Volumetric Analysis of the Sinus and Orbit in Silent Sinus Syndrome After Endoscopic Sinus Surgery.

Abstract

The term "silent sinus syndrome" (SSS) describes spontaneous enophthalmos secondary to subclinical maxillary sinus atelectasis. Debate remains on whether treatment with endoscopic maxillary antrostomy alone is adequate in reversing atelectasis and globe displacement. This study aims to determine the degree of volume change of the diseased sinus and orbit as well as the change in orbital height in patients treated with endoscopic antrostomy without orbital floor augmentation. Retrospective review with image analysis. Single tertiary care institution. Three-dimensional (3D) analysis of computed tomographic imaging data was performed using 3D Slicer. 3D models of the maxillary sinus and orbit of the diseased and normal sides were created, and volume measurements were calculated using the segmentation program. Thirteen patients with SSS who underwent endoscopic sinus surgery (ESS) and had follow-up computed tomographic imaging were analyzed. After endoscopic antrostomy, the mean volume of the diseased maxillary sinus significantly increased by 9.82%, from 6.37to 7.00 cm3 (p = .0302). There was no significant change in mean orbital volume; however, the mean orbital height decreased by 5.67%, from 38.09 to 35.93 mm from pretreatment to posttreatment samples (p = .0101). All patients had resolution of clinical or radiographic enophthalmos and orbital displacement with ESS alone. Endoscopic maxillary antrostomy alone in the treatment of SSS significantly increased maxillary sinus volume and decreased diseased orbital height. These changes were associated with clinical and radiographic improvement in globe displacement. These findings support performing ESS alone, reserving orbital augmentation for patients who do not exhibit adequate clinical improvement.