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

OBJECTIVE: 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. STUDY DESIGN: Retrospective review with image analysis. SETTING: Single tertiary care institution. METHODS: 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. RESULTS: 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 6.37 to 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. CONCLUSION: 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.

Does cryoneurolysis result in persistent motor deficits? A controlled study using a rat peroneal nerve injury model.

BACKGROUND: Cryoneurolysis of peripheral nerves uses localised intense cold to induce a prolonged block over multiple weeks that has the promise of providing potent analgesia outlasting the duration of postoperative pain following surgery, as well as treat other acute and chronic pain states. However, it remains unclear whether persistent functional motor deficits remain following cryoneurolysis of mixed sensorimotor peripheral nerves, greatly limiting clinical application of this modality. To help inform future research, we used a rat peroneal nerve injury model to evaluate if cryoneurolysis results in persistent deficits in motor function. METHODS: Male Lewis rats (n=30) had their common peroneal nerves exposed bilaterally at the proximal lateral margin of the knee and subsequently underwent cryoneurolysis on one limb and sham treatment on the contralateral limb. Outcomes were evaluated on days 3, 14, 30, 90 and 180. The primary end point was motor function, based on ankle dorsiflexion torque. In addition, sensory function was tested based on von Frey's filament sensitivity to the peroneal sensory distribution. A subset of animals was sacrificed following functional testing at each time point, and general tissue morphology, connective tissue deposition, and axon counts were evaluated. RESULTS: Motor deficits in treated limbs were observed at 3 and 14 days but had resolved at time points beyond 1 month. Bilateral sensory deficits were also observed at 3 and 14 days, and also resolved within 1 month. Consistent with motor functional deficits, axon counts trended lower in treated nerves compared with contralateral controls at 3 days; however, axon counts were not significantly different at later time points. CONCLUSIONS: When applied to a mixed sensorimotor nerve, cryoneurolysis did not result in persistent motor deficits.