mm)	Surgical incision first made using micro laryngeal scissors followed by successive Jackson laryngeal dilators followed by sequential balloon dilations
Assure fetal well-being during the high-risk surgical procedure in parturient	Continuous fetal heart rate monitoring in addition to standard ASA monitoring Bedside fetal ultrasound in PACU after the procedure by obstetrics team

ASA, American Society of Anesthesiology; PACU, post anaesthesia care unit.

Outcome and follow-up

The patient tolerated the procedure well. She reported immediate improvement in her breathing after recovery from anaesthesia in the operating room. She was discharged after 24 hours of observation with mild hoarseness. The rest of her pregnancy was uncomplicated. She delivered a baby girl full term via repeat c-section. She had persistent symptom relief for about 6 months, after which she developed progressive dyspnoea that required repeat subglottic balloon dilation during her postpartum period.

Discussion

ISS is a rare disorder. While the pathophysiology is not well understood, inflammation and scarring is usually present. It is almost exclusively in Caucasian women between the third and fifth decades of life.³ Hormonal factors such as the paucity of oestrogen receptors in the stenotic areas leading to increased release of fibroblast growth factor have been postulated as it occurs exclusively in women.^{3 4}

It may present with exertional dyspnoea, cough, difficulty with throat clearing, dysphonia or stridor. Though no universally accepted algorithm for its management exists, treatment options include observation, medical management, endoscopic intervention and open tracheal resection with reanastomosis.⁵ It is generally recommended that endoscopic therapy (which include radial incisions, rigid or balloon dilation, cryotherapy, topical steroid and mitomycin C application) be pursued initially before attempting open procedures.^6–8

Because ISS affects women predominantly, often at childbearing age, it is important to learn how to manage the disease in pregnant patients. Pregnancy results in a variety of respiratory changes that can lead to increased vascularity, mucosal congestion and bleeding. Recent study showed that there were worsening symptoms from ISS during pregnancy; however, there was no increase in operative or clinic interventions.⁹ Parturients are also at a significantly greater risk of aspiration of gastric contents especially with worsening of reflux during pregnancy. Hence, the airway management in such patient population can be extremely challenging.

Unfortunately, given the epidemiology of the disease, guidance for the management of ISS in pregnancy from the literature has been limited to small number of case reports and case series among which various treatment strategies have been considered in individual circumstances. Surgical options mentioned above maybe performed under local anaesthesia with or without intravenous sedation, general inhalational anaesthesia with intubation and total intravenous anaesthesia (TIVA) with jet or high-flow nasal cannula ventilation (table 2).^{1 10–19} There is no consensus regarding optimal management of these patients. We chose to administer TIVA with muscle relaxation with supraglottic jet ventilation to facilitate suspension laryngoscopy and balloon dilation despite risk of difficult airway and aspiration risk in pregnancy along with pneumothorax, bleeding and chances of miscarriage. Due to significant subglottic narrowing, the decision was made not to intubate the airway as even a small calibre endotracheal tube would cause an interference in the surgical field and affect surgical outcomes. The lack of any maternal and fetal complications and successful resolution in symptoms with an ability to carry the pregnancy to full term makes this a unique case.

Table 2.

Patient characteristics, surgical and anaesthetic management and outcomes from previous reports

Literature	Age	Gestational age	Presenting symptoms	Preoperative Cotton-Myer grading	Operative technique	Anaesthetic technique	Ventilation technique	Outcomes
Rumbak et al11	20	27	Difficulty breathing and stridor	Unknown	Cautery-assisted balloon dilation	Local, sedation	Unknown	NSVD
Rumbak et al11	21	32	Dyspnoea, cough, ‘tight’ throat	Unknown	Cautery-assisted balloon dilation	General, volatile anaesthetic	Endotracheal tube	NSVD
Engel et al12	29	37	None	Unknown	None	N/A	N/A	NSVD
Karippacheril et al13	28	40	None	Unknown	None	N/A	N/A	C-section, tracheostomy after delivery, followed by decannulation
Nash et al15	30	24	Stridor, hoarse voice	Unknown	Non-surgical management	N/A	N/A	NSVD
Carness and Berman1	31	28	Dyspnoea on exertion	Unknown	Laser-assisted balloon dilation	Local, sedation	Blow-by oxygen	NSVD
Hamersley et al16	31	Unknown	Unknown	Grade 3	Balloon dilation	Local, sedation	Unknown	Unknown
Damrose et al17	40	28	Unknown	Grade 3	Balloon dilation	General, TIVA	Jet ventilation	NSVD
Damrose et al17	30	31	Unknown	Grade 3	Balloon dilation	General, TIVA	Jet ventilation	NSVD
Damrose et al17	33	17	Unknown	Grade 3	Balloon dilation	General, TIVA	Jet ventilation	NSVD
Damrose et al17	42	30	Unknown	Grade 3	Balloon dilation	General, TIVA	High flow nasal cannula	NSVD
Walsh and Shostak18	37	33	Progressive stridor	Unknown	Balloon dilation	General, volatile anaesthetic	LMA, jet ventilation, tracheostomy until delivery	Unknown
Bourn et al19	29	21	Stridor	Grade 2	Balloon dilation	General, TIVA	Transnasal humidified rapid-insufflation ventilatory exchange	C-section

LMA, Laryngeal mask airway; N/A, Not applicable; NSVD, normal spontaneous vaginal delivery; TIVA, total intravenous anaesthesia.

Maternal and fetal safety in the case of airway compromise requires a multidisciplinary approach including obstetricians, otolaryngologists and anesthesiologists in addition to a thorough understanding of the possible complications that can be encountered in pregnant patients experiencing this condition.

Learning points.

• This is a case of successful management of idiopathic subglottic stenosis (ISS) in pregnancy which is rarely encountered with limited treatment options available.

• The management of ISS becomes more challenging in the setting of pregnancy which results in increased airway vascularity and mucosal congestion leading to bleeding in the setting of a high aspiration risk. A thorough understanding of possible foreseen complications is critical.

• A multidisciplinary approach among obstetricians, otolaryngologists and anesthesiologists is required to achieve appropriate management of both maternal and fetal safety.