Pediatric transoral robotic surgery has advantages over traditional endoscopic or open approaches as shown in this text. A wide variety of aerodigestive tract pathology is amenable to treatment via the robotic approach with full potential of the technology yet to demonstrated by future advances and experience.
23 Pediatric Transoral Robotic Surgery
Transoral robotic surgery (TORS) made its debut in the otolaryngology literature in 2005. As early as 2007, pediatric specific publications had appeared. 1 The potential advantages of TORS over other techniques includes improved 3D visualization of difficult to access sites, increased surgical agility and precision in tight anatomical spaces, decreased morbidity by avoiding external incisions, and reduced surgical time in certain cases. TORS also offers an opportunity for a supervising surgeon to offer real-time and on-screen guidance to the operating surgeon as demonstrated in this chapter. The main potential disadvantages of TORS relate to the expense of the equipment and the specialized training required of the surgeon and operative staff. Lack of tactile feedback for the surgeon working at the operating console and the addition of robot positioning time are also cited as potential disadvantages. In the authors’ experience, lack of haptics does not outweigh the other advantages and time spent on setup becomes negligible with proficiency. It is interesting to note that whereas adult TORS is often applied to malignant lesions, pediatric cases are most often directed toward benign congenital or acquired lesions of the aerodigestive tract. Some of the most commonly cited indications include laryngeal cleft repair, laryngoplasty, tongue base reduction, and pharyngeal stenosis or other benign lesions such as saccular cyst or lymphangiomas. Several authors have reported on the safety and efficacy of pediatric TORS while also reporting a very low incidence of conversion to traditional techniques. 2 , 3 These experiences make the application of robotics in pediatric head and neck surgery an innovation whose full potential is yet be seen. This chapter is intended to provide an overview of pediatric transoral surgery and should not be used as a substitute to formal robotic training and proctored cases as required by some facilities.
23.2 Preoperative Evaluation and Anesthesia
The preoperative assessment of robotic cases is similar to that of any head and neck procedure, with emphasis on reviewing previous operative reports detailing ease of transoral exposure and visualization of the different subsites. Imaging studies should be thoroughly reviewed. Communication with operating room staff and anesthesia providers is done before the patient is brought to the robotic operating theater. The patient is placed in supine position with enough space underneath the head of bed in order to accommodate placement of the robot’s base underneath the operating table. Depending on the operative table, this may require the patient’s head to be placed on the “foot side” of the table or simply rotating the head of the bed 90 degrees (▶ Fig. 23.1).
Anesthesia under spontaneous respiration with a native airway is requested for the initiation of procedures. We generally request that an experienced pediatric anesthesia provider perform a direct laryngoscopy and apply 2% lidocaine to the larynx in preparation for a planning endoscopy by the surgeon. After the airway is evaluated and secured to the team’s satisfaction, neuromuscular paralysis for the length of time the robot is docked near the patient should be strongly considered. We typically administer intraoperative dexamethasone in non-tracheostomy-dependent children to reduce airway edema that occurs with surgery.
23.3 Exposure, Setup, and Instrumentation
After induction of anesthesia, the operating table is turned 90 degrees toward the surgeons to optimize access to the airway. The surgeon performs a video direct laryngoscopy and bronchoscopy and secures the airway as described below. We use a custom maxillary tooth guard that is rapidly molded for the patient utilizing Aquaplast (Medline, Mundelein, IL). Exposure is individualized based on the child’s airway and the lesion in question. In neonates, it is possible to forgo use of a retractor or to employ a simple tongue stitch. In others, a McIvor oropharyngeal retractor with a flat tongue blade suspended onto a mustard stand will provide adequate exposure as distal as the larynx and proximal trachea (▶ Fig. 23.2). Given size limitations, the commonly used FK Retractor is used only for older, larger children. The robot’s base is docked underneath the patient’s head with the help of an assistant to ensure the patient is protected at all times. The articulating arms are positioned intraorally with either a 30-degree anterior facing telescope or a 0-degree telescope depending on which gives the best exposure with the least interference with the robotic arms (▶ Fig. 23.3). A bedside, robotics trained surgeon is assigned to provide additional instrumentation (i.e., suction, cautery, assistance with suturing) and directly oversee the patient’s airway and safety during the procedure (▶ Fig. 23.4).
The airway can be secured through a variety of ways for pediatric robotic cases. The patient can be intubated either transnasally or transorrally. The endotracheal tube can be tucked underneath the tongue blade for improved access to the posterior larynx as will be shown below. Standard laser safety precautions including a laser safe endotracheal tube and fraction of inspired oxygen less than 40% are utilized to reduce the risk of airway fire. A preexisting tracheostomy tube naturally simplifies management of the airway; however, the tube must be exchanged with either a laser safe tube or a metallic tracheostomy tube for laser cases. If an air leak occurs around the ventilation tube or tracheostomy tube we routinely pack the area of the subglottis with moist pledgets. A silicone catheter may also be placed in the pharynx and attached to suction to help prevent scope fogging. In addition to pledget safety sutures, optical forceps are prepared in case the pledgets become dislodged into the lower airway. A carbon dioxide (CO2) laser delivered via fiber is our preference for cases requiring laser, although the robotic cautery arm may be employed for hemostatic dissection as well.
23.4 Select Cases in Pediatric Robotic Surgery
23.4.1 Laryngeal Cleft Repair
A laryngeal cleft (LC) is a congenital defect of the posterior larynx with a wide spectrum of anatomical presentations. Patient symptoms may similarly vary from asymptomatic to oral feeding intolerance due to aspiration in severe cases. The Benjamin and Inglis classification system is the most commonly used grading scheme. 4 Grades 1 and 2 are defects that have traditionally been considered as amenable to repair via a transoral technique (▶ Fig. 23.5). The technique involves application of sutures to close the cleft within the tight confines of a pediatric endolarynx. For this reason, we have found the added agility and visualization of TORS to be useful in these cases.
The patient is setup in a similar fashion as previously described with a McIvor retractor and laser safe tube. We begin by creating raw opposing surfaces by excising either side of the cleft with a CO2 laser deployed via a fiber sheath manipulated with a robotic needle driver. The robotic Maryland retractor or needle driver on the non-laser robotic arm is used to provide traction to facilitate dissection (▶ Fig. 23.6). The cleft is then closed in three layers with dissolvable sutures (▶ Fig. 23.7 and ▶ Fig. 23.8). Postoperatively, the patient is extubated and allowed to resume regular oral intake after appropriate recovery from anesthesia. A follow-up modified barium swallow study is typically performed 3 to 4 weeks later as an outpatient. The patient is typically observed overnight in a monitored bed prior to discharge home.