1
Introduction
The importance of lingual tonsil hypertrophy has long been recognized as a significant factor in obstructive sleep apnea (OSA), but only recently with the advent of transoral robotic surgery (TORS) do sleep surgeons have a tool that can effectively and safely manage this pathology in the retrolingual region. Friedman and Myung Sung have recently provided details of lingual tonsil hypertrophy, including practical classification systems.
2
Indication and Contraindication
In our experience massive and diffuse lingual tonsil hypertrophy requiring a wide lingual tonsillectomy is associated with more favorable outcomes. Lingual tonsil hypertrophy phenotypes allow the surgeon to remove a significant amount of obstructing tissue with minimal morbidity and without violation of the underlying muscle. Lingual tonsil volume is a reliable prognostic index. The best candidates for TORS, especially for the novice surgeon, are those patients with localized, low (within the epiglottic valleculas area), lymphoid tongue base obstruction (the triple-L). A complete history, head and neck physical examination, upper airway flexible endoscopy, and drug-induced sedated endoscopy (DISE) are mandatory in the clinical approach to any patient with OSA being considered for robotic surgery. The initial office encounter will provide crucial information, including patient expectations, polysomnography results, subjective measures of daytime fatigue, and swallowing function, as well as anatomic characteristics such as lymphoid tissue hypertrophy, muscular tongue hypertrophy, elongated or narrow palate, and nasal obstruction. These data are integrated and provide both the patient and surgeon confidence in deciding to offer TORS multilevel surgery or, alternatively, to suggest other treatments both operative and nonoperative.
There are several important contraindications to TORS tongue base reduction (TBR). Surgery should not be offered to patients who are successfully treated nonoperatively. Other contraindications include comorbidities that result in an American Society of Anesthesiologists score >2 or that would suggest that sleep surgery not be performed, such as significant or unstable cardiovascular disease, progressive neuromuscular disease, need for anticoagulation, significant psychological instability, etc. Local contraindications to the procedure include the oral and neck anatomic constraints enumerated previously. Significant micrognathia and macroglossia (with high modified Mallampati–Friedman scores) can limit exposure for TORS procedures, though we have operated on many such patients successfully.
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Alternative Treatment Options
The unsurpassed visualization, dexterity, and control provided by the Da Vinci Surgical System offers the following benefits for the surgeon: superior exposure and three-dimensional (3-D) high-definition visualization of the target anatomy inside the pharynx, more precise dissection and improved preservation of intralingual vessels and nerves, shorter learning curve, faster operative time, and a more reproducible approach compared with traditional open as well as endoscopic techniques. One of the most important advantages is the possibility to perform blunt dissection in the muscular tissue, as well as an easier dissection of the lateral areas of the tongue base compared with the other endoscopic techniques. It also offers significant patient benefits: excellent cosmetic outcomes, no neck scars (except for tracheostomy, if necessary), reduced likelihood of iatrogenic injury to vessels and nerves, better and faster functional recovery compared with the transcervical approach, reduced operating room time, and shortened length of hospital stay.
4
Anesthesia
TORS TBR is performed under general anesthesia. The surgical team must be prepared for a difficult intubation, which could require the use of specialized instrumentation, such as a fiber-optic endoscope, GlideScope, light wand, etc. Extended anesthesia respiratory circuitry is necessary, as the anesthesiologist is stationed at the foot of the bed. This allows for the surgical assistant to sit at the head of the bed without interference and allows for the da Vinci Vision cart and patient cart to be positioned along the sides of the patient’s head as described for other TORS procedures. In Europe it is more customary to perform a tracheostomy immediately after intubation for lingual TORS surgery. This is not routinely advocated in the United States, and the surgery is done either via orotracheal or nasotracheal intubation with a small-caliber endotracheal tube. If a tracheostomy is thought to be indicated at the conclusion of the TORS procedure because of potential bleeding or airway edema, a tracheotomy can be performed at that point. Intravenous steroids are given to minimize lingual edema and for nausea prevention, and intravenous broad-spectrum antibiotics are infused preoperatively per hospital protocol or surgeon preference.
5
Technique
The patient is positioned supine in the sniffing position (neck flexed and head extended) to achieve the best exposure. Tongue base exposure is achieved in the standard TORS approach with a combination of tongue tip traction (with a 0 silk stitch horizontal mattress suture) and tongue body displacement by Storz and a Davis Meyer mouth gag (or other different mouth gags) under direct visualization by a head lamp. Repositioning of the tongue blade during the resection is rarely necessary. The 12-mm, 30-degree 3-D scope (upward facing) is our preferred choice. Only two robotic 5-mm Endo Wrist devices are routinely used for each patient: a Maryland dissector for grasping and dissecting tissues and a monopolar cautery with a spatula tip for dissection and coagulation. Surgical clip placement is usually not required, but in special cases clipping of large vessels may prove to be very helpful. A bipolar Dessi (Microfrance) coagulating device originally studied for sinus surgery may be helpful. The bedside assistant provides two additional suction devices (Lawton suction Cat. 160274 and/or Medicon suction Cat. 098508), which can be used for retraction and the evacuation of smoke and blood ( Fig. 55.1 ).
