Introduction
Transoral robotic surgery (TORS) has evolved from the endeavor of head and neck surgeons to perform minimally invasive targeted resection of lesions of the upper aerodigestive tract. Transoral resection of oral, oropharyngeal, hypopharyngeal, and laryngeal lesions has been performed from the 1800s. It has evolved from techniques initially crude to increasingly sophisticated headlights, the use of binocular loupes for magnification, and then to the use of microscopes and endoscopes. Technological advances with fiberoptics and light sources have improved visual access, and the use of LASER and other electrosurgical energy devices has improved resection capabilities.
The introduction of surgical robotic platforms has provided an ideal opportunity for transoral surgery with the availability of excellent illumination and a magnified, binocular three-dimensional visual access to the upper aerodigestive tract. Wristed surgical instruments deployed on slender arms allow exceptional surgical access. Telepresence surgery allows a surgeon at a console to conduct an operator-robot relationship to surgical arms deployed at a distal surgical cart placed by the patient bedside. This allows the surgeon to control at least two surgical arms, and allows a surgical assistant at the head end of the patient to deploy two other instruments and an assistant nurse to deploy a sucker, in effect having the ability to utilize five instruments transorally, simultaneously.
TORS has been applied to a range of surgical pathologies. The most common application has been in the treatment of oropharyngeal cancer, especially early tonsil cancer and tongue base cancer. It has also been used for hypopharyngeal cancer resection and for supraglottic partial laryngectomy, vertical partial laryngectomy, and total laryngectomy. TORS has an increasing role in the management of sleep disordered breathing and its application has been extended to resection of parapharyngeal space tumors and transpalatal approaches to the nasopharynx. Robot assisted surgery for neck dissection and thyroidectomy has also been performed.
General principles
TORS has made a significant impact on the management of early oropharyngeal cancer which has become an increasingly prevalent upper aerodigestive tract malignancy. The concept is to perform a targeted compartmentalized resection, ensuring clear margins and safely avoiding the vital neurovasculature structures that lie adjacent to the upper aerodigestive tract.
Preoperative assessment
History and examination
It is important to know the smoking habits of the patient as it provides risk stratification. Trismus, referred otalgia, and the fixity of any involved neck nodes to the primary tumor determine access and resectability.
Multiplanar imaging with computer tomography (CT) ± magnetic resonance imaging (MRI) provides vital information about the relationship of the tumor to:
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Vascular structures, including the internal and external carotid artery and its branches
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The styloglossus muscle
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The posterior belly of digastric
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Deep lobe of submandibular gland
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Mandible
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Extra capsular nodal spread
CT-PET scan defines:
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Distant metastases
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Contralateral tonsil or tongue base cancers
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Contralateral neck nodes
Examination under anesthesia and panendoscopy is performed ( Fig. 42.1 ) to:
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Determine mobility of the primary tumor from neck nodes and neurovascular structures
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Ensure that the tumor can be medialized from the pterygomandibular raphe
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Ensure TORS access
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TRISMUS (Jaw)
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Teeth
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Occlusion
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Transverse width of jaw
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TILT (Neck)
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Anterior larynx
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Circumference of neck
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Thyromental distance
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Sternomental distance
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Mobility
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Flexion/extension
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Radiation fibrosis
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TONGUE (Oral cavity)
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Size
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View of fauces
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Tonsils/lingual tonsils
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Epiglottis/laryngopharynx
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TUMOR
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Size
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Mobility
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Multidisciplinary consultative head and neck clinic
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All patients are discussed at a multidisciplinary clinic to gain insights about the radiologic features of the tumor, histological features of the tumor, in particular, the p16 status as the surrogate marker of HPV positive disease. The clinic also considers alternative treatment options and plans allied health and nursing rehabilitation strategies with regard to speech and safe swallowing.
Preanesthetics clinical assessment and physician assessment for frailty
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Plan oral or nasotracheal intubation, or rarely tracheostomy
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Anesthetic guidelines for management of blood pressure and heart rate as per protocols for obstructive sleep apnea and functional endoscopic sinus surgery with low heart rate and mean arterial pressure of 100 mmHg.
Operating room setup
The operating room needs to be of generous proportions to accommodate the robotic surgical cart, if possible, two surgeon consoles, the anesthetic machine, and the theater instrument carts. TORS access is best attained with the surgical cart docked at an angle of 15 degrees to the patient bed ( Fig. 42.2 ). The surgeon sits at the console and the assistant surgeon sits at the head end of the bedside and can further utilize two transoral instruments such as microlaryngoscopy forceps or ligaclip applicators. The robot nurse assistant can provide suction with a Yankauer sucker, and this keeps the surgical “mist” free as well as clears any bleeding. The surgical cart is managed by a scout nurse, and the robot nurse assistant keeps a close eye to manage instrument clashes that can restrict surgery and clashes of the distal end of the instrument with teeth or soft tissue obstacles during surgery.
