The Combined Endonasal and Transoral Approach for the Management of Skull Base and Nasopharyngeal Pathology: a Case Series

Neurosurg Focus 37 (4):E2, 2014 ©AANS, 2014

The combined endonasal and transoral approach for the management of skull base and nasopharyngeal pathology: a case series

Satyan B. Sreenath, B.S.,1 Rounak B. Rawal, M.D.,1 and Adam M. Zanation, M.D.1,2 1Department of Otolaryngology—Head and Neck Surgery, and 2Department of Neurosurgery, University of North Carolina at Chapel Hill, North Carolina

The posterior skull base and the nasopharynx have historically represented technically difficult regions to approach surgically given their central anatomical locations. Through continued improvements in endoscopic instrumentation and technology, the expanded endonasal approach (EEA) has introduced a new array of surgical options in the management of pathology involving these anatomically complex areas. Similarly, the transoral robotic surgical (TORS) approach was introduced as a minimally invasive surgical option to approach tongue base, nasopharyngeal, parapharyngeal, and laryngeal lesions. Although both the EEA and the TORS approach have been extensively described as viable surgical options in managing nasopharyngeal and centrally located head and neck pathology, both endonasal and transoral techniques have inherent limitations. Given these limitations, several institutions have published feasibility studies with the combined EEA and TORS approaches for a variety of skull base and nasopharyngeal pathologies. In this article, the authors present their clinical experience with the combined endonasal and transoral approach through a case series presentation, and discuss advantages and limitations of this approach for surgical management of the middle and posterior skull base and nasopharynx. In addition, a presentation is included of a unique, simultaneous endonasal and transoral dissection of the nasopharynx through an innovative intraoperative setup. (http://thejns.org/doi/abs/10.3171/2014.7.FOCUS14353)

Key Words • combined endoscopic transoral approach • robotic • endonasal • skull base • nasopharynx

he posterior skull base and the nasopharynx have troduced a new array of surgical options in the manage- historically represented technically difficult re- ment of pathology involving this anatomically complex gions to approach surgically, given their central an- area. Neoplastic lesions of this area have been success- Tatomical locations. Traditional approaches to this region fully resected with favorable outcomes and adherence to include creation of an anterior transfacial corridor (Le oncological principles.1,7,8,32 However, the pure endonasal Fort I osteotomy, maxillary swing, and midface deglov- route can be inadequate for surgical management of pa- ing), lateral transcranial corridor (pre- and postauricular thology extending beyond the anatomical boundaries, infratemporal fossa and subtemporal approaches), and such as for extension below the level of the soft palate in inferior oral or cervical corridor (transcervical-transman- the oropharynx (Table 1). Given these limitations, several dibular or transpalatal approaches).2,6,15,18,21,30,37 Although institutions initially published studies on their clinical these approaches were previously frequently used, they and laboratory experience of combining both the EEA were also associated with high clinical morbidity and and nonrobotic transoral approach for a variety of patho- less than ideal cosmetic outcomes, which has greatly logical processes.10,12,14,16,17 decreased their use since the advent of the endoscopic, In our initial experience with this combined tech- minimally invasive era.6,18,23,27,32,35,36 nique, we successfully repaired oronasal fistulas and Through continued improvements in the Hopkins surgically managed chronic granulomatous disease, both rod-lens endoscope (Karl Storz) and endoscopic instru- of which required surgical access through the endonasal mentation, the expanded endonasal approach (EEA) in- and transoral corridors. By combining these windows, a larger operating corridor may be established to obtain Abbreviations used in this paper: CVJ = costovertebral junction; surgical margins during resection of neoplastic lesions, EEA = expanded endonasal approach; ICA = internal carotid artery; while minimizing displacement or dissection of normal TORS = transoral robotic surgery. tissue in the approach to the area of interest. Although

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TABLE 1: Advantages and limitations of the EEA and TORS approaches to the nasopharynx and skull base

Approach Advantages Limitations EEA improved cosmetic outcomes limited access below the soft palate direct visualization & minimal tissue displacement 2D endoscopic view angled endoscopic cameras & instrumentation limited lateral mobility & access TORS 3D imaging lack of bone-drilling equipment increased articulation with 3–4 robotic arms bulky robotic instrumentation ability to suture within the operative field steep learning curve this original, combined technique offered many advan- management of disease, which yielded 3 patients. All 3 tages to utilizing either surgical corridor separately, limi- patients exhibited distinct nasopharyngeal and skull base tations included significant reduction in simultaneous pathology. Data were collected regarding patient history, maneuverability given difficult intraoperative position- surgical indications, operative technique, and postopera- ing with reduced surgical manipulation and limited vi- tive outcomes. All surgical procedures were performed sion through the transoral route. These limitations were by the senior author (A.M.Z.). addressed with the introduction of the transoral robotic 38 surgery (TORS) approach. Case Reports Transoral robotic surgery using the da Vinci surgical system (Intuitive Surgical, Inc.) has been extensively Case 1 described in the literature for the management of middle cranial fossa skull base tumors, along with tongue History and Presentation. A 35-year-old woman with base, nasopharyngeal, parapharyngeal, and laryngeal le- a history of papillary thyroid carcinoma status post, fol- sions.4,9,13,19,22,24–26,34,38 Advantages of TORS include superior 3D visualization, increased instrument access, pre- cise and tremor-free 3-handed surgery, and elimination of external incisions, while limitations include the lack of bone-drilling equipment, relatively bulky instrumentation, and a steep initial learning curve.22,24,25,40 TORS has been shown to be highly effective in obtaining a direct, illuminated surgical window into the nasopharynx, allowing for surgical management of nasopharyngeal carcinomas and performance of complete nasopharyngectomy. 25,33,34 However, without the capacity for bone resection via drilling instrumentation, the pure TORS approach is limited to dissection of soft tissue and may be inadequate to manage involvement of the skull base at the basiocciput region superiorly or medial pterygoid later- ally (Table 1). Thus, the next logical step was to combine the EEA and the TORS approach for the greatest possible surgical window with the greatest degree of surgical manipulation (Fig. 1). In this case series, we present our clinical experience with the combined endonasal and transoral approach and discuss its advantages, limitations, and possible future prospects. We also include presentation of a unique, simultaneous endonasal and transoral dissection of the nasopharynx through an innovative intraoperative setup of the endoscopic endonasal and robotic surgical equipment.

Methods After Institutional Review Board approval, a retro- spective, consecutive review was performed to identify Fig. 1. Illustration of the anatomical corridor and boundaries in the patients who underwent the combined endoscopic en- EEA (blue triangle) and the TORS approach (yellow triangle) to the na- donasal and transoral robotic approaches for surgical sopharynx.

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Unauthenticated | Downloaded 10/09/21 05:12 PM UTC Combined endonasal and transoral approach lowing total thyroidectomy with left neck dissection, pre- section portion of the procedure. With the robot positioned sented with a metastatic 1.5 cm × 2.5–cm retropharyngeal at the head of the bed, the articulating arms were fixed space lesion on routine surveillance MRI with contrast with a 30° endoscope, Maryland forceps, and monopolar administration. It was also noted on MRI that the internal electrocautery (Fig. 3). With the use of the angled endo- carotid artery (ICA) was inferior and lateral to the mass, scope, the surgical view through the robotic system was demonstrating the superomedial location of the mass in directly over the lateral pharyngeal recess and parapha- the parapharyngeal space, abutting the nasopharyngeal ryngeal space with minimal tissue and palatal retraction. region (Fig. 2). Given the extent and location of the tumor, The remainder of the excision of the skull base proceeded it was determined that the mass would be resected via the through the TORS approach, which was advantageous combined endonasal and transoral approach, as exposure in meticulously dissecting the lesion away from the ICA. of the superolateral portion of the mass would not be fea- Upon completion of the resection, the tonsillar and pharyn- sible through a purely transoral route. geal mucosa were reapproximated using vicryl sutures to Intraoperative Technique. Intraoperatively, the CT- ensure closure of the parapharyngeal space and ensure its MRI guidance system was used for constant stereotactic integrity from the nasopharyngeal region, to minimize any localization of the parapharyngeal lesion. Once the nasal postoperative complications. cavity was decongested with Afrin pledgets and the oral Postoperative Course. At her immediate postopera- cavity was opened with the use of the McIvor mouth gag, tive visit, the patient exhibited temporary trismus, but no a radical tonsillectomy was performed with exposure of evidence of neuropathy, velopharyngeal insufficiency, or the peritonsillar region. With the use of electrocautery swallowing issues. At a 2-year routine clinical and radio- and blunt dissection through the transoral route, a lateral logical follow-up visit, she remained free of complica- pharyngectomy was performed with dissection of the tions and has experienced no recurrence of disease. pharyngeal constrictor muscles for adequate exposure. Through the endonasal route, the superolateral extensions Case 2 of the lesion were exposed through superior incisions in the lateral nasopharyngeal region, abutting the parapha- History and Presentation. An 87-year-old woman ryngeal recess. was referred to our institution for management of a na- Once exposure was adequately achieved, the da Vinci sopharyngeal mass, previously identified as a mucosal surgical system was used in the transoral route for the re- melanoma on biopsy at an outside institution. On imaging

Fig. 2. Case 1. Pre- and postoperative MRI of retropharyngeal metastasis of a papillary thyroid carcinoma. A and B: Preop- erative sagittal and axial images show a retropharyngeal metastatic mass involving the nasopharynx. The blue rectangles demonstrate the extent of the lesion and proximity to the skull base. C and D: Postoperative sagittal and axial images demonstrate complete resection of the lesion with the combined approach.

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to be positioned at the patient’s side for simultaneous endonasal work as needed (Fig. 5). A 30° endoscope, Bo- vie electrocautery, and Maryland retractor were affixed to the robotic arms, and a right radial tonsillectomy with a small, lateral palatal incision was performed through the transoral corridor for adequate exposure. Given the extensions of the tumor into the fossa of Rosenmüller and parapharyngeal space, a radical resection of the lateral pharyngeal wall was performed with robotic assistance, with surgical margins obtained from all mucosal margins. The parapharyngeal extent of the tumor was dis- sected in an en bloc fashion in the transoral window. Attention was then returned to the nasal cavity for resection of the nasopharyngeal and skull base component of the lesion. Initially, the torus tubarius was cut on its posterior aspect for surgical margins and the tumor was debulked in an en bloc fashion again. For the posteroinferior extension in the nasopharyngeal space, a modified “2-surgeon, 4-handed” technique was employed, where an additional Hopkins rod-lens endoscope was operated manually through the endonasal route while the robotic instruments were used in the transoral corridor to allow full dissection from the nasopharynx down to the oropharynx (Fig. 5). This 2-surgeon technique allows a full range of visualization of the region from both corridors, which affords an increased level of safety during the nasopharyngectomy. The mass was resected in its entirety while obtaining adequate surgical margins for staging purposes. Postoperative Course. Postoperatively, the patient did quite well with no evidence of velopharyngeal in- Fig. 3. Operative setup of the da Vinci surgical system robotic arms in the oral cavity. In this setup, the central arm consists of the endo- sufficiency, weak phonation, or dysphagia. From a sur- scopic camera with dissection equipment fitted to the lateral arms. By gical standpoint, the combined endonasal and transoral positioning the base of the robot at the foot of the table, the assisting approach was highly effective in managing the patient’s surgeon working in the nasal cavity can stand at the head of the bed. anatomically complex nasopharyngeal lesion.

Case 3 review of the lesion, MRI demonstrated a 1.5 cm × 2 cm mass just right of the midline in the nasopharyngeal re- History and Presentation. A 39-year-old man with a gion, with involvement of the torus tubarius and posterior longstanding history of intranasal narcotics and cocaine pharyngeal wall (Fig. 4). Given the borders of the tumor abuse presented with complaints of significant nasal con- with superior and inferior extensions to the skull base and gestion, chronic nasal drainage, and difficulty passing air the oropharynx, respectively, and in consideration of the through his nose. On sinonasal endoscopy, he was noted required surgical margins, a decision was made to surgi- to have a persistent, large septal perforation. Additionally, cally manage this lesion through the combined endonasal from the posterior ledge of the soft palate to the posterior and transoral approach with use of the da Vinci surgical nasopharyngeal wall, there was diffuse scarring result- system. ing in complete nasopharyngeal obstruction and oblitera- tion, believed to be due to intranasal drug abuse (Fig. 6A). Intraoperative Technique. First, exposure in the en- Advancing the endoscope into the oropharyngeal space, donasal corridor was obtained on the right side with a further scar tissue was noted surrounding the tonisllar total ethmoidectomy and a complete middle turbinate pillars. Given these findings, the patient was deemed an resection. Upon exposure, a 0° endoscope was used to ideal candidate for the combined endonasal and transoral visualize the lesion, which was just posterior to the naso- approach. pharyngeal orifice of the Eustachian tube. Attention was then turned to the TORS approach, which began with Intraoperative Technique. Once the nasal cavity was placement of the McIvor mouth gag retractor and use of decongested with Afrin pledgets and the oral cavity was a rubber catheter through the contralateral nasal passage opened with the use of the McIvor mouth gag, the robot to assist in retraction of the soft palate. Again, the robot was docked at the head of the bed with articulating arms, was stationed at the head of the bed with the articulat- parallel to the patient, fixed with a 30° endoscope, Mary- ing arms positioned parallel to the patient’s head. In this land forceps, and monopolar electrocautery (Fig. 3). The case, this operating setup allowed for a second surgeon transoral portion with robotic assistance proceeded first,

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Fig. 4. Case 2. Pre- and postoperative MRI of mucosal melanoma. A–C: Preoperative sagittal (A) and axial images (B) and sagittal CT scan (C) of mucosal melanoma involving the nasopharynx. The blue rectangles demonstrate the extent of the lesion and proximity to the skull base. D: Postoperative sagittal MR image demonstrating complete resection of the lesion with the combined approach. which consisted of using monopolar cautery to make inci- was attributed to nasal trumpet placement. Otherwise, sions in the oropharyngeal aspect of the scar tissue bilat- the patient demonstrated good air movement through his erally, allowing for removal of these scar bands (Fig. 6B). nose without further complications. Once these initial incisions were made, the nasal corridor was addressed, which involved completing the nasophar- Discussion yngectomy by extending the initial incisions superiorly (Fig. 6C). Scar bands posterior to the palatoglossal and With the advent of the endoscopic era and applica- palatopharyngeal arches were also incised posteriorly tion of the da Vinci robotic technology in the realm of the and superiorly to the nasopharyngeal wall, allowing mo- head and neck, surgical management of the nasopharynx bility of the soft palate. Lastly, in the transoral corridor, and posterior skull base is continually evolving (Fig. 8). the nasopharyngeal resection was carried slightly ante- In our clinical experience with the combined endonasal riorly with the use of the robot, by removing of a por- and transoral approach, we demonstrated successful sur- tion of the soft palate and uvula involved by scar bands to gical management of a variety of nasopharyngeal and maximize the nasopharyngeal opening. As this anterior posterior skull base pathologies. Based on postopera- resection was performed, the “2-surgeon” technique was tive outcomes, all 3 patients whose cases are reported in employed with use of a Hopkins rod-lens through the na- this paper experienced ideal postoperative courses with sal cavity, assisting the TORS through visualization of minimal morbidity, including few to no complications. crucial nasopharyngeal structures in the superior aspect In this primary series, we highlighted patient pathology of the field, including the Eustachian tube openings. The that is highly suitable for the combined approach, while endoscopic endonasal image was routed to the surgeon at emphasizing innovative operative technique and clinical the robotic console, allowing for true simultaneous dis- outcomes. section through both corridors (Fig. 7). At the conclusion Relevant Anatomy in the Combined Endonasal and of the surgical procedure, 2 nasal trumpets were placed Transoral Approach through the nasal cavity into the nasopharyngectomy site to ensure maintenance of patency while healing (Fig. 7). Resection into the posterior skull base and inferior nasopharynx requires detailed knowledge of the relevant Postoperative Course. Postoperatively, this patient anatomy. The nasopharynx is the most superior division did very well with only temporary velopharyngeal insuf- of the pharynx and is closely associated with the nasal ficiency noted at his initial postsurgical clinic visit, which cavity and the skull base. The nasopharynx is a cuboi-

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Fig. 5. Intraoperative setup in the combined endonasal and robotic transoral approach. Left: Demonstration of the positioning of the da Vinci robot relative to the assisting surgeon. The robot’s arms are positioned at the head of the bed and angled toward the palate in the transoral approach, allowing for simultaneous endoscopic endonasal surgery. Right: View of the assisting surgeon at the head of the bed. Note the dual monitor setup for the assisting surgeon to simultaneously view the transnasal and transoral portions of the surgery. dal-shaped region that extends from the skull base to or fossa of Rosenmüller, which is a slitlike space that is the inferior limit of the soft palate.3 Borders are impor- posterolaterally directed.3 Posteriorly, 4 layers compose tant to remember to avoid violation into unwanted areas. the nasopharyngeal wall in the anteroposterior axis, in- Its anterior border opens to the sinonasal cavity via the cluding the mucous membrane, pharyngobasilar fascia, choanae and its posteroinferior border opens to the oro- superior constrictor and longus colli muscles, and bucco- pharyngeal region directly. The torus tubarius, the termi- pharyngeal fasia. Importantly, the ICA, ascending within nal portion of the cartilaginous Eustachian tube in the the parapharyngeal space, is separated from the bucco- nasopharyngeal region, defines the anterolateral border. pharyngeal fascia of the nasopharynx by a very thin layer The most posterolateral limit, composed of the buccopha- of fibrofatty tissue, which demonstrates the intimate rela- ryngeal fascia, extends to the medial edge of the medial tionship of the ICA to the nasopharynx pterygoid plates and defines the boundary between the nasopharynx and parapharyngeal space. In the anterolat- Current Perspectives of the Combined EEA and TORS eral boundary, the salpingopharyngeus muscle and mu- Approach cosal fold extend posteriorly from the torus tubarius and Through a comprehensive review of the literature, to insert into the pharyngeal wall. Immediately posterior to date we have found only 3 published studies addressing the salpingopharyngeal fold sits the pharyngeal recess, the application and feasibility of the combined endonasal

Fig. 6. Case 3. Intraoperative images. A: Endoscopic image of the nasopharyngeal scarring through the endonasal view with involvement of the pharyngeal wall (posteriorly), choanae (inferiorly), palate (anteriorly), and skull base (superiorly). B: Three-dimensional endoscopic image of the palate from the TORS view. Dissection of the nasopharynx using monopolar electrocautery and Maryland forceps fitted to the Endowrist robotic arms. C: Two-dimensional endoscopic image in the EEA of the nasopharyngeal scar with endonasal suction tip and tip of the robotic monopolar cautery observed at the inferior edge of the surgical field. With the use of the endonasal suction through the endonasal approach, the assisting surgeon can guide the primary surgeon at the robotic console and protect critical structures in the nasopharyngeal space.

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Fig. 7. Combined intraoperative views from the robotic surgical console. In these views, the endoscopic endonasal imaging was routed as a secondary source to the robotic operator, allowing for the surgeon to simultaneously observe the endonasal surgery (lower row) and transoral surgery (upper row). This setup allows for the primary and assisting surgeons to operate together through the transoral and endonasal corridors. Intraoperative bleeding was controlled in a safe manner by visualizing critical nasopharyngeal structures through both corridors simultaneously (left). With the combined intraoperative view, nasal stents were inserted through the nasal cavity and sewn into place at the nasopharyngectomy site using the robotic instruments through the transoral corridor (right).

endoscopic and transoral robotic surgical approach for 2 minimally invasive approaches, Yin Tsang and col- nasopharyngeal management.5,11,41 In 2010, Yin Tsang et leagues were able to successfully resect the nasopharyn- al. published an original case report on the resection of a geal carcinoma at the roof of the nasopharynx abutting recurrent nasopharyngeal carcinoma using the combined the skull base, while obtaining adequate surgical margins endonasal and transoral approach. In their experience, the in the nasopharyngeal cavity and adhering to oncological combined endonasal and transoral approach was required principles.32,41 given the close proximity of the lesion to the skull base, Dallan and colleagues published a study on the cadav- necessitating the use of an endoscopic drill for bone re- eric feasibility of a combined endonasal and transoral ap- section, a surgical element that is still not feasible in stan- proach, and also compared their version of the combined dard TORS. Additionally, in their report, a second sur- approach to traditional TORS.11 However, Dallan et al. geon worked subsequently in the nasal cavity, providing presented a modified combined approach, because their blood and smoke suction capacity and placing occasional “combined” approach was performed entirely with the da traction on the lesion. Therefore, through combining the Vinci surgical system, with a central, endoscopic robotic arm in the nasal cavity and the other 2 robotic arms inserted through small, transcervical paramandibular windows created by 5-mm paramandibular incisions.11 This placement method may also ease dissection of the basisphenoid and upper clivus at the skull base. However, given the additional external incisions required in this approach, further analysis of this technique may be required prior to clinical implementation, as Dallan and colleagues alluded to in their conclusion. Their study provided a novel and thought- provoking take on the combined endonasal and transoral approach to the nasopharynx in a cadaver model. Lastly, Carrau et al. most recently presented their experience with the combined endonasal and transoral approach for the resection of various malignancies of the nasopharynx and skull base.5 In their study, they demonstrated the feasibility of the combined approach Fig. 8. Photograph of the da Vinci robotic surgical system with the primary surgeon. The primary surgeon is stationed within the operating through cadaveric and clinical study to complete naso- theater at the robotic console and manipulates the robotic arms, while pharyngectomies with lateral and inferior extensions to in consistent contact with his assisting surgeon at the patient bed. This the middle skull base and costovertebral junction (CVJ), intraoperative setup allows for a true “2-surgeon, 4-handed” technique. respectively. Additionally, they presented their clinical

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Unauthenticated | Downloaded 10/09/21 05:12 PM UTC S. B. Sreenath, R. B. Rawal, and A. M. Zanation experience with these techniques in the surgical manage- As discussed earlier, given the proximity of the ICA ment of a large adenoid cystic carcinoma with involve- to the region of interest, visualization and proximal con- ment of the middle cranial fossa, nasopharynx, clivus, trol of the ICA becomes critically important. Rates of and sphenoid sinus. By combining an EEA to the naso- ICA injury in TORS cases have been found to be lower pharynx and middle cranial fossa with a TORS approach than those noted in open procedures or radiation therapy, to the tonsillar fossa and pterygoid plates, they were able although this may be due to the lower absolute number of to successfully resect the tumor with adequate surgical cases.39 If incurred, intraoperative ICA control may be in- margins. In their second case experience, Carrau and col- directly achieved through the robotic arms given the sur- leagues described their management of a large chordoma gical maneuverability and ability to suture with the use of with extensions from the middle skull base to the CVJ, the robotic arms. C-1 vertebra, and C-2 vertebra. Given the long features Lastly, when considering cost-effectiveness, current of this tumor, they again implemented the combined ap- literature offers conflicting evidence of TORS due to the proach without complication and successfully resected a high costs in purchasing the equipment but minimized large majority of the tumor. costs in postoperative overall health care and hospital The combined endonasal and transoral approach al- stay. 20,29,31 Further data are necessary to definitively as- lows for both EEA and TORS to complement each other sess the costs of TORS singularly and in conjunction with regarding their unique advantages and decrease their EEA via the combined endonasal and transoral approach. combined limitations. The EEA allows for the ability to Overall, each patient should be considered on a unique perform bone resection, achieve superolateral access in the nasopharyngeal region (as demonstrated in Case 2), basis regarding the feasibility and applicability of the and provide a larger array of available instrumentation combined endonasal and transoral approach in the surgi- given its historic implementation in sinonasal surgery. In cal management of his or her pathology. contrast, TORS creates the ability to approach the nasopharyngeal region below the soft palate while minimiz- Future Endeavors in the Combined Surgical Approach ing tissue displacement, perform a wide array of surgical As endoscopic and robotic technology continues to maneuvers that are impossible in manual surgery in the improve, the realm of clinical applications will continue narrow oral corridor, and achieve a 3D image of the oper- to expand due to multiple factors, particularly when con- ative field. Therefore, the combination of these techniques sidering a combination of approaches. First, the applica- may become established as a viable surgical option for tion of bone-drilling technology in TORS will greatly the skull base surgeon. In addition, while communication expand the range of surgical possibilities, especially in between surgeons was paramount during Cases 1 and the transoral approach to the CVJ and upper cervical ver- 2, Case 3 allowed for the endoscopic endonasal image tebrae. Second, as demonstrated in Case 1 in our clinical to be routed to the surgeon at the robotic console. The experience, the application of image-based neuronaviga- surgeon at the robotic console was therefore able to have tion software, an established component of endoscopic the exact same visualization as the endonasal surgeon, endonasal surgery, to TORS specifically has the capacity thus allowing for true simultaneous dissection through both corridors. This has not been performed previously to radically change current limitations in the transoral ap- and represents a technological innovation that decreases proach. Third, as described by Dallan et al., the possibility the chance for any miscommunication between surgical of utilizing transcervical ports in the transoral approach teams. to the nasopharynx has unique implications in combined surgery, because it opens the possibility of minimizing Safety and Cost-Effectiveness of the Combined Endonasal complications associated with the purely transoral ap- and Transoral Approach and TORS proach such as palatal or pharyngeal injury.11 Lastly, as described in our experience in Cases 2 and 3, we em- Although many of the advantages and disadvantages of combining these novel surgical techniques have been ployed a “2-surgeon, 4-handed” technique, an established previously discussed above, the safety and cost-effective- practice in endoscopic skull base surgery, as 1 surgeon ness of specifically the TORS approach requires further performed minimal, manual dissection in the nose while clarification. In 2012, a multicenter review by Weinstein the other surgeon was at the robotic console operating the et al.39 demonstrated the feasibility, safety, and effective- robot in the transoral corridor. This was further modified ness of TORS for selected head and neck tumors: 98.9% in Case 3 through an innovative intraoperative setup in of their intent-to-treat population was successfully treat- which available technology was used to allow for simul- ed with TORS without needing any form of intraopera- taneous visualization by the surgeon at the robotic helm tive conversion to an open approach. Also, the adequacy of both the endonasal and transoral corridors. Commu- of surgical margins achieved with TORS was comparable nication between the operating surgeons was facilitated to those achieved with open approaches to the nasophar- by merging the endoscopic imaging modalities, which ynx.39 Lastly, Weinstein et al. found that the incidences minimized risks and complications in operating in both of wound dehiscence and postoperative bleeding requir- corridors simultaneously.28 As instrumentation and tech- ing intervention associated with the TORS approach were nology in robotic and endoscopic surgery improve with overall lower than the incidences found with standard smaller-sized instruments and increased mobility, this transoral approaches during management of neoplastic true, 2-surgeon technique will allow for consistent, simul- disease.39 taneous surgical dissection.

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Conclusions 12. de Almeida J, Perez-Ordonez B, Gullane PJ: Combined endoscopic transnasal and transoral excision of a rare nasopharyn- The combined endoscopic endonasal and robotic geal pleomorphic adenoma: case report and review of the lit- transoral approach offers a unique surgical option for erature. J Otolaryngol Head Neck Surg 38:E51–E55, 2009 the management of a wide array of nasopharyngeal and 13. Durmus K, Rangarajan SV, Old MO, Agrawal A, Teknos TN, skull base pathologies. Through presentation of our in- Ozer E: Transoral robotic approach to carcinoma of unknown stitution’s experience with the combined endonasal and primary. Head Neck 36:848–852, 2014 14. El-Sayed IH, Wu JC, Ames CP, Balamurali G, Mummaneni transoral approach we have demonstrated the feasibility, PV: Combined transnasal and transoral endoscopic approach- clinical applications, and preliminary outcomes of this es to the craniovertebral junction. J Craniovertebr Junction relatively novel surgical technique. With the continual Spine 1:44–48, 2010 push for minimally invasive approaches and improve- 15. Fisch U, Fagan P, Valavanis A: The infratemporal fossa ap- ment in patient surgical outcomes, we believe that this proach for the lateral skull base. Otolaryngol Clin North Am combined surgical technique will continue to evolve and 17:513–552, 1984 have widespread clinical applicability. 16. Hassan M, AboEl-Ezz T, Youssef T: Combined transoral- transnasal approach in the repair of congenital posterior cho- anal atresia: clinical experience. J Otolaryngol Head Neck Disclosure Surg 40:271–276, 2011 The authors report no conflict of interest concerning the mate- 17. Jain K, Hsu J, Goyal P: The utility of a combined endoscopic rials or methods used in this study or the findings specified in this and transoral resection of maxillary ameloblastoma. Int Fo- paper. rum Allergy Rhinol 3:762–765, 2013 Author contributions to the study and manuscript prepara- 18. Janecka IP, Sen CN, Sekhar LN, Arriaga M: Facial transloca- tion include the following. Conception and design: all authors. tion: a new approach to the cranial base. Otolaryngol Head Acquisition of data: all authors. Analysis and interpretation of data: Neck Surg 103:413–419, 1990 all authors. Drafting the article: all authors. Critically revising the 19. Kim GG, Zanation AM: Transoral robotic surgery to resect article: all authors. Reviewed submitted version of manuscript: all skull base tumors via transpalatal and lateral pharyngeal ap- authors. Approved the final version of the manuscript on behalf of proaches. Laryngoscope 122:1575–1578, 2012 all authors: Zanation. Administrative/technical/material support: all 20. Lotan Y: Is robotic surgery cost-effective: no. Curr Opin authors. Study supervision: Zanation. Urol 22:66–69, 2012 21. 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principles of endonasal oncological surgery. J Surg Oncol 39. Weinstein GS, O’Malley BW Jr, Magnuson JS, Carroll WR, 97:658–664, 2008 Olsen KD, Daio L, et al: Transoral robotic surgery: a multi- 33. Tsang RK, Ho WK, Wei WI, Chan JY: Transoral robotic as- center study to assess feasibility, safety, and surgical margins. sisted nasopharyngectomy via a lateral palatal flap approach. Laryngoscope 122:1701–1707, 2012 Laryngoscope 123:2180–2183, 2013 40. White HN, Frederick J, Zimmerman T, Carroll WR, Magnu- 34. Tsang RK, To VS, Ho AC, Ho WK, Chan JY, Wei WI: Early son JS: Learning curve for transoral robotic surgery: a 4-year results of robotic assisted nasopharyngectomy for recurrent analysis. JAMA Otolaryngol Head Neck Surg 139:564– nasopharyngeal carcinoma. Head Neck [epub ahead of print], 567, 2013 2014 41. Yin Tsang RK, Ho WK, Wei WI: Combined transnasal endo- 35. Van Rompaey J, Suruliraj A, Carrau R, Panizza B, Solares scopic and transoral robotic resection of recurrent nasopha- CA: Access to the parapharyngeal space: an anatomical study ryngeal carcinoma. Head Neck 34:1190–1193, 2012 comparing the endoscopic and open approaches. Laryngo- scope 123:2378–2382, 2013 36. Wang QY, Chen HH, Lu YY: Comparison of two approaches to the surgical management of juvenile nasopharyngeal angiofibroma stages I and II. J Otolaryngol Head Neck Surg Manuscript submitted June 15, 2014. 40:14–18, 2011 Accepted July 17, 2014. 37. Wei WI, Ho CM, Yuen PW, Fung CF, Sham JS, Lam KH: Max- Please include this information when citing this paper: DOI: illary swing approach for resection of tumors in and around the 10.3171/2014.7.FOCUS14353. nasopharynx. Arch Otolaryngol Head Neck Surg 121:638– Address correspondence to: Adam M. Zanation, M.D., Depart- 642, 1995 ment of Otolaryngology—Head & Neck Surgery, University of 38. Weinstein GS, O’Malley BW Jr, Hockstein NG: Transoral ro- North Carolina at Chapel Hill, 170 Manning Dr., CB #7070, Physi- botic surgery: supraglottic laryngectomy in a canine model. cian’s Office Building, Rm. G-190, Chapel Hill, NC 27599. email: Laryngoscope 115:1315–1319, 2005 [email protected].

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