Endoscopic Management of Mucoceles With Significant Orbital Involvement

Patient Demographics, Clinical Presentation, and Preoperative Workup

Sinonasal mucoceles are benign lesions arising from progressive expansion of respiratory epithelium. Obstruction of the natural ostia of the corresponding sinus leads to noted expansion of the sinus epithelium with mucoid secretions. The mucocele can expand and exert mass effect on surrounding nasal, orbital, and intracranial structures. The inciting factor for mucocele development can range and include chronic infection, trauma, postoperative scarring, and systemic disease states.

Sinonasal mucoceles represent approximately 8% of all sinus masses. The most common site of occurrence is the frontal sinus followed by the ethmoid cavity. Approximately 70% to 90% of mucoceles occur in the frontoethmoidal region. The globe is therefore at risk owing to associated mass effects and potential infectious progression to a mucopyocele. In addition, there is a cytokine cascade with local upregulation of osteolytic cytokines such as interleukin 1 potentiating bony erosion of the orbit with mucocele propagation.

The onset of symptoms is typically insidious, and the spectrum of presentation of orbital mucoceles is variable. In a retrospective study of 102 patients with mucoceles who underwent operative intervention, the most common presenting symptoms were headache (42%), facial pressure (28%), and congestion (26%). Although patients traditionally present with accompanying symptoms of rhinosinusitis, a heightened index of suspicion should be included for patients with proptosis, diplopia, ophthalmoplegia, orbital cellulitis, or facial asymmetry. Retrospective studies of mucoceles with significant intraorbital extension have shown the most common presenting symptoms to include ptosis (33%) and periorbital swelling (29%).

Patients present to a wide spectrum of providers before diagnosis because of the interplay between the sinuses and the orbit. Diagnosing patients appropriately is dependent on clinical history, physical examination including endoscopic examination, and radiographic findings. Patients typically present with a long-standing history of rhinosinusitis symptoms, a history of sinus surgery, or facial trauma. Mucocele development is not an acute process, and the clinical history needs to include chronic conditions as there is a delay between sinonasal insult and mucocele development. One study noted patients presented on average 5.3 years after functional endoscopic sinus surgery (FESS), 17 years after maxillofacial trauma, and 18 years after open surgery.

In addition to the clinical history, a thorough physical examination can help identify sequelae of mucocele expansion. Providers should perform a comprehensive head and neck examination including a focus on the orbit. Visual acuity, visual field testing, and extraocular movements should all be included in the ophthalmologic test battery. Identifying vision loss is key, especially in the acute setting. A systematic review of patients with orbital mucoceles presenting with vision loss concluded that vision loss is potentially reversible in most cases. In a review of 207 patients, those who presented with vision equal to 20/650 or worse and had operative management within 6 days were those that were most likely to have a visual acuity improvement with an improvement comparable to progressing from 20/200 to 20/20. Therefore early identification and intervention are critical for any vision loss associated with orbital mucoceles.

Although a clinical index of suspicion can help identify patients with potential orbital mucoceles, maxillofacial/sinus imaging is critical to identify intracranial and intraorbital extension of mucoceles. Computed tomography helps delineate sinonasal structures and the extent of bony erosion. Magnetic resonance imaging is useful for the evaluation of the orbital, soft-tissue, and intracranial contents. Computed tomography and magnetic resonance imaging have a complementary role in identifying intracranial and intraorbital disease. At a tertiary referral center that surgically addressed 133 mucoceles, intracranial and intraorbital extension was identified preoperatively in 14% and 20% of cases, respectively. Intraorbital extension was most commonly associated with frontoethmoidal mucoceles.

Management of mucoceles requires surgical extirpation and long-term follow-up. Surgical approaches include open approaches, endoscopic approaches, or combined techniques. The varying techniques for surgically addressing sinonasal mucoceles with orbital involvement are discussed further in this chapter.

Approaches