Roser Florian, Rigante Luigi
Department of Neurosurgery, Neurological Institute, Cleveland Clinic Abu Dhabi, Al Maryah Island, Abu Dhabi, United Arab Emirates.
J Neurol Surg B Skull Base. 2021 May 17;83(Suppl 3):e641-e643. doi: 10.1055/s-0041-1727126. eCollection 2022 Aug.
This study was aimed to demonstrate the resection of anterior foramen magnum meningiomas through an endoscopic-assisted posterior midline suboccipital subtonsillar approach. This study was designed with illustration of the surgical steps and safety of this approach. Evidence of cerebrospinal fluid (CSF) cleft between the tumor and brainstem on MRI was studied ( Fig. 1A and B ). Preoperative tracheotomy was considered in cases of preoperative dysphagia to prevent any further neurological deterioration due to the bilateral access through the lower cranial nerves corridors. Semisitting position with extensive electrophysiological neuromonitoring and transesophageal echocardiogram was adopted. A standard midline incision with bilateral suboccipital craniotomy and C1-laminotomy was performed ( Fig. 2A ). After partial resection and elevation of the tonsils, tumor was debulked unilaterally around the lower cranial nerves and the vertebral artery, devascularized from the clival dura and then dissected from the brainstem ( Fig. 2B, C ). Endoscopic-assisted removal of its anterior portion followed. The same procedure was repeated from the opposite site for the contralateral portion, before approaching the purely anterior part with endoscope assistance ( Fig. 2D ). Four consecutive patients were included in the study. Grade of tumor resection and outcome (mRS) were primary measurement of this study. Clinical outcome and grade of resection are comparable to other series of patient treated with other foramen magnum approaches ( Fig. 1C and D ). Anterior foramen magnum meningiomas can be safely removed through this relatively faster midline suboccipital approach with bilateral exposure of lower cranial nerves (CNs) and vertebral arteries and lower approach-related morbidity (no condyle drilling). The surgical corridor is created by the tumor during debulking reducing need for brain retraction and the removal of the anterior dural attachment coagulated under the microscope is verified and completed endoscopically with pituitary curettes (Simpson's grade II) ( Fig. 1C and D ). The link to the video can be found at: https://youtu.be/9eACAJVwQBs .
本研究旨在通过内镜辅助下后正中枕下扁桃体下入路演示枕大孔前方脑膜瘤的切除术。本研究设计了该入路的手术步骤及安全性说明。研究了MRI上肿瘤与脑干之间脑脊液（CSF）间隙的情况（图1A和B）。对于术前有吞咽困难的病例，考虑行术前气管切开术，以防止因通过低位颅神经通道进行双侧手术而导致进一步的神经功能恶化。采用半坐位，进行广泛的电生理神经监测和经食管超声心动图检查。行标准的正中切口，双侧枕下开颅及C1椎板切开术（图2A）。部分切除并抬起扁桃体后，在低位颅神经和椎动脉周围单侧切除肿瘤，从斜坡硬脑膜离断血供，然后从脑干分离肿瘤（图2B、C）。随后在内镜辅助下切除其前部。对侧部分从对侧重复相同步骤，然后在内镜辅助下处理纯前部（图2D）。本研究纳入了连续4例患者。肿瘤切除分级和结果（改良Rankin量表[mRS]）是本研究的主要测量指标。临床结果和切除分级与其他采用枕大孔其他入路治疗的患者系列相当（图1C和D）。枕大孔前方脑膜瘤可通过这种相对更快的枕下正中入路安全切除，该入路可双侧暴露低位颅神经（CNs）和椎动脉，且手术相关并发症较低（无需磨除髁突）。在切除肿瘤时形成手术通道，减少了对脑牵拉的需求，并且在显微镜下凝固的硬脑膜前部附着点的切除在垂体刮匙辅助下通过内镜进行验证和完成（辛普森二级）（图1C和D）。视频链接可在：https://youtu.be/9eACAJVwQBs 找到。
