Tumors of the infratemporal fossa

Anatomic Considerations Guiding Single Versus Multiportal Endoscopic Approaches for Resection of Juvenile Nasopharyngeal Angiofibroma: Cases Series With Graded Multicorridor Resections

BACKGROUND

Juvenile nasopharyngeal angiofibromas (JNAs) are characterized by expansive and destructive growth, often invading the midline/paranasal sinuses, pterygopalatine fossa, and infratemporal fossa and can extend into the orbit, cavernous sinus, or intracranially.

OBJECTIVE

To evaluete the major benefits of the extended endoscopic endonasal approach (EEA) for JNA resection as compared with more traditional and invasive transpalatal and transfacial approaches. When JNAs extend into lateral anatomic compartments, the optimal operative trajectory often requires additional approach strategies or surgical staging.

METHODS

We retrospectively reviewed 8 cases of large JNAs arising in symptomatic adolescent boys (University of Pittsburgh Medical Center Stages II, III, and V) and discuss anatomic and tumor considerations guiding the decision of a pure EEA vs combined EEA and sublabial transmaxillary approach (Caldwell-Luc).

RESULTS

A pure extended EEA was used in 6 JNA cases (UPMC Stages II-III); a multiportal EEA + Caldwell-Luc maxillotomy was used in 2 cases. One of the 2 patients (UPMC Stage V) previously treated with multiportal EEA + Caldwell-Luc maxillotomy underwent staged left temporal/transzygomatic craniotomy, obtaining gross total resection. Seven patients ultimately underwent complete removal without recurrence. One patient with a small residual JNA (UPMC II) underwent stereotactic radiosurgery without progression to date.

CONCLUSION

JNAs with lateral extension into the infratemporal fossa often benefited from additional lateral exposure using a Caldwell-Luc maxillotomy. Cases with significant skull base and/or dural involvement may undergo staged surgical treatment; temporalis + transzygomatic craniotomy is often useful for second-stage approaches for residual tumor in these lateral infratemporal or intracranial regions. SRS should be considered for residual tumor if additional surgery is not warranted.

Morphometric analysis of the infratemporal fossa using three-dimensional (3D) digital models

PURPOSE

The infratemporal fossa contains important neurovascular components and is directly related to other anatomical regions and structures. The morphometric distances between the bones forming its borders have not been thoroughly investigated. The aim of this study was to determine the morphometry of the infratemporal fossa.

METHODS

3D models of the skull of 83 individuals were reconstructed from DICOM datasets, from which length, depth and width measurements were determined and compared between genders and the right and left sides.

RESULTS

All measurements obtained were significantly different between males and females. There were also significant differences between the left and right sides for depth and width measurements.

CONCLUSION

This is the first study to determine and investigate measurements of the infratemporal fossa; as such it provides a comprehensive view of the morphology of the fossa. It provides valuable information for surgical interventions and differential diagnoses of pathologies in this region, as well as enhancing its understanding in medical education.

Access to Pterygopalatine and Infratemporal Fossa Region by Newer Maxillary Suprastracture Swing Technique: A Report of Two Cases

Surgical access to pterygopalatine and infratemporal fossa has always been important for head and neck surgeons to deal with various benign and malignant tumours. Technical advancements leading to advent of microdebrider, coblation instruments and endoscopes, have proved helpful in gaining access to these complex anatomical areas, by way of endoscopic endonasal approaches but availability of instruments and learning curve remains a limiting factor. Thus older open surgical techniques like maxillary swing, Le Fort osteotomies and midfacial degloving still holds their importance in providing direct open access to these areas. We share our experience of the newer maxillary suprastracture swing technique in gaining direct open surgical access to these anatomical regions for two different cases i.e. neurofibroma located in infratemporal fossa and JNA involving both pterygopalatine and infratemporal fossa.

Synchronous pleomorphic adenoma in the infratemporal fossa and contralateral submandibular gland and endoscopic removal

The objective of this article is to elucidate on our experience with the first case reported in the literature of a synchronous presentation of pleomorphic adenoma (PA) in infratemporal fossa as well as the contralateral submandibular gland. PA most commonly arises from the major salivary glands but has also been reported to arise from minor salivary glands in unusual sites such as the nasal septum, main stem bronchus, trachea, lacrimal gland, external auditory canal, etc. However, it seldom involves the infratemporal fossa and extremely few cases are reported in the literature and coexistent contralateral synchronous PA is nowhere reported in literature. The infratemporal fossa tumour posed a diagnostic dilemma and therapeutic challenge because of its concealed location which we dealt successfully with endoscopic sublabial trans maxillary approach.

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.

An Extremely Rare Epithelioid Sarcoma Arising from the Infratemporal Fossa: A Case Report and Literature Review

INTRODUCTION

Epithelioid sarcoma (ES) is a rare histopathological type of soft tissue sarcoma. They are subcutaneous soft tissue masses that tend to arise in extremity sites (the classic type, formerly referred to as distal type) or proximal midline region of the body (the proximal type), such as the perineum, genital tract, and pelvis. The head and neck regions are rarely affected by ES, but the infratemporal fossa (ITF) is extremely rare. ES involving the ITF has not been reported before in literature. In this paper, the imaging features of ES were reviewed in detail, and the anatomical structure and epidemiology of ITF were briefly introduced.

SOURCES

We performed a systematic search from 3 databases, CNKI(China National Knowledge Internet), FMRS(Foreign Medical Literature Retrieval Service, Shenzhen METSTR Technology CO., Led. China), and PubMed, to obtain literature from January 1970 to July 2020. Epithelioid sarcoma, head and neck regions, infratemporal fossa, diagnostic imaging, anatomy, MRI, and CT were used as keywords for advanced retrieval. A study had to be found eligible for inclusion to be closely related to ES and/or ITF. A total of 129 related pieces of literature were retrieved successfully, of which 37 were closely related to this study. The case report in this article is from the Affiliated Hospital of North Sichuan Medical College. The present study was approved by the institutional review board of the Affiliated Hospital of North Sichuan Medical College and a written informed consent for the publication of the case was obtained from the patient.

CASE PRESENTATION

A 33-year-old man accidentally found a slowly growing, painless mass in the left cheek more than a month ago. On plain computed tomography (CT) scan of the outpatient department, an oval slightly low-density mass with well-defined and uniform boundary in the infratemporal fossa was revealed, and on the contrast-enhanced scan, it was homogeneous and moderately enhanced. Initially, the CT appearance favored benign lesions. However, the possibility of a malignant tumor can not be excluded completely. Finally, the patient was referred to the inpatient department a tumor arose from IF and underwent a selective operation. The tumor was completely removed. Histologic findings were compatible with epithelioid sarcoma. Post-operatively, the patient received 2 cycles of radiotherapy, and there was no evidence of recurrence after 6 months follow- up.

CONCLUSION

The imaging manifestations of ES are various. The anatomic structure of ITF is complex and the pathological types are various. It should be very careful in the qualitative diagnosis of tumors from the ITF, and advanced imaging techniques will be useful in imaging diagnosis.

Endoscopic transorbital approach to the infratemporal fossa and parapharyngeal space: a cadaveric study

OBJECTIVE

The infratemporal fossa (ITF) and parapharyngeal space are anatomical regions that can be challenging to access without the use of complex, cosmetically disfiguring approaches. With advances in endoscopic techniques, a new group of surgical approaches to access the intracranial space through the orbit has been recently referred to as transorbital neuroendoscopic surgery (TONES). The objective of this study was to establish a transorbital endoscopic approach utilizing the inferior orbital fissure (IOF) to gain access to the ITF and parapharyngeal space and provide a detailed endoscopic anatomical description of this approach.

METHODS

Four cadaveric heads (8 sides) were dissected using a TONES approach through the IOF to reach the ITF and parapharyngeal space, providing stepwise dissection with detailed anatomical findings and a description of each step.

RESULTS

An inferior eyelid approach was made with subperiosteal periorbital dissection to the IOF. The zygomatic and greater wing of the sphenoid were drilled, forming the boundaries of the IOF. The upper head of the lateral pterygoid muscle in the ITF and parapharyngeal space was removed, and 7 distinct planes were described, each with its own anatomical contents. The second part of the maxillary artery was mainly found in plane 1 between the temporalis laterally and the lateral pterygoid muscle in plane 2. The branches of the mandibular nerve (V3) and middle meningeal artery (MMA) were identified in plane 3. Plane 4 was formed by the fascia of the medial pterygoid muscle (MTM) and the tensor veli palatini muscle. The prestyloid segment, found in plane 5, was composed mainly of fat and lymph nodes. The parapharyngeal carotid artery in the poststyloid segment, found in plane 7, was identified after laterally dissecting the styloid diaphragm, found in plane 6. V3 and the origin of the levator and tensor veli palatini muscles serve as landmarks for identification of the parapharyngeal carotid artery.

CONCLUSIONS

The transorbital endoscopic approach provides excellent access to the ITF and parapharyngeal space compared to previously described complex and morbid transfacial or transcranial approaches. Using the IOF is an important and useful landmark that permits a wide exposure.

Infratemporal fossa surgical approaches to primary/recurrent malignancies of salivary origin: paradigm surgical shift, patient selection, and oncologic outcomes

PURPOSE OF REVIEW

To review, the surgical approaches available on diagnosing a patient with salivary gland malignancy in the infratemporal fossa (ITF). To comment on patient evaluation and method of treatment selection. To identify and report on patient outcome data and make recommendations on future needs.

RECENT FINDINGS

There is a need to define the anatomic boundaries contents of the ITF, masticator space, parapharyngeal space (PPS), pterygopalatine fossa, ventral skull base, and paramedian skull base, as evidence from publications. The pathological subtypes identified mainly include adenoid cystic and mucoepidermoid carcinomas. The source of these tumours originates from primary disease in the sinonasal tract and nasopharynx superiorly, and the PPS/deep lobe of parotid inferiorly. Current surgical options available, in suitable selected patient, available in tertiary head and neck cancer hospitals, which have available facilities and staffing is the endoscopic endonasal approach. This approach offers patients a 'complete margin-free surgical excision', minimal complications, shorter hospital stay, and no delay with commencement of any adjuvant treatment compared with the traditional 'open transcutaneous' approach.

SUMMARY

The current evidence specifically to the surgical management of salivary gland malignancy involving the ITF is sparse, with great difficult identifying treated patients and their details among a heterogeneous group of patients with many lesions. There is a need for patient data that have specific pathologic conditions to be amalgamated from such centers and publish on outcome events.

An unusual presentation of pleomorphic adenoma in a patient with thalassemia: A case report

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Pleomorphic adenoma benign mixed tumor is a benign heterogeneous tumor.

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Infratemporal fossa infarcted neoplasms may present clinically as an abscess.

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The combination of CT scan and MRI might be a helpful diagnostic tool.

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Treatment of Infratemporal fossa infarcted neoplasms tumors is surgical.

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Transcervical approach allows excellent control of the tumor and neurovascular elements.

We report the first case of spontaneous infarction occurring in pleomorphic adenoma located in infratemporal fossa mimicking parapharyngeal abscess, including clinical presentation, workups, and surgical approach. The final diagnosis was confirmed on a histological basis. The combination of CT scan and MRI might be helpful in distinguishing neoplasia from abscess collection in this area. Surgical intervention is the treatment of choice.

Benign temporomandibular joint tumours with extension to infratemporal fossa and skull base: condyle preserving approach

This article introduces a modified surgical approach combining condylotomy with posterior disc attachment release for the resection of large non-malignant masses located in the infratemporal fossa and involving the skull base. This retrospective study included 14 patients treated at Shanghai Ninth People's Hospital, Shanghai Jiao Tong University between January 2010 and December 2016. Clinical evaluations (visual analogue scale (VAS) for pain, maximum inter-incisal opening (MIO), and complications) and radiological findings (magnetic resonance imaging (MRI) and computed tomography (CT)) were collected pre- and postoperatively. All patients had satisfactory surgical exposure and complete resection of the neoplasms. During an average follow-up of 54.8 months, no clinical or radiographic signs of recurrence were reported. MIO increased from 28mm preoperatively to 35.4mm postoperatively (P<0.001). The pain VAS score changed from 5.4 preoperatively to 0.7 postoperatively (P<0.001). Neural function was normal for all patients. Postoperative MRI and CT scans showed a satisfactory disc position and condyle morphology, with no resorption. Three-dimensional reconstruction of the postoperative CT scan also demonstrated healing of the skull base defects. The modified surgical approach combining condylotomy with posterior disc attachment release is suitable for the removal of large non-malignant masses involving the infratemporal fossa and skull base.

Analysis of the far-medial transoral endoscopic approach to the infratemporal fossa

OBJECTIVES/HYPOTHESIS

To demonstrate anatomic relationships of the far-medial transoral endoscopic assisted approach (FMT-EAA) to the infratemporal fossa (ITF) and define the corridor dimensions, surgical freedom, and limitations associated with this approach.

STUDY DESIGN

Cadaveric study.

METHODS

Twenty ITFs (10 specimens) were dissected with the assistance of 0 °, 30 °, and 45 ° rod-lens endoscopes. Image guidance was used to confirm and measure the corridors' structural boundaries and document the anatomical relationships encountered in this approach.

RESULTS

Access to the ITF via the FMT-EAA can be divided into two secondary surgical corridors: the superomedial and inferolateral triangles, each of which provides access to different areas. The superomedial triangle is bounded medially by the lateral pterygoid plate and posterolateral maxillary sinus wall, superiorly by the greater sphenoid wing, and inferolaterally by the lateral pterygoid muscle. The inferolateral triangle is bounded superiorly by the lower head of the lateral pterygoid muscle, inferiorly by the medial pterygoid muscle, and laterally by the mandible. Using a standard 19-mm endoscope, the FMT-EAA achieves a mean surgical freedom of 231 mm and 161 mm in the vertical and horizontal planes, respectively.

CONCLUSIONS

FMT-EAA adequately exposes critical structures of the ITF. This technique is a viable option for the management of selected ITF lesions, either alone or in combination with alternative minimally invasive approaches to the region.

LEVEL OF EVIDENCE

NA Laryngoscope, 128:2273-2281, 2018.

Recurrent Ameloblastoma: A Surgical Challenge

Ameloblastoma is locally aggressive benign odontogenic tumour with increased risk of recurrence rate. The choice of treatment depends on the histologic subtype. Radical therapy is the recommended modality for solid ameloblastomas. The possibilities of recurrence even after enbloc resection are still high. The author presents two case reports of recurrent ameloblastomas postradical resection. First case describes the recurrence of ameloblastoma in the bone graft which was used for reconstruction, and the second case depicts recurrence in the infratemporal fossa. Intraoperative radiography of the frozen section of the soft tissue margin plays an important role in the holistic management of these lesions.

Endoscopic Transnasal Transpterygoid Excision of an Infratemporal Dermoid Cyst

OBJECTIVE

Intracranial dermoid cysts are rare, slow-growing masses of sellar, parasellar regions, and posterior cranial fossa. The symptomatology of these cysts depends on the localization and presence of rupture. The preoperative diagnosis of these cysts by imagining techniques is distinctive as they have characteristic appearances.

PATIENT

Endoscopic transnasal transpterygoid approach to infratemporal fossa for an extradural dermoid cyst of a 24 year-old woman is presented in this clinical report. Headache, dizziness, and retro orbital pain were her main complaints and diagnostic imagining studies designated an intracranial dermoid cyst preoperatively. The cyst was excised uneventfully with no recurrence 6 months after the operation.

CONCLUSION

Surgery of intracranial lesions neighboring critical vital neurovascular structures can be challenging to the surgeon. Alternative minimal invasive approaches should always be considered for averting life-threatening complications.

Auricular complications in parotid, temporal bone, infratemporal fossa, and lateral skull base surgery

Neoplasms located in the parotid region, temporal bone, infratemporal fossa, and lateral skull base represent a challenge due to their difficult anatomic location and surrounding neurovascular structures. A variety of surgical approaches are appropriate to access this area, although several of them can place the auricular blood supply in danger. If the auricular blood supply is compromised, ischemia and, eventually, avascular necrosis of the auricle can occur. Auricular necrosis often can cause patients a delay in adjuvant radiation therapy and result in the need for additional reconstructive procedures. Therefore, it is imperative to identify risk factors associated with the development of this disabling complication. We conducted a retrospective review of 32 individuals undergoing treatment of benign and malignant lesions in the parotid gland, infratemporal fossa, and lateral skull base. To identify potential risk factors for auricular necrosis, the patients were analyzed based on the type of neoplasm (malignant or benign), risk factors affecting blood flow (diabetes mellitus, smoking history, prior radiation, prior surgery), body mass index, and the length of surgery. In our population examined, 3 instances of auricular necrosis occurred. None of the potential risk factors proved to be statistically significant (although malignant pathology approached significance at p = 0.07). Two of the patients required an auriculectomy with reconstruction. The third had multiple postoperative clinic visits for surgical debridement. Although no potential risk factors were statistically significant, surgeons should remain cognizant of the auricular blood supply while performing surgery via preauricular and postauricular approaches to this area.

An unusual foreign body in the infratemporal fossa

Infratemporal fossa injuries are uncommon and often go undetected presenting later with complications. We present a case of an infratemporal fossa penetrating injury with a ball point spring following a vehicular accident. Post-traumatic trismus even following supposedly trivial injury in the area should raise suspicion of possible injury in this location.

The pterygopalatine fossa: imaging anatomy, communications, and pathology revisited

Abstract

The pterygopalatine fossa (PPF) is a small, clinically inaccessible, fat-filled space located in the deep face that serves as a major neurovascular crossroad between the oral cavity, nasal cavity, nasopharynx, orbit, masticator space, and the middle cranial fossa. Due to its inherent complex location and connections, it can potentially act as a natural conduit for the spread of inflammatory and neoplastic diseases across the various deep spaces in the head and neck. This review aims to acquaint the reader with the imaging anatomy of the PPF, its important communications, and to identify some major pathological conditions that can involve the PPF, especially in conditions where its involvement can have serious diagnostic and therapeutic implications, such as in perineural tumour spread.

Teaching points

• The PPF is a small neurovascular junction in the deep face with important to-and-fro connections.

• Awareness of anatomy of the PPF and its communications helps to simplify imaging of its pathology.

• Perineural tumour spread is clinically the most important pathology in this region.

A novel approach to neoplasms medial to the condyle: a condylectomy with anterior displacement of the condyle

Resecting neoplasms involving the infratemporal space has a high risk of damaging critical nerves and vessels, in addition to joint form and function. The purpose of this study was to introduce a novel approach to lesions medial to the condyle, which comprises a condylectomy with anterior displacement of the condyle. The indications evaluated using digital surgical simulation, the critical surgical technique, and the preliminary clinical effects are presented here. Five cases underwent this approach between January 2006 and December 2014. The common characteristics of the five masses were (1) that they were non-malignant neoplasms involving the posterior-medial region of the condyle; (2) the upper and lower borders were between the skull base and the lingula, while the anterior border did not exceed the coronoid process. All masses were resected successfully with no damage to any critical nerves or vessels. The average follow-up period was 29.8 months (range 6-56 months). There was no recurrence, secondary deformity, or facial paralysis. The average mouth opening improved from an original 27 mm to 34 mm after surgery. The condyles were well fixed, with no resorption, as shown on computed tomography scans.

Application of a computer-aided navigation technique in surgery for recurrent malignant infratemporal fossa tumors

BACKGROUND

Because of the complexity of the local anatomy, tumors in the infratemporal fossa present a great challenge to oral and maxillofacial surgeons. Recurrent malignant tumors in this area are particularly difficult and precarious to resect because scars from previous operations may dislocate some important structures.

METHODS

From August 2010 to December 2013, all recurrent cases of malignant infratemporal fossa tumors at Peking University Stomatological Hospital were enrolled in this study. The patients were divided into 2 groups: the navigation group and the nonnavigation group, with different managements. The following factors were evaluated: operation time, bleeding volume, tumor size, surgical approach and complications, follow-up survey, and outcomes.In addition, survival analyses were performed for all patients.

RESULTS

In total, 42 patients were investigated. The mean operation time for the navigation group was not significantly longer than that of the nonnavigation group (283.64 versus 252.10 min, respectively; P = 0.393); the group's mean intraoperative bleeding volumes were similar (536.36 versus 503.87 mL, respectively; P = 0.814). The surgical approach was determined and categorized as an inferior approach (transmandibular approach, with or without splitting of the mandible), anterior approach (transmaxillary approach), lateral approach (subtemporal-preauricular approach), or combined approach. The inferior approach was most frequently used in both groups (ie, 63.6% for the navigation group and 80.6% for the nonnavigation group). The tumors were completely resected in 4 patients from the navigation group and 24 patients from the nonnavigation group. Regarding complications in the navigation and nonnavigation groups, the incidence was not significantly different (27.2% versus 41.9%, respectively; P = 0.485). The 3-year survival for patients in the navigation group was 71.6% compared with 52.9% in the nonnavigation group, with no significant difference. In the survival analysis, no significant factor was determined.

CONCLUSIONS

A computer-aided navigation technique has been successfully introduced to resect infratemporal fossa tumors and was successfully applied to the resection of recurrent malignant tumors. This new technique alone does not determine the outcome of patients with recurrent malignant infratemporal fossa tumors. Although some improvements are necessary, the visible navigation during surgery could increase the accuracy and safety of the operations and enhance surgeon confidence.

Surgical Management of a Functional Paraganglioma of the Infratemporal Fossa

Background Paragangliomas are rare neural crest tumors that can manifest in the head and neck as either functional or more commonly as nonfunctional lesions. Paragangliomas of the infratemporal fossa are exceedingly rare, with no more than a handful of documented cases. Like other tumors of this space, surgical management is challenging on account of complex anatomy and nearby critical structures.

Methods A 44-year-old man presented with a right infratemporal fossa functional paraganglioma. Following preemptive embolization and autonomic pharmacotherapy, his tumor was successfully resected via a transfacial maxillary swing approach.

Results This case highlights the surgical management of a functional paraganglioma of the infratemporal fossa while demonstrating the effectiveness of a transfacial maxillary swing approach for both exposure and resection.

Conclusion Although this report summarizes much of the literature on paragangliomas, there is still much to uncover regarding the fundamental features and genetic etiology of these lesions.

Combined endonasal and sublabial endoscopic transmaxillary approach to the pterygopalatine fossa and orbital apex

BACKGROUND

The pterygopalatine fossa (PPF) and inferomedial orbital apex are difficult regions for open neurosurgical access. The traditional extensive anterior approach (transfacial or transmandibular) and lateral/posterolateral (transcranial) approach were used to access the PPF. The combined endonasal and sublabial transmaxillary approach is a less invasive access route for these lesions. In this study, we present the technical and clinical details of our experience with the combined endoscopic endonasal and transmaxillary approach.

METHODS

A retrospective analysis of our patients operated on using a combined endoscopic endonasal and transmaxillary approach was done. The preoperative, intraoperative and postoperative images and all the clinical data were evaluated. The accessibility to the area and extent of surgical resection were reviewed. The surgery-related complications and postoperative morbidities were analyzed. The main items of interest were the exposure of the target area and possibility for safe removal.

RESULTS

Five patients with pathologies located in the area of the PPF and orbital apex were operated on using the combined endoscopic sublabial and endonasal transmaxillary approach. The technique provided sufficient exposure of the area and allowed for safe removal of the preoperatively determined target in all of the patients. One patient developed dry eye and a neurotrophic corneal ulcer, and another patient developed temporary postoperative facial numbness. In the follow-up, only one patient with skull base chordoma had an asymptomatic tumor regrowth. The other patients had no recurrence or regrowth.

CONCLUSIONS

The combined endoscopic sublabial and endonasal transmaxillary approach is a safe and effective method for resection of lesions in the PPF and inferomedial orbital apex.

Endoscopic versus Open Approach to the Infratemporal Fossa: A Cadaver Study

Introduction Various lateral and anterior approaches to access the infratemporal fossa (ITF) have been described. We provide our observations regarding the endoscopic transpterygoid and preauricular subtemporal approaches, listing their respective advantages and limitations through cadaveric dissection. Methods A cadaver study was performed on five adult specimens. An endoscopic transpterygoid approach to the ITF was completed bilaterally in three specimens, and an open preauricular ITF approach was performed bilaterally in two specimens. Results After completing the cadaveric dissections, we studied differences between the endoscopic transpterygoid approach and open preauricular subtemporal approaches in regard to exposure and ease of dissection of different structures in the ITF. Conclusions In comparison with a lateral approach, the endonasal endoscopic transpterygoid approach provides better visualization and more direct exposure of median structures such as the nasopharynx, eustachian tube, sella, and clivus. We concluded that the endoscopic transpterygoid approach can be utilized to resect benign lesions and some select group of malignancies involving the infratemporal and middle cranial fossae. Open approaches continue to play an important role, especially in the resection of extensive malignant tumors extending to these regions.

Mini-invasive surgery of infratemporal fossa schwannomas

Background:

Infratemporal fossa schwannomas are benign, encapsulated tumours of the trigeminal nerve limited to the infratemporal fossa. Because of the complications and significant morbidity associated with traditional surgical approaches to the infratemporal fossa, which include facial nerve dysfunction, hearing loss, dental malocclusion and cosmetic problems, less invasive alternatives have been sought.

Methods:

This paper reports two cases of infratemporal fossa schwannomas treated in 2012 using mini-invasive approaches. The literature regarding different infratemporal fossa approaches was reviewed.

Results:

The first schwannoma was 30 mm in size and was removed completely by a preauricular subtemporal approach. The second one was 25 mm in size and was removed completely using a purely transnasal endoscopic approach. In both cases, there were no intra-operative or post-operative complications.

Conclusion:

These two approaches allow non-invasive and wide exposure of the infratemporal fossa as compared to classical approaches. Surgical approach should be selected according to the tumour's anatomical location with respect to the maxillary sinus posterior wall. The preauricular subtemporal approach is recommended for tumours localised posterolaterally with respect to the maxillary sinus posterior wall. Medial and anterior tumours near the maxillary sinus posterior wall can be best removed using a transnasal endoscopic approach.

Synovial sarcoma of the infratemporal fossa: A case report

Synovial sarcomas (SS) are high-grade soft-tissue sarcomas, predominantly found in the deep soft tissues of the lower extremities, with only 3-5% occurring in the head and neck region. Primary SS of the infratemporal fossa (ITF) is exceptionally uncommon. The present study reports the case of a 23-year-old female with an SS arising in the ITF. To the best of our knowledge, this case is only the second patient with intracranial involvement recorded in the literature. The patient was treated primarily with surgery, followed by a total of 60 Gy adjuvant radiotherapy and chemotherapy, consisting of cisplatin (25 mg/m² intravenously on days one to three), epirubicin (25 mg/m² intravenously on days one and two) and ifosfamide (1.8 g/m² intravenously on days one to five) for three cycles. At present, two years after this multimodal therapy, the patient exhibits no signs of loco-regional recurrence or distant metastases. This study highlights the importance of a multidisciplinary approach in the diagnosis and treatment of this extremely rare entity with intracranial extension. In addition, the study reviews the English literature with regard to SS of ITF and discusses the clinicopathological features, management and outcome.

Clinical correlates of the anatomical relationships of the foramen ovale: a radioanatomical study

Introduction Endonasal endoscopic transpterygoid approaches are commonly used techniques to access the infratemporal fossa and parapharyngeal space. Important endoscopic endonasal landmarks for the poststyloid parapharyngeal space, hence the internal carotid artery, include the mandibular nerve at the level of foramen ovale and the lateral pterygoid plate. This study aims to define the anatomical relationships of the foramen ovale, establishing its distance to other important anatomical landmarks such as the pterygoid process and columella. Methods Distances between the foramen ovale, foramen rotundum, and fixed anatomical landmarks like the columella and pterygoid process were measured using computed tomography (CT) scans and cadaveric dissections of the pterygopalatine and infratemporal fossae. Results The mean distances from the foramen ovale to columella and from the foramen rotundum to columella were found to be 9.15 cm and 7.09 cm, respectively. Analysis of radiologic measurements detected no statistically significant differences between sides or gender. Conclusions The pterygoid plates and V3 are prominent landmarks of the endonasal endoscopic approach to the infratemporal fossa and poststyloid parapharyngeal space. A better understanding of the endoscopic anatomy of the infratemporal fossa and awareness of the approximate distances and geometry among anatomical landmarks facilitates a safe and complete resection of lesions arising or extending to these regions.

Endonasal, transmaxillary, transpterygoid approach to the foramen ovale: radio-anatomical study of surgical feasibility

Objective:

This study aimed to examine the feasibility of an endonasal, transmaxillary, transpterygoid approach to the foramen ovale by examining key anatomical, radiological and surgical landmarks.

Method:

Measurements were taken from 183 patients' computed tomography scans using BrainLAB iPlan 1.1 Cranial software. Endoscopic dissection was then carried out on a cadaver to assess surgical viability.

Results:

We found that the distances from the posterior maxillary wall to the foramen ovale and from the anterior nasal spine to the foramen ovale were statistically significantly larger in men than women. The distance from the base of the lateral pterygoid plate to the foramen ovale, and the angle between the foramen ovale, the anterior nasal spine and the sphenoid rostrum, were constant between the sexes. The importance of the lateral pterygoid plate in locating the foramen ovale was demonstrated.

Conclusion:

With the increasing popularity of image guidance and assisted navigation in endoscopic surgery, these findings increase anatomico-radiological understanding of the surgical approach investigated.

Evaluating endoscopic and endoscopic-assisted access to the infratemporal fossa: a novel method for assessment and comparison of approaches

OBJECTIVES/HYPOTHESIS

Endoscopic infratemporal fossa (ITF) surgery is a growing clinical interest. This study presents a method of analyzing approach access and visualization, identifies relevant anatomy in an endoscopic approach to the ITF, and compares endoscopic medial maxillectomy (MMA) and endoscopic-assisted sublabial transmaxillary (SLT) approaches to the ITF as a model for this paradigm.

STUDY DESIGN

Human cadaver anatomic study.

METHODS

Five human cadaver heads (10 ITF dissections) were used. An SLT and MMA were performed on each side. For endoscopic dissections of the ITF, 0° and 30° endoscopes were used. Key landmarks were the posterior maxillary sinus wall, temporomandibular joint, pterygoid plates, foramen spinosum, and foramen ovale. Open dissection was used to confirm ITF landmarks. A novel measurement method using angles of approach and visualization was used to compare approaches.

RESULTS

Visualization and mobility in SLT and MMA were significantly different. The lateral extent and greatest average depth for dissection was 7.9 cm in MMA and 6.1 cm for SLT. The average angle of mobility in approach was 36.3° for MMA and 57.9° for SLT. Average visualization was 40.2° for MMA and 126.5° for SLT. Despite these differences, both surgical approaches allowed access and visualization to all targeted landmarks.

CONCLUSIONS

This evaluation paradigm provides useful data in evaluating an endoscopic or endoscopic-assisted approach to the ITF. Using this paradigm, the SLT and MMA were analyzed. Each provided adequate access to the ITF, but visualization and maneuverability were better in SLT.

Graduated endoscopic multiangle approach for access to the infratemporal fossa: a cadaveric study with clinical correlates

OBJECTIVE

The infratemporal fossa (ITF) has historically been one of the most difficult regions of the skull base to access surgically. Available open approaches are complex, are associated with high morbidity, and do not always afford optimal visualization. Endoscopic access to the ITF improves visualization for management of many sinonasal and lateral skull base lesions involving this region. The purpose of this study is to evaluate a graduated multiangle approach for endoscopic access to this area using a cadaveric model.

STUDY DESIGN AND SETTING

Cadaveric study at an academic medical center.

METHODS

Endoscopic dissection was performed on a total of 10 sides of 5 fresh cadaveric heads. Four different approaches to the ITF were studied: ipsilateral endonasal, endoscopically assisted Caldwell-Luc, contralateral endonasal via septotomy, and endoscopically assisted Gillies transtemporal. High-quality endoscopic pictures and high-definition videos of each technique were obtained in order to document the differences in access achieved with each approach.

RESULTS

The combination of the 4 different endoscopic techniques allowed complete access to all areas of the ITF. The endoscopically assisted Caldwell-Luc improved anteroposterior access, the contralateral septotomy approach resulted in excellent far lateral access, and the endoscopically assisted Gillies approach allowed posterosuperior visualization and instrumentation.

CONCLUSION

Endoscopic access to the ITF can be accomplished by each of the 4 methods described. A multiangle, graduated approach can provide surgeons the ability to customize surgical access depending on the location of a specific lesion within the ITF.

Microanatomy and surgical approaches to the infratemporal fossa: an anaglyphic three-dimensional stereoscopic printing study

OBJECTIVE

The infratemporal fossa (ITF) is a continuation of the temporal fossa between the internal surface of the zygoma and the external surface of the temporal bone and greater wing of the sphenoid bone that is sitting deep to the ramus of the mandible. The principal structure to understanding its relationships is the lateral pterygoid muscle. Other important structures are the medial pterygoid muscle, the maxillary artery, the pterygoid venous plexus, the otic ganglion, the chorda tympani nerve and the mandibular nerve. In this study, we describe the microsurgical anatomy of the ITF, as viewed by step-by-step anatomical dissection and also through the perspective of three lateral approaches and one anterior surgical approach.

METHODS

Eight cadaver specimens were dissected. In one side of all specimens, an anatomical dissection was done in which a wide preauricular incision from the neck on the anterior border of the sternoclidomastoid muscle at the level of the cricoid cartilage to the superior temporal line was made. The flap was displaced anteriorly and the structures of the neck were dissected followed by a zygomatic osteotomy and dissection of the ITF structures. On the other side were the surgical approaches to the ITF. The combined infratemporal and posterior fossa approach was done in two specimens, the subtemporal preauricular infratemporal fossa approach in two, the zygomatic approach in two, and the lateral transantral maxillotomy in two. The anatomical dissections were documented on the three-dimensional (3D) anaglyphic method to produce stereoscopic prints.

RESULTS

The lateral pterygoid muscle is one of the principal structures to enable understanding of the relationships into the ITF. The tendon of the temporal muscle inserts in the coronoid process at the ITF. The maxillary artery is the terminal branch of the external carotid artery that originates at the neck of the mandible and runs into the parotid gland. In our dissections the maxillary artery was lateral to the buccal, lingual, and inferior alveolar nerves. We found the second part of the maxillary artery superficial to the lateral pterygoid muscle in all specimens The anterior and posterior branches of the deep temporal artery supply the temporal muscle. In two cases we found a middle deep temporal artery. The different approaches that we used provided different views of the same anatomical landmarks and this provides not only safer surgery but also the best choice to approach the ITF according with the pathology extension.

CONCLUSIONS

The ITF is a complex region on the skull base that is affected by benign and malignant tumors. The study through different routes is helpful to disclose the relationship among the anatomical structures. Although the authors have shown four approaches, there are a variety of approaches and even a combination of these can be used. This type of anatomical knowledge is essential to choosing the best approach to treat lesions in this area.

Endoscopic Approach to the Infratemporal Fossa

OBJECTIVE

Classic surgical exposures of the infratemporal fossa region, including the adjacent intracranial space, temporal bone, and sinonasal region, require the extensive exposure associated with the transcranial, transfacial, and transmandibular approaches with their inherent neurological and cosmetic morbidities. In this study, we evaluated the feasibility and exposure afforded by combining 2 endoscopic transmaxillary approaches, endonasal and Caldwell-Luc supplement, to the infratemporal fossa.

METHODS

Endoscopic transmaxillary dissection was performed in 4 formalin-fixed cadaver heads (8 sides). We quantified the extent of exposure achieved within the pterygopalatine and infratemporal fossae after our initial dissection, which was endonasal with a medial antrostomy, and after addition of a Caldwell-Luc incision with an anterior antrostomy. Complementing this anatomic study, we report on a patient in whom this endoscopic transmaxillary approach combining the endonasal and Caldwell-Luc approaches was used for resection of a trigeminal schwannoma in the infratemporal fossa.

RESULTS

The combination of these 2 endoscopic transmaxillary approaches enabled visualization of the entire region of the pterygopalatine fossa and anteromedial aspect of the infratemporal fossa. Additional posterolateral exposure of the infratemporal fossa requires significant traumatic traction on the nose. Addition of the Caldwell-Luc transmaxillary approach exposed the remainder of the infratemporal fossa, including the mandibular nerve and branches, middle meningeal artery, and even the distal cervical portion of the internal carotid artery.

CONCLUSION

Endoscopic exposure of the infratemporal fossa is feasible. Using the combination of the endonasal and Caldwell-Luc approaches for direct transmaxillary access significantly extended exposure, allowing safe and effective resection of infratemporal fossa lesions.