Endoscopic transmaxillary transMüller's muscle approach for decompression of superior orbital fissure: a cadaveric study with illustrative case

Transmaxillary Approach for the Resection of Inferior Orbital Venous Varix: Technical Case Instruction

BACKGROUND AND IMPORTANCE

The optimal surgical approach for managing orbital venous varices, particularly those involving the inferior orbit, remains controversial. A transmaxillary approach offers a less invasive alternative to the transnasal approach and avoids disruption of the nasal cavity and medial maxillary wall. This report describes the details of a technique for ligating a venous varix between the inferior rectus and medial rectus muscles that aims to provide relief of symptoms and prevent recurrence.

CLINICAL PRESENTATION

A 77-year-old man presented with progressive left eye pain that was exacerbated by lying down or straining. Imaging revealed a large enhancing lesion in the left inferior medial orbit, consistent with a venous varix, which was not present on imaging a decade earlier. The patient underwent a single-stage transmaxillary approach, guided by the second division of the trigeminal nerve (V2), to ligate the varix. Postoperative imaging confirmed complete obliteration of the lesion, and the patient experienced immediate relief of symptoms without any described neurological deficits.

CONCLUSION

The transmaxillary approach for the resection of inferior orbital lesions is a safe and effective technique that can provide excellent clinical outcomes while preserving orbital structures and function.

Morphometric evaluation of the anatomical relationships between the superior orbital fissure and the orbital structures based on computed tomography images with clinical implications

PURPOSE

To assist in surgical planning in endoscopic approaches, we analyzed the morphometric measurements of the superior orbital fissure (SOF) and optic canal (OC) by three-dimensional multislice computed tomography (3D MDCT) and evaluated them according to age, gender, and lateralization.

METHODS

The study analyzed 219 MDCT images (114 women, 105 men) from individuals aged 18-90. Measurements of SOF and OC were performed on 3D MDCT images in the axial plane and with 3D-Slicer software.

RESULTS

The distance between the infraorbital foramen and the anterior entrance of the maxillary sinus (CBW) (p < 0.001), the distance between the CBW and the lateral point of the SOF (p = 0.001), and the Angle 1 (p = 0.028) were higher in women than in men. While the SOF length and on 3D the SOF width were higher in women than men (p < 0.001 and (p = 0.001, respectively), the lateral wall length OC was higher in men than women (p = 0.045). According to SOF classification, SOF length was highest in type II and lowest in type VIII (p = 0.025), SOF width was highest in type I and lowest in type VI (p < 0.001). No significant difference was found based on age groups and lateralization in all parameters.

CONCLUSION

We found that as the SOF width increased, the SOF length also increased, and there was a statistically strong positive correlation. These findings can contribute to a more effective and safe operation by improving and updating surgeons' knowledge about safe distances to SOF in endoscopic procedures from a 3D MDCT perspective.

Simultaneous Endoscopic Endonasal Decompression of the Optic Canal, Superior Orbital Fissure, and Proper Orbital Apex for Traumatic Orbital Apex Syndrome: Surgical Anatomy and Technical Note

Objectives

Traumatic orbital apex syndrome (TOAS) is an uncommon but severe ocular complication of craniomaxillofacial fracture. The optimal surgical strategy for TOAS has not been determined. To investigate the endoscopic anatomy of the orbital apex region, propose a protocol for simultaneous endoscopic endonasal decompression of the optic canal, superior orbital fissure, and proper orbital apex (EEDCFA) for TOAS and report its use in two patients.

Methods

An endoscopic endonasal approach was utilized to dissect the orbital apex region in two silicon-injected adult cadaveric heads. The details of the procedure used for decompression of the orbital apex were determined. The effects of this procedure were determined in two patients with TOAS who underwent simultaneous decompression of the optic canal, superior orbital fissure, and proper orbital apex.

Results

The orbital apex consisted of three portions, the contents of the optic canal superomedially; the contents of the superior orbital fissure inferolaterally; and the converging portion, or proper orbital apex, anteriorly. From an endoscopic endonasal approach, the optic nerve, superior orbital fissure, and orbital apex convergence prominences were found to form a π-shaped configuration. This π-shaped configuration was indicative of the orbital apex and was an important landmark for decompression of the orbital apex. Endonasal decompression of the orbital apex in the two patients resulted in the satisfactory recovery of extraocular mobility, with no surgical complications.

Conclusions

EEDCFA is feasible, effective, and safe for patients with TOAS caused by direct compression of displaced fracture segments. The π-shaped configuration is a valuable landmark for EEDCFA.

Endoscopic transorbital approach to the infratemporal fossa and parapharyngeal space: a cadaveric study

OBJECTIVE

The infratemporal fossa (ITF) and parapharyngeal space are anatomical regions that can be challenging to access without the use of complex, cosmetically disfiguring approaches. With advances in endoscopic techniques, a new group of surgical approaches to access the intracranial space through the orbit has been recently referred to as transorbital neuroendoscopic surgery (TONES). The objective of this study was to establish a transorbital endoscopic approach utilizing the inferior orbital fissure (IOF) to gain access to the ITF and parapharyngeal space and provide a detailed endoscopic anatomical description of this approach.

METHODS

Four cadaveric heads (8 sides) were dissected using a TONES approach through the IOF to reach the ITF and parapharyngeal space, providing stepwise dissection with detailed anatomical findings and a description of each step.

RESULTS

An inferior eyelid approach was made with subperiosteal periorbital dissection to the IOF. The zygomatic and greater wing of the sphenoid were drilled, forming the boundaries of the IOF. The upper head of the lateral pterygoid muscle in the ITF and parapharyngeal space was removed, and 7 distinct planes were described, each with its own anatomical contents. The second part of the maxillary artery was mainly found in plane 1 between the temporalis laterally and the lateral pterygoid muscle in plane 2. The branches of the mandibular nerve (V3) and middle meningeal artery (MMA) were identified in plane 3. Plane 4 was formed by the fascia of the medial pterygoid muscle (MTM) and the tensor veli palatini muscle. The prestyloid segment, found in plane 5, was composed mainly of fat and lymph nodes. The parapharyngeal carotid artery in the poststyloid segment, found in plane 7, was identified after laterally dissecting the styloid diaphragm, found in plane 6. V3 and the origin of the levator and tensor veli palatini muscles serve as landmarks for identification of the parapharyngeal carotid artery.

CONCLUSIONS

The transorbital endoscopic approach provides excellent access to the ITF and parapharyngeal space compared to previously described complex and morbid transfacial or transcranial approaches. Using the IOF is an important and useful landmark that permits a wide exposure.

Orbital Decompression for Treatment of Acute Visual Loss After Facial Trauma

Injury to the orbital region represents a significant proportion of emergency department attendances and it is a common injury in patients with multisystem trauma. To date, trauma remains a leading cause of monocular blindness.Traumatic optic neuropathy may be caused by direct trauma to the optic nerve and from compression caused by foreign bodies and bone fragments. Indirect trauma can lead to visual loss from transmitted force to the optic canal by blunt facial trauma without associated fractures. Occasionally traumatic optic neuropathy is due to reversible changes, such as edema or contusion.High-dose intravenous steroids and surgical decompression of the optic canal have been advocated for the management of acute traumatic optic neuropathy, but the efficacy and safety of these treatments have been questioned.The authors present 3 patients with traumatic optic nerve injury, 1 due to a gunshot wound to the face and 2 caused by blunt facial trauma, where fragments of bone intrude into the orbit leading to compression of its content. These injuries where successfully treated with both preoperative intravenous steroids followed by acute surgical decompression of the orbit with return of visual function.

Infratemporal fossa approach: the modified zygomatico-transmandibular approach

Background

The infratemporal fossa (ITF) is an anatomical lateral skull base space composed by the zygoma, temporal, and the greater wing of the sphenoid bone. Due to its difficult approach, surgical intervention at the ITF has remained a heavy burden to surgeons. The aim of this article is to review basic skull base approaches and ITF structures and to avoid severe complications based on the accurate surgical knowledge.

Methods

A search of the recent literature using MEDLINE (PubMed), Embase, Cochrane Library, and other online tools was executed using the following keyword combinations: infratemporal fossa, subtemporal fossa, transzygomatic approach, orbitozygomatic approach, transmaxillary approach, facial translocation approach, midface degloving, zygomatico-transmandibular approach, and lateral skull base. Aside from our Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) trial, there have been very few randomized controlled trials. The search data for this review are summarized based on the authors’ diverse clinical experiences.

Results

We divided our results based on representative skull base approaches and the anatomy of the ITF. Basic approaches to the ITF include endoscopic endonasal, transzygomatic, orbitozygomatic, zygomatico-transmandibular, transmaxillary, facial translocation, and the midfacial degloving approach. The borders and inner structures of the ITF (with basic lateral skull base dissection schemes) are summarized, and the modified zygomatico-transmandibular approach (ZTMA) is described in detail.

Conclusions

An anatomical basic knowledge would be required for the appropriate management of the ITF pathology for diverse specialized doctors, including maxillofacial, plastic, and vascular surgeons. The ITF approach, in conjunction with the application of microsurgical techniques and improved perioperative care, has permitted significant advances and successful curative outcomes for patients having malignancy in ITF.

Endoscopic Endonasal Approach to the Anteromedial Temporal Fossa and Mobilization of the Lateral Wall of the Cavernous Sinus Through the Inferior Orbital Fissure and V1-V2 Corridor: An Anatomic Study and Clinical Considerations

OBJECTIVE

The aim of this study was to identify key anatomic landmarks useful in gaining access to the anteromedial temporal region via the corridor formed by the inferior orbital fissure (IOF), the ophthalmic branch of the trigeminal nerve (V1), and the maxillary branch of the trigeminal nerve (V2) via an endoscopic endonasal approach (EEA).

METHODS

An anatomic dissection of 6 cadaver heads was performed to confirm the feasibility and applicability of an EEA for accessing the anteromedial temporal region.

RESULTS

After middle turbinectomy, the lateral recess of the sphenoid sinus was opened, the orbital apex was exposed, and the posterior wall of the maxillary sinus was removed, in sequence. The IOF and the pterygopalatine fossa (PPF) were then identified. After opening the foramen rotundum (FR) and removing the bony structure between the FR, V2 was transposed downward. The orbital muscle of Müller was removed. The PPF was mobilized downward exposing the greater wing of the sphenoid bone (GWS). The GWS between V1 and V2 was drilled, therefore exposing the temporal dura. With blunt dissection, the medial temporal dura was peeled away from the cavernous sinus to increase access to the anteromedial temporal region.

CONCLUSIONS

The anteromedial temporal fossa was exposed by drilling the V1-V2 triangle corridor via an EEA. Endoscopic endonasal exposure of the anteromedial temporal fossa is feasible and requires limited endonasal work. This approach may be considered as an alternate surgical corridor to the temporomesial lobe that offers the advantages of a direct route with less temporal lobe retraction.

Orbital apex disorders: a case series

Orbital apex syndrome is an uncommon disorder characterized by ophthalmoplegia, proptosis, ptosis, hypoesthesia of the forehead, and vision loss. It may be classified as part of a group of orbital apex disorders that includes superior orbital fissure syndrome and cavernous sinus syndrome. Superior orbital fissure syndrome presents similarly to orbital apex syndrome without optic nerve impairment. Cavernous sinus syndrome includes hypoesthesia of the cheek and lower eyelid in addition to the signs seen in orbital apex syndrome. While historically described separately, these three disorders share similar causes, diagnostic course, and management strategies. The purpose of this study was to report three cases of orbital apex disorders treated recently and to review the literature related to these conditions. Inflammatory and vascular disorders, neoplasm, infection, and trauma are potential causes of orbital apex disorders. Management is directed at the causative process. The cases described represent a rare but important group of conditions seen by the maxillofacial surgeon. A review of the clinical presentation, etiology, and management of these conditions may prompt timely recognition and treatment.

Endonasal identification of the orbital apex

OBJECTIVES/HYPOTHESIS

To describe anatomical landmarks for endoscopic endonasal approaches to the orbital apex and to measure the distances between those landmarks.

METHODS

In this anatomic study, the nasal fossae of 30 adult fresh cadavers were dissected (n = 60 half-skulls). One double-injected orbit was carefully dissected, mainly focusing on the neurovascular structures. The orbital apex was dissected under endoscopic endonasal visualization in all cases. The distances between the ethmoidal crest and choanal arch to the optic canal (OC) and superior orbital fissure (SOF) were measured and recorded.

RESULTS

The sample was predominantly male (63.3%, 19/30 cadavers). The following correlations between measurements according to side were observed: ethmoidal crest to OC, r = 0.748 (P = 0.0001); ethmoidal crest to SOF, r = 0.785 (P = 0.0001); choanal arch to OC, r = 0.835 (P = 0.0001); choanal arch to SOF, r = 0.820 (P = 0.0001).

CONCLUSIONS

In the cadavers studied in this sample, the ethmoidal crest and choanal arch were relevant structures and exhibited consistent measurements. Spearman correlation coefficients were greater than 0.7, which is indicative of good correlation between measurements obtained in the skull halves of each cadaver. Comparison of the measurements obtained in different sides showed similar values, with no statistically significant differences in the distances between any of the proposed anatomic landmarks.