ALTHOUGH vallecular cysts are often asymptomatic and harmless to the patient, discovery of a large vallecular cyst after induction of anesthesia is a potentially life-threatening problem for the patient and provides for the anesthesiologist a challenge in airway management. This report describes the treatment of a patient with an asymptomatic vallecular cyst that was discovered during rapid-sequence induction of general anesthesia.
A 47-year-old woman presented for elective right knee arthroscopy and removal of painful orthopedic hardware of the lower extremity. Her medical problems included obesity and a history suggestive of gastroesophageal reflux disease and hypertension treated with enalapril. She had no known drug allergies. A year previously she received general anesthesia via a size 4 laryngeal mask airway for knee arthroscopy. She admitted to a 25-pack-year history of smoking but denied symptoms of shortness of breath or cough. Physical examination revealed an obese woman (height 172 cm, weight 110 kg) who appeared older than her stated age. She was edentulous and had normal mouth opening and neck extension; no masses or distortion of the tongue or neck were observed. Chest auscultation revealed a mild expiratory wheeze.
She was premedicated with 10 mg metoclopramide intravenously and 30 ml sodium citrate orally. After application of routine monitoring devices, she was preoxygenated. Anesthesia and paralysis were induced with 200 mg propofol and 120 mg succinylcholine while cricoid pressure was applied. Direct laryngoscopy with a Macintosh 3 blade revealed a 2-cm cyst arising from the right side of the vallecula; it was pedunculated with a 5-mm stalk, making it somewhat mobile. The cyst completely obscured the view of the epiglottis and larynx, preventing intubation despite multiple attempts by two anesthesiologists using Macintosh 3 and Miller 2 blades, and increased neck extension and thyroid pressure. Because of a decrease in oxygen saturation (SaO2) the patient was ventilated via mask as cricoid pressure was maintained. Despite insertion of an oropharyngeal airway, this proved to be difficult; laryngospasm began to develop as muscle relaxation waned. after a second 80-mg dose of succinylcholine, intubation was attempted using a Miller 2 laryngoscope blade and a styletted 7.0-mm endotracheal tube. By using the tube to push the cyst aside, intubation of the trachea was performed after a brief although limited view of the laryngeal inlet.
The remainder of the anesthetic proceeded uneventfully. While the patient remained anesthetized, an otolaryngologist was consulted and the cyst was surgically removed. Dexamethasone 10 mg was given as suggested by the otolaryngologist. Anesthesia was discontinued and 100% oxygen was administered; after the patient awakened, the pharynx was carefully suctioned and the trachea was extubated.
Her postoperative course was also uneventful and she was discharged to home on the same day without any airway-related problems apart from a sore throat. During further questioning in the postanesthesia care unit she admitted to a several-year history of dysphagia. The pathology report confirmed the findings of a 2.2 × 2.2 × 0.5 cm, 0.3-cm thick membranous wall vallecular cyst.
Cysts of the larynx are rare and usually follow a benign course. They can, however, present with acute airway obstruction by nature of their location. Laryngeal cysts have been previously reported in the anesthesia literature. 1–4However, this case presented the additional challenge of producing unanticipated upper airway obstruction during rapid-sequence induction general anesthesia with subsequent successful intubation of the trachea by manipulation of the cyst with a styletted endotracheal tube.
Laryngeal cysts have been extensively studied and classified by site, size, contents, and relation to the laryngeal mucosa. Ductal cysts or mucous retention cysts are the most common type of laryngeal cysts, comprising 75% of cases, and are formed by distention of obstructed collective glandular ducts. (Saccular cysts, which comprise the remaining 25%, arise from the saccule, an extension of the ventricle; they may cause respiratory symptoms by enlarging the aryepiglottic fold). 5,6Ductal cysts are usually small, approximately 1–5 mm in diameter and as such are often asymptomatic. 5They are usually only discovered incidentally at the time of routine otolaryngologic examination or at postmortem examination. 1,7As a result, the exact incidence of laryngeal cysts is unknown but is estimated to be quite low. 8There is no gender predominance and, although they may occur at any age, a greater prevalence in the fifth and sixth decades has been observed. 5,6The most common location of ductal cysts is on the true vocal cords, whereas the second most common site is in the vicinity of the epiglottis—on its lingual surface or in the vallecula itself. 5–7Although they are usually asymptomatic, they may occasionally cause symptoms of stridor and failure to thrive (particularly in the newborn), 8–10cough, dysphonia, foreign body sensation and dysphagia. 6
In our case, a previously undiagnosed vallecular cyst presented as a difficult intubation. We had no reason to suspect any difficulties with intubation because the patient had no symptoms preoperatively—the patient's history of dysphagia was only elicited on specific, symptom-directed questioning postoperatively. In view of her normal airway examination, previous uneventful general anesthesia and history of gastroesophageal reflux disease, we thought that rapid-sequence induction of anesthesia and tracheal intubation was appropriate for our patient. Had both tracheal intubation and mask ventilation been impossible, aspiration of the cyst via a spinal needle might have been an option. In contrast to previous case reports in which intubation was either abandoned or performed blindly with the aid of an gum elastic bougie, 1–4we were able to intubate the trachea by displacing the pedunculated vallecular cyst with the endotracheal tube. We elected to obtain an otolaryngology consultation while the patient was still anesthetized so the cyst could be removed before extubation. This avoided the risk of any airway obstruction after extubation caused by the potential “ball-valve” effect of the cyst. This case would certainly have been managed differently had we known that the cyst was present before induction of anesthesia. For example, regional anesthesia or awake fiberoptic intubation would have been reasonable alternatives.
In summary, there are several causes for an unanticipated difficult intubation during rapid-sequence induction of general anesthesia. This case report helps to highlight one such cause—an asymptomatic vallecular cyst—and its subsequent management, resulting in successful tracheal intubation.