Morphometric assessment of important landmarks on skull intended for Vidian nerve surgery

Radiologic evaluation of the Vidian canal in the pediatric population

PURPOSE

This examination aimed to display the size and topographic position of the Vidian canal (VC) in normal children.

METHODS

180 pediatric subjects aged 1-18 years were included this computed tomography examination. The distances of VC to certain landmarks, and VC length were measured. The locations of VC according to the sphenoid sinus, and the medial plate of pterygoid process were classified as three types, separately.

RESULTS

The distances of VC to the vomerine crest, midsagittal plane, round foramen, and the superior wall of sphenoid sinus were measured as 12.68 ± 3.17 mm, 10.76 ± 2.52 mm, 8.62 ± 2.35 mm, and 14.16 ± 5.00 mm, respectively. The length and angle of VC were measured as 12.00 ± 2.52 mm, and 16.60 ± 9.76°, respectively. According to the sphenoid bone, VC location was identified as Type 1 in 113 sides (47.5%), as Type 2 in 70 sides (29.4%), and as Type 3 in 55 sides (23.1%). According to the medial plate of pterygoid process, VC location was identified as Type A in 274 sides (76.1%), as Type B in 55 sides (15.3%), and as Type C in 31 sides (8.6%). VC location types correlated with pediatric ages, but not sex or side.

CONCLUSION

With advancing pediatric age, the protrusion of VC into the sphenoid sinus increases, and VC shifts from medial to lateral side of the medial plate of pterygoid process.

Anatomical variations of interest for posterior nasal nerve cryotherapy in the treatment of chronic rhinitis: A radioanatomic study

KEY POINTS

An unfavorable insertion of the middle turbinate for cryotherapy was present in 74.2% of cases. Placing cryoprobe 15-30 mm above the nasal floor targets the nerves in 95.8% of cases. Centering the cryoprobe 38 mm behind the inferior turbinate axilla targets the nerves in 94.6% of cases.

Neurovascular structures in the lateral recess of the sphenoid sinus. A computed tomography evaluation

INTRODUCTION AND OBJECTIVES

Anatomical variations of the lateral recess of the sphenoid sinus and its relations with the adjacent neurovascular structures should be preoperatively evaluated to plan an adequate surgical approach and avoid iatrogenic injuries. This study aims to analyze the patterns of pneumatization of the lateral recess of the sphenoid sinus and their association with the presence of protrusion and dehiscence of the optic canal, carotid canal, vidian canal, and maxillary nerve.

MATERIALS AND METHODS

A retrospective evaluation of 320 sphenoid sinuses by computed tomography was performed. Studied variables included type of lateral recess, and protrusion, and dehiscence of the optic and carotid canal, and vidian and maxillary nerve.

RESULTS

The mean age was 45.67±17.43. A total of 55.6% (n=178) of the evaluated sphenoid sinuses corresponded to male subjects. Protrusion of the carotid canal, maxillary nerve, and vidian canal was associated with a type 3 lateral recess pneumatization, while dehiscence of these structures was most commonly observed in a type 2 lateral recess (p=<0.001).

CONCLUSIONS

Protrusion or dehiscence of neurovascular structures surrounding the sphenoid sinus has been associated with the extent of pneumatization of the lateral recess, increasing the risk of intraoperative injury. Preoperative identification of anatomical variations is mandatory to select the best approach for skull base lesions and avoid iatrogenic injuries.