枕下乙状窦后"锁孔"入路显微手术切除听神经瘤

背景与目的：听神经瘤是颅内常见良性肿瘤,治疗以手术切除为主,本文探讨听神经瘤枕下乙状窦后“锁孔”入路的手术方法,以减少并发症和手术损伤。方法：对13例听神经瘤采用单侧枕下乙状窦后“丿”形皮肤切口,后颅窝开颅术改咬骨窗为开骨瓣术,枕下乙状窦后“锁孔”入路显微手术切除肿瘤。结果：11例肿瘤全切除,2例次全切除;面神经解剖保留11例,术后3-15个月复查,面神经House-Brackmann(H-B)Ⅰ-Ⅱ级8例,H-BⅢ-Ⅳ级4例,Ⅴ级1例,术后7例可监测到听力（53.8%),5例保留了有效听力（38.5%),其中3例听力较术前明显好转,术后无死亡及严重并发症。结论：改良枕下乙状窦后“锁孔”入路,充分利用了有效的骨窗,减少无效脑暴露。同时,骨瓣解剖复位,手术创伤小,并发症少,并有利于美容,对地中,小型听神经瘤显微切除是一种有效,安全、便捷的微创手术方法。     

大型听神经瘤的显微手术治疗：附45例分析

背景与目的:听神经瘤为常见颅内良性肿瘤之一,治疗以手术为主,本文探讨经枕下-乙状窦后(Suboccipital retrosigmoid approach,SO)入路显微手术治疗大型听神经瘤的操作技巧及治疗效果。方法:回顾性分析经枕下-乙状窦后入路显微手术治疗的45例大型听神经瘤。结果:本组肿瘤全切40例(88.9%),次全切除5例(11.1%)。面神经解剖学保留率为86.7%(39例)。对40例进行1年以上的随访评估,面神经功能获得满意恢复者为32例(71.1%)。结论:经枕下-乙状窦后入路显微手术切除大型听神经瘤,面神经可获得解剖学与功能的保护,能明显降低并发症与病死率。     

枕下乙状窦后锁孔入路显微手术切除听神经瘤的临床观察

为了总结枕下乙状窦后锁孔入路显微手术切听神经瘤的经验,回顾性分析我院2006-01-2009-04应用枕下乙状窭后锁孔入路显微手术治疗的31例听神经瘤临床资料.单侧耳后6 cm长切口.约3.0 cm×3.0 cm的骨瓣,充分释放小脑延髓池脑脊液后,在减少损伤的前提下切除肿瘤.结果:肿瘤全切除27例,次全切除4例.面神经解剖保留达31例(100%),听力保留24例(77.4%),无死亡病例及严重并发症.初步研究结果提示,枕下乙状窦后锁孔入路创伤小,骨瓣复位,术后并发症少,手术时间短,是显微切除中、小型听神经瘤的一种安全、有效的手术方式.     

116例大型听神经瘤的手术治疗

目的 探讨大型听神经瘤手术的入路、术中保留面、听神经的方法。方法 112例采用一侧枕下入路，4例采用颞枕天幕上入路，81例肉眼下全切除，18例显微镜下全切除，次全切除17例。结果 术后周围性面瘫104例，其中24例在术后6个月恢复，面神经功能保留率为31．0％。4例出现颅内血肿。结论 手术入路的选择，显微镜下精细操作及熟悉桥小脑角显微解剖对听视瘤切除、保留面神经至关重要，适当的术前、术后处理，可提高疗效。     

听神经瘤的微侵袭外科治疗

目的改进听神经瘤的手术技巧,减少手术创伤,提高手术效果。方法 58个听神经瘤均经枕下乙状窦后Keyhole入路,在全程电生理监测下应用"4S(4 steps)"法切除肿瘤:1S:显露、切开、剥离内耳门周围硬脑膜;2S:磨除内听道后壁,游离其内肿瘤组织,找到面、听神经;3S:囊内彻底切除肿瘤组织,使之"囊皮化";4S:免电凝、无张力顺行剥除"囊皮",保护面、听神经及其血供,会师内耳门,全切肿瘤。结果全组无手术死亡、偏瘫病例。肿瘤全切除57例(98.3%),面神经解剖保留58例(100%),听神经解剖保留35例(60.7%);最后一次随访时面神经功能保留(House BrackmannⅠ~Ⅱ级)48例(82.7%),有效听力保留19例(32.7%);术前有残存听力者,有效听力保留17例(40.4%)。结论采用枕下乙状窦后"Keyhole"入路、4S法微侵袭技术切除听神经瘤创伤小,肿瘤全切及面听神经功能保留率高。     

微小听神经瘤治疗方式探讨

目的:探讨及评估微小听神经瘤(2 cm以下)各种治疗方式及其治疗效果。方法:直径2 cm以下听神经瘤22例。均经MR I扫描诊断,分别采用中颅凹入路、乙状窦后入路、γ-刀放射治疗,对患者进行术前、术后听力及面神经功能测定。结果:完全生长在内听道的听神经瘤,经中颅凹入路手术治疗后,听力保存率83%,面神经功能完好率66%;经乙状窦后入路手术治疗后,听力保存率75%,面神经功能完好率100%;经γ-刀治疗后,听力保存率33%,面神经功能完好率为零。听神经瘤直径1 cm以下患者,经中颅凹入路手术治疗后,听力保存率83%,面神经功能完好率50%;经乙状窦后入路手术治疗后,听力保存率50%。面神经功能完好率50%;经γ-刀治疗后,听力保存率为零,面神经功能完好率也为零。结论:对于完全生长在听道的听神经瘤,最佳的治疗方式是经过中颅凹入路切除肿瘤;直径小于1 cm的听神经瘤,经中颅凹入路和乙状窦后入路切除肿瘤均可,但中颅凹入路术野开阔,利于手术操作;直径1 cm~2 cm之间的肿瘤,应采用乙状窦后入路切除肿瘤,这种入路对面神经的损伤较小。     

乙状窦后入路切除听神经瘤术中神经电生理监测保护面神经的应用

目的：探讨乙状窦后入路切除听神经瘤术中神经电生理监测保护面神经的应用方法与效果。方法将88例听神经瘤患者根据随机抽签原则分为治疗组44例与对照组44例。2组都采用显微手术治疗,对照组采用经中颅窝入路,治疗组采用经乙状窦后入路。结果2组患者均顺利完成手术,2组手术时间、术中出血量及术后住院时间等对比,差异无统计学意义（P＞0．05）。术后3个月治疗组后组颅神经功能障碍、耳鸣、泪腺分泌异常、平衡障碍等并发症发生情况明显少于对照组（P＜0．05）。与对照组相比,治疗组术后3个月的面神经功能明显较好（P＜0．05）;治疗组的生活质量评分为（83．44±4．13）分,明显高于对照组的（72．14±4．98）分（P＜0．05）。结论显微手术治疗听神经瘤具有很好的微创性,采用乙状窦后入路能有效减少术后并发症的发生,术中神经电生理监测的应用有利于保护患者的面神经功能,从而提高患者的生活质量。     

显微手术切除大型听神经瘤术后听力的保留

背景与目的：大型听神经瘤在全切除肿瘤的同时保留患者的面、听神经功能是神经外科医生的难题,本研究探讨在面、听神经功能监护下,显微手术切除大型听神经瘤术后听力保留的可能性。方法：对2002年1月至2008年4月湘雅医院神经外科同一术者（袁贤瑞教授）在面肌肌电图和耳蜗神经监测下,经乙状窦后入路显微手术切除的127例大型听神经瘤手术中有完整听力随访资料的41例病例进行回顾性研究。听功能采用北京市耳鼻咽喉科研究所研制的普通话言语测试材料（mandarin speech test materials,MSTMs）句表进行言语识别率测试和纯音听阈测定（PTA）,并使用New Hannover Classification听力分级法进行术后听力分级。结果：127例患者中,术中10例获得明确的听神经解剖学保留,其余117例术中未能找到确切的听神经。对随访到的41例听神经瘤患者进行术后听功能评价,听力保留率为26.8%。结论：对于有相当经验的神经外科医生来说,在面、听神经监护下,经乙状窦后-内听道入路显微手术全切除大型听神经瘤的同时可以保留部分患者的听神经功能。     

OUR旋转式伽玛刀治疗听神经瘤23例临床分析

背景与目的：听神经瘤是桥小脑角(C—P角)区常见的良性肿瘤，以往治疗多以手术切除为主。近年来，听神经瘤的伽玛刀治疗逐年增多。本文主要探讨OUR旋转式伽玛刀治疗听神经瘤临床疗效。方法：采用OUR旋转式伽玛刀治疗23例听神经瘤患者，观察术后病情变化。结果：本组伽玛刀治疗病例随访6个月—36个月，其中肿瘤缩小12例(52．17％)，肿瘤体积不变9例(39．13％)，肿瘤增大2例(8．69％)，肿瘤控制率91．3％，面神经保留率95．65％，听力保留率78．3％。结论：伽玛刀治疗听神经瘤的疗效肯定，损伤小，并发症少，能有效提高患者生存质量。     

混合现实在听神经瘤手术治疗与医患沟通中的应用

目的 探讨混合现实技术在听神经瘤手术治疗与医患沟通的应用价值及意义。方法 随机选取13例接受手术治疗的听神经瘤患者,术前建立三维模型并利用混合现实技术制定手术方案与辅助医患谈话,术中利用混合现实辅助乙状窦后入路开颅、肿瘤切除与面神经的保护,收集医患沟通调查问卷并记录患者术后1周的面神经功能。结果 利用混合现实技术成功显示13例听神经瘤全息模型影像,10例术前重建的面神经位置与术中实际位置完全符合（84.6%）,经术前分析后决定磨除部分内听道后壁11例;13例医患沟通调查问卷均提示家属与患者对病情、手术方式及风险理解透彻,对术前谈话过程表示满意;13例均实现肿瘤全切,术中无1例静脉窦损伤,术后1周患者面神经功能Ⅰ级（House-Brackmann分级）3例,Ⅱ级6例,Ⅲ级3例,Ⅳ级1例。结论 混合现实技术有助于术前制定个体化的听神经瘤手术方案、提高医患沟通效率,可作为一种手术辅助手段减少手术副损伤、有助于保留面神经的功能。     

大型听神经瘤的微骨窗手术切除技巧

背景与目的：大型听神经瘤的全切和功能保留对神经外科来说仍旧是一个挑战。本研究探讨大型听神经瘤的微骨窗手术显露、内听道磨开及囊性肿瘤切除等技巧。方法：总结41例大型听神经瘤经乙状窦后入路微骨窗（切口长6cm,骨窗直径约3cm）手术切除的临床资料,并对手术中的技巧操作进行分析。结果：肿瘤全切除39例（95%）,次全切除2例（5%）;面神经解剖保留36例（88%）,最后一次随访时神经功能（HB分级）Ⅰ级7例（17%）,Ⅱ级15例（37%）,Ⅲ级5例（12%）,Ⅳ～Ⅴ级9例（22%）,Ⅵ级5例（12%）;耳蜗神经解剖保留9例（22%）,保留有效听力7例（17%）。结论：经枕下乙状窦后入路微骨窗手术切除大型听神经瘤是一种理想的微创手术方法。     

Acoustic neuromas following childhood radiation treatment for benign conditions of the head and neck

Childhood radiation exposure has been associated with an increased risk for developing several neoplasms, particularly benign and malignant thyroid tumors, but little is known about the risk of developing acoustic neuromas. The aim of this study was to confirm whether there is a risk for acoustic neuromas and, if so, to determine its magnitude and duration. We investigated the time trend and dose-response relationships for acoustic neuroma incidence in a cohort of 3,112 individuals who were irradiated as children between 1939 and 1962. Most of the patients were treated to reduce the size of their tonsils and adenoids and received substantial radiation exposure to the cerebellopontine angle, the site of acoustic neuromas. Forty-three patients developed benign acoustic neuromas, forty of them surgically resected, far in excess of what might be expected from data derived from brain tumor registries. The mean dose (+/-SD) to the cerebellopontine angle was 4.6 +/- 1.9 Gy. The relative risk per Gy was 1.14 (95% confidence interval 1.0-1.3). The earliest case occurred 20.4 years after exposure and the latest 55 years after exposure (mean 38.3 +/- 10.1 years). Our study provides support for an association between acoustic neuromas and childhood radiation exposure. Although acoustic neuromas are usually benign and often asymptomatic, many cause significant morbidity. Following childhood radiation exposure, they appear after a long latency and continue to occur many decades afterward. Any symptoms of an acoustic neuroma in a patient with a history of radiation to the head and neck area should be investigated carefully, and the threshold for employing imaging should be lowered.     

Use of mobile phones in Norway and risk of intracranial tumours.

To test the hypothesis that exposure to radio-frequency electromagnetic fields from mobile phones increases the incidence of gliomas, meningiomas and acoustic neuromas in adults. The incident cases were of patients aged 19-69 years who were diagnosed during 2001-2002 in Southern Norway. Population controls were selected and frequency-matched for age, sex, and residential area. Detailed information about mobile phone use was collected from 289 glioma (response rate 77%), 207 meningioma patients (71%), and 45 acoustic neuroma patients (68%) and from 358 (69%) controls. For regular mobile phone use, defined as use on average at least once a week or more for at least 6 months, the odds ratio was 0.6 (95% confidence interval 0.4-0.9) for gliomas, 0.8 (95% confidence interval 0.5-1.1) for meningiomas and 0.5 (95% confidence interval 0.2-1.0) for acoustic neuromas. Similar results were found with mobile phone use for 6 years or more for gliomas and acoustic neuromas. An exception was meningiomas, where the odds ratio was 1.2 (95% confidence interval 0.6-2.2). Furthermore, no increasing trend was observed for gliomas or acoustic neuromas by increasing duration of regular use, the time since first regular use or cumulative use of mobile phones. The results from the present study indicate that use of mobile phones is not associated with an increased risk of gliomas, meningiomas or acoustic neuromas.     

Conventionally fractionated stereotactic radiotherapy (FSRT) for acoustic neuromas

Purpose: Analysis of local tumor control and functional outcome following conventionally fractionated stereotactic radiotherapy (FSRT) for acoustic neuromas.

Patients and Methods: From 11/1989 to 9/1999 51 patients with acoustic neuromas have been treated by FSRT. Mean total dose was 57.6 ± 2.5 Gy. Forty-two patients have been followed for at least 12 months and were subject of an outcome analysis. Mean follow-up was 42 months. We analyzed local control, hearing preservation, and facial and trigeminal nerve functional preservation. We evaluated influences of tumor size, age, and association with neurofibromatosis Type 2 (NF2) on outcome and treatment related toxicity.

Results: Actuarial 2- and 5-year tumor control rates were 100% and 97.7%, respectively. Actuarial useful hearing preservation rate was 85% at 2 and 5 years. New hearing loss was diagnosed in 4 NF2 patients. Pretreatment normal facial nerve function was preserved in all cases. Two cases of new or impaired trigeminal nerve dysesthesia required medication. No other cranial nerve deficit was observed.

In Patients without NF2 tumor size or age had no influence on tumor control and cranial nerve toxicity. Diagnosis of NF2 was associated with higher risk of hearing impairment (p = 0.0002), the hearing preservation rate in this subgroup was 60%.

Conclusion: FSRT has been shown to be an effective means of local tumor control. Excellent hearing preservation rates and 5th and 7th nerve functional preservation rates were achieved. The results support the conclusion that FSRT can be recommended to patients with acoustic neuromas where special attention has to be taken to preserve useful hearing and normal cranial nerve function. For NF2 patients, FSRT may be the treatment of choice with superior functional outcome compared to treatment alternatives.     

Suboccipital Retrosigmoid Surgical Approach For Internal Auditory Canal––A Morphometric Anatomical Study on Dry Human Temporal Bones

Suboccipital retrosigmoid craniotomy with removal of posterior wall of internal auditory canal is preferred by many surgeons operating on acoustic neuromas, as it is a simple and safe approach. To study the topographic landmarks of the posterior surface of the temporal bone. We studied the surgical anatomy of 224 dry adult human temporal bones, measured the various distances on posterior wall of petrous bone relevant for suboccipital surgical approach to internal auditory canal. The internal auditory canal (IAC) lies within 32–44 mm from posterior wall of sigmoid sulcus and within 3–8 mm from the superior border of petrous bone. The point corresponding to highest point of jugular bulb was found between 4 and 9 mm away from the inferior border of IAC. The maximum distance found between bony orifice of vestibular aqueduct and IAC was 14 mm and the minimum distance was 6 mm.The vertical diameter of IAC ranged between 3 and 7 mm. These parameters may help the surgeons for better exposure of internal auditory canal and for avoiding damage to vital surrounding structures.     

Cigarette smoking and risk of acoustic neuromas and pituitary tumours in the Million Women Study

Background:

The relationship between cigarette smoking and incidence of acoustic neuromas and pituitary tumours is uncertain.

Methods:

We examined the relation between smoking and risk of acoustic neuromas and pituitary tumours in a prospective study of 1.2 million middle-aged women in the United Kingdom.

Results:

Over 10.2 million person years of follow-up, 177 women were diagnosed with acoustic neuromas and 174 with pituitary tumours. Current smokers at recruitment were at significantly reduced risk of incident acoustic neuroma compared with never smokers (adjusted relative risk (RR)=0.41, 95% confidence interval (CI)=0.24–0.70, P=0.001). Past smokers did not have significantly different risk of acoustic neuroma than never smokers (RR=0.87, 95% CI=0.62–1.22, P=0.4). Smoking was not associated with incidence of pituitary tumours (RR in current vs never smokers=0.91, 95% CI=0.60–1.40, P=0.7).

Conclusion:

Women who smoke are at a significantly reduced risk of acoustic neuromas, but not of pituitary tumours, compared with never smokers. Acoustic neuromas are much rarer than the cancers that are increased among smokers.