The Orbit as Seen Through Different Surgical Windows: Extensive Anatomosurgical Study

A retrospective analysis of the management and surgical treatment of orbital lesions: Outcomes and rationale

The orbital cavity is a subject of interest for various specialists, and achieving optimal outcomes requires comprehensive, multidisciplinary management. This study aims to report 10 years of experience in the preoperative, surgical, and postoperative care of patients with orbital lesions, examining their clinical, radiological, and anatomopathological features and outcomes. A retrospective review of 125 patients who underwent surgical treatment for intraorbital masses between January 2012 and December 2021 was performed. Outcome measures included postoperative diplopia, exophthalmos, decimal visual acuity, eyeball position, ocular motility, operative time, complications, and aesthetic results. A total of 107 patients were included. All cases were discussed with a neuroradiologist to determine the best therapeutic approach based on preoperative imaging. Preoperative diplopia was linked to extraconal (p = 0.03) and anterior (p = 0.001) lesions, and exophthalmos and visual acuity deterioration were associated with intraconal (p = 0.02; p = 0.03) and retrobulbar (p = 0.001; p = 0.02) lesions. Complications (11.2%) included diplopia, worsened visual acuity, postoperative blepharoptosis, and postoperative ectropion. Of the patients, 80.4% reported an "excellent" aesthetic outcome. This study underscores the importance of a multidisciplinary approach based on a thorough analysis of preoperative imaging. Periorbital approaches tailored to the lesion's three-dimensional location enables safe access to most intraorbital lesions, resulting in minimal complications and good aesthetic results.

Morphometric Analysis of the Ophthalmic and Central Retinal Arteries via the Endoscopic Endonasal Trans-ethmoidal Approach: Surgical Relevance of Vascular Components Within the Medial Intraconal Zones

BACKGROUND

The endoscopic endonasal approach (EEA) offers a minimally invasive route to treat medial intraconal space (MIS) lesions. Understanding the configuration of the ophthalmic artery (OphA) and the central retinal artery (CRA) is crucial.

METHODS

An EEA to the MIS was performed on 30 orbits. The description of the intraorbital part of the OphA was divided into 3 segments and classified as type 1 and type 2 and the MIS was divided into three surgical zones (A, B, C). The CRA's origin, course, and point of penetration (PP) were analyzed. The relationship between the position of the CRA in the MIS and the OphA type was analyzed.

RESULTS

The OphA type 2 was present in 20% of specimens. The site of origin of the CRA from the OphA was found on the medial surface in type 1 and on the lateral surface of type 2. The point of penetrationof the central retinal arterywas found in 87% of the specimens on the inferomedial surface, just anterior to the inferior muscular trunk, at an average distance of 9.5 mm ± 1 from the globe and 17 mm ± 1.5 from the AZ. The presence of the CRA in Zone C was associated only with OphA type 1.

CONCLUSIONS

OphA type 2 is a common finding and can compromise the feasibility of an EEA to the MIS. A detailed preoperative analysis of the OphA and CRA should be conducted prior to approaching the MIS due to the implications of the anatomical variations that can compromise safe intraconal maneuverability during an EEA.

Anterolateral Routes to the Skull Base-The Frontotemporal Approaches and Exposure of the Sellar and Parasellar Regions

Surgical approaches to the sellar and parasellar regions are highly challenging due to the densely packed nature of the traversing neurovasculature. The frontotemporal-orbitozygomatic approach offers a wide angle of exposure for the management of lesions involving the cavernous sinus, parasellar region, upper clivus, and adjacent neurovascular structures. It combines the pterional approach with different osteotomies that remove the superior and lateral walls of the orbit and zygomatic arch. Extradural exposure and preparation of the periclinoid region, whether as initial preparation for a combined intraextradural approach to deep-seated skull base targets or as the main avenue of surgical exposure, can substantially enlarge surgical corridors and minimize the need for brain retraction in this very confined microsurgical space. We provide a stepwise description of how we perform the fronto-orbitozygomatic approach and an associated series of surgical maneuvers and techniques that can be utilized in a variety of anterior and anterolateral approaches, either alone or in combination, to tailor exposure to a given lesion. These techniques are not limited to traditional skull base approaches and represent a valuable addition to every neurosurgeon's armamentarium as enhancements to common surgical approaches.

The Learning Curve in Skullbase Surgery Part 2–From the Microsurgical Lab Training to the Operative Room

In this second part, the authors review and suggest a methodology for studies in skull base surgery and training in microsurgical laboratory, based on their experiences and reflections. Not only are the foundations for the acquisition of microsurgical skills presented, but also what is needed to be an effective skullbase surgeon with good results. The present article reflects in particular the philosophy of professor Evandro de Oliveira and also serves to present to the neurosurgical community a new state-of-the-art laboratory for hands-on courses in Brazil, at the Faculdade Evangélica Mackenzie do Paraná.

Strategies for Optic Pathways Decompression for Extra-Axial Tumors or Intracranial Aneurysms: A Technical Note

BACKGROUND

 Different types of skull base tumors and intracranial aneurysms may lead to compression of the optic pathways. Since most of them are biologically benign conditions, the first aim of surgery is preservation of optic nerves rather than the oncologic radicality.

MATERIALS AND METHODS

 Based on the progressive technical refinements coming from our institutional experience of optic nerve compression from aneurysms and extra-axial tumors, we analyzed the surgical steps to release nerves and chiasm during tumor debulking and aneurysm clipping.

RESULTS

 We distinguished vascular and tumor lesions according to the main direction of optic nerve compression: lateral to medial, medial to lateral, inferior to superior, and anterior to posterior. We also identified four fundamental sequential maneuvers to release the optic nerve, which are (1) falciform ligament (FL) section, (2) optic canal unroofing, (3) anterior clinoid process drilling, and (4) optic strut removal. The FL section is always recommended when a gentle manipulation of the optic nerve is required. Optic canal unroofing is suggested in case of lateral-to-medial compression (i.e., clinoid meningiomas), medial-to-lateral compression (i.e., tuberculum sellae meningiomas), and inferior-to-superior compression (i.e., suprasellar lesions). Anterior clinoidectomy and optic strut removal may be necessary in case of lateral-to-medial compression from paraclinoid aneurysms or meningiomas.

CONCLUSIONS

 Preservation of the visual function is the main goal of surgery for tumors and aneurysms causing optic nerve compression. This mandatory principle guides the approach, the timing, and the technical strategy to release the optic nerve, and is principally based on the direction of the compression vector.

Surgical anatomy of the orbit. A systematic and clear study of a complex structure

BACKGROUND AND OBJECTIVE

The orbit is a structure of interest for many medical specialties. Surgical approaches to the orbit present significant difficulties for the general neurosurgeon. Whoever decides to practice orbital surgery must have vast anatomical knowledge of this structure. However, although many of the existing publications about orbital anatomy show the complexity of this structure in detail, they fail to facilitate their understanding. The purpose of this study was to systematise and simplify the anatomical study of the orbit from a surgical perspective, to facilitate its understanding.

MATERIALS AND METHODS

A review of the international literature on the subject was carried out, and the principle of the rule of 7was followed for its ordering. For illustration purposes, photographs of cadaveric preparations and digital drawings were used.

RESULTS

The orbits are 2cavities located symmetrically on both sides of the nose. They have a pyramidal shape, with 4sides, a posterior vertex, an anterior base and their axis established from the sagittal plane at a 20-degree angle. A distinctive feature of the orbit is that its elements are organised into groups of seven: 7bones, 7intraorbital extraocular muscles and 7nerves.

CONCLUSION

A systematisation of the orbital anatomy was performed with clear illustrations to simplify its study. The understanding of the anatomy of the orbit is vital to classify lesions and provides a solid basis when choosing the most appropriate approach for their treatment.