ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Institutes of Biomedical Sciences, Fudan University, Shanghai, China.
NHC Key Laboratory of Hearing Medicine, Fudan University, Shanghai, China.
ORL J Otorhinolaryngol Relat Spec. 2022;84(6):480-487. doi: 10.1159/000523926. Epub 2022 Jul 7.
The aim of this study was to determine the prevalence of facial nerve (FN) bifurcation in patients who undergo stapes surgery, and to ascertain the correlation between the intraoperative and radiographic findings in cases where an unexpected branch malformation for patients undergoing stapes surgery. Patients who underwent stapes surgery were retroactively examined for confirmed FN bifurcation. Among the 887 patients, 10 had a bifurcated FN confirmed during surgery and had a preoperative high-resolution computed tomography (HRCT) scan. The HRCT scans were examined by two radiologists who were blinded to the operational findings. The diagnostic accuracy of HRCT imaging was examined along with their preoperative audiometry. In total, 887 patients underwent stapes surgery and among them the prevalence of FN bifurcation was 1.13%. These 10 patients had a 1:1 male-female ratio with a mean age of 17.9 ± 7.0 years. From a surgical review, all cases had bifurcation at the horizontal segment of FN, including 1 case of FN trifurcation. The diagnostic difference between HRCT imaging and intraoperation observations for malformations in the middle ear varies widely depending on the location, ranging from 0% to 90%. The prevalence of incus and stapes malformations was high in both imaging and operation findings (≥60%). The detection rate of abnormal positioning and bifurcation of the FN during HRCT imaging was 30% and 0%, respectively. The mean air-bone gap hearing threshold for patients was significantly improved from 42.3 dB preoperatively to 15.6 dB postoperatively without any complications. These results showed that it is extremely difficult to predict the FN bifurcation prior to surgery with a detection rate of 0%. The diagnostic difference between HRCT imaging and intraoperation observations for malformations of different parts of the middle ear varies widely. These results highlight the importance of being vigilant in regard to FN anatomical variation during stapes surgery for any unexpected malformations that are not detected during HRCT evaluation. In addition, the surgical outcomes for these patients were optimal when treatment was performed by senior surgeons.
本研究旨在确定接受镫骨手术的患者面神经（FN）分叉的发生率，并确定术中与影像学发现之间的相关性，以了解接受镫骨手术的患者中意外分支畸形的情况。对接受镫骨手术的患者进行回顾性检查，以确认 FN 分叉。在 887 例患者中，10 例患者术中证实 FN 分叉，术前进行高分辨率计算机断层扫描（HRCT）。两名放射科医生对 HRCT 扫描进行检查，他们对手术结果不知情。检查了 HRCT 成像的诊断准确性及其术前听力。共有 887 例患者接受了镫骨手术，其中 FN 分叉的发生率为 1.13%。这 10 例患者的男女比例为 1:1，平均年龄为 17.9±7.0 岁。从手术回顾来看，所有病例均在 FN 水平段发生分叉，包括 1 例 FN 三叉。HRCT 成像与中耳畸形术中观察的诊断差异因位置而异，范围从 0%到 90%不等。影像学和手术发现中砧骨和镫骨畸形的发生率均较高（≥60%）。HRCT 成像中 FN 异常定位和分叉的检出率分别为 30%和 0%。患者的气骨导差平均听力阈值从术前的 42.3dB 显著改善至术后的 15.6dB，无任何并发症。这些结果表明，术前 FN 分叉的检出率为 0%，极难预测。中耳不同部位畸形的 HRCT 成像与术中观察的诊断差异很大。这些结果强调了在镫骨手术中警惕 FN 解剖变异的重要性，对于 HRCT 评估未发现的任何意外畸形。此外，由资深外科医生进行治疗时，这些患者的手术结果最佳。
