Modified Hemi-Lothrop Procedure for Supraorbital Ethmoid Lesion Access

Background: The supraorbital ethmoid (SOE) cell is an accessory ethmoid cell in the frontal area that extends into and pneumatizes superolaterally along the orbital plate of the frontal bone. The outflow pathway of the SOE cell can become obstructed, leading to a SOE mucocele. Given their lateral location, SOE lesions are traditionally treated through external approaches, although some authors have advocated treatment through standard endoscopic routes. We present a case of a large supraorbital ethmoid mucocele treated with a novel modified hemi-Lothrop procedure (MHLP). This technique provides the benefit of an angulated approach to increase lateral visualization and bimanual binostril instrumentation through a superior septectomy window.

Methods: Case report and review of the literature are presented.

Results: A 43-year-old gentleman presented with a 5-year history of progressive diplopia and right-eye proptosis. Oculoplastic examination revealed 6 mm of right proptosis, 7 mm of right hypoglobus, and diplopia on upward gaze with slight hypotropia. Nasal endoscopy revealed a rightward deviated nasal septum. CT scan showed a large right SOE mass with significant proptosis of the right eye with marked inferior displacement and minimal lateral displacement. MRI showed a right SOE mass consistent with a SOE mucocele. The patient underwent endoscopic drainage of the SOE mucocele using a MHLPtechnique. The procedure consisted of a right anterior ethmoidectomy/maxillary antrostomy and an endoscopic Draf IIB with a superior septectomy to gain access from the contralateral nasal cavity and allow bimanual binostril dissection. The wall between the right frontal sinus and the SOE cavity was resected to combine and enlarge the drainage pathway of these adjacent cavities. Postoperatively, the patient's proptosis was significantly decreased. He maintained full extraocular movement and reported resolution of diplopia. His postoperative CT scan showed widely patent right frontal sinus and SOE cavities.

Conclusions: The SOE cell can be difficult to access endoscopically. The modified hemi-Lothrop procedure represents a novel and feasible way to access this area from the contralateral nasal cavity through a superior septectomy window. This approach is useful in addressing difficult-to-access supraorbital ethmoid lesions that may otherwise require more extensive endoscopic or external approaches.