A Review of Facial Nerve Outcome in 100 Consecutive Cases of Acoustic Tumor Surgery

Objective To determine the facial nerve outcomes at a tertiary neurotological referral center specializing in acoustic neuroma and skull base surgery. Study Design Retrospective review of 100 consecutive patients in whom acoustic neuromas were removed using all of the standard surgical approaches. Methods Functional facial nerve outcomes were independently assessed using the House‐Brackmann facial nerve grading system. Results The tumors were categorized as small, medium, large, and giant. If one excludes the three patients with preoperative facial palsies, 100% of the small tumors, 98.6% of the medium tumors, 100% of the large tumors, and 71% of the giant tumors had facial nerve function grade I‐II/VI after surgery. Conclusion Facial nerve results from alternative nonsurgical treatments must be compared with facial nerve outcomes from experienced surgical centers. Based on the facial nerve outcomes from our 100 consecutive patients, microsurgical resection remains the preferred treatment modality for acoustic tumors.     

Hearing Preservation in Acoustic Neuroma Surgery

Introduction An acoustic neuroma (AN) is a neurinoma arisingfrom the vestibular branch of the VIIIth cranial nerve,thereby also termed “vestibular schawnnomas (VS)”.The histo-pathologically benign nature of this tumorgives the possibility for neuro-otologists to preserve thecochlear nerve and hearing in tumor resection sur-geries. Advances in imaging technology have greatlyimproved early diagnosis of ANs with very small sizesand made tumor removal without significantly insultinghearing. …     

Translabyrinthine and transotic surgery for acoustic neuroma

The results and complications of translabyrinthine and transotic surgery for petrous apex lesions between 1980 and 1992 are presented. An acoustic neuroma was found in 52 patients. In 1988, the translabyrinthine approach was modified into the transotic approach and replaced the former technique. There was no mortality in this series, but two patients had mild brainstem infarcts and there was post-operative bleeding into the cerebellopontine angle in one. Cerebrospinal fluid (CSF) leakage was seen in six patients and meningitis in two. Three suffered deep vein thrombosis in their legs. There was one case each of herniation of the cerebellum and gastric bleeding. Post-operative facial nerve function was good in 88%, moderate in 10% and poor in 2%. In the case of acoustic neuromas the aim was total tumour removal, but if there was a serious risk of damaging the nerve anatomically, near total or subtotal removal was performed. During the study period, there was a gradual decrease in facial nerve morbidity and surgical complications. This was attributed to increasing experience, the modified wider approach and better post-operative care.     

Facial Nerve Function After Petrosectomy

Objectives: Evaluation of facial nerve function after petrosectomy in a patient series with facial nerve denudation-decompression, forward or backward rerouting, and facial nerve suture and grafting. Study Design: Fifty-six patients with petrosectomies performed for 24 benign and 9 malignant tumors of the petrous bone, 13 malignant tumors of the parotid gland or of the infratemporal spaces with infiltration of the petrous bone, 8 traumatic facial nerve disruptions, and 2 osteoradionecroses were retrospectively evaluated with respect to facial nerve function. Sixteen cases involved a partial, 25 a subtotal, and 15 an extended subtotal petrosectomy. Methods: The treatment of the facial nerve included 15 denudation-compressions, 23 denudation-compressions with rerouting, 4 primary sutures, and 14 nerve grafts. The House-Brackmann grading system was used for facial nerve evaluation. Results: Normal or nearly normal facial nerve function was obtained in facial nerve denudation-decompression with and without rerouting (House-Brackmann Grade I or II) except in cases of malignant tumors and osteoradionecrosis, where preoperative impaired function remained. Satisfactory results were obtained with nerve suturing and nerve grafting after petrous bone fracture (Grade III or IV, in one case practically Grade II) except in a case of late repair 3 years after the trauma (Grade V). Variable results were obtained with nerve grafting in cases with tumor infiltration: Satisfactory results (5 of Grade III or IV) were obtained when the tumor was healed and also when postoperative radiotherapy was applied; poor results were obtained in the case of tumor recurrence (6 of Grade V or VI). Conclusions: Our results show that petrosectomy with denudation-decompression of the facial nerve with or without rerouting usually results in a normal mimic of the face. When the facial nerve is disrupted by trauma or when the nerve is infiltrated by tumor, early reconstruction with nerve suture or grafting mostly leads to a partial and quite acceptable reinnervation of the face.     

Rehabilitation of facial nerve palsy

Forty-nine patients underwent 158 procedures (including 19 revisions) for complete facial palsy. The variety of causes of facial palsy are enumerated, with the various procedures used to rehabilitate the face. Some improvement is invariably achieved. It is concluded that a readiness to intervene with a wide choice of procedures as early as realistically possible offers the best outcome in function and cosmetic appearance.     

听神经瘤的早期诊断

为解决听神经瘤早期诊断的问题，对１９８４～１９９４年间收治３１例（３２耳）听神经瘤患者进行了临床资料分析。各种症状出现率以听力障碍（９４％）最高，耳鸣次之（９１％）；初发症状也以听力障碍和耳鸣最多见。听力减退的方式以进行性加重最多（８７％）。提示有单侧进行性听力减退或耳鸣的患者，需排除听神经瘤的可能。听力障碍者中，３耳表现为突发性聋，具前庭症状者占６２％，三叉神经受累者占３４％，后者多发生于较大肿瘤者。另外，肿瘤大小与初发症状出现时间有一定的相关性，即肿瘤愈大初发症状出现的时间愈长。肿瘤大小与听力损失程度之间无明确的关系。３１例患者ＡＢＲ结果均异常，诊断符合率为１００％。认为ＡＢＲ测试是初步筛选听神经瘤敏感而有用的检查方法。     

听神经瘤患者术中面神经刺激阈与术后早期面神经功能的关系

目的 探讨听神经瘤患者术中面神经监测动作电位阈值与术后早期面神经功能的关系,以期预测术后面神经功能.方法 122例听神经瘤患者均在全麻下行肿瘤完全切除后以NIM监护仪刺激脑干段面神经,记录引出面神经动作电位的最小毫安数即为面神经刺激阈.依据House-Brackmann(H-B)分级标准对术后2周患者的面神经功能进行评估,比较不同级别面神经功能患者术中面神经刺激阈.结果 术后面神经功能Ⅰ-Ⅱ级组术中面神经刺激阈值为0.1±0.09 mA,与Ⅲ-Ⅳ级(0.26±0.27 mA)、Ⅳ级(0.32±0.33 mA)、Ⅴ-Ⅵ级组(0.63±0.54 mA)阈值比较差异有统计学意义(P<0.05);Ⅰ～Ⅲ级组(0.145±0.13 mA)与Ⅳ级、Ⅴ-Ⅵ级组比较差异也有统计学意义(P<0.05);术中面神经刺激刺激阈值小于0.1 mA组术后面神经功能明显好于术中面神经刺激监测阈值0.1～0.2 mA组和大于0.2 mA组患者(P<0.05).结论 术中面神经阈值能有效地预测术后面神经功能,阈值小于0.1 mA者提示术后面神经功能可能恢复良好.     

Use of the KTP-532 Laser in Acoustic Neuroma Surgery

The potassium titanyl phosphate (KTP-532) laser has been applied to otologic surgery with a proven record of both safety and efficacy. The aim of this study was to demonstrate the use, safety, and advantages of laser dissection in the surgical treatment of acoustic neuromas. The authors' experience with 111 patients in whom laser surgery was used in acoustic neuroma is presented, with emphasis on surgical technique employed and facial nerve functional outcome. The method of laser dissection did not result in deleterious neurologic sequelae or laser-specific complications. In addition, laser dissection afforded certain advantages to traditional techniques, especially in larger tumors. The facial nerve functional outcome as assessed by the House-Brackmann grading system revealed that 90.2% of small tumors, 72.2% of medium tumors, and 75.0% of large tumors achieved satisfactory (grades I and II) functional results. These results compare favorably with the literature describing nonlaser dissection techniques. The observations and results reported in this article demonstrate the safety of the KTP-532 laser in the posterior cranial fossa, and specific advantages that this technology may offer to the surgical armamentarium of the neuro-otologist are outlined.     

Hypoglossal‐facial nerve anastomosis: assessment of clinical results and patient benefit for facial nerve palsy following acoustic neuroma excision

Despite advances in neuro‐otological techniques permanent complete facial palsy may still occur in up to 10% of patients undergoing removal of cerebellopontine angle tumours. Hypoglossal‐facial nerve anastomosis is the procedure of choice in our unit for facial reanimation in such patients and below we report the results of hypoglossal‐facial nerve anastomosis performed on 29 patients. Assessment of patient benefit from hypoglossal‐facial nerve anastomosis was obtained using a questionnaire based on the Glasgow Benefit Inventory. The results showed all patients to have an improvement in their House Brackmann grade following hypoglossal‐facial anastomosis with 65% achieving grade III or better. Of the 20 patients who completed the questionnaire, 18 showed a positive benefit (median score 59.5, range 40–77). There was a significant correlation (P < 0.045) between the Glasgow benefit inventory score and House Brackmann grade. Outcome was not affected by the time interval between the acoustic neuroma surgery and performing the hypoglossal‐facial nerve anastomosis, sex or length of follow‐up. However the Glasgow benefit score was significantly influenced by age (P = 0.023) with younger patients showing more benefit independent of improvement in facial nerve function.     

Nerve of origin, tumor size, hearing preservation, and facial nerve outcomes in 359 vestibular schwannoma resections at a tertiary care academic center

Objective: To determine nerve of origin, tumor size, hearing preservation rates, and facial nerve outcomes in a retrospective cohort study of patients undergoing translabyrinthine (TL), middle cranial fossa (MCF), and retrosigmoid/suboccipital (SO) approaches to vestibular schwannomas (VS). Study Design: Retrospective. Methods: Chart review. Results: Patient charts from 231 TL, 70 MCF, 53 SO, and 5 combined TL/SO procedures for VS were evaluated in 356 patients. The inferior vestibular nerve (IVN) was the nerve of origin in 84 of 359 cases (23.3%), while the superior vestibular nerve (SVN) was the nerve of origin in 36 patients (10%). In 239 of 359 cases (66.6%), the nerve of origin was not identified. Forty patients undergoing hearing preservation surgery had hearing results and nerve of origin data available for review. Functional hearing (<50dB PTA and >50% speech discrimination) was preserved in 10 of 15 patients (75%) with SVN tumors, while only 7 of 25 patients (28%) with IVN tumors retained functional hearing. Facial nerve outcomes and nerve of origin were recorded simultaneously in 109 patients. Seventy‐one of 74 patients (95%) patients with IVN tumors achieved a House‐Brackmann (HB) grade I–III, while 35 of 35 patients (100%) with SVN tumors retained HB I–III facial function. Looking at tumor size versus hearing preservation, functional hearing was preserved in 22 of 49 patients (45%) with <1‐cm tumors, and 4 of 20 patients (20%) with 1‐ to 1.5‐cm tumors. For all cases with documented facial nerve function, HB I–III were achieved in 96% of SO, 94% of MCF, and 88% of TL procedures. Conclusions: Our retrospective data indicated that IVN tumors were twice as common as SVN tumors. The nerve of origin did not affect facial nerve outcomes but did impact hearing preservation rates. Patients with tumors <1 cm in size had the best chance for hearing preservation. Overall facial nerve preservation was excellent with >90% achieving HB 1 to 3 function at final follow‐up.     

Suboccipital surgery for acoustic neuroma

A retrospective study was performed on 106 consecutive patients with an acoustic neuroma who underwent suboccipital surgery for the first time between 1980 and 1992. Complete follow-up data were available for all the patients, including regular imaging up to 1 January 1994. Incomplete removal of the tumours was chosen in preference to radical surgery in a large proportion of the patients, to avoid the risk of postoperative morbidity. The recurrence rate in this series was 20%. Comparison of the results of suboccipital surgery to those obtained using other surgical approaches, while taking the tumour size into consideration, showed that better results can be obtained after total removal of the tumour without any additional risk to post-operative facial nerve function. The long-term results of subtotal removal using the suboccipital approach were disappointing. It is therefore necessary to review the indications for non-radical surgery in patients with an acoustic neuroma.     

Effects of Partial Neuromuscular Blockade on Facial Nerve Monitorization in Otologic Surgery

Objective—Neuromuscular blockade (NMB) is administered as part of a general anesthetic in order to keep the patient immobilized during surgery and has been known to hinder intraoperative neuromonitorization. The aim of this study was to determine the effects of different levels of NMB on electrical stimulation thresholds of the facial nerve during otologic surgery. Material and Methods—Intraoperative facial nerve monitorization was performed in 29 patients with advanced middle ear disease. Electromyographic (EMG) responses were recorded by insertion of needle electrodes into the orbicularis oris and orbicularis oculi muscles. Minimal facial nerve stimulations causing EMG responses in the facial musculature were measured during full recovery from the effects of muscular relaxants and with 25%, 50%, 75% and 100% levels of NMB. These defined NMB levels were maintained by the administration of a drip infusion of atracurium and were assessed objectively by recording the hypothenar muscle action. Results—All of the patients had detectable EMG responses of the facial musculature at the 50% and 75% levels of NMB in response to the electrical stimulation of the facial nerve. The corresponding mean stimulation thresholds were 0.10±0.08 and 0.11±0.09 mA, respectively. No responses were measured in 31% of the patients when the level of peripheral NMB was 100%. Conclusion—This study suggests that a regulated 50% level of peripheral NMB provides reliable intraoperative EMG monitoring of the facial musculature in response to electrical stimulation and adequate anesthesia, with full immobilization of the patient.     

Comparison of postoperative facial nerve outcomes between translabyrinthine and retrosigmoid approaches in matched-pair patients

OBJECTIVES/HYPOTHESIS: The objective was to assess whether the translabyrinthine approach for acoustic tumor removal offers better postoperative facial nerve function compared with the retrosigmoid approach. STUDY DESIGN: Retrospective case review from a tertiary otology referral center. METHODS: Patients who had undergone either retrosigmoid or translabyrinthine approach for removal of acoustic neuroma from January 1, 1980, to December 31, 1999, were included in the study. Two groups of patients were created, one containing retrosigmoid cases and the other, translabyrinthine. Attempts were made to match each retrosigmoid case to a translabyrinthine case with regard to tumor size, patient age, and date of operation. This matching served to eliminate these variables from influencing postoperative facial nerve outcomes. From an initial pool of 450 patients, 35 pairs of patients were matched for the study. Facial nerve functions were reported at immediate, 3-month, and 1-year postoperative periods. RESULTS: Patient demographics demonstrated that matched patients had almost identical tumor size, patient age, and date of operation. Comparisons of postoperative facial nerve functions between the matched groups revealed that retrosigmoid approach carried 2.86 times higher risk of facial nerve dysfunction during the immediate postoperative period. However, by 1 year, the facial nerve outcomes were similar between the two groups. CONCLUSION: Compared with the translabyrinthine approach, retrosigmoid approach carries a higher risk of postoperative facial nerve dysfunction during the immediate postoperative period. However, long-term facial nerve outcomes are identical between the two approaches.     

扩大迷路径路切除经枕下径路手术后复发的听神经瘤

目的：探讨听神经瘤经枕下径路手术后复发、后经扩大迷路径路再次切除肿瘤的方法及效果。方法：对5例复发的听神经瘤患者，采用扩大迷路径路手术，在经典迷路径路的基础上，通过充分切除岩骨骨质扩大手术视野，将复发的肿瘤组织完全切除。结果：5例听神经瘤直径为2．5～4．0cm，均全部切除，无死亡病例，未发生颅内感染及脑脊液漏；面神经功能与术前一致；术后CT和MRI复查均显示无肿瘤残存，小脑、脑干位置恢复正常。经0．5～2年7个月的随访，至今未见复发，患者已恢复正常生活和工作。结论：枕下径路手术容易残留内听道内的肿瘤，再次手术采用扩大迷路径路可直接暴露肿瘤并到达脑干，既可避免瘢痕粘连区，方便定位面神经，又能全部切除复发的肿瘤，且具有创伤小、面神经功能保存完好等优点。     

听神经瘤术中听力监测及术后听力保留影响因素分析

目的探讨听神经瘤术中听力监测的应用及术后听力保留的可能影响因素。方法16例采用乙状窦后入路手术切除听神经瘤的成年患者,分为两组,术中采用听性脑干反应(auditory brainstem response,ABR)和耳蜗电图(electrocochleogram,ECochG)联合监测为监测组(8例),未监测者为未监测组(8例),比较两组患者术后听力保留情况,采用单因素分析,分析影响听力保留的可能因素,包括:年龄、病程、肿瘤大小、术前纯音听阈和言语识别率、术中是否行ABR和ECochG联合监测、内听道是否扩大、肿瘤和神经是否粘连等。结果前庭诱发肌源性电位(VEMP)提示16例患者肿瘤来源于前庭上神经,监测组中6例术中及术毕ABR波Ⅰ、Ⅴ和复合动作电位(CAP)持续存在,术后听力保留;1例术中ABR波Ⅰ、Ⅴ和ECochG CAP持续存在,但术后无可用听力;1例术中切除肿瘤时ECochG与基线重复性良好,ABR波V消失,手术结束波V仍未恢复;监测组术后听力保留率为75.0%(6/8),未监测组术后无一例保留听力,差异有统计学意义(P=0.007)。单因素分析显示,年龄、病程、肿瘤大小、术前纯音听阈以及内听道扩大与术后听力保留率无关(P>0.05),术前言语识别率、术中ABR和ECochG联合监测、肿瘤和神经粘连与否与术后听力保留率相关(P<0.05)。结论听神经瘤切除术中ABR和ECochG连续监测对指导手术和提高术后听力保留率有重要意义,肿瘤与神经粘连是术后听力保留的重要影响因素,手术技巧、术前听力、肿瘤大小、内听道扩大等是否是术后听力保留的影响因素需扩大样本进一步研究验证。     

Corticosteroid Treatment for Idiopathic Facial Nerve Paralysis: A Meta‐analysis

Objective A meta‐analysis was designed to evaluate facial recovery in patients with complete idiopathic facial nerve paralysis (IFNP) by comparing outcomes of those treated with corticosteroid therapy with outcomes of those treated with placebo or no treatment. Study Design Meta‐analysis of prospective trials evaluating corticosteroid therapy for idiopathic facial nerve paralysis. Methods A protocol was followed outlining methods for trial selection, data extraction, and statistical analysis. A MEDLINE search of the English language literature was performed to identify clinical trials evaluating steroid treatment of IFNP. Three independent observers used an eight‐point analysis to determine inclusion criteria. Data analysis was limited to individuals with clinically complete IFNP. The endpoints measured were clinically complete or incomplete facial motor recovery. Effect magnitude and significance were evaluated by calculating the rate difference and Fisher's Exact Test P value. Pooled analysis was performed with a random effects model. Results Forty‐seven trials were identified. Of those, 27 were prospective and 20 retrospective. Three prospective trials met the inclusion criteria. Tests of heterogeneity indicate the trial with the smallest sample size (RD = ?0.19; 95% CI, ?0.58–0.20), to be an outlier. It was excluded from the final analysis. Analyses of data from the remaining two studies indicate corticosteroid treatment improves complete facial motor recovery for individuals with complete IFNP. Rate difference demonstrates a 17% (99% CI, 0.01–0.32) improvement in clinically complete recovery for the treatment group based on the random effects model. Conclusions Corticosteroid treatment provides a clinically and statistically significant improvement in recovery of function in complete IFNP.