A series of 112 fully endoscopic resections of vestibular schwannomas.

We report a consecutive series of 112 patients with unilateral vestibular schwannoma (VS) having undergone fully endoscopic resection of their tumors in the period from October, 2001 to January, 2005. Patients' outcomes were evaluated especially with regards to cochlear nerve (hearing) preservation, facial nerve preservation, postoperative complications and completeness of the resection. The patient population consisted of 112 consecutive cases with unilateral, "de novo" VS(s); patients with neurofibromatosis type 2 (NFT2) or with a recurrent tumor were excluded from this study. Tumors ranged in size from 0.6-5.7 cm, most tumors were less than 3 cm in diameter (mean: 2.6 cm). This shift towards smaller and also less symptomatic tumors may be due to an increase in the awareness of patients and earlier detection of their tumors (MRI era). Tumors were removed via 1.5-cm "keyhole" retrosigmoid craniotomies. Utilizing the fully endoscopic technique, 106/112 (95%) tumors were completely removed; subtotal removal was performed in 6/112 (5%) patients in an attempt to preserve their hearing. Anatomic preservation of the facial nerve was achieved in all of the patients and of the cochlear nerve in 83/101 (82%) hearing ears. Functionally, measurable hearing (serviceable/some) was preserved in 59/101 (58%) cases who had either "serviceable" or "some" hearing preoperatively, 2 patients who had "some" hearing preoperatively had an improvement that was more than 30 db in their hearing postoperatively. There were no major neurological complications such as quadriparesis, hemiparesis, bacterial or aseptic meningitis, lower cranial nerve deficits, or deaths. From our experience, we conclude that the endoscope is ideally suited for a minimally invasive approach for the resection of vestibular schwannomas.     

Delayed facial palsy after resection of vestibular schwannoma

OBJECT: In this study the authors investigate delayed facial palsy (DFP), which is an underreported phenomenon after surgery for vestibular schwannoma (VS). The authors identified 15 (4.8%) patients from a consecutive series of 314 who underwent surgery for VS between 1988 and 2000, and in whom DFP developed. Delayed facial palsy was defined as a deterioration of facial nerve function from House-Brackmann Grades 1 or 2 more than 3 days postoperatively. METHODS: All patients underwent intraoperative neurophysiological monitoring of facial nerve function. The average latency of DFP was 10.9 days (range 4-30 days). In six patients (40%) minor deterioration (< or = two House-Brackmann grades) had occurred at a mean of 10.2 days postsurgery, whereas in nine patients (60%) moderate deterioration (> or = three House-Brackmann grades) had occurred at a mean of 11.8 days postoperatively. Five (33%) of 15 patients recovered to Grade 1 of 2 function within 6 weeks of DFP onset. Of the 15 patients with DFP, 14 had completed 1 year of follow up at the time of this study. Twelve (80%) of these 15 patients recovered to Grade 1 or 2 function within 3 months, and 13 (93%) of 14 patients recovered within 1 year. In all cases, stimulation of the seventh cranial nerve on completion of tumor resection revealed the nerve to be intact, both anatomically and functionally, to proximal and distal stimulation at 0.1 mA. A smaller tumor diameter correlated with greater recovery of facial nerve function. There was no correlation between the latency or severity of or recovery from DFP, and the patient's age or sex, the surgical approach, frequency of neurotonic seventh nerve discharges, anatomical relationship of the facial nerve to the tumor, patient's history of tobacco use, or cardiovascular disease. CONCLUSIONS: It appears that DFP is an uncommon consequence of surgery for VS. Although excellent recovery of facial nerve function to its original postoperative status nearly always occurs after DFP, the magnitude and time course of the disorder were not predictors for subsequent recovery of facial nerve function.     

大型听神经瘤手术面神经功能的保留

目的 评估大型听神经瘤显微手术治疗后远期面神经功能,分析影响术后面神经功能的因素.方法 回顾性分析2002年1月至2009年11月实施的连续176例大型听神经瘤(直径≥30mm)手术的患者资料.采用House-Brackmann(HB)面神经功能分级系统评价术前及术后远期面神经功能.肿瘤大小与面神经功能结果的关系采用线性趋势检验统计学方法进行分析.结果 肿瘤全切除168例(95.5%),术后死亡3例(1.7%).面神经完整解剖保留169例(96.0%).共随访到135例患者,失访41例.随访时间3个月～7年,平均3年.随访＞1年的96例听神经瘤面神经功能HB 1～2级79例(82.3%),其中55例巨大型(直径＞40 mm)听神经瘤患者面神经功能HB 1～2级40例(72.7%).分析显示面神经功能结果与肿瘤直径之间存在线性关系(P＜0.05).结论 经乙状窦后入路切除大型听神经瘤,绝大部分肿瘤切除后可获得优良的远期面神经功能.肿瘤大小是影响术后面神经功能的重要因素.

Abstract：

Objectiyes To evaluate the long-term facial nerve function of patients following microsurgical removal of large and huge acoustic neuroma, and to identify the factors that influence these outcomes. Methods A retrospective review was performed which included 176 consecutive patients with a large acoustic neuroma(≥30 mm)underwent a retrosigmoid craniotomy for tumor resection between January 2002 to November 2009. House-Brackmann(HB)Scale was used preoperatively and in a long-term follow-up after surgery. Test for linear trend was applied for statistic analysis. Results Complete resection was achieved in 168(95. 5%)of these 176 patients with a mortality of 1.7%. Anatomic preservation of the facial nerve was attained in 96. 0% of the patients. In the series of 96 patients who had at least 1-year follow-up(mean 3.0 years)the facial nerve function preservation(HB grade 1-2)was totally attained in 79 patients(82.3 %), and 40 of 55 patients(72. 7 %)who presented huge tumors(diameter ＞ 40 mm)among the 96 patients had facial nerve function preserved. Analysis showed that facial nerve function correlated linearly with tumor sizes(x2 = 14. 114, v, = 1, P ＜ 0. 05). Conclusions Complete removal of large and giant acoustic neuroma may abtained via retrosigmoid approach with facial nerve preservation. Excellent longterm facial function can be expected in the majority of patients who undergo microsurgical removal of vestibular schwannoma via the suboccipital retrosigmoid approach. Tumor size is a significant prognostic parameter for facial nerve function following vestibular schwannoma surgery.     

Facial nerve schwannomas: different manifestations and outcomes

BACKGROUND: The purpose of this study was to provide data on the different clinical presentations of facial nerve schwannoma, the appropriate planning for the management of schwannoma of various origins, and the predictive outcomes of surgical management. METHODS: A retrospective study was conducted in a tertiary referral hospital. We reviewed 8 consecutive cases of facial nerve schwannoma diagnosed and managed between 1993 and 2001. RESULTS: Facial nerve schwannomas originated in the internal auditory canal (IAC) (2 cases), parotid gland (2 cases), intratemporal portion (3 cases), and stylomastoid foramen (1 case). Tumor of the stylomastoid foramen presented as an intra- and extratemporal mass. The initial presenting symptom of the 8 patients was facial nerve paralysis in 4 patients, hearing loss in 2, facial numbness in 1, and an infra-auricular mass in 1. Facial palsy occurred in 7 patients during the course of the disease. One patient with a mass in the parotid gland did not show facial palsy up to 1 year after presentation of the initial symptom (facial numbness). Facial nerve paralysis was most severe in intratemporal tumors and less severe in parotid tumors. The patients with IAC suffered from hearing loss and intermittent vertigo and showed decreased vestibular function. The patients with intratemporal tumors also complained of hearing loss. The tumors were completely removed by superficial parotidectomy for parotid tumors; the translabyrinthine approach for 1 IAC tumor and 1 intratemporal tumor; the middle fossa approach for the other IAC tumor; the transmastoid approach for mastoid tumors; and the infratemporal fossa approach for intratemporal and extratemporal tumors. End-to-end cable grafts for the facial nerve were performed in 5 out of 8 cases. In 2 cases, the facial nerve was preserved after the resection of the mass. One case showed complete loss of the peripheral branch of the facial nerve. CONCLUSIONS: Facial nerve schwannoma can present in various ways. By examining the site of origin and the presenting symptoms and signs, we were able to diagnose facial nerve schwannoma preoperatively. According to the operative management of the facial nerve, the postoperative outcome of facial function could be estimated. Our finding could be pivotal in the management of the facial nerve schwannoma.     

Proton beam radiosurgery for vestibular schwannoma: tumor control and cranial nerve toxicity

OBJECTIVE: We sought to determine the tumor control rate and cranial nerve function outcomes in patients with vestibular schwannomas who were treated with proton beam stereotactic radiosurgery. METHODS: Between November 1992 and August 2000, 88 patients with vestibular schwannomas were treated at the Harvard Cyclotron Laboratory with proton beam stereotactic radiosurgery in which two to four convergent fixed beams of 160-MeV protons were applied. The median transverse diameter was 16 mm (range, 2.5-35 mm), and the median tumor volume was 1.4 cm(3) (range, 0.1-15.9 cm(3)). Surgical resection had been performed previously in 15 patients (17%). Facial nerve function (House-Brackmann Grade 1) and trigeminal nerve function were normal in 79 patients (89.8%). Eight patients (9%) had good or excellent hearing (Gardner-Robertson [GR] Grade 1), and 13 patients (15%) had serviceable hearing (GR Grade 2). A median dose of 12 cobalt Gray equivalents (range, 10-18 cobalt Gray equivalents) was prescribed to the 70 to 108% isodose lines (median, 70%). The median follow-up period was 38.7 months (range, 12-102.6 mo). RESULTS: The actuarial 2- and 5-year tumor control rates were 95.3% (95% confidence interval [CI], 90.9-99.9%) and 93.6% (95% CI, 88.3-99.3%). Salvage radiosurgery was performed in one patient 32.5 months after treatment, and a craniotomy was required 19.1 months after treatment in another patient with hemorrhage in the vicinity of a stable tumor. Three patients (3.4%) underwent shunting for hydrocephalus, and a subsequent partial resection was performed in one of these patients. The actuarial 5-year cumulative radiological reduction rate was 94.7% (95% CI, 81.2-98.3%). Of the 21 patients (24%) with functional hearing (GR Grade 1 or 2), 7 (33.3%) retained serviceable hearing ability (GR Grade 2). Actuarial 5-year normal facial and trigeminal nerve function preservation rates were 91.1% (95% CI, 85-97.6%) and 89.4% (95% CI, 82-96.7%). Univariate analysis revealed that prescribed dose (P = 0.005), maximum dose (P = 0.006), and the inhomogeneity coefficient (P = 0.03) were associated with a significant risk of long-term facial neuropathy. No other cranial nerve deficits or cancer relapses were observed. CONCLUSION: Proton beam stereotactic radiosurgery has been shown to be an effective means of tumor control. A high radiological response rate was observed. Excellent facial and trigeminal nerve function preservation rates were achieved. A reduced prescribed dose is associated with a significant decrease in facial neuropathy.     

Large facial nerve schwannomas without facial palsy: case reports and review of the literature

Although approximately 30% of facial nerve schwannoma cases present with no facial palsy, a large facial nerve schwannoma extending to the middle and posterior cranial fossa quite rarely presents without facial palsy. The authors encountered two patients with large facial nerve schwannoma who presented with only hearing impairment and no facial palsy. The first patient was a 64-year-old woman who presented with right auditory impairment without facial palsy. MR images demonstrated a dumbbell-shaped tumor in the cerebellopontine angle. Another patient, a 40-year-old woman, also presented with vertigo and right tinnitus without facial palsy. MR images demonstrated a huge tumor expanding into both the posterior cranial fossa and middle cranial fossa. In both cases, intraoperative findings confirmed that the tumors had grown from the facial nerve. Facial nerve schwannoma can be easily diagnosed if detailed neurological evaluations and appropriate neuroimagings are conducted. However, in spite of such huge tumoral size and expanding pattern, the facial nerve function was relatively preserved. Anatomical features of the facial schwannoma are discussed. A tumor extending to the middle and posterior cranial fossa should remind neurosurgeons to consider facial nerve schwannomas even in the absence of facial palsy.     

Surgical management of vestibular schwannomas after failed radiation treatment

Increasing numbers of patients with vestibular schwannoma (VS) have been treated with focused-beam stereotactic radiation treatment (SRT) including Gamma knife, CyberKnife, X-knife, Novalis, or proton beam therapy. The purpose of this study was to document the incidence of tumor regrowth or symptoms that worsened or first developed following SRT and to discuss surgical strategies for patients who have failed SRT for VS. A consecutive series of 39 patients with SRT failed VS were surgically treated. Clinical symptoms, tumor regrowth at follow-up, intraoperative findings, and surgical outcome were evaluated. There were 15 males and 24 females with a mean age of 51.8 years. Thirty-six patients (92.3 %) demonstrated steady tumor growth after SRT. Two (5.1 %) patients with slight increase of the mass underwent surgical resection because of development of unbearable facial pain. Symptoms that worsened or newly developed following SRT in this series were deafness (41 %), dizziness (35.9 %), facial numbness (25.6 %), tinnitus (20.5 %), facial nerve palsy (7.7 %), and facial pain (7.7 %). Intraoperative findings demonstrated fibrous changes of the tumor mass, cyst formation, and brownish-yellow or purple discoloration of the tumor capsule. Severe adhesions between the tumor capsule and cranial nerves, vessels, and the brainstem were observed in 69.2 %. Additionally, the facial nerve was more fragile and irritable in all cases. Gross total resection (GTR) was achieved in 33.3 % of patients, near-total resection (NTR) in 35.9 %, and subtotal resection (STR) in 30.8 % of patients. New facial nerve palsy was seen in seven patients (19.4 %) postoperatively. Our findings suggest that patients with VS who fail SRT with either tumor progression or worsening of clinical symptoms will have an increased rate of adhesions to the neurovascular structures and may have radiation-influenced neuromalacia. Salvage surgery of radiation-failed tumors is more difficult and will have a higher risk of postoperative complications. Radical total resection may not be feasible, and conservative modality of subtotal resection needs to be considered to avoid new neurologic deficits.     

Radiosurgery for facial schwannoma

OBJECT: The aim of this study was to evaluate the results of radiosurgery in patients with facial schwannoma. METHODS: The study population consisted of 14 patients, six men and eight women, with a mean age of 45.4 years. Most of the patients had presented with facial palsy (11 of 14 patients) and/or hearing disturbance (nine of 14 patients). Prior treatment in nine of the 14 cases consisted of tumor resection or tumor biopsy. Tumor volume ranged from 0.98 to 20.8 cm3, and the mean tumor volume was 5.5 cm3. The mean maximum radiation dose and mean tumor margin dose used for radiosurgery were 24.0 and 12.9 Gy, respectively. During the mean follow-up period of 31.4 months (range 12-120 months), 10 of the tumors shrank and four remained unchanged. The tumor response and tumor control rates were 57 and 100%, respectively. None of the tumors progressed, and no subsequent resection was required. Facial nerve function improved in five cases, remained unchanged in eight, and became worse in one. There was no change in hearing function in any of the patients. Complications developed in only one patient: the onset of facial palsy immediately after treatment, which subsequently recovered to House-Brackmann Grade III. CONCLUSIONS: In summary, radiosurgery was found to be a very useful method of treating facial schwannoma, for both tumor control and functional control. Radiosurgery should therefore be the treatment of first choice for facial schwannomas.     

Resection of large vestibular schwannomas: facial nerve preservation in the context of surgical approach and patient-assessed outcome

OBJECT: Vestibular schwannoma surgery has evolved as new therapeutic options have emerged, patients' expectations have risen, and the psychological effect of facial nerve paralysis has been studied. For large vestibular schwannomas for which extirpation is the primary therapy, the goals remain complete tumor resection and maintenance of normal neurological function. Improved microsurgical techniques and intraoperative facial nerve monitoring have decreased the complication rate and increased the likelihood of normal to near-normal postoperative facial function. Nevertheless, the impairment most frequently reported by patients as an adverse effect of surgery continues to be facial nerve paralysis. In addition, patient assessment has provided a different, less optimistic view of outcome. The authors evaluated the extent of facial function, timing of facial nerve recovery, patients' perceptions of this recovery and function, and the prognostic value of intraoperative facial nerve monitoring following resection of large vestibular schwannomas; they then analyzed these results with respect to different surgical approaches. METHODS: The authors retrospectively reviewed a database of 67 patients with 71 vestibular schwannomas measuring 3 cm or larger in diameter. The patients had undergone surgery via translabyrinthine, retrosigmoid, or combined approaches. Clinical outcomes were analyzed with respect to intraoperative facial nerve activity, responses to intraoperative stimulation, and time course of recovery. Eighty percent of patients obtained normal to near-normal facial function (House-Brackmann Grades I and II). Patients' perceptions of facial nerve function and recovery correlated well with the clinical observations. CONCLUSIONS: Trends in the data lead the authors to suggest that a retrosigmoid exposure, alone or in combination with a translabyrinthine approach, offers the best chance of facial nerve preservation in patients with large vestibular schwannomas.     

Facial Nerve Outcomes in Middle Cranial Fossa vs Translabyrinthine Approaches

OBJECTIVE: To compare the final facial nerve outcomes between middle cranial fossa (MCF) vs translabyrinthine (TL) resection of size-matched vestibular schwannomas. STUDY DESIGN AND SETTING: Retrospective case review at a tertiary care hospital. All patients who underwent resection utilizing either MCF or TL approaches with tumors 18 mm or smaller and complete data were included in the analysis. One hundred twenty-four patients were identified meeting the above criteria, with sixty-three in the translabyrinthine group and sixty-one in the middle fossa group. One-week-postoperative and final facial nerve examinations were compared in the two surgical groups. Patients were separately analyzed in subgroups: tumors smaller than 10 mm and those that were between 10 and 18 mm. RESULTS: The tumor size range for the MCF group was 3-18 mm while it was 4-18 mm for the TL group. No statistically significant difference was found in facial nerve outcomes between the two surgical groups, at the first postoperative visit week and at last follow-up. CONCLUSION: Facial nerve outcomes are similar using TL and MCF approaches for resection of vestibular schwannomas up to 18 mm in size. SIGNIFICANCE: Patients undergoing the MCF approach for hearing preservation can be counseled that there is no increased risk of permanent facial nerve weakness, compared to the TL approach.     

Management of large and giant vestibular schwannomas

The study was conducted to analyze outcomes following surgical management of large and giant vestibular schwannomas and management options for residual disease. This retrospective case note study includes patients who had undergone microsurgical resection of sporadic, large, or giant vestibular schwannomas from 1986 to 2008. Tumors are classified as large if the largest extracanalicular diameter was 3.5 cm or greater and giant if 4.5 cm or greater. The study included 45 patients (33 large, 12 giant tumors), mean tumor size 4.1 cm. Total excision was achieved in 14 cases (31.1%), near-total in 26 (57.8%), and subtotal in 5 (11.1%). Facial nerve outcome was House-Brackmann Grade I/II in 25 cases (55.6%), III/IV in 16 (35.6%), and V/VI in 4 (8.9%). No recurrence has been detected in those undergoing a complete resection. No residual tumor growth been observed in 15 of 26 who underwent near-total resection (57.7%). Of 11 patients, 10 received further treatment as their residual tumors showed growth. In the subtotal excision group, one patient died, three have demonstrated no growth, and one residual tumor has grown slightly but not required intervention. Optimal management for patients with large or giant vestibular schwannomas has yet to be determined. Management decisions must balance long term function with tumor control.     

Anterior belly of digastric muscle transfer: a useful technique in head and neck surgery

BACKGROUND: Permanent loss of the marginal mandibular branch of the facial nerve (MMBFN) may result from an inadvertent injury or an intentional sacrifice during tumor resection. This may occur in isolation or as a part of total facial nerve palsy. The loss of the MMBFN results in paralysis of the depressors of the ipsilateral lower lip with troublesome cosmetic and functional deficits. METHOD: A series of 14 patients with permanent loss of the MMBFN during resection of head and neck tumors were treated with the anterior belly of digastric muscle transfer (ABDMT). The loss of the MMBFN occurred in isolation in five patients and formed a part of total facial nerve palsy in nine. Immediate reconstruction was performed on nine patients, and it was done as a secondary procedure in the remainder. Two patients in the latter group had prior facial reanimation, although the paralyzed lower lip was not reconstructed. RESULTS: The average follow-up period was 23.2 (range, 3-48) months. Satisfactory results were achieved in all of the patients, although revision of the ABDMT was required in one patient. CONCLUSIONS: ABDMT is a simple and reliable reconstructive technique for restoring the depressor function of the lower lip resulting from MMBFN palsy. It is the treatment of choice during primary extirpative surgery for head and neck tumors when the MMBFN requires sacrifice for tumor clearance or is inadvertently injured. The reconstructive options for MMBFN palsy, particularly in the absence of the anterior belly of digastric muscle, are discussed.     

Cranial Nerve Preservation in Surgery for Large Acoustic Neuromas

Facial nerve outcomes and surgical complication rates for other cranial nerves were evaluated retrospectively after the resection of large acoustic neuromas. The charts of all patients who underwent surgical removal of an acoustic neuroma between 1992 and 2001 at New York University Medical Center were reviewed. Fifty-four patients with tumors measuring 3 cm or larger were included in the study. Four patients had neurofibromatosis type 2, two of whom underwent bilateral removal of acoustic neuromas. Translabyrinthine microsurgical removal of tumor was performed in 47 of 56 cases (84%). In all cases, EMG monitoring, improved sharp microdissection, and ultrasonic aspiration were employed. Facial nerve function was assessed using the House-Brackmann facial nerve grading system immediately after surgery and at follow-up visits. A House-Brackmann grade III or better was achieved in 90% of patients, and a grade II or better was achieved in 84% of patients. Ultimate facial nerve outcome was excellent after the surgical resection of large acoustic neuromas. Preoperative cranial nerve palsies also improved after surgery. The translabyrinthine approach for tumor removal is our treatment of choice for acoustic neuromas 3 cm or larger.     

Facial Nerve Neuroma: Surgical Concept and Functional Results

This study reviewed the management and outcomes of 11 facial nerve neuromas treated in our institution during the past two decades with particular emphasis on surgical concepts and functional outcomes. All patients underwent complete surgical resection of their tumor. Eight patients (73%) were followed on an outpatient basis. A retrospective chart review for pre- and postoperative clinical and radiological data was performed. All facial neuromas were multi-segment tumors. All segments of the facial nerve were represented, but 54% involved the geniculate ganglion and 45% involved the labyrinthine or tympanic portions of the nerve, or both. Depending on the extent of sensorineural hearing loss, surgical removal was performed through the middle cranial fossa or translabyrinthine approach. To obtain adequate nerve reconstruction, we combined intra- and extracranial approaches (e.g., the transmastoidal and transtemporal routes). Regardless of the type of nerve reconstruction, the best recovery achieved was moderate facial weakness (House-Brackmann Grade III) in 75% of the patients, even in a patient who was Grade IV preoperatively. The choice of treatment for facial neuromas and surgical approach depends on the extent of tumor, grade of facial palsy, and hearing function. When facial palsy is present, complete resection is clearly indicated. In patients without facial dysfunction, a conservative strategy consisting of clinical and radiological observation should be considered as a treatment option.     

Occurrence of vestibular and facial nerve injury following cerebellopontine angle operations

Summary To elucidate how surgery in the cerebellopontine (CP) angle may cause vestibular and facial nerve injury, the 7th and 8th cranial nerves of dogs were manipulated as in human surgery along with monitoring of auditory evoked brain stem responses. Postoperatively, histological examinations were performed to investigate the effect of the surgical manipulations.We found that the occurrence of vestibular, facial and cochlear nerve injury was dependent on the direction of theexcessive movement of the nerves in the cerebellopontine (CP) angle. Caudal-to-rostral shift of the nerve trunk most effectively avulsed the vestibular nerve. Haemorrhages were revealed between the vestibular ganglion and the fundus of the internal auditory canal. This caudal-to-rostral retraction could also damage the facial nerve in its intrapetrous labyrinthine portion. This was likely to be one of the pathophysiological mechanisms responsible for postoperative facial nerve palsy occasionally observed in human cases.Rostral-to-caudal retraction of the cerebellum damaged the cochlear nerve selectively. Although caudal-to-rostral retraction, instead of lateral-to-medial one, has been recommended to protect the cochlear nerve, this retraction was shown to be dangerous to the vestibular nerve if excessive.The clinical significance of the fragility of the vestibular nerve was discussed and the importance of preserving the vestibular nerve function is stressed.     

Operative management of acoustic neuromas: the priority of neurologic function over complete resection

The objective of surgical management of acoustic tumors is to remove them entirely and preserve facial nerve function and hearing when possible. A dilemma arises when it is not possible to remove the entire tumor without incurring additional neurologic deficits. Twenty patients who underwent intentional incomplete surgical removal of an acoustic neuroma to avoid further neurologic deficit were retrospectively reviewed. They were divided into a subtotal group (resection of less than 95% of tumor) and a near-total group (resection of 95% or more of tumor) and were followed yearly with either computed tomography or magnetic resonance imaging. The subtotal group was planned and consisted of elderly patients (mean age, 68.5 years) with large tumors (mean, 3.1 cm). The near-total group consisted of younger patients (mean age, 45.8 years) and smaller tumors (mean, 2.3 cm). The mean length of followup for all patients was 5.0 years. Ninety percent of patients had House grade I or II facial function post-operatively. Radiologically detectable tumor regrowth occurred in only one patient, who was in the subtotal resection group. Near-total resection of acoustic tumor was not associated with radiologic evidence of regrowth of tumor for the period of observation. Within the limits of the follow-up period of this study, subtotal resection of acoustic neuroma in elderly patients was not associated with clinically significant recurrence in most patients and produced highly satisfactory rates of facial preservation with low surgical morbidity.     

Facial nerve paralysis secondary to occult malignant neoplasms.

OBJECTIVE: This study reviewed patients with unilateral facial paralysis and normal clinical and imaging findings who underwent diagnostic facial nerve exploration.Study design and setting Fifteen patients with facial paralysis and normal findings were seen in the Mayo Clinic Department of Otorhinolaryngology. RESULTS: Eleven patients were misdiagnosed as having Bell palsy or idiopathic paralysis. Progressive facial paralysis with sequential involvement of adjacent facial nerve branches occurred in all 15 patients. Seven patients had a history of regional skin squamous cell carcinoma, 13 patients had surgical exploration to rule out a neoplastic process, and 2 patients had negative exploration. At last follow-up, 5 patients were alive. CONCLUSIONS: Patients with facial paralysis and normal clinical and imaging findings should be considered for facial nerve exploration when the patient has a history of pain or regional skin cancer, involvement of other cranial nerves, and prolonged facial paralysis. SIGNIFICANCE: Occult malignancy of the facial nerve may cause unilateral facial paralysis in patients with normal clinical and imaging findings.     

Malignant parotid tumor and facial palsy.

OBJECTIVE: To evaluate risk factors for postoperative facial palsy in patients with parotid carcinoma. STUDY DESIGN AND SETTING: We conducted a retrospective chart review of patients with parotid carcinoma who underwent parotidectomy at National Taiwan University Hospital from 1980 to 2000. RESULTS: Eighty-eight patients with a mean age of 53 +/- 17 y were recruited. Sixty patients (68.2%) experienced postoperative facial palsy. Tumor size of larger than 4 cm was associated with an increased incidence of facial palsy (P = 0.0422). Facial palsy was noted in 95.5 percent of patients with facial nerve involvement and 51.3 percent of patients without facial nerve involvement (P = 0.0004). Of 42 patients with tumor over the deep lobe, 37 (88.1%) had facial palsy but only 50 percent (23 of 46) of those with tumor over the superficial lobe had facial palsy (P = 0.0001). CONCLUSION: There were no significant associations between histopathology and facial palsy. Increasing tumor size, deep lobe tumor location, and tumor invasion of facial nerve increased the incidence of postparotidectomy facial palsy. SIGNIFICANCE: By paying attention to these risk factors a reduction of postoperative facial nerve palsy my be achieved.     

Radiosurgery of Residual and Recurrent Vestibular Schwannomas

Summary.  Radiosurgery is either a primary or an adjunctive management approach used to treat patients with vestibular schwannomas. We sought to determine outcomes measuring the potential benefits against the neurological risks in patients who underwent radiosurgery after previous microsurgical subtotal resection or recurrence of the tumour after total resection. Gamma Knife radiosurgery was applied as an adjunctive treatment modality for 86 patients with vestibular schwannomas from April 1992 to August 2001. We evaluated the results of 50 patients who had a follow-up of at least 3.5 years (median 75 months, range 42–114 months). In 16 patients a recurrence of disease was observed after previous total resection. The median treatment volume was 3.4 ccm with a median dose to the tumour margin of 13 Gy. Tumour control rate was 96%. Two tumours progressed after adjunctive radiosurgery. Useful hearing (Gardner-Robertson II) (4 patients (8%)) and residual hearing (Gardner-Roberson III) (10 patients (20%)) remained unchanged in all patients, who presented with it before radiosurgery, respectively. Clinical neurological improvement was observed in 24 patients (46%). Adverse effects comprised transient neurological symptoms and signs (incomplete facial palsy, House-Brackman II/III) in five cases (recovered completely), mild trigeminal neuropathy in four cases, and morphological changes displaying rapid enlargement of a pre-existing macrocyst in one patient and tumour growth in another one. No permanent new cranial nerve deficit was observed.  Radiosurgery appears to be an effective adjunctive method for growth control of vestibular schwannomas and is associated with both a low mortality rate and a good quality of life. Accordingly, radiosurgery is a rewarding therapeutic approach for the preservation of cranial nerve function in the management of patients with vestibular schwannoma in whom prior microsurgical resection failed. Published online July 18, 2002     

Hypoglossal-facial nerve anastomosis for facial nerve palsy following surgery for cerebellopontine angle tumors.

Hypoglossal-facial nerve anastomosis is one of the procedures frequently performed to restore function after facial palsy secondary to surgery for removal of cerebellopontine angle tumors. The published results of hypoglossal-facial nerve anastomosis have been variable, and there are still questions about the indications, timing, and surgical techniques for this procedure. The goals of the present retrospective analysis of 22 cases of hypoglossal-facial nerve anastomosis were to assess the extent of the functional recovery and to analyze the factors affecting this recovery. The 22 cases of complete facial palsy were gleaned from a series of 245 cases of cerebellopontine angle tumors treated surgically by one of the authors. Twenty patients had an acoustic neuroma (average size 3.5 cm), one patient had a petrous meningioma, and one patient had a facial neuroma. The average age of the patients was 47.3 years (range 19 to 69 years). The average interval from tumor surgery to hypoglossal-facial nerve anastomosis was 6.4 months (range 12 days to 17 months), and the average follow-up period after the procedure was 65 months. The results were graded as good, fair, poor, or failure according to a new method of classifying facial nerve function after hypoglossal-facial nerve anastomosis. The results were good in 14 cases (63.6%), fair in three (13.6%), and poor in four (18.2%); one (4.5%) was a failure. Good and fair results occurred with higher frequency in younger patients who were operated on within shorter intervals, although these relationships were not statistically significant. There were no surgical complications. Good or fair results were achieved in 17 (77.3%) of the 22 cases, and thus hypoglossal-facial nerve anastomosis is considered an effective procedure for most patients with facial palsy after surgery for cerebellopontine angle tumors.