Microsurgical resection of ventral foramen magnum meningiomas via a far-lateral suboccipital approach

BACKGROUND: In recent years some reports have been published propagating microsurgical resection of ventral foramen magnum meningiomas (VFMMs). Operative approaches to these lesions have been studied by various authors, but remain controversial. OBJECTIVE: To discuss the operative technique and outcome in patients with VFMMs who had been treated via a far lateral suboccipital approach. DESIGN: Retrospectively clinic case investigation. SETTING: Department of Neurosurgery, the Ninth People's Hospital, Medical School of Shanghai Jiao Tong University. PARTICIPANTS: Between January 1997 and June 2003, 10 patients were treated surgically with VFMMs in Department of Neurosurgery, the Ninth People's Hospital, Medical School of Shanghai Jiao Tong University. In the series of 10 patients, ages ranged from 37 to 72 years, mean (53±10) years, were consisted of 6 males and 4 females. All the subjects were informed of the treatment plan and agreed to join the experiment. Early symptoms included headache and upper cervical pain. The time between the first occurrence of symptoms and the diagnosis ranged from 6 months to 17 months, mean (10.3±3.4) months. Main presenting symptoms were unilateral upper extremity sensory and motor deficits in 6 cases, swallowing difficulties in 2 and spastic quadriparesis in 2. VFMMs were demonstrated as round by the computed tomographic (CT) scan and magnetic resonance imaging (MRI) in all patients. The maximum diameter of tumors ranged from 2 to 4 cm, mean (2.55±0.57) cm, including 2 cm in one case, 2.0-3.0 cm in six and 3.0-4.0 cm in three. METHODS: ①All tumors were removed via the far lateral suboccipital approach. Resection of the posterior 5 mm of the condyle was necessary in one patient whose tumors' diameter were 2 cm. The patient was situated in the lateral decubitus position. The head was fixed in a Mayfield headrest. A C-shaped incision made behind the ear 2 cm medial to the mastoid process, turning vertically down to the level C4, to expose the extradural segment of the vertebral artery (VA). After the dura was opened longitudinally behind VA entry point, the tumor was revealed to identify the complete cranial nerves and the intracranial VA under magnification of the surgical microscope. Every attempt should be made to keep the arachnoid and the dentate ligament was sectioned. Then the tumor was debulked significantly, and dissected away from the cranial nerves and the blood vessels with microsurgical techniques. If it was risk to dissect tumor from the vertebral artery, its branches, or any cranial nerve, the progression was discontinued and portion of the tumor was left behind. After resection of the tumor, the site of its attachment was coagulated and the involved layer of dura was resected. ②The degree of tumor resection was classified based on Al-Mefty's grade into three categories: gross-total resection: excision of the dural attachment and drilling of adjacent bone; near-total resection: a few millimeters of insulated and cauterized tumor were left on the vertebral artery or other vital; subtotal resection: more than 50% of the tumor mass were removed. ③All patients underwent clinical examination for lower cranial nerves or long tract deficits on the first day postoperatively. CT or MRI and neurological examinations were performed at 3 months of follow-up. MAIN OUTCOME MEASURES: Operative effect. RESULTS: All ten patients with VFMMs were treated via a far lateral suboccipital approach. Gross total resection was achieved in 6 patients, near-total resection was carried out in 2 and subtotal resection in 2 patients. One patients died in the postoperative period due to acute respiratory distress syndrome, five patients kept normal neurological status, whereas other four patients suffered from lower cranial nerve deficits and aspiration pneumonia was observed in two of them. The data of following up for 3 months showed that 2 patients still had lower cranial nerve deficit and others recovered from their illness. No tumor relapse or increment was found in CT or MRI scans. CONCLUSION: Most of VFMMs could be totally removed via a far lateral suboccipital approach with or without resection of the occipital condyle according to the tumor size, allowing most of these patients to achieve a good outcome in a 3 months follow-up.

The classification and microsurgery of magnum foramen tumor

Objective To explore classification and surgical approach of magnum foramen tumor. Methods A retrospective analysis was performed for 43 surgically treated patients with tumors involving foramen magnum. According to the site of tumor,the classification was divided into:Type Ⅰ,located at dorsal,Ⅰ a extra-medullary,

Primary Meningeal Melanocytoma Located in Foramen Magnum:a Case Report and Review of the Literatures

LIMAS and Tio1 proposed the term meningeal melanocytoma first time in 1972 to describe a primary melanotic tumor of the leptomeninges with prolonged clinical course and benign histology.Meningeal melanocytoma of the central nervous system is rare and benign primary meningeal melanocytoma (PMM) is more exceptional,and also less usual than the malignant types.2 This rare tumor falls under the subclassification of primary melanocytic lesions in the World Health Organization's classification of central nervous system tumors.3 PMM located in the foramen magnum region is an unusual cause of bulbus medullae and fourth ventricle compression.Here we report a 48-year-old man with a PMM which is located in the foramen magnum inducing supratentorial obstructive hydrocephalus.

An Extremely Rare Case Report of Foramen Magnum Dermoid Cyst Presenting as an Acute Progressive Neurologic Deficit

Intracranial dermoid cysts are nonneoplastic lesions that present a rare clinical entity. They account for 0.04% to 0.6% of all intracranial tumors. Such cystic lesions usually contain different ectodermal derivatives including hairs, sebaceous glands, apocrine gland and teeth. Dermoid cysts of foramen magnum occur very rarely, with few cases reported in the literature. Computed tomography (CT) and magnetic resonance imaging (MRI) are two main diagnostic tools. Here in this paper, we described a case of intracranial (foramen magnum) dermoid cyst presented with neurologic deficits that completely removed surgically.

Endoscopic foramen magnum decompression for Chiari malformation

Objective To investigate the methods and effectiveness to treat Chiari malformation with surgical decompression of foramen magnum under endoscope. Methods 23 cases with Chiari malformation. (withoutatlanto-axial dislocation and basilar invagination) diagnosed by magnetic resonance imaging(MRI) were operated with the surgical decompression for foramen magnum under the endoscope. Results 23

经髁后入路显微手术切除枕骨大孔腹侧或腹外侧脑膜瘤

目的评价枕大孔(FM)腹侧或腹外侧脑膜瘤手术入路及治疗策略变化。方法回顾性分析解放军总医院2007年1月—2022年1月采用显微外科技术切除的72例枕大孔腹侧或腹外侧脑膜瘤的临床资料,并结合相关文献进行复习。结果所有患者均经一侧远外侧髁后入路显微手术切除。全切除65例(90%),次全切除7例(10%)。次全切除的患者行赛博刀放射外科治疗。12例(17%)发生舌下神经功能障碍,8例术后3个月内好转。18例(25%)出现声音嘶哑和(或)吞咽困难,15例在术后3个月内好转,1例患者因后组颅神经麻痹而行气管切开。1例因脊髓前动脉损伤偏瘫。无手术死亡。随访12~60个月,无患者出现肿瘤复发。结论经髁后入路显微手术切除枕骨大孔腹侧或腹外脑膜瘤既能满足手术显露需要,又避免了磨除过多的骨质,可取得很好的全切率、较低的并发症和长期满意疗效。术后偏瘫等严重并发症的发生主要是因为术中血管损伤。

儿童枕骨髁及枕骨大孔数字化测量的临床意义

背景:由于儿童年龄较小,枕骨髁和枕骨大孔尚未发育完全,容易发生枕颈交界区的各种疾病与创伤,严重时需手术治疗。但目前缺乏对儿童枕骨髁和枕骨大孔发育的解剖学参数。目的:利用三维重建技术对枕骨髁和枕骨大孔形态学结构进行相关测量,为枕颈交界区病变以及相关外科手术和法医鉴定提供重要的解剖学参数。方法:收集行螺旋CT扫描涉及颅底的原始儿童及青少年影像资料389例,其中男247例,女142例,年龄1-18岁。按照年龄分为1-3岁组、4-6岁组、7-9岁组、10-12岁组、13-15岁组和16-18岁组。利用Mimics 16.0软件三维重建颅底,测量枕骨大孔长度和宽度,并且利用公式计算出枕骨大孔面积和指数,测量枕骨髁长度、宽度、高度,枕骨髁长轴与矢状轴的夹角(O-S角),枕骨大孔前、后缘中点连线与枕骨髁后缘和枕骨大孔交点连线的夹角(F-O角),枕骨大孔前、后缘连线中点与舌下神经管后壁中点连线的夹角(F-H角)。对各指标间进行性别、侧别和年龄差异分析。结果与结论:①枕骨大孔测量除枕骨大孔指数不存在性别间的显著性差异(P>0.05)外,枕骨大孔最大长度和最大宽度、枕骨大孔面积均存在性别间差异(P<0.05);②枕骨髁的O-S角、F-O角和F-H角在性别间无显著性差异(P>0.05),枕骨髁长、枕骨髁高、枕骨髁宽在性别间差异(P<0.05);③枕骨髁长在侧别间无显著性差异(P>0.05),枕骨髁高、枕骨髁宽、O-S角、F-O角和F-H角在侧别间差异均有显著性意义(P<0.05);④枕骨大孔最大长度和最大宽度、枕骨大孔面积、枕骨髁长、枕骨髁高和枕骨髁宽随着年龄的增长呈波浪状递增的趋势;而O-S角、F-O角和F-H角随着年龄的增长呈波浪状递减趋势;枕骨大孔指数则无明显变化;⑤提示儿童枕骨大孔和枕骨髁的形态学指标在性别和侧别间存在差异,这些差异可为临床外科手术入路选择及法医检测提供重要的参考意义。

相位对比电影MRI及术中超声在Chiari畸形1型手术方式选择中的临床应用进展

枕大孔减压术是治疗Chiari畸形1型(CM1)患者的通用手术,但减压范围、临床疗效存在争议,没有单一、明确的治疗方法。脑脊液流体动力学的改善可能与临床症状的缓解有关,相位对比电影MRI(PC-MRI)联合术中超声(IOUS)可以准确评估颅颈交界区的脑脊液流体动力学改变,两者结合可以为损害程度评估提供有效信息,指导手术方式的选择,预测临床改善效果,减少再手术的发生。本文对PC-RMI联合IOUS在CM1术式选择中的临床应用进行综述。

Classification and microsurgical treatment of foramen magnum meningioma

Background To investigate the classification and microsurgical treatment of foramen magnum meningioma(FMM).Methods We retrospectively analyzed 76 patients with FMM and classified them into two classifications,classification ABS according to the relationship between the FMM and the brainstem and classification SIM according to the relationship between the FMM and the vertebral artery(VA).All patients underwent either the far lateral approach(54 cases)or the suboccipital midline approach(22 cases).Results Of the 76 cases,47 cases were located ahead of the brainstem(A),16 cases at the back of the brainstem(B),and 13 cases were located laterally to the brainstem(S).There were 15 cases located superior to the VA(S),49 cases were inferior(I),and 12 cases were mixed type(M).Among 76 cases,71 cases were resected with Simpson grade 2(93.42%),3 with Simpson grade 3(3.95%),and 2 with Simpson grade 4(2.63%).We summarized four anatomical triangles:triangles SOT,VOT,JVV,and TVV.The mean postoperative Karnofsky performance score was improved in all patients(p<0.05).However,several complications occurred,including hoarseness and CSF leak.Conclusion ABS and SIM classifications are objective indices for choosing the surgical approach and predicting the difficulty of FMMs,and it is of great importance to master the content,position relationship with the tumor,and variable anatomical structures in the four"triangles"for the success of the operation.

枕骨大孔腹侧脑膜瘤手术入路:枕下中线or远外侧?

脑膜瘤是枕骨大孔区的常见疾病,由于生长缓慢,患者在很长一段时间内都没有症状,所以就诊时肿瘤往往已经生长得很大,由于该处空间狭小,周围有许多重要结构,例如脑干、后组颅神经、椎动脉,所以手术非常困难,尤其是枕骨大孔腹侧脑膜瘤。由于延颈髓、椎动脉、后组颅神经的阻挡,肿瘤显露困难。充分地显露是枕骨大孔腹侧脑膜瘤手术成功的关键,因此远外侧入路理所当然成为首选入路。然而,远外侧入路也存在着开颅复杂、花费时间多、肌肉损伤严重、椎动脉损伤风险高等缺点。临床实践中,绝大多数的枕骨大孔腹侧脑膜瘤将延颈髓推向一侧,形成了自然的肿瘤通道;利用此通道,采用枕下中线入路,笔者成功切除了19例枕骨大孔区腹侧脑膜瘤。枕下中线入路是切除枕骨大孔腹侧脑膜瘤的理想入路,能简单、快捷、低风险地切除几乎所有的枕骨大孔腹侧脑膜瘤。

3D Slicer三维重建技术辅助手术治疗枕骨大孔区硬脑膜动静脉瘘:附1例报道并文献复习

目的探讨枕骨大孔区硬脑膜动静脉瘘(DAVF)的影像学特征以及3D Slicer三维重建技术辅助手术治疗的疗效。方法回顾性分析2021年6月收治的1例枕骨大孔区DAVF的临床资料,并结合相关文献进行分析。结果50岁男性,因双下肢麻木及疼痛不适1个月入院。脊柱MRI显示延髓至颈5水平颈髓异常信号。双侧颈内动脉、双侧颈外动脉、右侧椎动脉造影未发现异常,左侧椎动脉造影显示枕骨大孔区DAVF,由脑膜后动脉多个分支供血,经小脑表面及数支硬脑膜迂曲扩张的皮质静脉引流汇入左侧横窦、岩上窦及基底窦,并可见迂曲的硬脊膜前、后静脉参与瘘口血液引流;左侧小脑后下动脉(PICA)靠近瘘口部位走行且迂曲。3D Slicer三维重建影像清晰显示DAVF的位置、供血动脉和引流静脉,多模态重建显示瘘口位于枕部后正中枕骨大孔上区域并靠近硬脑膜。采取枕颈部后正中入路手术,术中吲哚菁绿荧光造影确认DAVF消失。术后3个月,双下肢麻木及疼痛感均有减轻;复查MRI显示脑干和脊髓水肿消失,DSA显示DAVF完全闭塞。结论枕骨大孔区DAVF手术治疗可以显著改善病人预后,应用3D Slicer三维重建技术对DAVF进行精准定位能够在很大程度上节省手术时间并提高手术质量。

枕下远外侧入路解剖研究与临床应用

目的 探讨枕下远外侧入路的相关解剖研究和临床应用效果。方法 选用 2 0例成人头颅湿标本进行显微解剖测量。应用枕下远外侧入路切除枕大孔区和前外侧肿瘤 10例。结果 枕骨髁为术中重要的解剖标志 ,枕下三角为显露椎动脉的重要标志 ,枕下三角由三条肌肉形成 ,即头后大直肌、头上斜肌和头下斜肌。枕下三角内有椎动脉及肌支 ,椎静脉丛和颈 1神经。测量寰椎横突孔外缘至椎动脉入颅处距离 ,左侧 (16 .87± 2 .0 8)mm、右侧 (16 .79± 1.90 )mm。枕大孔区肿瘤 10例手术中 ,肿瘤全切 6例 ,次全切 3例 ,大部分切除 1例 ,无手术死亡。结论 枕下远外侧入路手术应了解枕大孔区的相关解剖参数和局部解剖结构 ,该入路优点能增加术野空间 ,最大程度上显露肿瘤组织 ,减少对脑干和重要血管神经牵拉。

枕骨大孔区脑膜瘤的外科治疗

目的 提高对枕骨大孔区脑膜瘤的认识。方法 回顾性分析我院 1993年 1月～ 1999年 12月收治的 9例枕骨大孔区脑膜瘤。采用枕下正中入路、枕下远外侧入路。结果 肿瘤全切除 8例 ,次全切除 1例。无手术死亡。结论 合理选择手术入路能提高肿瘤全切除率和脑神经保护率 ,枕下远外侧入路是切除枕骨大孔区脑膜瘤的有效手术入路之一。

枕骨大孔扩大术治疗上颈椎与颅底先天性畸形伴寰枢关节脱位的远期疗效

随访了１９８２～１９８９年间因上颈椎与颅底先天性畸形伴寰枢关节脱位而施行枕骨大孔扩大术治疗患者１２例，平均随访７．４年。结果发现１２例患者术后短期内神经症状均有不同程度缓解，而随访时有１１例神经症状复发或加重，占９１．７％。随访结果分析表明：枕骨大孔扩大术仍是一种治疗上颈椎与颅底先天性畸形伴寰枢椎脱位的有效方法，但应强调在枕骨大孔扩大减压后必须重建枕颈部的稳定性。

远外侧入路切除枕大孔区肿瘤

目的总结枕大孔区肿瘤的临床特点、治疗经验、远外侧入路的优点及显微手术技巧,以期进一步提高对枕大孔区肿瘤的诊断和治疗水平。方法回顾性分析1998年3月2003年12月北京天坛医院神经外科采用远外侧入路治疗的92例枕大孔区肿瘤病例。结果全部病例均采用经远外侧入路显微外科手术切除肿瘤。肿瘤全部切除66例(71.7%);近全切除22例(23.9%);大部切除4例(4.3%)。术后有41例病人出现并发症,发生率为44.6%。术后死亡2例,病死率2.17%。结论经远外侧入路显微神经外科手术可以直接显露下斜坡,暴露延髓颈髓腹侧,对脑神经提供良好的显露,易于控制椎动脉近端、远端及其分支,可以避免对脑干的牵拉,可以提高手术全切除率,降低手术损伤及术后并发症,使手术更加安全和成功。

后颅窝重建手术治疗Chiari畸形合并脊髓空洞症

目的探讨后颅窝重建这种手术方法对Chiari畸形合并脊髓空洞症的治疗及其效果。方法枕下正中入路,以枕大孔为中心,在其上和两侧2cm左右范围内去除枕骨鳞部,咬除环椎后弓,剪开硬膜,如需要打开蛛网膜,应尽量保持软脑膜完整。取自体肌筋膜或硬脑膜替代材料扩大修补。结果30例病人,术后症状均有不同程度的改善,术后3个月复查MRI见脊髓空洞缩小。结论手术使颅颈交界区充分减压,改善了脑脊液循环状态,有效地缓解了临床症状,并对脊髓空洞有明显的治疗作用。扩大修补硬脑膜有利于减少术后并发症的发生。

枕骨大孔减压伴硬膜外层切开术在治疗Chiari畸形Ⅰ型中的应用

目的通过临床表现及影像学检查确诊为Chiari畸形的患者,以改善枕大孔区脑脊液循环为目的,采用枕骨大孔减压伴硬膜外层切开的手术方法治疗,随访观察分析手术前后患者临床表现的改善程度,脊髓空洞大小的变化,及其与临床症状改善的相关性。方法收集整理行枕骨大孔减压伴硬膜外层切开术治疗的45名Chiari畸形I型患者的临床症状资料以及MRI检查结果,将患者分为2组,Ⅰ组为不伴有脊髓空洞的Chiari畸形Ⅰ型患者17例,Ⅱ组为伴有脊髓空洞的患者28例,对比手术前后患者临床症状的改善情况,以及手术前后MRI的变化。结果Ⅰ组患者术后主要临床症状获得明显的缓解,术后均未再次出现临床症状,行MRI复查示小脑扁桃体位置上升,枕大池深度扩大,未出现脊髓空洞。而Ⅱ组的28例患者中尽管脊髓空洞的大小有不同程度的缩小甚至消失,但由于脊髓空洞导致的常见症状如肢体麻木、疼痛,感觉缺失虽有不同程度的缓解,而像肌肉萎缩,括约肌功能障碍等临床症状几乎无明显改善。结论枕骨大孔减压伴硬膜外层切除术治疗Chiari畸形Ⅰ型患者有较好疗效;对于Ⅰ组的患者,枕骨大孔减压伴硬膜外层切开术不仅能够使患者得到较高的临床症状缓解率,针对此组患者早期手术极有可能降低脊髓空洞的发生率。

枕下扩大外侧入路手术切除枕大孔区脑膜瘤(英文)

目的：分析影响枕大孔区脑膜瘤手术疗效的因素，比较有关手术入路的优缺点。方法：应用枕下外侧扩大入路切除枕大孔脑膜瘤11例。结果：手术全切肿瘤7例(7/11，64%)，次全切2例(2/11，18%)，部分切除2例(2/11，18%)。无手术死亡和严重的手术并发症。结论：枕下外侧扩大入路足以显露和切除枕大孔区肿瘤。肿瘤切除程度取决于肿瘤与椎动脉、脑干和颅神经的关系。

枕下远外侧入路切除枕大孔前方及外侧肿瘤

目的 探讨枕下远外侧入路显微外科切除枕骨大孔区前方及外侧肿瘤的手术方法。方法自 1995年 9月至 2 0 0 2年 10月应用枕下远外侧入路切除枕骨大孔区前、外侧肿瘤 10例 ,其中脑膜瘤5例、复发性脊索瘤 2例、舌下神经鞘瘤 2例、颈静脉球瘤 1例。结果 本组 10例中 ,肿瘤全切除 6例、次全切除 3例、大部分切除 1例、术后出现后组颅神经麻痹 2例 ,无手术死亡。结论 该入路可增加术野空间 ,从更大程度上显露肿瘤组织 ,有利于减少对脑干和重要血管。

伴寰枢椎脱位颅底凹陷症患者后路减压失败的再手术治疗

目的：探讨伴有寰枢椎脱位的颅底凹陷症患者后路减压失败的再手术对策。方法：2006年2月-2010年10月我院收治9例在外院接受后颅窝减压手术术后症状加重的伴寰枢椎脱位颅底凹陷症患者，入院时患者均有站立或行走不稳，肢体麻木、无力，JOA评分7-11分，平均7．8±2．1分，影像学检查显示枕骨大孔周围大部分骨质均被咬除，且均有明显的寰枢椎脱位，枢椎齿状突向上脱入枕骨内并压迫脑干和延髓，脑干脊髓角105°-138°，平均125°±11°。均采用经口前路齿状突复位、钢板内固定、植骨治疗。随访患者神经功能改善情况，术后3个月及末次随访时对患者进行JOA评分,计算脊髓神经功能改善率；在颈椎MRI片上测量脑干脊髓角，并与术前比较。结果：手术均顺利完成，未出现硬脊膜破裂、切口感染等并发症。随访10-26个月，平均14个月．9例患者神经功能均有不同程度的改善，术后3个月时JOA评分为13．7±1．8分，改善率为64．1％；脑干脊髓角改善至148°±15°。末次随访时JOA评分为14．4±2．1分，改善率为71．7％；脑干脊髓角维持良好。8例患者在术后6个月左右复查CT均显示植骨达到骨性融合；1例患者随访期间头部外伤致内固定松动，再次翻修，随访10个月植骨获得骨性融合。结论：后颅窝减压术不能解决寰枢椎脱位造成的脑干前方压迫问题，不适合治疗伴有寰枢椎脱位的颅底凹陷症，经口前路齿状突复位钢板内固定手术可以将寰枢椎脱位有效复位，恢复枕颈交界区域的有效椎管直径，纠正脑干脊髓角度，可以作为后颅窝减压失败后的补救手术。