Posterior clinoid process in children: morphometric analysis, pneumatization ratio, and surgical implications.

PURPOSE: To describe pneumatization and topographic position of the posterior clinoid process (PCP) in healthy children when approaching the anterior and middle fossae. METHODS: The study consisted of computed tomography images of 180 pediatric patients (90 males / 90 females), aged 1-18 years. The presence or absence of PCP pneumatization was noted, and the distances of certain landmarks to PCP were measured. RESULTS: The distances of the foramen ovale, foramen rotundum, superior orbital fissure, anterior clinoid process (ACP), foramen magnum and crista galli to PCP were measured as 18.59 ± 3.36 mm, 15.37 ± 3.45 mm, 14.60 ± 3.05 mm, 5.27 ± 3.24 mm, 32.03 ± 3.27 mm, and 30.45 ± 3.93 mm, respectively. These parameters increased with growth (between 1-18 years), but the distance between PCP and ACP decreased with an irregular pattern. In 11 sides (3.10%), a fusion between PCP and ACP was determined. PCP pneumatization was identified in 32 sides (8.9%). Its pneumatization correlated with pediatric ages (p < 0.001), but not gender (p = 0.459) or side (p = 0.711). Most of PCP pneumatization appeared after late childhood period (i.e., between 10-18 years). CONCLUSION: Our study provides beneficial data for neurosurgeons to use PCP as a reference point for creating a skull base map in children, because of the incomparable position of PCP in the skull base center.

Mixed Reality Assisted Navigation Guided Microsurgical Removal of Cranial Lesions.

AIM: To demonstrate the possible use of mixed reality (MR) technology in neurosurgery for multiple purposes, including preoperative planning, training, and three-dimensional (3D) navigation. MATERIAL AND METHODS: Using magnetic resonance imaging (MRI) and computed tomography (CT), 3D holographic images of three patients were created and inspected using a remote control. Preoperative planning was performed in a conference room using holographic images. Intraoperatively, the 3D images were matched and the adjacent structures were examined. RESULTS: The MR System (MRS) was a useful tool for preoperative planning and intraoperative navigation during the cranial intervention. It reduces operative time, decreases complication rates, increases surgical success, and enhances surgical outcomes. Eventually, MRS may be more economical. CONCLUSION: The MRS can be used for intraoperative navigation by displaying a 3D hologram at the surgeon's fingertips and for preoperative 3D examination of the lesions and its surrounding structures. The MRS enhances surgical efficacy, reduces healthcare costs, and has a shorter learning curve than the conventional methods. It also enables customized patient-specific surgery.

Vidian Canal in Chiari Type I Malformation: A Computed Tomography Study.

OBJECTIVE: To evaluate the position and dimension of the Vidian canal (VC) in Chiari type I malformation (CIM). MATERIALS AND METHODS: Radiologic views of 49 CIM (mean age: 23.58±15.62 y, sex: 23 males/26 females) and 51 healthy subjects (mean age: 42.50±20.12 y, sex: 21 males/30 females) were included in this computed tomography study. RESULTS: In comparison with controls, the VC angle and the distance of the round foramen to VC were greater in CIM, but VC length and the distances of the superior wall of the bony sphenoidal sinus, midsagittal plane, and vomerine crest to VC were smaller in CIM. Relative to the sphenoid bone, the position of VC in CIM was determined as type 1 (59.2%) >type 2 (28.6%) >type 3 (12.2%), whereas in controls as type 1 (54.9%) >type 3 (25.5%) >type 2 (19.6%). Relative to the medial pterygoid plate, the position of VC in CIM was determined as type A (63.3%) >type B (20.4%) >type C (16.3%), while in controls as type B (43.1%) >type A (40.2%) >type C (16.7%). CONCLUSION: VC size and position correlated with CIM. Compared with controls, CIM patients had more partially protruded VC into the bony sphenoidal sinus and more medially located VC according to the medial pterygoid plate.

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.

Topographic Anatomy and Pneumatization of the Posterior Clinoid Process in Chiari Type I Malformation.

OBJECTIVE: This study aimed to examine pneumatization and topographic location of the posterior clinoid process (PCP) in Chiari type I malformation (CIM) for skull base approaches. METHODS: Computed tomography images of 52 (23 males/29 females) CIM subjects aged 23.87 ± 16.09 years and 71 (26 males/45 females) healthy subjects aged 42.48 ± 21.48 years constituted the study universe. RESULTS: The distances of PCP to the foramen magnum (P = 0.037), superior orbital fissure (P < 0.001), foramen rotundum (P < 0.001), and foramen ovale (P < 0.001) were smaller, but the distance of PCP to the crista galli (P = 0.038) was greater in CIM patients, compared with normal subjects. In CIM, the fusion between PCP and the anterior clinoid process was observed in 9 sides (8.70%), while in controls it was observed in 12 sides (8.50%). PCP pneumatization was observed in 40 sides (38.50%) in CIM patients, while it was observed in 28 sides (19.70%) in normal subjects. These data displayed that PCP pneumatization was affected by CIM (P < 0.001). CONCLUSIONS: The distances of PCP to the crista galli and foramen magnum indicate the anterior fossa length and the posterior fossa depth, respectively; thus CIM patients have a longer anterior fossa and a shallow posterior fossa. In addition, the distances of PCP to the superior orbital fissure, foramen rotundum, and foramen ovale indicate the middle fossa width; hence CIM patients have less middle fossa width than normal individuals. CIM patients have an approximately 50% higher PCP pneumatization rate, and this may increase the risk of complications such as cerebrospinal fluid fistula during the application of posterior clinoidectomy.

Posterior median surgical approach to anterior sacral meningocele complicated by rectothecal fistula.

In this case report, we aimed to describe the clinical presentation, surgical approach, and follow-up of a patient with rare anterior meningocele associated with rectothecal fistula. An 17-year-old female patient was admitted to the emergency department with meningitis. On further examinations, an anterior sacral meningocele accompanied by rectothecal fistula was detected. Appropriate antibiotic treatment was arranged and surgical plan was made with the pediatric surgery clinic. The patient underwent meningocele repair via posterior approach and colostomy operation. The patient did not experience any neurological issues after the surgery. The colostomy was reversed 3 months later, and third-month follow-up MRI showed complete regression of the meningocele sac with no neurological complications. Anterior meningocele accompanied by a rectothecal fistula is a rare and complicated case. Only seven cases of coexisting ASM and RTF have been reported in literature. Although both anterior and posterior approaches have been used for the treatment of ASM, the choice of treatment is essentially based on the patient's clinical and imaging findings.