Endoscopic transnasal approach to medial orbital lesions

Intraoperative Ultrasonography in Endoscopic Approaches for Orbital Lesions: A Single-Center Case Series

BACKGROUND

Recently, endoscopic approaches for orbital lesions have been proposed. Their results seem promising; however, orbital surgery remains challenging with possible significant morbidity, mostly because of orbital structures manipulation. Ultrasonography is an innovative intraoperative imaging technique that can assist the surgeon in these approaches.

OBJECTIVE

To assess the role of intraoperative ultrasound (IOUS) in endoscopic orbital surgery.

METHODS

All consecutive patients with orbital tumors operated in our institution through an endoscopic approach with IOUS have been prospectively collected from 2019 to May 2021.

RESULTS

Fifteen patients were included. Based on tumor location, evaluated on preoperative MRI, the endoscopic endonasal approach was preferred in 7 tumors in medial quadrants while the endoscopic transpalpebral in 8 lateral ones. During surgery, IOUS allowed us to identify the tumors and the most relevant anatomic structures in all cases. Time spent for IOUS preparation before the first scan was 8 ± 6 minutes on average, and each intraoperative scan took approximately 30 to 120 seconds. Gross tumor removal was achieved in 8 patients, subtotal in 3, while in 4 patients, surgery was limited to a biopsy. No surgical complications were observed.

CONCLUSION

IOUS has allowed us to localize the lesion and to identify the straighter surgical corridor and assess the tumor resection, effectively helping the surgeon and potentially reducing operative complications. This tool provides a real-time image, not affected by the orbital structures shift, which can be dynamically assessed multiple times during surgery. However, it is hampered by the need of specific training and possible artifacts.

Surgery around the Orbit: How to Select an Approach

Orbital region pathologies may be safely and effectively treated through a various number of approaches. As the concept of "outcome" and minimally invasive surgery keeps gaining popularity in neurosurgery, these approaches-each with specific indications and limitations-together provide the best surgical options.

Endoscopic Endonasal Approaches to the Medial Intraconal Space: Comparison of Transethmoidal and Prelacrimal Corridors

BACKGROUND

Endoscopic transethmoidal and prelacrimal approaches can access the medial intraconal space (MIS).

OBJECTIVE

This study aimed to compare advantages and drawbacks of these two approaches, and to explore their appropriate indications for management of lesions at various locations within the MIS.

METHODS

Six injected cadaveric specimens were dissected using an endonasal approach performing a transethmoidal approach on one side and a prelacrimal approach on the contralateral side. The MIS was divided into three Zones: Zone 1 was defined as the area above the superior border of the medial rectus muscle (MRM), Zone 2 as the area between the MRM and the optic nerve, and Zone 3 as the area below the inferior border of MRM. The exposure provided by these two approaches to various Zones within the MIS was assessed and compared.

RESULTS

The average height of Zone 1 to 3 was 10.35 ± 0.45 mm, 11.07 ± 0.59 mm, and 6.53 ± 0.59 mm, respectively. Both approaches provided adequate exposure of Zone 2 and 3; however, the prelacrimal approach provided direct exposure of the posterosuperior aspect of Zone 2 without retraction of MRM. Retraction of MRM was unavoidable using a transethmoidal approach to enhance further exposure. Access to Zone 1 was adequately achieved through the corridor between superior oblique muscle and MRM via a transethmoidal corridor.

CONCLUSION

Conceptualizing the MIS into the three aforementioned Zones seems beneficial to select the optimal approach for lesions restricted to each specific Zone. Both the transethmoidal and prelacrimal approaches provide adequate exposure for select lesions in the MIS.

Intraconal Anatomy of the Anterior Ethmoidal Neurovascular Bundle: Implications for Surgery in the Superomedial Orbit

Background

The anterior ethmoidal artery (AEA) branches from the ophthalmic artery in the superomedial intraconal space. The feasibility of management of lesions arising from the superomedial intraconal space via an endoscopic endonasal approach has not been sufficiently explored.

Objective

To yield a detailed anatomic description of the anterior ethmoidal neurovascular bundle and its variants to serve as the foundation for possible management of lesions in the superomedial intraconal space.

Methods

Eight cadaveric specimens (16 sides) were dissected using an endonasal approach, tracing the AEA proximally through the superomedial intraconal space. Furthermore, the anatomy of adjacent structures was noted, and distances from the anterior ethmoidal foramen to the origin of the AEA at the ophthalmic artery were measured.

Results

Supraorbital cells were found in 13/16 sides (81.25%), and a bony dehiscence of the anterior ethmoidal canal was observed in 5/16 sides (31.25%). The nasociliary nerve, ophthalmic artery, superior division of the oculomotor nerve, superior rectus muscle, and levator palpebrae superioris were routinely identified in the superomedial intraconal space. The AEA passed through a corridor between the medial rectus and superior oblique muscles after arising from the ophthalmic artery (lateral to the foramen) in all specimens. The average distance from its origin to the anterior ethmoidal foramen was 5.19 ± 0.98 mm.

Conclusion

Anatomically, it is feasible to access the superomedial intraconal space via an endoscopic endonasal approach. This study provides the anatomical basis for procedures in the superomedial intraconal space.

Endoscopic approaches to orbital lesions: case series and systematic literature review

OBJECTIVE

Surgical treatment of orbital lesions is challenging because complex approaches with a high risk of postoperative sequelae are required. Recently, minimally invasive endoscopic approaches through endonasal (EEA) and transpalpebral (ETP) routes have been proposed. The objective of this study was to assess outcomes of EEA and ETP in the authors' series of patients with orbital lesions.

METHODS

Data from all patients who underwent operations for an orbital tumor through an endoscopic approach at the authors' institution from 2002 to 2018 were retrospectively collected. All patients underwent preoperative MRI and ophthalmological evaluation, which was repeated 3 months after surgery and then at regular follow-up intervals. A systematic review of the literature was also performed using Medline, Embase, and Web of Science databases.

RESULTS

The series includes 23 patients (14 males); the mean patient age was 48 ± 23.9 years. Most of the lesions were intraconal (n = 19, 83%). The more frequent histotype was cavernous hemangioma (n = 5, 22%). Exophthalmos was the most common symptom (21 of 23 patients). EEA was performed in 16 cases (70%) and ETP in 7 (30%). The aim of the surgery was achieved in 94% of the cases after an EEA (successful biopsy in 5 of 6 cases and radical resection in all 10 remaining patients), and in 86% after an ETP (successful biopsy in 2 cases and radical tumor resection in 4 of 5 cases). Complications consisted of 3 cases (13%) of transitory diplopia. One recurrence (4%) was observed at follow-up (mean 59 ± 55 months).

CONCLUSIONS

The EEA and ETP have demonstrated to be safe and effective for tumors located respectively in medial and lateral quadrants, permitting one to approach orbital lesions endoscopically at 360°. Innovative surgical tools, including intraoperative ultrasonography, may be useful to potentially reduce surgical morbidity. Larger series are needed to validate these preliminary suggestions.

Transnasal prelacrimal approach to the inferior intraconal space: a feasibility study

BACKGROUND

Endonasal access to the inferomedial and inferolateral intraconal space via the orbital floor has not been reported. The primary purpose of this study was to assess the feasibility of accessing the inferior intraconal space through the orbital floor via a transnasal prelacrimal approach. Secondarily, it aims to highlight anatomical relationships of neurovascular structures in this space, as a requirement to prevent complications.

METHODS

Six cadaveric heads (12 sides) were dissected using a transnasal prelacrimal approach. The orbital floor, medial to the infraorbital canal, was removed and the periorbita opened to expose the inferior rectus muscle. The inferomedial and inferolateral intraconal space was accessed alongside the medial and lateral border of inferior rectus muscle, respectively. Various anatomical relationships of adjacent neurovascular structures were recorded, and the distances among the recti muscles and optic nerve were also measured.

RESULTS

The infraorbital nerve is located at the inferolateral aspect of inferior rectus muscle. In the inferomedial intraconal space, we identified the inferomedial muscular trunk of the ophthalmic artery, optic nerve, and branches of the oculomotor nerve; whereas the inferolateral intraconal space contained the inferolateral muscular trunk of ophthalmic artery, branches of the oculomotor and nasociliary nerve, and abducens nerve. Distances from the medial, inferior, and lateral recti muscles to the optic nerve were (mean ± standard deviation) 4.70 ± 1.18 mm, 5.60 ± 0.93 mm, and 7.98 ± 1.99 mm, respectively. Distances from the inferior rectus muscle to the inferior borders of medial and lateral recti muscles were 4.45 ± 1.23 mm and 8.77 ± 1.80 mm.

CONCLUSION

It is feasible to access the inferior intraconal space through the orbital floor via a transnasal prelacrimal approach. The access may be subdivided into inferomedial and inferolateral corridors according to the entry point at the medial or lateral border of the inferior rectus muscle. Neurovascular structures in the inferior intraconal space are visualized directly, which should enhance their preservation.

Endoscopic Transnasal Cryo-Assisted Removal of Orbital Cavernous Hemangiomas: Case Report and Technical Hints

BACKGROUND

Cryoprobe devices are used by ophthalmic and orbital surgeons for extraction of fluid-filled intraorbital lesions. No series has described cryodissection via an exclusively transnasal approach. We describe 2 cases of purely endoscopic transnasal removal of intraconal orbital hemangiomas with the aid of a dedicated cryoprobe.

METHODS

All transnasal endoscopic intraorbital procedures were collected and analyzed. In cases in which intraorbital dissection was performed with the use of an Optikon Cryo-line probe, clinical features, histology, size and location of the lesion, early and late complications, surgical procedure time, and hospital length of stay were analyzed. Patient follow-up included endoscopic endonasal evaluations performed at 2, 4, and 8 weeks after surgery and ophthalmologic and orthoptic evaluations performed 2 days and 2 months after surgery.

RESULTS

Two transnasal intraorbital endoscopic procedures with the aid of the dedicated Cryo-line probe were collected. Lesions were located in the intraconal space, medial to the optic nerve. In both patients, the histologic evaluation was compatible with cavernous hemangioma, and complete resection was obtained. Mean hospital stay was 5.5 days. Postoperative ophthalmologic and orthoptic evaluations performed 2 months postoperatively revealed complete resolution of preoperative symptoms.

CONCLUSIONS

Cryoprobes represent an adjunctive tool in the orbital surgeon's armamentarium useful in the extraction of fluid-filled intraorbital lesions. This preliminary experience suggests that their use can ease the removal of intraconal hemangiomas with an exclusively transnasal approach. The analysis of further cases is necessary to confirm safety and efficacy.

Endonasal Approach to Orbital Pathology

PURPOSE

Transnasal endoscopic orbital surgery in an emerging surgical field. The surgical field has expanded from orbital decompression to excision of tumours from the medial orbit and over the last 20 years. As instrumentation has improved, the nature, location and size of tumours being excised has changed.

METHODS

This article discusses the salient surgical considerations when approaching an orbital lesion via a transnasal endoscopic route and reviews the literature.

RESULTS

An endonasal approach offers a potential space surgeons can utilise to access the orbit, possibly providing additional exposure, illumination and magnification to the medial and apical aspects of selected lesions.

CONCLUSIONS

An endonasal approach may be useful as a sole or adjunctive approach in selected cases of orbital tumour excision.