This blog post discusses two articles in the January 2013 issue of the medical journal Otolaryngology—Head and Neck Surgery that report outcomes for sleep apnea surgery involving removing part of the back of the tongue.
Two of the major factors that cause obstructive sleep apnea and snoring are head and neck structure (anatomy) and the muscle relaxation that occurs naturally during sleep. For an estimated 60% of all sleep apnea patients, the tongue is recognized as a major contributor, due to both of these factors. Studies have shown that weight gain can lead to the deposition of fat in the tongue itself, making the tongue physically larger. This enlargement compounds the tendency of the tongue, largely comprised of muscle, to fall backwards during sleep and block breathing.
A number of tongue-directed procedures have been developed to reduce the size of the tongue and/or prevent it from falling backwards. Many otolaryngologists are less familiar with these procedures because the techniques are relatively new and because the procedures are more difficult. As a result, I lecture frequently about how to perform them as well as how to choose the best procedure for an individual patient. Studies have shown that combining these tongue region procedures with palate procedures achieves better results than palate procedures alone. But all tongue procedures are not equal. Some tongue-directed procedures are more involved, such as the family of procedures that remove part of the back of the tongue (under the umbrella term of “midline glossectomy”) and the tonsil on the back of the tongue (lingual tonsillectomy).
Evolving Techniques and Decision Making for Midline Glossectomy
When the midline glossectomy technique was first described, surgeons used standard carbon dioxide lasers or electrocautery to perform the procedure, but this resulted in substantial swelling, pain, and risks. Newer technologies have reduced the risks, but a major question for surgeons is who can benefit from the less-involved procedures such as tongue radiofrequency or genioglossus advancement and who needs a procedure like midline glossectomy. Studies have shown consistently that heavier patients, perhaps due to their enlarged tongues, do not do as well with the less-involved approaches and may need to consider a procedure like midline glossectomy. Specifically, those with a body mass index above 32 kg/m2 (you can calculate your own body mass index using the National Institutes of Health website) generally have poor outcomes with the less-aggressive approaches. With the obesity pandemic facing the world, more patients with obstructive sleep apnea are falling into this range, leading to a greater interest in the techniques and outcomes for midline glossectomy.
The New Studies
Dr. Indunil Gunawardena and other colleagues of Dr. Sam Robinson from Flinders Private Hospital in Adelaide, Australia, reported outcomes of the combination of palate surgery and submucosal lingualplasty. Sam passed away far too young in October 2010 but was a widely-respected, innovative sleep apnea surgeon who developed the submucosal lingualplasty technique (illustrations below). This procedure involves physical removal of a portion of the tongue in the central area between the major blood vessels and nerves of the tongue, followed by additional removal of tissue towards the sides of the tongue but above those same blood vessels and nerves. Among midline glossectomy techniques, submucosal lingualplasty enables more tissue removal and also enables the surgeon to see any bleeding during surgery directly. Although this is more time-consuming and performed by few surgeons, it may be well-suited to those tongues that are particularly large. I was fortunate to discuss the procedure and learn so much from Sam, benefitting from his answers to my many questions about the procedure. While the procedure has numerous challenges, the importance of this paper is to show that the results were excellent. Three-quarters (74%, 20/27) achieve a major improvement in their breathing patterns, based on at least 50% reduction in the apnea-hypopnea index to a level below 15 events/hour (no or mild sleep apnea). The average apnea-hypopnea index decreased from 44 to 12 events/hour, and the improvement was even more dramatic for those with moderate-to-severe sleep apnea. In addition, there were improvements in sleepiness and snoring and relatively few complications.
Dr. Gerald Suh of St. Johns-Riverside Hospital and Mt. Sinai Medical Center in New York utilized a midline glossectomy technique that started with a lingual tonsillectomy that is extended into the central portion of the tongue base, again staying away from the major blood vessels and nerves. After combined palate surgery and midline glossectomy, there was also a major improvement in breathing patterns (average apnea-hypopnea index decreased from 52 to 18 events/hour), with 56% (28/50) achieving major reductions to have no sleep apnea or only mild sleep apnea following surgery. Gerry produced a detailed analysis, taking the critical step to examine factors that were associated with better outcomes: markedly enlarged lingual tonsils, relative tongue size, and the severity of sleep apnea. These all make sense. The larger the lingual tonsils, the more space that is created for breathing when they are removed. Because there are limitations on the extent of tongue tissue removal, those with the largest tongues did not do as well (29% vs. 76% success). Finally, when you are starting out with an apnea-hypopnea index above 60 events/hour (well in the severe sleep apnea range), it can be more difficult to end up with no sleep apnea or mild sleep apnea after surgery.
The Bottom Line
Tongue resection procedures, under the umbrella term of midline glossectomy, are often necessary for those with enlarged tongues and/or lingual tonsils. Surgeons must understand the factors that play a role in sleep apnea in individual patients and how specific procedures work to restore normal breathing. Even among the midline glossectomy techniques, the more-aggressive options (like submucosal lingualplasty) may be needed to address the most-challenging patients, but less-aggressive options have an important role. At the risk of being redundant, these two publications reinforce the principles of having a wide array of procedures available to treat the diversity of patients with sleep apnea rather than treating every patient with the same procedure. The balance between risks and benefits is key. You do not need a sledgehammer to drive in a nail, and you certainly would not want to use a nail hammer to drive in a railroad spike either.