Prevalence of facial canal dehiscence and other bone defects by computed tomography.

INTRODUCTION: The facial nerve is the most vulnerable structure during otological surgeries. Facial canal dehiscence (FCD) is the main risk factor for iatrogenic injuries. Its prevalence in clinical studies ranges between 6 and 33.3%, while anatomical studies report 25-57%. The objective was to determine the prevalence of FCD stratified by age and gender in a healthy population. MATERIALS AND METHODS: Temporal bones from high-resolution computed tomography (CT) were analyzed. Patients with a history of trauma or tumors of the temporal bone, cholesteatomas, chronic middle ear disease, and any pathology that could modify the bone's anatomy, were excluded. RESULTS: A total of 184 temporal bones were included. FCD was observed in 94 (51.2%) of the analyzed bones. The tympanic portion was the most frequently affected site with 91 (49.5%), followed by the mastoid segment with 3 (1.6%). No dehiscence was found in the labyrinth portion. We observed 30 (31.9%) of the FCD involved the oval window. Other bone defects identified with the FCD included: 11 (11.7%) with a lateral semicircular canal fistula and 7 (7.4%) with tegmen tympani erosions. CONCLUSION: FCD has a high prevalence among healthy patients. A pre-surgical otological evaluation using high-resolution CT should be indicated to properly assess the patient and reduce the risk of injury.

Does axillary lymph node size predict better metastatic involvement than apparent diffusion coefficient (ADC) value in women with newly diagnosed breast cancer?

BACKGROUND: It has been demonstrated that the number of metastatic axillary lymph nodes (mALNs) influence disease-free and overall survival in patients with breast cancer. PURPOSE: To determine if the ALN size is more accurate than the ALN apparent diffusion coefficient (ADC) value to predict metastatic involvement in newly diagnosed breast cancer. MATERIAL AND METHODS: A total of 44 patients with breast cancer were included. Magnetic resonance imaging (MRI) examinations were performed on a 1.5-T system with sagittal T1-weighted fast spin-echo non-fat saturated, sagittal T2-weighted fast spin-echo non-fat saturated, axial diffusion-weighted imaging echo-planar (b values of 0 and 700 s/mm2), and non-contrast axial VIBRANT sequences. The size and the ADC value were obtained for ALN ipsilateral and contralateral to breast cancer. The reference standard was the histopathologic lymph node status. RESULTS: mALN had a greater cortical thickness compared to contralateral non-mALN (10.3 ± 5.32 mm vs. 4 ± 1.17 mm, P ≤ 0.001). The threshold of ≥6.7 mm for predicting axillary metastatic involvement had a sensitivity and a specificity of 80.0% and 97.7%, respectively. The ADC value of mALN was significantly higher than the contralateral non-mALN (0.90 ± 0.12 × 10-3mm2/s vs. 0.78 ± 0.12 × 10-3mm2/s; P = 0.001). The threshold of ≥0.86 × 10-3mm2/s had a sensitivity and a specificity of 66.7% and 76.7%, respectively. CONCLUSION: Our results indicate that the cortical thickness has a better diagnostic performance in the differentiation of metastatic and non-metastatic lymph nodes than the lymph node ADC.

Impact of bilateral nasal polyposis on the interoptic and interzygomatic distance.

PURPOSE: To identify and determine variations on eye distance in patients with bilateral nasal polyposis (BNP) compared to a healthy control group. METHODS: This is a case-control study that included 20 BNP patients and 40 healthy controls. We included all patients with BNP confirmed by pathology and a computed tomography scan. A healthy control group was admitted, filtered by the exclusion criteria of nasal polyposis, craniofacial malformations, and encephalocele. Paranasal sinus CT scans were performed in all participants, and two measures were evaluated, the interoptic (soft tissue) and the interzygomatic (bone structure) distances. RESULTS: A total of 20 BNP subjects, 13 (65%) male and 7 (35%) female, with a mean age of 38.8 years, and 40 healthy controls, 16 (40%) male and 24 (60%) female with a mean age of 43.2 years, were included. The mean interoptic distance was 69.7 mm (71.9 mm men, 66.4 mm women) and interzygomatic distance was 103.1 mm (104.5 mm men, 100.6 mm women). A significant increase of the interoptic (p < 0.001) and interzygomatic (p < 0.002) measurements was found in patients with polyposis compared to the controls. In the receptor operative curve analysis, the interoptic distance had an area under a curve of 96% and the threshold that maximizes the sensitivity and specificity was 59.85 mm (sensitivity 90%, specificity 95%, PPV 90%, NPV 95%). CONCLUSIONS: An increase in ocular and orbital distances was identified in patients with BNP. Polyposis may be identified by measuring eye separation. The established cut point distance identifies patients that may benefit from follow-up. Further research in this study line is suggested.

Anatomical variations of the ethmoidal roof: differences between men and women.

AIM: During the paranasal sinuses surgery different complications may occur, both vascular and bony. The objective of the present study was to evaluate the ethmoidal roof configuration through the Keros and Yenigun classifications, analyzing results stratified by gender and side. MATERIALS AND METHODS: We retrospectively analyzed 120 high-resolution computed tomography paranasal sinus study images and measured the depth of the cribriform plate in a coronal view and the anterior-posterior length in a cross section. RESULTS: The Keros Type II was the most frequent and no statistically significant difference was found when comparing by gender. Yenigun type I was more prevalent, and a statistically significant difference was found between men and women in types I and II (p = 0.010 and p = 0.049, respectively). Statistical difference was observed in anterior-posterior means in the comparison between both classifications. In both, right and left side for men (p = 0.003 and p = 0.05) and women (p = 0.029 and p = 0.039). CONCLUSION: We demonstrate the morphological variability that exists in this region. Gender differences that must be considered by the surgeon to avoid complications. Further studies are needed to evaluate the value of these findings when predicting surgical complications. A CT before PNS surgery is already widely accepted.