Transoral Robotic Surgery (TORS) Excision of a Base of Tongue Venolymphatic Malformation in a Pediatric Patient

Procedure: Transoral Robotic Surgery (TORS) Excision of a Base of Tongue Venous Malformation Introduction: TORS has been utilized sparingly in pediatric airway surgery since its introduction in 2007. Here we present the first documented case of complete TORS excision of a base of tongue venolymphatic malformation in a pediatric patient. Materials and Methods: A 6-year-old boy presented with a bluish mass at the base of tongue that was visible transorally and was consistent with a large venolymphatic malformation on flexible laryngoscopy and MRI. He was recommended to undergo pre-operative embolization followed by TORS excision of the lesion. During robotic surgery, the oral cavity can be exposed using a Feyh-Kastenbauer (FK), Dingman, McIvor, or Crowe-Davis retractor depending on the location of the lesion and the patient’s anatomy. The da Vinci Xi robot is docked in with a 30-degree rigid endoscope. Robotic Bovie monopolar cautery and Maryland Bipolar Forceps are used. Once adequate 3-dimensional visualization is obtained, the mass can be grasped, retracted, and dissected off of the base of tongue using the monopolar cautery. An assistant surgeon at the patient’s head facilitates visualization and manipulation of the tissue and ensures that the robotic arms are in good position to avoid any accidental trauma. Results: In collaboration with our institution’s Vascular Anomalies Clinic, interventional radiology was consulted and recommended a preoperative glue embolization to facilitate a more bloodless excision. The patient underwent successful pre-operative embolization followed by transoral robotic resection of the mass with a da Vinci Xi robot. The surgery and post-operative period were uncomplicated—he healed well, required minimal pain medication, and was able to tolerate a regular diet with no signs or symptoms of aspiration. Pathology was consistent with a venolymphatic malformation. Conclusion: TORS is a useful and minimally invasive option for the resection of benign base of tongue lesions in the pediatric population. For vascular lesions, pre-operative embolization can help minimize surgical risk.

Since 2007, Transoral Robotic Surgery has provided head and neck surgeons with a tool to perform surgeries with a high level of dexterity and precision in difficult to access locations. These include the oropharynx, hypopharynx, and larynx.  The use of TORS is a relatively recent development in pediatric airway surgery.  Rahbar et al. published the initial case series consisting of 5 attempted and 2 successful laryngeal cleft repairs (Rahbar).  Since that time, numerous case reports and series have demonstrated both the feasibility and safety of TORS as a modality for pediatric airway surgery (Erkul). Venous malformations (VM) are slow growing, low-flow vascular anomalies consisting of ectatic venous channels lacking in smooth muscle.  In the head and neck, VM can cause a wide range of symptoms such as cosmetic disfigurement, functional loss, sleep apnea, and airway obstruction. Treatment options include sclerotherapy, Nd:YAG laser ablation, and complete surgical excision.  The use of surgical excision is ideal when dealing with localized disease as it provides durable treatment with a low rate of recurrence. However, the risk of intraoperative bleeding must be managed in these cases (Richter). This video demonstrates the first reported case of TORS excision of a base of tongue venolymphatic malformation in a pediatric patient.  A multidisciplinary approach with pre-operative embolization on the day of surgery was utilized to minimize intraoperative blood loss and maximize intraoperative tissue handling.

A 6-year-old male presented to the Emergency Department with a bluish mass in his pharynx that his mother noticed incidentally in the setting of a streptococcal pharyngitis. At the time of presentation, he denied any symptoms related to the mass including dysphagia, odynophagia, or difficulty breathing. Flexible laryngoscopy was notable for a large, pedunculated, lobulated mass with bluish discoloration at the base of the tongue that obscured the vallecula and caused retroflexion of the epiglottis. The larynx was unobstructed and the vocal cords were noted to be mobile bilaterally. A magnetic resonance imaging (MRI) scan demonstrated a lobulated mass at the base of tongue measuring 2.6 cm by 3.3 cm by 2.7 cm that contained areas of enhancement on T2 weighted images anteriorly, a smaller, non-enhancing posterior component, and fluid-fluid levels consistent with a mixed venolymphatic malformation, but the lesion was predominantly venous. No definitive enlarged feeding vessels were identified. At the patient’s follow up appointment, his mother noted the development of new onset snoring. Given the new symptoms and the localized nature of the mass, the decision was made to proceed with TORS excision. Preoperative consultation with interventional radiology through our multidisciplinary Vascular Lesion Clinic was obtained. Interventional radiology recommended pre-operative glue embolization to reduce intraoperative blood loss and enhance intraoperative tissue handling. Therefore, on the day of the planned resection, Interventional radiology (IR) obtained direct access into the midline base of tongue lesion percutaneously through the floor of mouth. Intralesional angiography was performed followed by embolization with 1 in 6 N-butyl cyanoacrylate (NBCA)/lipiodol (radio-opaque). IR was able to glue embolize the anterior 80% of the lesion; the posterior 20%, corresponding to the non-enhancing aspect of the lesion on MRI, was noted to be too low flow to be effectively embolized. The patient was then taken directly to the operating room for excision of the lesion, which is demonstrated in the video. Age and weight appropriate doses of Ancef and Decadron were administered. The maxillary and mandibular teeth were protected with customized Aquaplast splints. The tongue was retracted anteriorly with a silk retraction suture and a Crowe-Davis mouth gag was placed. The mouth gag was placed in suspension and the da Vinci Xi robot (Intuitive Surgical, Sunnyvale, CA) was brought into the field and docked with the patient. We utilized the following robotic instruments to visualize and resect the lesion: a 30-degree endoscope, monopolar Bovie electrocautery, and a Maryland bipolar dissector. The primary surgeon controlled the instruments via the robotic console. An assistant surgeon—who was positioned at the patient’s head—assisted the primary surgeon with direct tasks, such as suctioning and retracting with a Hurd elevator. Once adequate 3-dimensional visualization was obtained, the mass was grasped, retracted posteriorly, and dissected off of the tongue base in a circumferential manner with Bovie monopolar electrocautery. A broad base of attachment was noted along the base of tongue down into the vallecula.  A combination of monopolar and bipolar electrocautery was used throughout the procedure for hemostasis. The mass was retracted anteriorly and was noted to involve the mucosa of the lingual surface of the epiglottis. This mucosa was dissected off of the underlying epiglottic cartilage with the Maryland Bipolar Forceps. Monopolar cautery was again used to truncate the mass from its remaining attachments to the base of tongue. Bleeding was minimal throughout the case owing to the preoperative embolization. The wound bed was irrigated and meticulous hemostasis was achieved. The mass was sent to pathology and was confirmed to be a venolymphatic malformation. The patient was awoken from anesthesia, extubated in the operating room, and transferred to the post-anesthesia care unit (PACU) in stable condition. He was started on a soft diet and pain was controlled with acetaminophen and ibuprofen with opioids for breakthrough pain. He was discharged home on post-operative day 1.

This video demonstrates successful TORS excision of a large, midline, base of tongue venolymphatic malformation after pre-operative embolization in a pediatric patient. On post-operative day 8, he was seen in clinic and had returned to his baseline state of health with no subjective complaints. Flexible laryngoscopy demonstrated a white eschar consistent with normal post-operative healing.

The use of robotic surgery has increased dramatically since its initial introduction in the 1990s. While pediatric robotic surgery initially began in 2001, its introduction in the head and neck began in 2007 (Meininger, Rahbar). To date, the literature on pediatric TORS is scant, consisting of case series and case reports, the largest of which is 16 patients (Zdanski, Erkul). Such data has focused on the feasibility of using such technology, along with parameters such as safety and efficiency, while also attempting to increase the types of procedures and pathologies that can be addressed with his technology. The majority of these procedures fall into one of two categories: laryngeal cleft repairs or base of tongue procedures, such as lingual tonsillectomy, for the treatment of OSA (Rahbar, Erkul). Currently, there are concerns that limited access may prevent the successful and complete excision of base of tongue or supraglottic masses utilizing this technique. However, TORS has been successfully utilized to remove lingual thyroglossal duct cysts in patients as young as 2 months as well as a saccular cyst, oropharyngeal sarcoma, base of tongue hamartoma, and recently, 3 hypopharyngeal and supraglottic lymphatic malformations (Kayhan, Zdanski, Erkul). To date, there is one published report of a TORS excision of a lymphatic malformation of the base of tongue (Zdanski). Here we report the first complete TORS excision of a venolymphatic malformation of the base of tongue. Utilizing this technology, the surgeon was able to obtain a three-dimensional, magnified view of the lesion and achieve a complete resection via a minimally invasive approach. The success of the surgery was also dependent on the multidisciplinary collaboration with the expertise of the interventional radiology team. Blood loss, operative time, overall morbidity, and hospital length of stay were minimized by utilizing pre-operative embolization. Venous malformations are a type of vascular anomaly that consist solely of aberrant, ectatic venous channels (Richter). They have a characteristic appearance on physical exam of a bluish, compressible mass that enlarges with maneuvers that increase hydrostatic pressure such as Valsalva (Johnson). Due to their slow flow state, they also form pathognomonic phleboliths—or calcified thrombi—that can lead to pain, or in rare cases, distal emboli (Richter). While they can remain asymptomatic, VM can cause symptoms due expansion from venous congestion and elastic vascular expansion, or from pain caused by phleboliths that form within the vascular channels. In more serious cases, large head and neck lesions can lead to functional loss, obstructive sleep apnea, airway obstruction, or significant thrombosis with distal emboli. MRI is the most valuable imaging modality as it is used for both diagnosis and treatment planning (Konez). Treatment options for venous malformations include 3 different modalities: surgery, laser therapy, and sclerotherapy (Richter). Multiple rounds of treatment, and a combination of approaches, may be necessary to treat large or multifocal disease. While each therapy has its advantages, there are disadvantages to non-surgical therapy. Complications can arise due to the side effects of sclerosing agents, including neuropathy and tissue necrosis (Castren). Additionally, post-operative swelling can be seen after the use of sclerosants, which can be especially dangerous in the pediatric airway where even a small degree of swelling can lead to airway compromise (Rabe). Laser therapy can also cause nearby nerve injury and often requires multiple treatments in order to achieve significant reduction of disease burden (Richter). Surgery can limit these complications and has the advantage of delivering a complete cure when full resection is achieved; however, it is often not feasible in the airway due to limited access. In this case, the utilization of TORS helped provide excellent visualization of the lesion, instrument access, and allowed for a complete resection of the lesion. Robotic surgery is currently not approved by the Food and Drug Administration (FDA) for use in children. Therefore, careful informed consent with an explanation of the risks, benefits, and off-label use of the robot should be obtained from pediatric patients and their families when proposing the use of TORS. Surgical excision of complex vascular lesions remains difficult secondary to the potential for significant morbidity and thus requires a multidisciplinary approach. In the appropriate setting, TORS is a useful and minimally invasive option for the resection of benign base of tongue lesions in the pediatric population. Preoperative embolization can be used prior to excision to decrease blood loss, surgical risk, and post-operative morbidity.

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Thank you to Dr. Johnston and Dr. Daram for providing footage of their TORS resection.

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