Prevalence of the Onodi cell in the Polish adult population: an anatomical computed tomography study.

BACKGROUND: Onodi cell is a posterior ethmoid air cell with the optic canal bulging into it; the common position of the bulge is into the sphenoid sinus, usually immediately posterior to the posterior ethmoid air cells. Variable pneumatisation patterns lead to various structures of lamellae and sinuses occasionally exposing important nerves and vessels, such as the optic and vidian nerves, internal carotid artery and cavernous sinus. In clinical practice, special imaging techniques are used to navigate through the paranasal sinuses and hence avoid injury to these structures. This study is aimed to determine the prevalence of the Onodi cell in the Polish population and compare it with other reported occurrences. MATERIALS AND METHODS: A retrospective analysis of 296 computed tomography (CT) scans of patients treated in Krakow, Poland, using a Siemens Somatom Sensation 16 spiral CT scanner. No contrast medium was administered. RESULTS: The Onodi cell was found in 31 out of the 296 patients, or approximately 10.5%, consistent with the majority of research reporting on Onodi variants. Additionally, there was one presentation of a bilateral Onodi cell in a male patient. No statistically significant difference was found between the male and female populations with a positive identification of the variant (p = 0.095, Chi2 test). CONCLUSIONS: This study helped approximate the Onodi variant prevalence of 10.47%, falling within a commonly reported range 8-14%. This gives clinicians and surgeons a better understanding of this variant's structure and significance, and therefore an opportunity to improve treatment outcomes and research.

The occipital-vertebral anastomosis revisited.

BACKGROUND: The goal of the study was to provide relevant data about the location and prevalence of the occipital artery-vertebral artery (OA-VA) anastomosis in patients without visible occlusive disease, as well as to thoroughly discuss the clinical significance of these anastomotic channels. Furthermore, the morphometric properties of the OA and its branches were also analysed. MATERIALS AND METHODS: A retrospective study was carried out to indicate anatomical variations, their prevalence, and morphometrical data on the OA and its branches. The study was performed on 55 randomly selected computed tomography angiographies (CTA) of the head and neck region. Each CTA result was analysed bilaterally. Thus, 110 results were originally assessed. RESULTS: The OA median maximal diameter was demonstrated at 4.85 mm (lower quartile [LQ]: 4.11; upper quartile [UQ]: 5.53) and the median maximal diameter of VA at 3.60 mm (LQ: 2.79; UQ: 4.38). The distances between OA and its branches were also measured giving a median result of 21.73, 30.29, 60.84, 34.88, 18.02, 55.16 mm for the lower and upper sternocleidomastoid branch, meningeal branch, mastoid branch, and descending branch, respectively. The median distance between OA and its first anastomosis was set to be 51.15 mm (LQ: 37.20; UQ: 60.10). Moreover, a set of additional measurements was carried out in order to create a three-dimensional anatomical heat-map of the occurrence of the OA-VA anastomosis. CONCLUSIONS: Knowledge about the anatomy of the OA-VA anastomosis might be of immense importance to avoid potentially fatal complications during embolisation of the OA and its branches.

A computed tomography comprehensive evaluation of the ostium of the sphenoid sinus and its clinical significance.

BACKGROUND: The purpose of this research was to evaluate the size of the sphenoid sinuses' ostia, the distance between them and the distance between the medial margin of the ostia and the median line in the Polish adult population. MATERIALS AND METHODS: The analysis was undertaken as a retrospective study of 296 computed tomography (CT) scans of patients (147 females, 149 males) with no comorbidities in their sphenoid sinuses. The paranasal sinuses were investigated by using Spiral CT Scanner (Siemens Somatom Sensation 16), in the option Siemens CARE Dose 4D, without administering any contrast medium. Having obtained transverse planes, multiplans reconstruction tool was used in order to glean sagittal and frontal planes. RESULTS: The average size of both sphenoid sinus ostia was 0.31 cm for both genders (for females ranging from 0.1 to 0.5 cm and from 0.1 to 0.6 cm for males). The mean distance between both sphenoid sinus ostia was 0.6 cm for both genders (the range for females was 0.1-1.4 cm, whereas 0.1-1.8 cm for males). The average distance between the medial margin of the ostium and the median line was 0.32 cm for both genders (0.31 cm for females in the range of 0-0.9 cm and 0.32 cm for males in the range of 0-1 cm). CONCLUSIONS: Intraoperative identification of the sphenoid sinus ostia might prove difficult and their inadequate excision could lead to potential iatrogenic complications, hence detailed anatomical descriptions are still warranted in specific populations in order to perform safe and effective procedures.

Agenesis of the sphenoid sinus and a single sphenoid sinus: a computed tomography anatomical evaluation.

BACKGROUND: Sphenoid sinuses are pneumatic spaces within the body of the sphenoid bone. Their development begins in the prenatal life and continues until the adulthood. Agenesis of the sphenoid sinuses is a situation in which they are undeveloped. On the other hand, a single sphenoid sinus lacks the presence of the main septum, leading to the formation of a single antrum. Contemporary use of transnasal transsphenoidal approaches for the pituitary surgery, as well as functional endoscopic sinus surgery urges medical professionals to be well acquainted with the aforementioned variant. MATERIALS AND METHODS: Paranasal sinuses of 300 patients (150 females, 150 males) were evaluated using computed tomography, without the use of contrast medium. Inclusion criteria involved absence of any identifiable pathology within the sphenoid sinuses and age over 18 years. Subgroup analysis involved probing for potential sources of heterogeneity, namely gender. RESULTS: In the whole research material of 300 patients, agenesis of the sphenoid sinuses was noted in 1% of the patients. No statistically significant differences were noted between the absence of the sphenoid sinuses and gender (p = 0.999). A single sphenoid sinus was found in 0.33% of the patients. There were no statistically significant differences found between the presence of fully developed sphenoid sinuses and gender (p = 0.498). CONCLUSIONS: Both agenesis of the sphenoid sinuses and a single sphenoid sinus are rare anatomical variants. Adequate planning for transsphenoidal surgeries with preoperative medical imaging is of essence in order to perform a safe and quality procedure.

The dimensions of the sphenoid sinuses: evaluation before the functional endoscopic sinus surgery.

BACKGROUND: The following study aimed to evaluate the dimensions (anteroposterior, transverse and vertical) of the sphenoid sinuses in the adult population. MATERIALS AND METHODS: The study was conducted as a retrospective analysis of the computed tomography (CT) scans of the paranasal sinuses of 296 patients (147 females and 149 males), who did not present any pathology in the sphenoid sinuses. The CT scans of the paranasal sinuses were done with the spiral CT scanner, without using any contrast medium. After obtaining transverse planes, frontal and sagittal planes were created using secondary reconstruction tool. RESULTS: The anteroposterior dimension was found to be 2.65 cm on average, in the range of 0.5-4.3 cm. The transverse dimension was on average 1.98 cm, ranging from 0.5 cm to 4.9 cm. The average vertical dimension was found to be 2.1 cm, in the range of 0.7-3.7 cm. CONCLUSIONS: Due to the high incidence of the anatomical variants of the paranasal sinuses, a CT scan is recommended in all patients before a planned surgery in order to avoid the potential iatrogenic complications. Dimensions of the sphenoid sinuses might point towards more at risk variants, but there is still a substantial amount of research that needs to be done in that aspect.

Extensive pneumatisation of the sphenoid bone: anatomical investigation of the recesses of the sphenoid sinuses and their clinical importance.

BACKGROUND: There is a great variance between the extents of pneumatisation of the sphenoid sinuses that can reach beyond the body of the sphenoid bone. The purpose of this study was to find the prevalence of the recesses of the sphenoid sinuses in Polish adult population. MATERIALS AND METHODS: Two hundred ninety-six computed tomography (CT) scans of patients who did not present any pathology in the sphenoid sinuses were evaluated in this retrospective analysis. Spiral CT scanner (Siemens Somatom Sensation 16) was used to glean the medical images. Standard scan procedure was applied, with Siemens CARE Dose 4D option enabled. No contrast medium was administered. RESULTS: In the majority of the patients (93.92%), the pneumatisation of the sphenoid sinuses expanded beyond the body of the sphenoid bone; hence, there were recesses of the sinuses present. The most common variant was the presence of two recesses - 12.84% of cases. The prevalence of all the 17 recesses was only 0.34%. Amongst the uneven recesses present, the sphenoidal rostrum's recess (61.15% of the patients) and the inferior clinoid recess (56.42%) were the most common. Amongst the even recesses present, the lateral recess was prevalent in the majority (65.88%), whereas the posterior clinoid process' recess was the least common (9.8%). CONCLUSIONS: Presence of the recesses might facilitate access to the cranial fossae; hence, comprehensive evaluation of the sphenoid sinuses is of immense importance in order to avoid unnecessary drills through the hard bone, which could potentially damage the nearby neurovascular structures.

Protrusion of the carotid canal into the sphenoid sinuses: evaluation before endonasal endoscopic sinus surgery.

BACKGROUND: Many reports have previously indicated the vast number of anatomical variations of the sphenoid sinuses, e.g. presence of the recesses. Notwithstanding, there are a few crucial neurovascular structures directly neighbouring with the sinuses. The following research aimed to evaluate frequency prevalence of the carotid canal's protrusion into the sphenoid sinuses in adult population. MATERIALS AND METHODS: Computed tomography (CT) scans of the paranasal sinuses of 296 patients (147 females, 149 males) were analysed in this retrospective study. The patients did not present any pathology in the sinuses. Spiral CT scanner Siemens Somatom Sensation 16 was used in the standard procedure in the option Siemens CARE Dose 4D. RESULTS: Protrusion of the carotid canal was found in the majority of the patients - 55.74%, more frequently in males (65.1% of the patients) than in females (46.26% of the patients). The said variant - regardless of gender - was noted more often bilaterally (41.55% of the cases: 29.93% females, 53.02% males) than unilaterally (14.19% of the cases: 16.33% females, 12.08% males). In the unilateral type (regardless of gender), the protrusion was more common for the left sphenoid sinus - 10.81% of the patients (12.24% females, 9.4% males) than for the right - 3.38% of the patients (4.08% females, 2.68% males). CONCLUSIONS: Complicated structure of the paranasal sinuses, derived from the high prevalence of their anatomical variations, may perplex routine surgical interventions. Henceforth, referral for a CT scan is imperative in order to abate the risks associated with an invasive procedure in the said region.