The video demonstrates successful endoscopic coblation of lingual tonsils and residual palatine tonsils as well as successful TORS reduction of obstructive base of tongue tissue.
Procedure: Endoscopic Assisted Coblation Lingual Tonsillectomy and Transoral Robotic Surgical Approach
Introduction: Obstructive sleep apnea can persist despite adenotonsillectomy in children. One of the main causes of refractory OSA is base of tongue hypertrophy. This video presents two surgical approaches to base of tongue reduction: endoscopic assisted coblation and transoral robotic surgery.
Indications: Pediatric patients with persistent obstructive sleep apnea following adenotonsillectomy with obstructive base of tongue tissue confirmed by nasolaryngoscopy or drug induced sleep examination.
Materials and Methods: Endoscopic assisted coblation and TORS base of tongue reduction procedures were conducted in patients suffering from persistent OSA following successful adenotonsillectomy. In both cases, optimal view of the base of tongue included visualization of the circumvallate papillae superiorly, epiglottis inferiorly, and the palatine tonsils laterally. For the endoscopic case, a Crowe-Davis was secured in place to allow retraction of the tongue, enabling an appropriate view for the utilization of a 30-degree endoscope. This view allowed for proper coblation of lingual and palatine tonsils. Similar technique was implemented in the TORS base of tongue reduction case, however an improved surgical field and more working arms allowed for en-bloc resection of obstructing tissue.
Results: The video demonstrates successful endoscopic coblation of lingual tonsils and residual palatine tonsils as well as successful TORS reduction of obstructive base of tongue tissue. Both patients tolerated the procedure well.
Conclusion: Endoscopic assisted coblation and TORS are two techniques that are effective in resecting hypertrophied base of tongue tissue in pediatric patients with persistent sleep apnea following adenotonsillectomy.
Obstructive Sleep Apnea (OSA) is common in the pediatric population and is associated with significant morbidity if left untreated.1 First line treatment in healthy children suffering from moderate to severe OSA is adenotonsillectomy. Although adenotonsillectomy has shown to improve health outcomes, up to 20 percent of pediatric patients can present with persistent OSA following successful surgery.2 Base of tongue hypertrophy is a common culprit for persistent OSA in children. Newer technologies and techniques have increased efforts in reducing hypertrophied tongue tissue in children as a means to treat refractory OSA. Two notable approaches under investigation are endoscopic assisted coblation and transoral robotic (TORS) base of tongue reduction.
The use of endoscopic coblation base of tongue reduction in a pediatric population was first described in 2009. The operative indications include patients with persistent polysomnogram-proven OSA following adenotonsillectomy, where lingual hypertrophy is determined as the main cause of obstruction. Level of obstruction is typically determined by flexible nasolaryngoscopy or drug induced sleep endoscopy.3 In comparison to prior techniques, the endoscopic approach provides the surgeon with optimal exposure of the lingual tonsils, ensuring accurate and complete resection of hypertrophied tissue. In addition, the use of low thermal coblation for hemostasis makes the procedure more tolerable for children, resulting in low amounts of postoperative pain.4 Of note, because coblation is an ablative technique, a specimen is not explicitly delivered.
In 2006, TORS provided a revolutionary approach for resection of oropharyngeal neoplasms. In 2010, the first reported case of OSA was treated with TORS.5 Studies have since demonstrated the efficacy and safety of TORS in base of tongue reduction. Advantages for TORS include an improved visualization of the surgical field with an increased range of motion thus allowing deeper penetration and resection of obstructing tissue. The purpose of this study is to describe and evaluate the surgical technique and efficacy of endoscopic and TORS base of tongue reduction in a pediatric population.
In both endoscopic and TORS base of tongue reduction, an optimal view of the base of tongue includes visualization of the edge of the circumvallate papillae superiorly, epiglottis inferiorly, and the palatine tonsils laterally. For the endoscopic case, the tongue was retracted beyond the tooth line and the Crowe-Davis was secured in place. This enabled an appropriate view with the utilization of a 30-degree endoscope. Coblation of both the hypertrophied lingual tonsils along the base of tongue as well as remnant palatine tonsils was successful. Care was taken to avoid injury to the surface of the epiglottis and tongue musculature. After coblation of the tonsils and adequate hemostasis is achieved, the patient was extubated and admitted overnight for monitoring due to history of sleep apnea and risk of post-operative bleeding. The patient tolerated the procedure well. Similar technique was utilized in the patient undergoing TORS base of tongue reduction. However, with an improved surgical field and more working arms, en-bloc resection of obstructing base of tongue tissue was successfully achieved along with adequate hemostasis. The patient was also admitted overnight for observation due to history of sleep apnea and risk of post-operative bleeding. Neither patient suffered any post-operative complications. Post-operatively, they were each evaluated with repeat polysomnography revealing much reduced AHI.
Surgery was carried out successfully and without complications for both patients. Remnant sleep apnea was successfully reduced with post-operative polysomnography revealing reduced apnea-hypopnea indices and reduced snoring intensity. The view afforded by TORS is far superior to that in the endoscopic approach. Further, en-bloc removed of the hypertrophied tongue region is easily possible with TORS. Access to TORS is limited for most institutions and the approach required for successful endoscopic view is thus presented as well.
Obstructive sleep apnea is commonly treated with adenotonsillectomy in the pediatric population.1 Most children will notice marked improvement in symptoms; however, a randomized trial by Marcus et. al revealed that 79 percent of pediatric patients had a normalization of polysomnogram findings, leaving over 20 percent of patients with persistent OSA.2 Refractory OSA is usually due to continued obstruction of the airway following surgery at the level of the soft palate, lateral oropharynx, epiglottis, and/or the base of tongue. A meta-analysis of drug induced sleep endoscopy results conducted by Lee et. al reports base of tongue hypertrophy as an emerging culprit for persistent symptoms, with a prevalence of 51.6 percent in 2,950 patients.6 As base of tongue obstruction becomes more recognized as a cause of persistent OSA, newer tongue base procedures are being implemented in the reduction and resection of hypertrophied tissue.
Operating at the base of tongue has been a challenging endeavor for many years. The complex relationship of the base of tongue to surrounding structures including significant vascularity, the limited access to the oropharynx, and the tongue’s important physiologic functions have made tongue-based procedures complicated. One of the first base of tongue operations reported was a transcervical suprahyoid approach which was not only technically difficult but also ridden with its associated morbidities. The microscopic laser assisted approach was then developed as one of the first minimally invasive techniques. However, due to poor post-operative pain results and tongue function, the method was mostly abandoned.5 The need for improved surgical visualization of the base of tongue served as a catalyst for the use of endoscopes.
Endoscopic-assisted coblation lingual tonsillectomy was first used in a pediatric population in 2009. The study conducted by Lin et al. showed that endoscopic assisted lingual tonsillectomy was both safe and efficacious in children, reporting a significant decrease in the mean obstructive apnea index of 26 children after surgery (18.1 versus 2.2 events/hour).3 Notable advantages of this surgery include an improved surgical field with either a 30 or 70 degree endoscope, the coblator’s low thermal energy, and ease of achieving hemostasis. The patient set-up varies from surgeon to surgeon. To first gain access to the oropharynx, we used a Crowe-Davis mouth gag to open the mouth and secure the retracted tongue beyond the tooth line. A 30 degree endoscope was held in one hand while the coblator was used in the other. Proper visualization was achieved once the epiglottis, palatine tonsils, and edge of the circumvallate papillae were identified. Coblation of the lingual and palatine tonsils was performed until the obstructive tissue was removed. One of the major disadvantages of this technique is that because the procedure is ablative, no specimen can be delivered. The operation overall is well-tolerated, with low post-operative pain profiles and an earlier start to tolerating a regular diet.
With transoral robotic surgery gaining momentum in the field oropharyngeal cancer, it was not until 2010 when TORS was first used for the treatment of persistent OSA.5 The set-up of the robot depends on its particular system and mouth gag used. The three-dimensional camera allows for improved visualization of the surgical field, making it easier to discern tissue planes at any angle. The robotic arms also allow for two working hands with greater range of motion to manipulate and reduce base of tongue tissue. In the presented, a more precise and deep excision was accomplished. A study by H.S Lin et al in 2013 evaluated the efficacy of TORS on 12 patients with base of tongue obstruction alone and showed statistically significant improvements in OSA symptoms based on mean Epworth Sleepiness Scale (13.7 ± 5.2 vs 6.4 ± 4.5, P <0.001), mean apnea-hypopnea index (43.9 ± 41.1 vs 17.6 ± 16.2, P =0.007), and snoring intensity.7 A systematic review of TORS base of tongue reductions in adults by Miller et al. in 2016 echoed Lin et. al’s findings, reporting a surgical success rate of 68.4 percent.8 Drawbacks of TORS in these studies include increased operating time due to prolonged set-up, higher costs of operating the robot, and reduced access to robotic technology.
When comparing the two, a retrospective review of 33 cases (16 TORS vs 17 Coblation) by Wei-Che et al. in 2019 revealed that there were no statistically significant differences between TORS and coblation in regards to AHI (24.9 ± 26.5 events/h vs. 19.4 ± 24.8 events/h respectively, p=.631), ESS (3.8 ± 6.6 vs. 3.1 ± 9.2, respectively, p = .873), and complication rate (50% vs 35.3% respectively, p=.393). TORS patients did have a statistically significant longer stay in the hospital compared to those who underwent coblation (5.5 ± 1.2 vs. 4.4 ± 0.7 respectively, p=.004).9
In conclusion, both endoscopic and transoral robotic surgical approaches are promising for treatment of persistent OSA in the pediatric population, provide sufficient surgical field visualization and manipulation of the base of tongue. Though TORS is efficacious because it offers a better range of motion and the ability to use a second working hand, its access is limited thereby keeping endoscopic approaches highly utilized. Further investigation of these techniques is warranted in the pediatric population.
Thank you to Dr. Mehta and Dr. Duvvuri for providing footage of their endoscopic assisted coblation and TORS resection.
1. Marcus, C. L., Brooks, L. J., Draper, K. A., Gozal, D., Halbower, A. C., Jones, J., … Shiffman, R. N. (2012). Diagnosis and management of childhood obstructive sleep apnea syndrome. Pediatrics. https://doi.org/10.1542/peds.2012-1671
2. Marcus, C. L., Moore, R. H., Rosen, C. L., Giordani, B., Garetz, S. L., Taylor, H. G., … Redline, S. (2013). A randomized trial of adenotonsillectomy for childhood sleep apnea. New England Journal of Medicine. https://doi.org/10.1056/NEJMoa1215881
3. Lin, A. C., & Koltai, P. J. (2009). Persistent pediatric obstructive sleep apnea and lingual tonsillectomy. Otolaryngology - Head and Neck Surgery. https://doi.org/10.1016/j.otohns.2009.03.011
4. Leitzbach, S. U., Bodlaj, R., Maurer, J. T., Hörmann, K., & Stuck, B. A. (2014). Safety of cold ablation (coblation) in the treatment of tonsillar hypertrophy of the tongue base. European Archives of Oto-Rhino-Laryngology. https://doi.org/10.1007/s00405-013-2845
5. Vicini, C., Dallan, I., Canzi, P., Frassineti, S., La Pietra, M. G., & Montevecchi, F. (2010). Transoral robotic tongue base resection in obstructive sleep apnoea-hypopnoea syndrome: A preliminary report. ORL. https://doi.org/10.1159/000284352
6. Lee, E. J., and Cho J. H. “Meta‐Analysis of Obstruction Site Observed with Drug‐Induced Sleep Endoscopy in Patients with Obstructive Sleep Apnea.” The Laryngoscope, vol. 129, no. 5, 2019, pp. 1235–1243., doi:10.1002/lary.27320.
7. Lin, H. S., Rowley, J. A., Badr, M. S., Folbe, A. J., Yoo, G. H., Victor, L., … Chen, W. (2013). Transoral robotic surgery for treatment of obstructive sleep apnea-hypopnea syndrome. Laryngoscope. https://doi.org/10.1002/lary.23913
8. Miller, S. C., Nguyen, S. A., Ong, A. A., & Gillespie, M. B. (2017). Transoral robotic base of tongue reduction for obstructive sleep apnea: A systematic review and meta-analysis. Laryngoscope. https://doi.org/10.1002/lary.26060
9. Lan, Wei-Che, et al. “Trans-Oral Robotic Surgery versus Coblation Tongue Base Reduction for Obstructive Sleep Apnea Syndrome.” PeerJ, vol. 7, 2019, doi:10.7717/peerj.7812.