Combined transoral transnasal robotic-assisted nasopharyngectomy: a cadaveric feasibility study

Transoral Robotic-Assisted Neurosurgery for Skull Base and Upper Spine Lesions

OBJECTIVE

The application of the da Vinci Surgical System in neurosurgery is limited due to technical difficulties requiring precise maneuvers and small instruments. This study details the advantages and disadvantages of robotics in neurosurgery and the reachable range of the transoral approach to lesions of the skull base and upper cervical spine.

METHODS

In a cadaver study, the da Vinci Xi robot, lacking haptic feedback, was utilized for sagittal and coronal approaches on 5 heads, facilitating dura suturing in 3, with a 30°-angled drill for bone removal.

RESULTS

Perfect exposure of all the nasopharyngeal sites, clivus, sellar, and choana, including the bilateral eustachian tubes, was achieved without any external incisions using this palatal split approach of transoral robotic surgery. The time required to perform a single stitch, knot, and complete single suture in robotic suturing of deep-seated were significantly less compared to manual suturing via the endonasal approach.

CONCLUSION

This is the first report to show the feasibility of suturing the dural defect in deep-seated lesions transorally and revealed that the limit of reach in the coronal plane via a transoral approach with incision of the soft palate is the foramen ovale. This preclinical investigation also showed that the transoral robotic approach is feasible for lesions extending from the sellar to the C2 in the sagittal plane. Refinement of robotic instruments for specific anatomic sites and future neurosurgical studies are needed to further demonstrate the feasibility and effectiveness of this system in treating benign and malignant skull base lesions.

Single-Port Versus Multiport da Vinci System for Transoral Robotic Surgery of Hypopharyngeal and Laryngeal Carcinoma

OBJECTIVE

Da Vinci single port (SP) has been recently approved for transoral robotic surgery (TORS). Its characteristics make it particularly feasible for laryngeal and hypopharyngeal surgery. We report our experience comparing intra- and postoperative outcomes, technical advantages, and shortcomings of transoral laryngeal and hypopharyngeal resections performed with the da Vinci SP and the da Vinci Si/Xi systems.

STUDY DESIGN

Retrospective database review.

SETTING

Single academic tertiary care hospital.

METHODS

Subjects included adult patients with laryngeal and hypopharyngeal carcinoma who underwent TORS between 2008 and 2022. The SP and multiport (MP) systems were compared in terms of intraoperative times, short-term postoperative outcomes, and TORS-related complications after a propensity score matching.

RESULTS

A total of 185 patients were enrolled (56 SP vs 129 MP patients), and a cohort of 112 patients was analyzed after matching. The docking time was reduced in the SP group (8.84 ± 4.67 vs 6.45 ± 3.11 minutes; p = .003), as well as console time (53.91 ± 29.38 vs 42.70 ± 13.72 minutes; p = .035). Positive margins were more frequent in the MP group (52% vs 43%; p = .34). The mean decannulation time was 1.86 days longer in the SP group (p = .046). No significant differences emerged from the analysis of the duration of hospitalization, enteral feeding, and TORS-related complications.

CONCLUSION

SP safety profile is comparable to that of previous models, while it showed advantages in terms of reduced docking times. Console times were also shortened due to improved maneuverability and field visualization.

Combined endoscopic endonasal & transoral approach to transpatial lesion involving the infratemporal fossa and masticator space: A case study and literature review

Transpatial skull base lesions involving the infratemporal fossa (ITF) are challenging due to the complex neurovascular structures of the region. Open approaches have traditionally been utilized to access these spaces. We present a 55-year-old woman presented with a mesenchymal mass involving the left ITF and masticator space. A combined endoscopic endonasal transpterygoid approach was performed followed by an endoscopic transoral-transmandibular corridor to access and resect the tumor. The post-operative course was unremarkable with no recurrence during her follow-up. Combined endoscopic approaches for transpatial tumor resection offered sufficient exposure to access safely each space.

The 'Maxillary Pull-through' Technique: A Minimally Invasive Endoscopic-Assisted Approach to Nasal Septum Neoformations with Maxillary Bone Infiltration

Study Design

Description and validation of a surgical technique.

Objective

En-bloc maxillectomy with removal of the nasal septum is a rare procedure; preservation of the nasal bones and integrity of the alveolar ridge is even rarer. These procedures traditionally required a combined transfacial-transoral approach based on lateral rhinotomy. We describe a combined endoscopic transnasal-transoral approach for treatment of nasal septal malignancies that involve the hard palate.

Methods

Excision of malignant tumours arising from the nasal septum was achieved in 4 patients using a transnasal-transoral endoscopic approach. Using 4-mm optics angled at 0° and 30°, the septum was freed from the ethmoid and removed en-bloc with the hard palate, by pulling the septum down through the hard palate.

Results

Of the 4 patients, 2 underwent complete removal of septal chondrosarcomas, one removal of a sinonasal undifferentiated carcinoma and one removal of a mucoepidermoid carcinoma. In two cases, the palatal mucosa was spared and repositioned to restore separation between the nose and oral cavity. The remaining two cases underwent complete resection of the hard palate; one palate was reconstructed using a pedicled temporalis muscle flap and the other by employing an obturator. No infection was encountered. Partial ethmoidectomy was performed in all four cases. The mean hospital stay was 5 days. All patients are free of disease after a mean follow-up of 4 years (range: 2-7 years).

Conclusions

Our new approach allows for minimally invasive resection of nasal septal malignancies that extend to the palate. Our maxillary pull-through technique is a valuable new surgical procedure for malignant pathologies of the nasal septum; the only drawback is that endoscopic surgery has a steep learning curve.

Robotic transmaxillary approach to the lateral infratemporal fossa: A preclinical cadaveric study using a next-generation single-port robotic system

Robotic transmaxillary skull base surgery has been described using multiport systems. This cadaveric study investigates the feasibility of transmaxillary skull base surgery using a next-generation robot. An extended Caldwell-Luc antrostomy, measuring 3.3 cm by 4.0 cm, was performed in 15 min using a Kerrison rongeur and the robotic endoscope. A single-port, robotic system (da Vinci Sp®, Intuitive Surgical, Inc, Sunnyvale, CA, USA) was then deployed throught the extended Caldwell-Luc approach and provided sufficient reach, visualization, and maneuverability to work within the pterygopalatine fossa (PPF) and the infratemporal fossa (ITF) using three surgical instruments. The ITF dissection was easiest with two instruments using the third instrument to retract the muscles of mastication. This study demonstrates the feasibility of single-port robotic transmaxillary approaches to the lateral ITF. Using a single-port robotic system, the operating surgeon can for the first time work in the PPF and ITF using two functional arms for tumor dissection and a third to retract.

Endoscopic transoral nasopharyngectomy

BACKGROUND

A minimal access technique for the management of nasopharyngeal tumors extending below the palatal plane and laterally beyond the pterygoid musculature is yet to be developed. In this study we demonstrate the feasibility of endoscopic transoral nasopharyngectomy (ETON) for resection of large nasopharyngeal lesions as a natural orifice alternative to traditional approaches.

METHODS

ETON was completed in three latex-injected specimens. Surgical freedom (SF) and angles of attack (AoA) were calculated along the internal carotid artery (ICA).

RESULTS

An endoscopic transoral approach was successfully used to identify the parapharyngeal ICA and subsequently perform a complete nasopharyngeal resection. SF and AoA (sagittal) were found to be the greatest at the anterior genu of the ICA.

CONCLUSIONS

ETON is feasible. It provides wide exposure of the skull base and proximal control of the ICA. It may be indicated for the management of nasopharyngeal tumors with inferolateral extension, involving the ICA.

Setup and initial testing of an endoscope manipulator system for assistance in transoral endoscopic surgery

Purpose For the treatment of malignant diseases of the oral cavity and the larynx, a total or partial resection is the standard therapy, while in special cases chemo- and/or external radiation therapy is considered. Transoral access reduces trauma and hospitalization time. Transoral surgery is usually executed using external microscopic imaging. Therefore, the microscope is placed in the visual line of the opening of the mouth and throat. However, specific anatomical structures like the posterior commissure (dorsal end of the vocal cords) are not visible in these procedures. An endoscopic approach can improve this problem. We introduce a new prototype system for endoscopic assisted transoral surgery. Methods Based on clinical observation and discussions with professional users and surgeons, the clinical need was identified and specified. A general concept or an endoscopic manipulator to assist microlaryngeal surgery was designed. For that a steerable rigid endoscope was combined with an actuator that allows translational and rotational movement. A quick release fastener was designed allowing for fast change of the endoscope and independence from its shape and type. The actuator was fixed on a commercially available, semi-active medical holding arm for easy positioning. The holder can be fixed to the standard rails of the surgical table. The piezoelectric drives integrated in the actuator are activated with a foot pedal. This allows easy and fast fine positioning, while the hands are free to perform the surgery with standard instruments for microlaryngeal surgery. Results A prototype of the system for endoscopic assisted transoral surgery was developed. The entire technical setup was tested in terms of usability and performance in a simulated surgical scenario. A basic phantom, representing the throat and vocal cords was created and placed on a surgical table. The system was installed on the table and the clinical workflow of a simulated endoscopic assisted surgery on the vocal cords was performed. The performance of the setup and the procedure success was evaluated by clinical users. Conclusion Fixture of the system on the surgical table is fast and easy due to its low weight and compact design. The medical holder allows a fast initial positioning of the system in front of the phantom patient. An easy insertion and removal of the endoscope was realized using the quick release fastener. The developed endoscope fixation is universally adaptable and not limited to a single type of endoscope. The piezoelectric drives, combined with the foot pedal, allow a precise placement and readjustment of the endoscope during surgery. The use of a multi view endoscope enables a variable view on the surgical situs. The size and shape of the whole setup offer excellent access to the targeted structures. The development was classified beneficial by the clinical users.

[Robotic Surgery - Who is The Boss?]

In the head and neck region, great potential is seen in robot-assisted surgery (RAS). Mainly in cancer surgery, the use of robotic systems seems to be of interest. Until today, two robotic systems (DaVinci® und FLEX®) have gained approval for clinical use in the head and neck region, and multiple other systems are currently in pre-clinical testing. Although, certain groups of patients may benefit from RAS, no unbiased randomized clinical studies are available. Until today, it was not possible to satisfactorily prove any advantage of RAS as compared to standard procedures. The limited clinical benefit and the additional financial burden seem to be the main reasons, why the comprehensive application of RAS has not been realized so far.This review article describes the large variety of clinical applications for RAS in the head and neck region. In addition, the financial and technical challenges, as well as ongoing developments of RAS are highlighted. Special focus is put on risks associated with RAS and current clinical studies. We believe, that RAS will find its way into clinical routine during the next years. Therefore, medical staff will have to increasingly face the technical, scientific and ethical features of RAS.

Direct and Oblique Approaches to the Craniovertebral Junction: Nuances of Microsurgical and Endoscope-Assisted Techniques Along with a Review of the Literature

PURPOSE

The aim of this review is to provide an update of the technical nuances of microsurgical and endoscopic-assisted approaches to the craniovertebral junction (transnasal, transoral, and transcervical), and to report on the available clinical results in order to identify the best strategy.

METHODS

A nonsystematic update of the reviews and reporting on the anatomical and clinical results of endoscopic-assisted and microsurgical approaches to the craniovertebral junction (CVJ) was performed.

RESULTS

Pure endonasal and cervical endoscopic approaches still have some disadvantages, including their steep learning curves and their deeper surgical fields. Endoscopically assisted transoral surgery with 30° endoscopes represents an emerging option compared with standard microsurgical techniques for transoral approaches to the anterior CVJ. This approach should be considered as complementary to, rather than as an alternative to the traditional transoral-transpharyngeal approach.

CONCLUSIONS

The transoral (microsurgical or video-assisted) approach with sparing of the soft palate still remains the gold standard compared with the "pure" transnasal and transcervical approaches, due to the wider working channel provided by the former technique. The transnasal endoscopic approach alone appears to be superior when the CVJ lesion exceeds the upper limit of the inferior third of the clivus. Of particular interest is the evidence that advances in reduction techniques can avoid the ventral approach.

Robot-assisted endoscope guidance versus manual endoscope guidance in functional endonasal sinus surgery (FESS)

BACKGROUND

Having one hand occupied with the endoscope is the major disadvantage for the surgeon when it comes to functional endoscopic sinus surgery (FESS). Only the other hand is free to use the surgical instruments. Tiredness or frequent instrument changes can thus lead to shaky endoscopic images.

METHODS

We collected the pose data (position and orientation) of the rigid 0° endoscope and all the instruments used in 16 FESS procedures with manual endoscope guidance as well as robot-assisted endoscope guidance. In combination with the DICOM CT data, we tracked the endoscope poses and workspaces using self-developed tracking markers.

RESULTS

All surgeries were performed once with the robot and once with the surgeon holding the endoscope. Looking at the durations required, we observed a decrease in the operating time because one surgeon doing all the procedures and so a learning curve occurred what we expected. The visual inspection of the specimens showed no damages to any of the structures outside the paranasal sinuses.

CONCLUSION

Robot-assisted endoscope guidance in sinus surgery is possible. Further CT data, however, are desirable for the surgical analysis of a tracker-based navigation within the anatomic borders. Our marker-based tracking of the endoscope as well as the instruments makes an automated endoscope guidance feasible. On the subjective side, we see that RASS brings a relief for the surgeon.

The Four-Port Bradoo Technique: An Alternative to the Modified Endoscopic Denker's Approach for Giant JNA

The aim of this study is to emphasise the importance of preserving the anterior facial skeleton in angiofibroma surgery and to introduce a new approach by which tumors with far lateral extensions can be operated upon successfully without disruption of the anterior facial skeleton. This is a prospective study conducted at a tertiary referral academic centre. Two patients with extensive juvenile nasopharyngeal angiofibroma with far lateral extensions were recruited and they underwent surgery between July and August 2016. Both patients were not embolised prior to surgery. Complete tumor removal was achieved in both cases without any evidence of recurrence of disease. The facial contour was well maintained. They are under regular follow-up at our centre, having completed their third 3 monthly follow-up. The main outcome measures are preservation of the anterior facial skeleton and complete tumor removal. The Four-Port Bradoo Technique allows for maximum access to the angiofibroma whilst maintaining the anterior facial skeleton, thus ensuring complete removal with minimal morbidity to the patient.

The Role of Robotic Surgery in Sinonasal and Ventral Skull Base Malignancy

Over the past decade, robotic surgery has gained wide popularity, making a significant impact on multiple surgical specialties. In the head and neck arena, transoral robotic surgery has proven to be safe and associated with acceptable oncological and superior functional outcomes for surgery of the oropharynx, hypopharynx, supraglottis, and glottis; thus, changing the paradigm for the management of tumors in these anatomic locations. Robotic surgery of the ventral skull base is at an early stage of development. In this article reviews the literature discussing the role of robotic surgery in managing sinonasal and ventral skull base malignant lesions.

Expanded Endonasal Endoscopic Approaches to the Skull Base for the Radiologist

The cranial base is a complex 3-D region that contains critical neurovascular structures. Pathologies affecting this region represent some of the most challenging lesions to manage due to difficulty with access and risk of significant postoperative morbidity. With the development of expanded endonasal endoscopic approaches, skull base surgeons use the nose and paranasal sinuses as a corridor to access selected ventral skull base lesions. This review discusses high-resolution imaging in the evaluation of patients with skull base lesions considered for endonasal endoscopic surgery, summarizes various expanded endonasal endoscopic approaches, and provides examples of commonly used expanded endonasal endoscopic procedures.

Multiport Combined Endoscopic Approach to Nonembolized Juvenile Nasopharyngeal Angiofibroma with Parapharyngeal Extension: An Emerging Concept

Background. Surgical approaches to the parapharyngeal space (PPS) are challenging by virtue of deep location and neurovascular content. Juvenile Nasopharyngeal Angiofibroma (JNA) is a formidable hypervascular tumor that involves multiple compartments with increase in size. In tumors with extension to parapharyngeal space, the endonasal approach was observed to be inadequate. Combined Endoscopic Endonasal Approaches and Endoscopic Transoral Surgery (EEA-ETOS) approach has provided a customized alternative of multicorridor approach to access JNA for its safe and efficient resection. Methods. The study demonstrates a case series of patients of JNA with prestyloid parapharyngeal space extension operated by endoscopic endonasal and endoscopic transoral approach for tumor excision. Results. The multiport EEA-ETOS approach was used to provide wide exposure to access JNA in parapharyngeal space. No major complications were observed. No conversion to external approach was required. Postoperative morbidity was low and postoperative scans showed no residual tumor. A one-year follow-up was maintained and there was no evidence of disease recurrence. Conclusion. Although preliminary, our experience demonstrates safety and efficacy of multiport approach in providing access to multiple compartments, facilitating total excision of JNA in selected cases.

Comprehensive review on endonasal endoscopic sinus surgery

Endonasal endoscopic sinus surgery is the standard procedure for surgery of most paranasal sinus diseases. Appropriate frame conditions provided, the respective procedures are safe and successful. These prerequisites encompass appropriate technical equipment, anatomical oriented surgical technique, proper patient selection, and individually adapted extent of surgery. The range of endonasal sinus operations has dramatically increased during the last 20 years and reaches from partial uncinectomy to pansinus surgery with extended surgery of the frontal (Draf type III), maxillary (grade 3-4, medial maxillectomy, prelacrimal approach) and sphenoid sinus. In addition there are operations outside and beyond the paranasal sinuses. The development of surgical technique is still constantly evolving. This article gives a comprehensive review on the most recent state of the art in endoscopic sinus surgery according to the literature with the following aspects: principles and fundamentals, surgical techniques, indications, outcome, postoperative care, nasal packing and stents, technical equipment.

Videoassisted anterior surgical approaches to the craniocervical junction: rationale and clinical results

PURPOSE

In this narrative review, we aim to give an update on the anatomic fundamentals of endoscopic assisted surgery to the craniocervical junction (transnasal, transoral and transcervical), and to report on the available clinical results.

METHODS

A non-systematic review and reporting on the anatomical and clinical results of endoscopic assisted approaches to the craniocervical junction (CVJ) is performed.

RESULTS

Pure endonasal and cervical endoscopic approaches still have some disadvantages, including the learning curve and the lack of 3-dimensional perception of the surgical field. Endoscopically assisted transoral surgery with 30° endoscopes represents an emerging alternative to standard microsurgical techniques for transoral approaches to the anterior CVJ. Used in conjunction with traditional microsurgery and intraoperative fluoroscopy, it provides a safe and improved method for anterior decompression with or without a reduced need for extensive soft palate splitting, hard palate resection, or extended maxillotomy.

CONCLUSIONS

Transoral (microsurgical or video-assisted) approach with sparing of the soft palate still remains the gold standard compared to the "pure" transnasal and transcervical approaches due to the wider working channel provided by the former technique. Transnasal endoscopic approach alone appears to be superior when the CVJ lesion exceeds the upper limit of the inferior third of the clivus. Combined transnasal and transoral procedures can be tailored according to the specific pathological and radiological findings.

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

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.

Potential Advantages of a Single-Port, Operator-Controlled Flexible Endoscope System for Transoral Surgery of the Larynx

Introduction:

Transoral surgery of the larynx is commonly performed with a rigid laryngoscope, a microscope, and a laser. We investigated the potential utility of a flexible, single-port, robot-assisted and physician-controlled endoscopic system to enable easy, transoral surgical access to the larynx.

Methods:

Transoral laryngeal surgery was performed in human cadavers (n = 4) using the Flex System and compatible flexible instruments. Anatomical landmarks were identified, and mock surgical procedures were performed.

Results:

Standard laryngeal surgical procedures were completed successfully in a human cadaver model. The built-in HD digital camera enabled high-quality visualization of the larynx. Epiglottectomy, as well as posterior cordectomy, were performed by laser and radio-frequency resection. The flexible design of the compatible tools enabled a nontraumatic approach.

Conclusion:

The Flex System has the potential to improve surgical access to the larynx, especially in patients with challenging anatomy. The associated flexible instruments enabled completion of surgical procedures in the larynx in a human cadaveric model. Further clinical studies, as well as the development of supplemental technology and tools, are recommended for future clinical applications.

Endoscopic endonasal technique: treatment of paranasal and anterior skull base malignancies

Objective

Method

Conclusion

Transoral robotic surgery of the central skull base: preclinical investigations

In this study we explored possible applications of the da Vinci system in approaching the skull base at optic chiasm level on two cryopreserved cadavers, using an entirely transoral robotic technique (TORS). We used a standard 12 mm endoscopy and 8 mm terminals. Bone drilling was performed manually. The da Vinci system is equipped with very good illumination and 3D viewing, thus providing excellent vision and great maneuverability even in the less accessible areas of the skull. Our experience demonstrates that an entirely transoral skull base robotic approach to this complex anatomical region has many advantages as compared to traditional techniques.

Endoscopic Endonasal Nasopharyngectomy in Selected Cancers

Objective

To describe the different surgical techniques for nasopharyngeal endoscopic resection (NER) and to support the efficacy of the endoscopic endonasal approach in the management of selected primary and locally recurrent nasopharyngeal tumors (NPTs).

Study Design

Case series with chart review.

Setting

Patients affected by NPTs who underwent NER from 1997 to 2011 at two Italian referral centers.

Subjects and Methods

NER was tailored to the NPT extension and classified as follows: type 1 NER, resection of the posterior nasopharyngeal wall; type 2 NER, resection superiorly extended to the sphenoid; type 3 NER, trans-pterygoid approach to the postero-lateral nasopharynx with removal of pterygoid plates and Eustachian tube, under control of parapharyngeal-petrous-cavernous segments of the internal carotid artery.

Results

Thirty-six consecutive patients with primary (9 cases) or locally recurrent (27 cases) NPTs were enrolled. The lesions were staged as follows: stage I, 16 (44.4%); stage II, 3 (8.4%); stage III, 15 (41.6%); and stage IVA, 2 (5.6%). Type 1 NER was performed in 6 cases, type 2 NER in 12, type 3 NER in 16, and bilateral-extended type 3 NER in 2. No perioperative mortality or major complications were observed. Postoperatively, 11 patients received intensity-modulated radiotherapy, with or without chemotherapy. Follow-up ranged from 2 to 173 months (mean: 38 months). Five years overall, disease-specific, and disease-free survivals were 75.1% ± 9.13%, 80.9% ± 7.79%, and 58.1% ± 14.8%, respectively.

Conclusion

NER is a feasible and minimally invasive surgical approach for the management of selected primary and locally recurrent NPTs. Our preliminary outcomes are promising, with local control rates comparable to those of conventional procedures. Larger case series and longer follow-up are needed to validate the reproducibility and efficacy of the technique.

Lateral palatal flap approach to the nasopharynx and parapharyngeal space for transoral robotic surgery: a cadaveric study

The da Vinci surgical robot has been used for minimally invasive surgery of the head and neck region including resection of tumors in the nasopharynx. Access to and vision of the nasopharynx with the robot are difficult. A pure transoral approach and midline palatal split approach have been described. The disadvantage of these approaches is the limited lateral access to the parapharyngeal space. The objective of this study was to investigate the feasibility of accessing the nasopharynx and parapharyngeal space with a lateral palatal flap. Two complete nasopharyngectomies with resection of the parapharyngeal space and exposure of the internal carotid artery and branches of the mandibular nerves were performed on two fresh cadavers with the da Vinci surgical robot. The set up of the robot, the surgical procedure of elevating the lateral palatal flap, and robotic resection of the nasopharynx and parapharyngeal space are described.

Combined transoral robotic surgery and endoscopic endonasal approach for the resection of extensive malignancies of the skull base

BACKGROUND

Oncologic resection of the clivus, nasopharynx, craniovertebral junction, and infratemporal fossa is a challenging endeavor because of their complex and protected anatomy. Our goals were to design a cadaveric model and identify advantages and limitations of combining the transoral robotic surgery (TORS) and endoscopic endonasal approach (EEA) techniques.

METHODS

Cadaveric specimens were dissected using a da Vinci surgical robot and endoscopic endonasal instruments in a fashion that mimicked our operating room environment. We then applied these techniques clinically.

RESULTS

EEA was performed to provide a detailed dissection of the infratemporal fossa, nasopharynx, posterior skull base (clivus), and craniovertebral junction. Using TORS, we dissected the parapharyngeal space, infratemporal fossa, and nasopharynx below the eustachian tube, which represented a transition zone that delineated the most effective resection field of each approach.

CONCLUSIONS

TORS and EEA seem to be complementary techniques; thus, their combined use seems advantageous for selected advanced tumors in these complex areas.