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Purpose: Dural exposure during cholesteatoma surgery can pose a risk of cerebrospinal fluid leakage or residual disease. Therefore, delicate handling of the area surrounding the bone defect in the cranial fossa is required. However, in small-sized defects, preoperative prediction of dural exposure can be challenging. This study aimed to evaluate the diagnostic value of computed tomography (CT) for preoperative prediction of cholesteatoma-related dural exposure in bone discontinuities in the skull base. Methods: We evaluated serial high-resolution CT images showing bone density discontinuities in the middle cranial fossa (MCF) requiring mastoidectomy for cholesteatoma. The CT and intraoperative findings were analyzed retrospectively. We evaluated the length between the superior margins of the bone density discontinuities using coronal CT planes. Receiver operating characteristic (ROC) curves were constructed to determine the optimal cut-off values. Results: We extracted data from 107 bone density discontinuities, among which 54 (50.5%) showed dural exposure intraoperatively. Discontinuities with dural exposure (n = 54) had significantly greater lengths than did those without (n = 53) (p < 0.001, Wilcoxon rank-sum test). The area under the curve was 0.9780 according to the ROC analysis, and the optimal cut-off value was determined to be 2.99 mm (sensitivity 92.59%; specificity 94.34%). Conclusion: A bone density discontinuity length of > 2.99 mm in the MCF on coronal CT plane is a reliable diagnostic marker for cholesteatoma-related dural exposure. Thus, preoperative high-resolution CT analysis can inform optimal surgical preparation and planning before manipulating the area surrounding the osteolytic lesion in the MCF. [ABSTRACT FROM AUTHOR]

Purpose: Appropriate reconstruction of the canal wall or maintenance of the middle ear pressure in cholesteatoma may help in preventing recurrence. Retrograde mastoidectomy with canal wall reconstruction (RMR) can overcome the challenge of a wider canal wall defect or temporal bone immaturity, which possibly increases the recurrence risk. This study compared the outcomes of RMR and intact canal wall tympanomastoidectomy (ICW) for cholesteatomas with minimal mastoid extension and quantitatively evaluate the relationship between anatomical features and recurrence. Methods: This single-center retrospective cohort study included patients who had undergone primary ICW or RMR for pars flaccida cholesteatoma with minimal mastoid extension from 2009 to 2019. The main outcome measures were anatomical measurements of the shortest distance between the cranial fossa and the upper canal wall (SCU), attic volume, and bony defect area of the canal wall (BDC) on computed tomography; recidivism; and postoperative air–bone gap (ABG). Results: There were no significant differences in the preoperative anatomical factors, recidivism incidence, and postoperative ABG between the RMR (n = 20) and ICW (n = 60) groups. However, the median BDC was significantly greater in the RMR group (58.3 vs. 37.0 mm2). There was no significant difference in the SCU and attic volume between patients with and without recurrence. Conclusion: Selection of RMR or ICW may not affect recidivism and hearing outcomes in cholesteatoma with minimal mastoid extension. Bony defect size and attic narrowness were not associated with recurrence. Considering wider visualization and one-staged operation, RMR can be more adaptable than ICW for cholesteatoma with minimal mastoid extension. [ABSTRACT FROM AUTHOR]

Objectives: We aimed to clarify the usefulness of high-resolution computed tomography (HRCT) and establish HRCT criteria for presurgical assessment of the mastoid extension in pars flaccida cholesteatomas of the middle ear.Methods: Retrospective observational study. Patients who underwent primary surgery for pars flaccida cholesteatoma and those who underwent temporal bone HRCT for pretreatment evaluation were reviewed. The distance in the anterior-most portion of the mastoid sinus on HRCT was measured, and the presence of surgically verified mastoid extension of cholesteatoma was evaluated. All cases were subclassified as M+ (surgically mastoid extension-positive) or M- (surgically mastoid extension-negative).Results: A total of 107 patients with pars flaccida cholesteatoma were included. The distance in the M+ cases was significantly longer than that in the M- cases, and the cutoff value was 3.6 mm. The difference between the ipsilateral/diseased-side distance and the contralateral/evaluable side (difference value) in M+ cases was larger than that in M- cases, with a cutoff value of 0.6 mm. The inter-rater reliability of this distance measurement was excellent, regardless of imaging experience.Conclusions: The cutoff values of the distance and the difference value can be used for pretreatment HRCT evaluation of mastoid extension in middle ear cholesteatoma with relatively high accuracy, regardless of the experience and skill levels of the evaluator. [ABSTRACT FROM AUTHOR]