Transorbital Endoscopic Approach for Middle Fossa Floor/Lateral Cavernous Sinus Meningioma: 2-Dimensional Operative Video

Exposure of the Cavernous Sinus via the Endoscopic Transorbital and Endoscopic Endonasal Approaches: A Comparative Study

OBJECTIVE

To compare the endoscopic transorbital approach (ETOA) and endoscopic endonasal approach (EEA) in terms of cavernous sinus (CS) exposure.

METHODS

Four cadaveric heads (8 sides) were dissected. The CS was accessed using the EEA and ETOA. Stereotactic measurements of the length of the main structures exposed, angles of attack, depths of surgical corridor, and areas of exposure were obtained and compared between the approaches. An illustrative case is also presented.

RESULTS

The endoscopic transorbital approach (ETOA) exposed the lateral and superior compartments of the CS without obstruction by the internal carotid artery (ICA). The EEA exposed all compartments after mobilizing the ICA. Both approaches enabled similar exposure of the cranial nerves. The depth of surgical corridor was significantly shorter with the ETOA (P < 0.01). The areas of lateral compartment exposure were similar. As the number of instruments placed into the surgical channel increased, the available angles of attack with the ETOA became smaller and were smaller than those of the EEA. In the clinical case presented, the tumor was successfully removed without complications.

CONCLUSIONS

The ETOA has the advantages of a sterile surgical channel, short operation time, little patient trauma, short surgical corridor, large exposure area, and interdural pathway; moreover, it allows dissection through the interdural space without entering the neurovascular compartment of the CS. Although the space for manipulation of instruments is limited, the ETOA is suitable for treating selected tumors in the superior and lateral compartments of the CS.

The Transorbital Approach, A Game-Changer in Neurosurgery: A Guide to Safe and Reliable Surgery Based on Anatomical Principles

During the last few years, the superior eyelid endoscopic transorbital approach has been proposed as a new minimally invasive pathway to access skull base lesions, mostly in ophthalmologic, otolaryngologic, and maxillofacial surgeries. However, most neurosurgeons performing minimally invasive endoscopic neurosurgery do not usually employ the orbit as a surgical corridor. The authors undertook this technical and anatomical study to contribute a neurosurgical perspective, exploring the different possibilities of this novel route. Ten dissections were performed on ten formalin-fixed specimens to further refine the transorbital technique. As part of the study, the authors also report an illustrative transorbital surgery case to further detail key surgical landmarks. Herein, we would like to discuss equipment, key anatomical landmarks, and surgical skills and stress the steps and details to ensure a safe and successful procedure. We believe it could be critical to promote and encourage the neurosurgical community to overcome difficulties and ensure a successful surgery by following these key recommendations.

Lateral Transorbital Endoscope-Assisted Approach to the Cavernous Sinus

BACKGROUND AND OBJECTIVES

Surgical access to the cavernous sinus (CS) poses a unique challenge to the neurosurgeon given the concentration of delicate structures in the confines of a very small anatomic space. The lateral transorbital approach (LTOA) is a minimally invasive, keyhole approach that can provide direct access to the lateral CS.

METHODS

A retrospective review of CS lesions treated by a LTOA at a single institution was performed between 2020 and 2023. Patient indications, surgical outcomes, and complications are described.

RESULTS

Six patients underwent a LTOA for a variety of pathologies including a dermoid cyst, schwannoma, prolactinoma, craniopharyngioma, and solitary fibrous tumor. The goals of surgery (ie, drainage of cyst, debulking, and pathological diagnosis) were achieved in all cases. The mean extent of resection was 64.6% (±34%). Half of the patients with preoperative cranial neuropathies (n = 4) improved postoperatively. There were no new permanent cranial neuropathies. One patient had a vascular injury repaired endovascularly with no neurological deficits.

CONCLUSION

The LTOA provides a minimal access corridor to the lateral CS. Careful case selection and reasonable goals of surgery are critical to successful outcome.