1
Introduction
For the clinician and surgeon treating patients with obstructed sleep apnea and related maladies, the retrolingual airway is of great importance. This area, often difficult to examine and identify as an area of concern, has recently been the site of much academic and surgical attention. For with its difficult location comes increased complexity in surgical cure, plagued with both intra-operative and postoperative challenges. Although the palatal–pharyngeal area is often the site of primary obstruction in patients with sleep apnea, there are often areas of secondary blockage, and the tongue base may be an area of interest with the added concern of hypertrophic lingual tonsils.
2
Patient Selection
Obstruction may not be the only presenting sign of hypertrophic lingual tonsils. Symptoms may be classified into two main categories, resulting from problems with either inflammation and infection or hypertrophy and hyperplasia. Inflammation may present with dysphagia and odynophagia with complaints originating at the tongue base or suprahyoid region. These symptoms may occasionally result in lingual tonsillar abscess and recurrent epiglottitis. Hypertrophic or hyperplastic tonsils may plague the patient with dysphagia and globus. These patients may have increased symptoms in the supine position, with those afflicted with obstructive sleep apnea having a worsening obstructive process in the deeper stages of sleep. Interestingly, lingual tonsil enlargement is a relatively common finding in children with persistent obstructive sleep apnea after adenotonsillectomy, further intensifying the finding of compensatory lingual tonsil hypertrophy after such a procedure.
The differentiation of lingual tonsil and tongue base pathology is often difficult. Furthermore, the very definition of lingual tonsil hypertrophy has not been standardized. However, if the lingual tonsils are larger than “10 mm in diameter and abutting both the posterior border of the tongue and the posterior pharyngeal wall,” they may be considered clearly enlarged, due to a known relationship to patients with obstructive sleep apnea. Determination between lingual tonsil hypertrophy and an enlarged tongue base is critical, for these two entities often require different therapies, with both needing attention. Careful history taking and physical examination when combined with ancillary studies may help the surgeon successfully treat the patient with retrolingual pathology.
There are multiple descriptions of how to surgically address the lingual tonsils, including scalpel, electrocautery, snares, laser, and removal with the suction debrider. However, these procedures are often fraught with difficult exposure, painstaking dissection, poor visualization, difficult hemostasis, excessive postoperative pain, and possible airway edema. In 2006, Robinson et al. described the novel technique of utilizing bipolar radiofrequency plasma excision, or the Coblator, for direct visual removal of the lingual tonsil pad using suspension laryngoscopy and an operating microscope. Advantages of this technique include improved exposure, visualization, and hemostasis with decreased postoperative edema and pain when compared with previously described techniques. However, after multiple cases, we find the suspension laryngoscopy and the use of the operating microscope to be burdensome and unnecessary. Of note, the laryngoscope is bulky, distorts the lingual anatomy, and requires intra-operative adjustment and resuspension. Also, even bivalved laryngoscopes may restrict full surgical access to the lateral portion of the tonsil and may increase the risk of laryngoscope-associated complications, including injury to the patient’s dentition, temporary dysgeusia, and altered tongue mobility. Adding to the difficulty, use of the microscope is tedious and it only works in the straightforward position. Here, we offer our experience with endoscopic Coblation lingual tonsillectomy. Being otolaryngologists and already comfortable with the increased visualization and applications offered from our endoscopes, why not apply these superior optics to surgery in a difficult spot?
Lingual tonsillectomy may be indicated for those patients with complaints of hypertrophy or repeated infection. The history, as previously discussed, may alert the clinician to the lingual tonsil as a source of concern. These patients may be pediatric or adult, and our surgical approach applies to both patient types.
Due to the difficulty in examining the retrolingual airway by the front-line primary health care provider, it is critical that the otolaryngologist be familiar with the different tools of preoperative assessment. Examination with laryngeal mirror and flexible endoscopy is critical, for these are the best methods of visualization. Finger palpation is also standard, for tongue base concerns may occasionally stem from foreign bodies or tumors. Visualization is also important in the clinical differentiation of lingual tonsil and tongue base musculature hypertrophy. Because these entities are treated differently, incorrect identification of the area of concern may lead to decreased treatment success. Enlarged lingual tonsils may appear with multiple enlarged follicles, soft to the touch, and occasionally filling the vallecula to the point of glottis concealment from a posterior pushed epiglottis. One must characterize the space between the lingual tonsils posterior extent to the posterior oral and hypopharyngeal wall. The Mueller maneuver may add clues to the responsible levels of obstruction. Drug-induced sleep endoscopy is another recent advancement that can add information regarding level of obstruction, particularly in the pediatric population where fiber-optic awake examination cannot be performed or is non-demonstrative of obstruction site. Lateral neck radiographs may offer information on tongue position and relative size of the lingual tonsils ; however, when in question, we find magnetic resonance imaging (MRI) with gadolinium enhancement to be crucial in imaging the tongue base. This modality, which characteristically enhances the lingual tonsils from tongue base musculature, helps to determine the nature of retrolingual obstruction, be it lingual tonsil hypertrophy or tongue base enlargement, while appropriately exposing other possibilities, such as tumor. If lingual tonsil hypertrophy is suspected and there are no clinical contraindications, a short burst of oral steroids with re-examination in 1 week is another way to determine culpability of the lingual tonsil; if the retrolingual airspace widens, the lingual tonsils are likely the perpetrator. If there is no difference, suspect the tongue base. This method may provide a quicker and less expensive clinical method than MRI; however, the chosen modality is ultimately up to the clinician.
In addition, great care must be given to addressing the non-surgical treatments of lingual tonsil hypertrophy, which is often due to allergies, sinusitis, and gastroesophageal reflux, of which hypertrophy may be a presenting sign with the latter. Often, after appropriate medicinal treatment, such as with an empiric trial of proton pump inhibitors and/or topical nasal steroids, clinical improvement over 4 to 6 weeks may eradicate the need for surgery. Finally, polysomnogram is the gold-standard examination for evaluating concerns of sleep-disordered breathing. Extra caution must be given to patients with suspected neuromuscular abnormalities; hypotonia and related disorders (such as cerebral palsy and Down syndrome) may suffer from obstructive as well as central apnea.
