Miura Yuki, Noda Masao, Koshu Ryota, Ito Makoto
Otolaryngology - Head and Neck Surgery, Jichi Medical University, Shimotsuke, JPN.
Cureus. 2024 Jul 25;16(7):e65391. doi: 10.7759/cureus.65391. eCollection 2024 Jul.
The intricate distribution of the facial nerve within the temporal bone is crucial in otological surgery. Anomalous facial nerve pathways are occasionally observed in middle ear malformations, although intra-tympanic bifurcation of the facial nerve is rare. When managing ossicular malformations with atypical facial nerve trajectories, hearing reconstruction should be prioritized based on the trajectory pattern and presence of the oval window. In this case, stapes surgery was performed due to facial nerve bifurcation within the tympanic cavity. In this case report, a 15-year-old female underwent stapes surgery due to gradually worsening conductive hearing loss. She was monitored at another hospital because of left-sided hearing loss at birth screening using automated auditory brainstem response. Her left ear initially had mild hearing loss, while her right ear remained within normal limits. However, her hearing deteriorated progressively, leading to significant daily challenges by age seven, prompting referral to our hospital. Intraoperatively, findings included defects in the incus-long process and stapes head, along with facial nerve bifurcation around the oval window, and the stapes footplate had poor flexibility. Stapedotomy was performed cautiously to preserve the facial nerve, utilizing a Teflon piston wire for sound transmission reconstruction. Postoperatively, the patient experienced no complications or facial nerve palsy, with hearing improving to 28.8 dB. Understanding the precise pathophysiology of middle ear anomalies is crucial for selecting appropriate surgical approaches. Even though the anomalies could not be evaluated prior to surgery, surgeons must carefully consider the risk of facial nerve injury and choose the optimal technique and reconstruction method tailored to each case, as predicting outcomes solely from preoperative evaluations can be challenging.
面神经在颞骨内的复杂分布在耳科手术中至关重要。中耳畸形时偶尔会观察到面神经走行异常，尽管面神经鼓室内分叉很少见。在处理伴有非典型面神经走行的听骨链畸形时，应根据走行模式和卵圆窗的情况优先考虑听力重建。在本病例中，由于鼓室内面神经分叉而进行了镫骨手术。在本病例报告中，一名15岁女性因传导性听力损失逐渐加重而接受了镫骨手术。她因出生筛查时左耳听力损失通过自动听性脑干反应在另一家医院接受监测。她的左耳最初有轻度听力损失，而右耳仍在正常范围内。然而，她的听力逐渐恶化，到7岁时导致了严重的日常挑战，促使转诊至我院。术中发现包括砧骨长突和镫骨头缺损，以及卵圆窗周围面神经分叉，镫骨底板活动度差。谨慎进行镫骨开窗术以保留面神经，使用聚四氟乙烯活塞钢丝进行声音传导重建。术后，患者未出现并发症或面神经麻痹，听力提高到28.8 dB。了解中耳畸形的确切病理生理学对于选择合适的手术方法至关重要。尽管术前无法评估畸形情况，但外科医生必须仔细考虑面神经损伤的风险，并针对每个病例选择最佳技术和重建方法，因为仅根据术前评估预测结果可能具有挑战性。
