To the Editor:—
We read with great interest the recent case report by Omote et al. 1of an airway obstruction caused by lingual tonsil papillomas in Cowden disease. The event echoes the previously reported cases of lingual tonsil hyperplasia (LTH) that resulted in a “cannot intubate, cannot ventilate” crisis, necessitating the creation of a surgical airway, 2,3or resulted in the patient’s death. 3The report of Omote et al. 1includes two issues of particular concern to anesthesia practitioners: lingual tonsil airway obstruction often is unanticipated, and there appears to be no effective solution. Neither a laryngeal mask airway (LMA) 2nor a flexible fiberoptic laryngoscope 1works well in such cases of significant periglottic obstruction. 4
We share herein our experience with a rigid tubular fiberoptic laryngoscope, the WuScope (Achi Corp., Fremont, CA, and Asahi Optical Co.-Pentax, Tokyo, Japan), in a patient with unanticipated LTH (patient 1) and in a patient with symptomatic LTH who was scheduled to undergo surgical removal (patient 2). Patient 1 was a 39-yr-old, morbidly obese man (136 kg, 173 cm) with a history of heavy snoring. He declined regional anesthesia for an elective orthopedic procedure. Preoperative assessment showed bull neck and a Mallampati classification III airway. After the patient was preoxygenated, general anesthesia was induced with 450 mg sodium thiopental and 160 mg succinylcholine. Attempted mask ventilation was difficult with an oral airway in place, and the WuScope was inserted quickly into the patient’s mouth. Abundant papillomatous tonsil tissue was seen as the WuScope blade approached the vallecula. However, the larynx was easily exposed and intubated (fig. 1)
in 40 s, with oxygen saturation at 98% throughout the procedure. Diagnosis of LTH was later confirmed. Patient 2 was a stocky 45-yr-old man (97 kg, 178 cm). The presenting symptom of LTH was obstructive sleep apnea, which included “choking and gasping for air while asleep,” despite treatment with continuous positive airway pressure. He also had a Mallampati classification III airway. Without complications, he had undergone nasal WuScope intubation during general anesthesia for diagnostic endoscopy and biopsies 3 months previously. Nasal WuScope intubation was performed again without difficulty for lingual tonsillectomy. Although the two patients were scheduled to undergo anticipated difficult direct laryngoscopy, with our extensive experience with the WuScope, we were comfortable enough to perform tracheal intubation during general anesthesia.
As Omote et al. 1mentioned, lack of space, which impedes advancement of the fiberscope, and bloody secretions, which can obscure the visual field, are the problems with the flexible fiberoptic technique in cases such as the one described. In contrast, the WuScope tubular blade provides a mechanical means to gently push away the tonsillar tissue. The wedged tip enters the vallecula, stretches the glossoepiglottic mucous membrane, and lifts the epiglottis, thus locating and exposing the larynx easily. To remove blood in the airway, we first used a Yankauer suction (ConMed Corp., Utica, NY) to clean thoroughly the posterior pharyngeal wall, where the blood usually is collected. As the blade enters the oropharynx and advances toward the larynx, additional blood may be removed using an 18-French suction catheter through the endotracheal tube lumen.
WuScope intubation, as opposed to the LMA technique, is an entirely visually guided procedure. We agree with previous authors 2,4that the LMA may be inadvisable in such cases of periglottic soft tissue obstruction. Because of the blind nature of the LMA technique, placing an LMA or intubating through it could potentially worsen the situation by further pushing the redundant soft tissue to block the glottic opening or causing more bleeding.
As also mentioned by the authors, lingual tonsil airway obstruction often was unanticipated. However, from the two cases described, we believe that history of heavy snoring or obstructive sleep apnea, particularly in a not-so-obese patient, may be an important clue in preanesthetic airway evaluation to alert the practitioners of possible periglottic lesions, such as LTH, which may cause soft tissue airway obstruction during anesthesia.
The WuScope technique has worked well for us in dealing with pharyngeal soft tissue obstructions, such as in patients with LTH, and should be considered by others in managing this difficult airway problem.