Transoral robotic surgery (TORS) enables head and neck surgeons to safely extirpate oropharyngeal tumors that were previously inaccessible without utility of traditional approaches involving a lip-split incision and mandibulotomy.1–5 The primary advantage of this approach compared to traditional open approaches is decreased morbidity for patients,6, 7 with faster return of swallowing function, decreased blood loss, and improved cosmesis. For TORS resections of small oropharyngeal tumors, wounds are allowed to heal secondarily or closed primarily. This does not affect deglutition or speech function, as the defect size is relatively limited, and scar formation is limited. For larger resections of the base of tongue, lateral oropharyngeal wall, and soft palate, as well coverage over the carotid artery following transoral robotic resection soft tissue, reconstruction is essential.
Free tissue transfer has been utilized successfully over the last 20 years for head and neck reconstruction of complex defects, such as oropharyngeal defects. The objective of this work is to describe the reconstruction of oropharyngeal defects utilizing transoral robotic surgery to inset free flaps, a relatively new technique.8 The primary advantages of this approach are avoidance of the standard lip-split, mandibulotomy approach, and improved functional results after large oropharyngeal resections utilizing TORS techniques.
MATERIALS AND METHODS
Patients undergoing TORS procedures who will undergo free-flap reconstruction will have neck dissections and tracheostomy performed in the same setting, as well as a nasogastric feeding tube placement. Free-flap harvest is performed simultaneous during the neck dissection, after the completion of the transoral resection of the oropharynx with the DaVinci S-Robot (Intuitive Surgical Inc., Sunnyvale, CA). The oropharyngeal defect is exposed by placing an Feyh-Kastenbauer (FK) retractor (Gyrus ENT, LLC, Bartlett, TN) with appropriate tongue blade, refer to Figure 1. Due to its thin structure and pliability, and long pedicle, the radial forearm free flap is utilized for the oropharyngeal reconstruction. However, anterolateral thigh free flap can also be utilized, but has the disadvantage of having more bulk. Figure 2 illustrates the resection specimen from a tongue resection that includes a portion of right oral tongue, with half of base of tongue, and lateral oropharyngectomy including resection of half of the soft palate. For this case the flap pedicle is inserted into the mouth and passed into the neck defect via a 1-inch pen rose drain, as illustrated in Figure 3. The flap is temporarily secured intraorally with one or two 2-0 silk sutures once appropriate orientation for the flap is established. It is critical to establish the orientation prior to microanastamosis of the flap vessels to avoid twisting or kinking of the flap vessels. After the microanastamoses are performed in the neck utilizing loupe magnification or a surgical microscope, the DaVinci S-Robot (Intuitive Surgical Inc.) is brought into the field to perform the skin paddle inset into the oropharynx. Either a 0° or 30° camera can be utilized depending on the visualization required. For base of tongue or inferior oropharyngeal regions a 30° scope is helpful, but for soft palate and tonsillar fossa a 0° scope is more appropriate. The two robotic arms are equipped with 5-mm PN 400117/420117 needle drivers (Intuitive Surgical Inc.). The flap is inset with horizontal mattress 3-0 Vicryl (Ethicon, Somerville, NJ) suture on an RB-1 needle (please refer to the attached video). The advantage of the RB-1 needle is that its curvature and size make it ideal for suturing in limited space conditions. Figure 4 shows a radial forearm flap utilized to reconstruction the right tonsillar fossa, base of tongue, and a portion of the soft palate.
Transoral robotic free-flap reconstruction was successfully performed in four patients, and pertinent data are summarized in Table I. All the free-flap were successful. Three flaps were radial forearm, and one patient due to his occupation requiring delicate hand work, underwent a free vastus lateralis free flap as the skin paddle for the anterolateral thigh flap would have been too bulky for the oropharyngeal reconstruction. Complications noted in this cohort included a minor dehiscence along the anterior tonsillar pillar in a radial forearm, which healed secondarily without sequela. One patient developed a neck infection on the ipsilateral side of the flap that was treated with intravenous antibiotics. There were no fistulas, and three out of four have are taking diet by mouth 2-4 weeks post op. One patient is dependent on feeding but less than one month from finishing chemoradiation, and is currently working with speech therapy for swallowing rehabilitation.
Vastus lateralis muscle
Right oral tongue and base of tongue
Right tonsil, base of tongue, and oral tongue
Transoral robotic surgery has enabled head and neck surgeons access to difficult to reach places in the oropharynx. With more complex resections, the ability to reconstruct three-dimensional volume, and create a water tight closure becomes paramount for optimal swallowing and speech functions. Furthermore, neck dissections can be performed with decreased risk of salivary fistula into the neck, thus saving the patient a second surgery for planned neck dissections. The same precision of movement, and excellent visualization afforded by robotic surgery for cancer resection in the oropharynx, can also be utilized to inset free flaps in the oropharynx. Currently the indications for free tissue reconstruction of the oropharynx for transoral robotic surgery include: carotid exposure, base of tongue defects greater than 50% of the base tongue, soft palate defects that cannot be close primarily or with local flap reconstruction, and defects involving a large portion of the soft palate, tonsillar fossa, and base of tongue.