Combined biportal unilateral endoscopic endonasal and endoscopic anterior transmaxillary approach for resection of lesions involving the infratemporal fossa

Combined Endoscopic Transmaxillary Approach for Resection of an Extracranial V3 Schwannoma: 2-Dimensional Operative Video

Tumours of the pterygopalatine (PPF) and infratemporal fossa (ITF) are rare tumours and are difficult to access. The lateral cervical approach is hampered by the mandibular angle and the vascular nervous elements.1 The classic endonasal endoscopic medial maxillectomy approach has been developed over the past 2 decades but does not allow good control of the most lateral and inferior part of the ITF.2 The surgical video presents a 68-year-old woman with trigeminal neuralgia. The radiologic workup showed a trigeminal V3 schwannoma (TS) into the PPF and ITF. This tumor grew during the follow-up despite fractionated radiosurgery. A 2-dimensional intraoperative video illustrates the gross total removal of the TS through a combined endoscopic endonasal and transgingival transmaxillary approach. The combination of these 2 approaches allows on the one hand, a better view of the lateral and inferior part of the maxillary sinus and ITF and on the other hand, a gain of handling in the operating field and security for our surgical procedure.3 The mini-Caldwell-Luc approach gives good aesthetic results without stomatological complication. Neuralgia disappeared after the surgery, and a gross total resection was achieved, and no recurrence was observed during the follow-up. This combined approach is a good alternative of medial extended maxillectomy, which presents a risk for the lacrimal duct risk and postoperative aesthetic deformity because of the removal of the medial and anterior wall of the maxillary sinus. The patient consented to the procedure and publication of her image.

Anatomical Step-by-Step Dissection of Complex Skull Base Approaches for Trainees: Surgical Anatomy of the Endoscopic Endonasal and Endoscopic-Assisted Transmaxillary Transpterygoid Approaches

Introduction  The endoscopic endonasal transpterygoid approach (EETPA) with or without the addition of the endoscopic-assisted sublabial anterior transmaxillary approach (ESTA) has become increasingly utilized for lesions posterior to the pterygopalatine fossa (PPF), including infratemporal fossa (ITF), lateral recess of the sphenoid sinus, Meckel's cave, petrous apex, and parapharyngeal space. The main goal of this study is to develop an educational resource to learn the steps of the EETPA for trainees. Methods  EETPA and ESTA were performed in 12 specimens by neurosurgery trainees, under supervision from the senior authors. One EETPA and one ESTA were performed on each specimen on opposite sides. Dissections were supplemented with representative cases. Results  After a wide unilateral sphenoidotomy, ethmoidectomy, and partial medial maxillectomy, the anteromedial bone limits of the PPF were identified and drilled out. The pterygoid progress was modularly removed. By enlarging the opening of the posterior and lateral walls of the maxillary sinus through EETPA and ESTA, respectively, the neurovascular and muscular compartments of the PPF and ITF were better identified. The EETPA opens direct corridors to the PPF, medial ITF, middle cranial fossa, cavernous sinus, Meckel's cave, petrous apex, and internal carotid artery. If a more lateral exposure of the ITF is needed, the ESTA is an appropriate addition. Conclusion  Despite the steep learning curve of the EETPA, granular knowledge of its surgical anatomy and basic surgical steps are vital for those advancing their learning in complex endoscopic approaches to the ventral skull base when expanding the approach laterally in the coronal plane.

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.

Recent progress in endoscopic skull base surgery: Functional preservation and multiportal approaches

Over the past couple of decades, endoscopic skull base surgery (ESBS) has significantly evolved and is applied to a broad range of skull base pathologies, including sinonasal malignancies. Recent studies have demonstrated remarkable progress of ESBS in complete resection with low morbidity and extension of its application to larger and more complex lesions. In this review, we focus on the evolution of functional preservation and multiportal approaches. Progress in preoperative assessments and surgical techniques improved the preservation of olfactory function after ESBS. The technical feasibility of olfaction preservation even after resection of olfactory groove lesions has been reported. To overcome the limitations of extending use of the endoscopic endonasal approach in surgical fields, various types of multiportal approaches, including combinations of the endoscopic endonasal and transorbital, transmaxillary, or transoral approach, have been reported, as they are useful for complete resection of extensive pathologies while limiting morbidity. These innovative techniques are still in the process of maturation. Hence, an ongoing critical evaluation is essential to ensure efficacy.

Combined endoscopic endonasal transpterygoid and sublabial transmaxillary approaches for a large infratemporal fossa trigeminal schwannoma

BACKGROUND

Trigeminal schwannomas (TSs) with solitary extracranial location are rare, and surgical excision is challenging. In recent years, the endoscopic endonasal transmaxillary transpterygoid approach (EETPA) has been advocated as an effective strategy for TSs in the infratemporal fossa (ITF).

METHOD

We describe the steps of the EETPA combined with the sublabial transmaxillary approach for the surgical excision of a giant mandibular schwannoma of the ITF. Indications, advantages, and approach-specific complications are also discussed. The main surgical steps are shown in an operative video.

CONCLUSION

A combined EETPA and sublabial transmaxillary approach represents a safe and effective option for the surgical excision of extracranial TSs.