Zhang Tianyu, Wang Zhengmin, Chi Fanglu, Li Shufeng
Department of Otolaryngology, Affiliated Eye Ear Nose Throat Hospital of Fudan University, Shanghai, 200031, China.
Lin Chuang Er Bi Yan Hou Ke Za Zhi. 2005 Feb;19(4):153-4.
To investigate CT, the clinical features and the management strategy of labyrinthine fistula (LF) caused by chronic otitis media (COM).
A retrospective review were investigated in 1068 patients with COM and 89 patients (8.33%) with LF. The positive fistula test was 22 (42.3%) in 52 patients. The clinical symptoms includes 34 patients (38.2%) with vertigo, 17 patients with headache, 7 patients with tinnitus or facial palsy and anacusis preoperatively. According to the extent of LF, the patients were classified into three groups. Group 1: intact labyrinth (blue line) 37 patients. Group 2: bony erosions (bony fistula) 48 patients. Group 3: complete erosions (perilymphatic fistula) 4 patients. With respect to surgical technique, the canal-wall-down procedure was performed in 86.5%, and the modified mastoidectomy performed in 13.5%. The site of LFs were 83 ears (93.3%) on lateral semicircle canal, 4 ears on superior semicircle cannal, 2 ears on posterior semicircle cannal, and 4 ears on cochlear respectively.
90% patients underwent preoperative CT scans. The fistula was detected radiologically in 51 of 80 patients. Preoperative coronal computed tomography is sensitive for diagnosing LF. There were 65 patients underwent coronal CT and 48 patients (73.8%) detected with LF, and 15 patients underwent horizontal CT and 3 patients (20.0%) with LF. Hearing improved in 50 patients postoperatively. The air-bone gap was 20dB in 28 patients and 21-40 dB in 22 patients. There were 11 patients bone conduction improved and 8 patients bone conduction descend. There were 32 patients experienced hearing threshold deteriorate and 4 patients with anacusis postoperatively. Generally we attempted to completely remove the matrix with operative microscope, to graft the fistulous area with temporalis fascia and bone dust promptly, and to reconstruct the middle ear mechanism in single stage. Long-term follow up revealed the vertigo of all patients eliminated or alleviated.
We must emphasis on the possibility of labyrinthine fistula in all COM patients. Even though the preoperative diagnosis is now more easily accessible with the HRCT, the surgeon should always remain aware that a fistula could be present in spite of a negative CT examination. The matrix on the fistula areas must be removed completely in the latest stage of operations. The coronal CT scan is a significant method in show of LSC fistula.
探讨慢性中耳炎（COM）所致迷路瘘管（LF）的CT表现、临床特征及治疗策略。
回顾性分析1068例COM患者，其中89例（8.33%）合并LF。52例患者中阳性瘘管试验者22例（42.3%）。临床症状包括眩晕34例（38.2%）、头痛17例、耳鸣或面瘫7例，术前耳聋7例。根据LF范围将患者分为三组。第1组：迷路完整（蓝线）37例。第2组：骨质侵蚀（骨瘘）48例。第3组：完全侵蚀（外淋巴瘘）4例。手术方式上，86.5%采用开放式乳突手术，13.5%采用改良乳突根治术。LF部位分别为：水平半规管83耳（93.3%）、上半规管4耳、后半规管2耳、耳蜗4耳。
90%的患者术前行CT扫描。80例患者中51例影像学检查发现瘘管。术前冠状位CT对LF诊断敏感。65例行冠状位CT检查，48例（73.8%）发现LF；15例行水平位CT检查，3例（20.0%）发现LF。术后50例患者听力改善。气骨导差20dB者28例，21 - 40dB者22例。11例骨导改善，8例骨导下降。术后32例患者听力阈值恶化，4例全聋。术中一般用手术显微镜彻底清除病灶，及时用颞肌筋膜和骨粉修补瘘管区，一期重建中耳结构。长期随访显示所有患者眩晕消失或减轻。
对所有COM患者均应重视迷路瘘管的可能性。尽管高分辨率CT（HRCT）使术前诊断更容易，但外科医生应始终意识到，即使CT检查阴性也可能存在瘘管。术中应在手术最后阶段彻底清除瘘管区病灶。冠状位CT扫描是显示水平半规管瘘的重要方法。
