The value of high-resolution CT in preoperative staging and surgical planning for external auditory canal cholesteatoma

QIAN Wang; ZHANG Qinghua; WANG Chenhua; GAO Yuanhui; WANG Yajie; LI Jianfeng; YU Shudong; HE Mingqiang; CHEN Chengfang; LI Hong

doi:10.20258/j.cnki.1006-9011.2025.07.004

Abstract：Objective To explore the value of high-resolution CT in preoperative staging and surgical planning for external auditory canal cholesteatoma(EACC).Methods 93 patients(97 ears)with EACC who underwent surgery were prospectively collected.EACC was classified into three stages according to the temporal bone high-resolution CT(HRCT)findings.Stage Ⅰ pa-tients were needed only cholesteatoma cleaning,and skin grafting was performed when large skin defects were found during the operation.Stage Ⅱ patients without significant external auditory canal narrowing were subjected to canaloplasty with oticendo-scope,otherwise,to postauricular canaloplasty with microscope.For Stage Ⅲ patients,the choice of surgical approach depended on the extent of the lesions and the degree of mastoid aeration.Endoscopic surgery was chosen for lesions limited to the tympanic cavity and semicircular.Canal wall-up type radical mastoidectomy(CWUM)was conducted for lesions limited to the pneumatic mastoid,and combing CWUM and endoscopic procedures was performed for lesions involving both the mastoid and tympanic cav-ity.Modified radical mastoidectomy and external auditory canal reconstruction were performed in patients with poor mastoid aera-tion.Results All affected ears exhibited low-density shadows within the external auditory canal on CT imaging.Bony erosion of the external auditory canal was observed in 77 ears,involving the inferior wall in 70 ears,posterior wall in 62 ears,anterior wall in 46 ears,and superior wall in 37 ears.Among the 97 ears diagnosed with external auditory canal cholesteatoma(EACC),CT-based staging classified 20 ears(20.6％)as stage Ⅰ,24 ears(24.7％)as stage Ⅱ,and 53 ears(54.6％)as stage Ⅲ-including 20 ears(20.6％)as stage Ⅲa,7 ears(7.2％)as stage Ⅲb,and 26 ears(26.8％)as stage Ⅲc.The overall concordance rate be-tween CT staging and intraoperative findings was 91.8％(89/97).During postoperative follow-up ranging from 6 months to 2 years,the average air-bone gap was significantly reduced by(17.8±12.0)dB(t=8.361,P<0.001).Conclusion This staging system is accurate and easily applicable for use when deciding the surgical modality for patients with EACC.