Minimally Invasive Lateral Endoscopic Multiport Approach to the Infratemporal Fossa: A Cadaveric Study

Advantages and caveats of endoscopic to the infratemporal fossa as isolated and combined techniques

Objective

Identify the benefits and caveats of combining minimal access approaches to the infratemporal fossa (ITF), such as the endoscopic transnasal, endoscopic transorbital, endoscopic transoral, and endoscopic sublabial transmaxillary approaches to address extensive lesions not amenable to a single approach. The study provides anatomical metrics including area of exposure and degree of surgical freedom.

Methods

Five human cadaveric specimens (10 sides) were dissected to expose and methodically analyze the anatomical intricacies of the ITF using the following minimal access approaches: endoscopic transnasal transpterygoid (EETA), endoscopic sublabial transmaxillary, endoscopic transorbital via infraorbital foramen, and endoscopic transoral techniques. Area of exposure at the pterygopalatine fossa and surgical freedom at the ITF were obtained for each approach.

Results

The endoscopic sublabial transmaxillary sinus and the combined approach afford a significantly greater exposure than an isolated EETA. The difference in exposure (mean) between the endoscopic sublabial transmaxillary and EETA was 1.62 ± 0.85 cm2 (p < 0.001), and the difference between the combined approach and EETA was 4.25 ± 0.85 cm2 (p < 0.001).

Conclusions

Combining minimal access endoscopic approaches to the ITF can provide significantly greater exposure than an isolated EETA; thus, providing enhanced access to address lesions with extensive involvement of the ITF, especially those with superolateral and inferolateral extensions. In addition, some approaches may have an adjunctive role to the resection, such as the endoscopic transoral approach offering the potential for early control of the internal maxillary artery and its branches, some of which may be supplying the tumor in the ITF; or the endoscopic transorbital approach yielding a direct line of sight to the superior ITF and middle cranial fossa.

Level of Evidence

NA.

Endoscopic Multiport Approach for Exenteration of the Infratemporal Fossa

OBJECTIVE

To demonstrate anatomic relationships pertinent to the endoscopic multiport approach to the infratemporal fossa (ITF). Discuss advantages and limitations of each individual approach.

STUDY DESIGN

Cadaveric study.

METHODS

Endoscopic and endoscopic-assisted endonasal transpterygoid, sublabial transmaxillary, endoscopic transorbital, and endoscopic transoral approaches to accessing the ITF were completed in five silicone-injected fresh cadaveric specimens (10 sides) with the assistance of 0, 30, and 45⁰ rods-lens endoscopes. Image guidance was used to confirm and document the anatomical relationships encountered in each approach.

RESULTS

The endonasal endoscopic transpterygoid approach provides better visualization and more direct exposure to median structures. Endoscopic-assisted sublabial transmaxillary approach enhances the field of exposure, angle of attack, and ease of instrumentation to the lateral part of the ITF. Endoscopic-assisted transorbital approach via the inferior orbital fissure provided cephalic and anterior access. Endoscopic-assisted transoral approach complements the access to lesions extending inferior to the hard palate or far lateral to the mandibular condyle.

CONCLUSIONS

A combination of minimal access infratemporal approaches can provide adequate exposure of the entire ITF while avoiding some of the morbidity associated with open approaches.

LEVEL OF EVIDENCE

NA Laryngoscope, 2023.

Endoscopic Paramaxillary Approach to the Infratemporal Fossa and Pterygomaxillary Space: Computer Modeling Analysis and Clinical Series

Objective Several different open and endoscopic approaches for the pterygomaxillary space and infratemporal fossa have been described. Limitations to these approaches include restricted exposure of the infratemporal fossa and difficult surgical manipulation.

Study Design Consecutive clinical cases utilizing a novel approach to access lesions in the infratemporal fossa and pterygomaxillary space were reviewed. Data was collected on pathology, lesion location, and surgical approach(es) performed. Computer modeling was performed to analyze the full extent of surgical access provided by the paramaxillary approach to the range of target locations.

Results Ten consecutive cases met inclusion criteria. Surgical access to the target lesion was achieved in all cases. Computer modeling of the approach derived the anatomical boundaries of the paramaxillary approach. Wide access to the posterior maxilla, and lateral or medial to the mandibular condyle allows for variability in endoscopic angles and access to more medial pterygomaxillary space lesions. The lateral extent is limited proximally only by the extent of cheek/soft tissue retraction and by the zygomatic arch more superiorly. The superior limit of dissection is at the temporal line.

Conclusion The endoscopic paramaxillary approach is a transoral minimally disruptive approach to the ITF and PS that provides excellent surgical exposure for resection of lesions involving these areas. Compared with previously described endoscopic approaches, there are no external incisions; tumor manipulation is straightforward without angled endoscopy, and all areas of the infratemporal fossa and pterygomaxillary space can be accessed.

Expanded Endonasal Approach for Resection of Extradural Infratemporal Fossa Trigeminal Schwannoma: 2-Dimensional Operative Video

The infratemporal fossa (ITF) is bounded superiorly by the skull base, specifically the greater wing of the sphenoid, which contains foramen ovale. It is bordered posteriorly by the temporal bone, including the petrous portion of the carotid canal, anteriorly by the posterior wall of the maxillary sinus, laterally by the mandible, and medially by the pterygoid body and lateral pterygoid plate.1-3 In this video, we report a case of a rare, exclusively extradural, schwannoma originating from the third division of the trigeminal nerve with a widened foramen ovale at the skull base. The tumor filled the ITF and extended laterally just through the sigmoid notch of the mandible. The patient complained of left cheek and lower jaw numbness and intermittent left jaw spasms. The tumor was deemed appropriate for endoscopic resection. To access the ITF, left-sided endoscopic sinus surgery, a modified endoscopic Denker's approach,4 and posterior nasal septectomy were first performed. A nasoseptal flap was also harvested in case an intraoperative cerebrospinal fluid (CSF) leak required repair. Dissection was carried out through the posterior wall of the maxillary sinus and pterygopalatine fossa to reach the ITF. Tumor resection was achieved through a 2-surgeon, 4-handed approach in which appropriate traction and countertraction were carefully applied to tease the tumor away from the skull base and dehiscent carotid canal. No CSF leak or carotid injury occurred, and the posterior maxillary sinus wall defect was repaired with the nasoseptal flap. The patient did well postoperatively. The patient consented to the procedure in a standard fashion.

Endoscopic Trans-Lateral Molar Approach to Infratemporal Fossa Lesions

BACKGROUND

To study the endoscopic trans-lateral molar (ETLM) approach to infratemporal fossa (ITF) lesions and analyze the advantages and disadvantages of this method.

METHODS

Four cases of ITF lesions were analyzed retrospectively. The clinical features, diagnosis and treatments, the operative process, and clinical applications of this surgical approach were discussed.

RESULTS

Postoperative pathologies were 2 pleomorphic adenomas, 1 schwannoma, and 1 inflammatory lesion. All patients had self-resolving cheek swelling and pharyngalgia in the short term, but 2 patients had numbness in the long term. There was no infection or bleeding in the postoperative period, and no difficulty in chewing after disease recovery. There was no tumor recurrence during the follow-up period.

CONCLUSION

The ETLM approach is convenient, minimally invasive, and allows complete excision of benign ITF lesions, posterior to the lateral pterygoid muscle and mainly below the level of the hard palate. It is a simple and direct access to the ITF, but it is a narrow access because of the limitations of bones and soft tissues. Appropriate patient selection is mandatory for successful surgery.

CT-MRI Image Fusion-Based Computer-Assisted Navigation Management of Communicative Tumors Involved the Infratemporal-Middle Cranial Fossa

Objective  Computed tomography (CT) and magnetic resonance imaging (MRI) are crucial for preoperative assessment of the three-dimensional (3D) spatial position relationships of tumor, vital vessels, brain tissue, and craniomaxillofacial bones precisely. The value of CT-MRI-based image fusion was explored for the preoperative assessment, virtual planning, and navigation surgery application during the treatment of communicative tumors involved the infratemporal fossa (ITF) and middle cranial fossa. Methods  Eight patients with infratemporal-middle cranial fossa communicative tumors (ICFCTs) were enrolled in this retrospective study. Plain CT, contrast CT, and MRI image data were imported into a workstation for image fusion, which were used for 3D image reconstruction, virtual surgical planning, and intraoperative navigation sequentially. Therapeutic effect was evaluated through the clinical data analysis of ICFCT patients after CT-MRI image fusion-based navigation-guided biopsy or surgery. Results  High-quality CT-MRI image fusion and 3D reconstruction were obtained in all eight cases. Image fusion combined with 3D image reconstruction enhanced the preoperative assessment of ICFCT, and improved the surgical performance via virtual planning. Definite pathological diagnosis was obtained in all four navigation-guided core needle biopsies. Complete removal of the tumor was achieved with one exception among the seven navigation-guided operations. Postoperative cerebrospinal fluid leakage occurred in one patient with recurrent meningioma. Conclusion  CT-MRI image fusion combined with computer-assisted navigation management, optimized the accuracy, safety, and surgical results for core needle biopsy and surgery of ICFCTs.

Endoscopic-Assisted Lateral Corridor to the Infratemporal Fossa: Proposal and Quantitative Comparison to the Endoscopic Transpterygoid Approach

Objective  This study was aimed to propose an expanded endoscopic-assisted lateral approach to the infratemporal fossa (ITF) and compare its area of exposure and surgical freedom with the endoscopic endonasal transptergyoid approach (EETA). Methods  Anatomical dissections were performed in five cadaver heads (10 sides). The ITF was first examined through the endoscopically assisted lateral corridor, herein referred to as the endoscopic-assisted transtemporal fossa approach (TTFA). After that, the EETA was performed and coupled with two sequential maxillary procedures (medial maxillectomy [MM], and endoscopic-assisted Denker's approach [DA]). Using the stereotactic neuronavigation, measurements of the area of exposure and surgical freedom at the foramen ovale were determined for the previously mentioned approaches. Results  Bimanual exploration of the ITF through the endoscopic-assisted lateral approach was achieved in all specimens. The DA (729 ± 49 mm ² ) provided a larger area of exposure than MM (568 ± 46 mm ² ; p <  0.0001). However, areas of exposure were similar between the DA and the TTFA (677 ± 35 mm ² ; p  = 0.09). The surgical freedom offered by the TTFA (109.3 ± 19 cm ² ) was much greater than the DA (24.7 ± 4.8 cm ² ; p <  0.0001), and the MM (15.2 ± 3.2 cm ² , p <  0.0001). Conclusion  The study demonstrates the feasibility of the proposed approach to provide direct access to the extreme extensions of the ITF. The lateral corridor offers an ideal working area in the posterior compartment of the ITF without crossing over important neurovascular structures. The new technique may be used alone in selected primary ITF lesions or in combination with endonasal approaches in pathologies spreading laterally from the nose or nasopharynx.

[Multimodal image fusion technology for diagnosis and treatment of the skull base-infratemporal tumors]

OBJECTIVE

To explore the value of incorporated multimodal image fusion technology with computer-aided design of the skull base-infratemporal tumor treatment.

METHODS

A retrospective study was carried out to enroll seventeen patients with skull base-infratemporal tumors treated at Peking University Hospital of Stomatology from February 2011 to September 2018. Plain CT, enhanced CT and MRI data were imported into the iPlan 3.0 software (BrainLab navigation system), and the image fusion was performed for each patient preoperatively. Then the three-dimensional images of the tumor, vital vessels and craniofacial bones were reconstructed to prepare virtual operation design. We evaluated the application of multimodal image fusion technology that had been incorporated with computer-aided planning during the navigation-guided biopsy or surgery, through the analysis of the biopsy and operation data and regular follow-up postoperatively.

RESULTS

The mean age of 17 patients (7 males and 10 females) was 46 years. Primary tumors occurred in 11 cases, and recurrent tumors in 6 cases. The size of the 17 tumors ranged from 2.9 cm to 9 cm, and the mean size was 4.35 cm. There were 7 cases with skull base bone destruction and/or intracranial extension, and 10 cases with tumors adjacent to the skull base. High-quality multimodal fused images were obtained in all the 17 cases. The spatial-position relationships of the tumors, adjacent craniomaxillofacial bones and vital vessels labeled with different colors were displayed well on the generated fusion images. The multimodal image fusion technology that incorporated with computer-aided three-dimensional reconstruction and then applied in navigation-guided biopsy or surgery showed that, preoperative analysis and virtual operation design functioned with good results, especially in cases with small tumor size, recurrence or illdefined borders in the skull base-infratemporal region. Operation was carried out in 16 cases after preoperative diagnosis and assessment, and 1 case was performed by navigation-guided biopsy only. The proportions of navigation-guided surgery and biopsy were 70.6% (12/17) and 17.6% (3/17) individually. The positive rate of pathologic diagnosis using navigation-guided biopsy was 100% (3/3). All the navigation-guided biopsies or operations were carried out successfully. Complications included 1 case of cerebrospinal fluid leak from a recurred meningioma patient postoperatively, and 1 case of facial paralysis resulting from parotid-gland deep lobe tumor. Most (14/15) tumors got complete removal with safe boundary through intra-operative navigation verification and post-operative imaging confirmation, except for one case of subtotal resection to avoid the injury of cavernous sinus. The pathological results of the tumors could be classified to mesenchymal (10), adenogenous (3), neurogenic (3) or epithelial (1) resources. The follow-up time ranged from 3 to 94 months, with the median follow-up time of 9 months.

CONCLUSION

Taking full advantages of individualized multimodal images, could help analyze the three-dimensional spatial position relationship of tumors, vital vessels and craniofacial bones properly, and then complete the virtual operation design well. The incorporated multimodal image fusion technology with navigation technology may improve the accuracy and safety of core needle biopsy and surgical treatment of skull base-infratemporal tumors.

Transoral (transvestibular-paramandibular) endoscopic approach for benign tumours in the infratemporal fossa

We describe a minimally invasive transoral approach to the infratemporal fossa, by means of endoscopy, which facilitates examination and resection of lesions in this area. Furthermore, we outline the technique employed and a case treated with this approach, which permits a rapid access with very low patient morbidity, due to the use of endoscopy and of transoral access, instead of traditional transfacial approaches.