A Case of 40-Year-Old Male with Onodi Cell Mucocele

Sphenoethmoidal (Onodi) cells originate from the ethmoid sinus and are located at the posterior and lateral direction. The obstruction of the sinus ostium leads to the accumulation of mucous fluid and eventually leads to the formation of a mucocele. Onodi cell mucoceles can cause visual loss or disturbance due to the adjacency to the orbital apex. Here we report a case of Onodi cell mucocele with a visual field disturbance, where the patient underwent an endoscopic sinus surgery 12 days after the initial symptom. After 21 days of onset, the subjective symptom started to subside. For Onodi cell mucocele patients with visual disturbance, we recommend rapid diagnosis with computed tomography and early marsupialization of the mucocele.

Study of Anatomical Variations of Nose and Para-nasal Sinuses in Computed Tomography Scan

Introduction: Computed tomography (CT) has nowadays become the investigation of choice for diagnosis and evaluation of anatomical variations of the nose and paranasal sinuses. Methods: A cross sectional study was conducted in the Department of Radiology of Lumbini Medical College Hospital from June 2019 to May 2020. Total of 130 patients were enrolled for the study. All patients were subjected to Siemens Somatom scope 16 slice CT scan. Each scan was studied for the presence of agger nasi cell, concha bullosa, deviated nasal septum, haller cell, onodi cell, uncinate process variation and type of olfactory fossa. Results: The mean age of patients was 36. 86 ±12.06 years. There were 76 males (58.5%) and 54 females (41.5%) with male: female ratio of 1.4:1 with highest range in age group of 31 to 45 years (46.9%). Anatomical variation between male and female was statistically not significant (p>0.05). The most common anatomical variation noted was nasal septal deviation (73.1%), then agger nasi cell (59.3%), concha bullosa (24.6%), paradoxical medial turbinate (7.7%), onodi cell (6.9%), uncinate process variation (5.4%) and least was haller cell (4.6%). Most of the scans had more than one anatomical variation, which was statistically significant (p<0.05). The most common type of olfactory fossa depth was Keros type II (61.5%). Conclusion: Computed tomography of the paranasal sinus has improved the visualization of anatomical variation hence radiologist must pay close attention to variants.

Radiologic Analysis of Balloon Sinuplasty in a Human Cadaver Model: Observed Effects on Sinonasal Anatomy

Background Balloon sinuplasty is increasingly used in the outpatient clinic for treatment of chronic rhinosinusitis, but radiologic analysis of its effects on sinonasal anatomy is largely uncharacterized in the known literature. Objective The purpose of this study is to examine the anatomic effects of balloon sinuplasty in a cadaveric model. Methods Five fresh cadaver heads underwent sequential endoscopic balloon dilation of maxillary ostia, frontal recess outflow tracts, and sphenoid ostia bilaterally by fellowship-trained rhinologists. Pre- and post-procedural CT imaging was obtained. CT scans were imported into Mimics™ software and sinonasal anatomy was analyzed systematically. Results Visual confirmation of balloon dilation was achieved in all 3 sites bilaterally in each cadaver. Radiologic analysis demonstrated that the frontal sinus outflow tract was appropriately dilated 60% (6/10 sites) of the time while the agger was inadvertently dilated 30% of the time (3/10). The sphenoid os was successfully dilated 70% (7/10 sites) of the time. In two cases, a posterior sphenoethmoid (Onodi) cell was dilated instead of the sphenoid. Successful dilation of maxillary os was noted 60% of the time (6/10 sites). No significant change in maxillary os was noted after balloon dilation. Normal middle turbinates were significantly medialized following balloon dilation 75% (6/8 sites) of the time. Conclusions While the goal of balloon sinuplasty is to improve natural sinonasal drainage by dilating existing outflow tracts, as evidenced by radiologic evaluation the procedure appears not to achieve this in all cases, while occasionally creating unintended changes in sinonasal anatomy as well. These unrecognized changes in anatomy may be responsible for the post-procedure change in symptomatology that some patients experience.

Location of the Sphenoid Sinus Ostium in Relation to Adjacent Anatomical Landmarks

Purpose: The variability of sphenoid pneumatization and its relationship with the surrounding structures has been suggested. The aim of this study was to examine the effect of the surrounding bony structures on the position of the sphenoid ostium (SO). Methods: A prospective radiological review of computed tomography images of paranasal sinuses of 150 patients (300 sides) was conducted. Parameters investigated included the presence of Onodi cells, sphenoid rostrum pneumatization, and the type of sphenoid pneumatization on the coronal and sagittal planes. Their effect was studied on the vertical and horizontal plane using lines of measurement 1 through 5. Results: The most common location of the SO on the horizontal plane was found to be in the middle third and was significantly affected by the rostrum pneumatization ( P value <.001) and sphenoid pneumatization on the coronal plane ( P value = .018). The location of the SO on the vertical plane was most commonly in the middle third. It was significantly affected by Onodi cell pneumatization ( P value = .021) as well as the sphenoid height ( P value <.001). Conclusions: Pneumatization of the sphenoid sinus and adjacent bony structures can affect the location of the SO. Presence of rostrum pneumatization and lateral sphenoid pneumatization shift the SO laterally. Presence of Onodi cell and low sphenoid roof shift the SO inferiorly. These variations need to be studied carefully before surgery in order to avoid operative complications.

A 16-Year Study on Incidence and Progression of Diseased Sphenoethmoidal (Onodi) Cell

Traumatic operative injury of the optic nerve in an endoscopic sinus surgery may cause immediate or delayed blindness. It should be cautioned when operating in a sphenoethmoidal cell, or known as Onodi cell, with contact or bulge of the optic canal. It remains unclear how frequent progression to visual loss occurs and how long it progresses to visual loss because of a diseased sphenoethmoidal cell. Research to discuss these questions is expected to help decision making to treat diseased sphenoethmoidal cells. From July 2001 to June 2017, 216 patients received conservative endoscopic sinus surgery without opening a diseased sphenoethmoidal cell. We used their computed tomography images of paranasal sinuses to identify diseased sphenoethmoidal cells that could be associated with progression to visual loss. Among the 216 patients, 52.3% had at least one sphenoethmoidal cell, and 14.8% developed at least one diseased sphenoethmoidal cell. One patient developed acute visual loss 4412 days after the first computed tomography. Our results show that over half of the patients have a sphenoethmoidal cell but suggest a rare incidence of a diseased sphenoethmoidal cell progressing to visual loss during the follow-up period.