Facial nerve rerouting in skull base surgery

Facial nerve rerouting techniques were developed to facilitate re-section of extensive tumors occupying the skull base. Facial nerve rerouting has its own limitations and risks, requiring microsurgical expertise, additional surgical time, and often some degree of facial nerve paresis. This article presents different degrees of anterior and posterior facial nerve rerouting, techniques of facial nerve rerouting, and a comprehensive review of outcomes. It then reviews anatomic and functional preservation of the facial nerve in acoustic neuroma resection, technical aspects of facial nerve dissection, intracranial facial nerve repair options, and outcomes for successful acoustic neuroma surgery.     

KTP-532 laser tonsillectomy: a comparison with standard technique

It has been stated that laser excision of oral and oropharyngeal lesions result in less intraoperative blood loss, reduced postoperative pain, and quicker wound healing, but few controlled studies have been done to substantiate these claims. A study was undertaken to examine the benefits of the KTP-532 laser in a group of 31 patients who underwent tonsillectomy. One tonsil was removed with the KTP-532 laser and the other was excised with conventional dissection and snare technique. Patients were not told which tonsil was removed with the laser. Pain, healing, and intraoperative blood loss comparing one side to the other was assessed. On the evening of surgery, 83% of patients selected the side that underwent standard dissection and snare tonsillectomy as the most painful. By midweek, however, approximately equal numbers of patients selected the laser side as the most painful. At the end of 1 week, 63% of patients felt more pain on the laser dissection side. Possible reasons for these results are discussed. Intraoperative blood loss was significantly reduced with the use of the KTP-532 laser, but healing was not accelerated.     

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.     

Facial nerve monitoring in middle ear and mastoid surgery

HYPOTHESIS: Intraoperative electromyographic facial nerve monitoring, long accepted as the standard of care in surgery for acoustic neuroma and other cerebellopontine angle tumors, may be of aid in middle ear and mastoid surgery. STUDY DESIGN: Retrospective series of 262 cases of middle ear/mastoid surgery in which monitoring was performed by a neurophysiologist. METHODS: Neurophysiological monitoring events were classified as mechanical or electrical. The voltages producing facial nerve stimulation were compiled and compared with observed facial nerve dehiscence. RESULTS: The most common use of monitoring was localization of the facial nerve by electrical stimulation (60%) or identification of mechanically evoked activity (39%). In 57 cases (36%), the first electrical stimulation event evoked a facial nerve response at less than 1 V threshold, indicating little or no bony covering. The minimum stimulation threshold throughout each of these cases was less than 1 V in 88 of the 159 cases (55%) in which stimulation was attempted. In contrast, the facial nerve was visibly dehiscent in only 35 cases (13%). Neurophysiological monitoring confirmed aberrant facial nerve course through the temporal bone in four cases resulting in cancellation of surgical treatment in two cases. Postoperative facial nerve function was preserved in all cases when present preoperatively. CONCLUSIONS: An electrical stimulation threshold of less than 1 V is a more useful criterion of dehiscence than observation under the operating microscope. The absence of monitoring events allows safe dissection. Monitoring can help locate the facial nerve, guide the dissection and drilling, and confirm its integrity, thereby allowing more definitive surgical treatment while preserving neural function.     

Advantage and disadvantage of KTP-532 laser tonsillectomy compared with conventional method

Objective: The purpose of this prospective study is to define the advantages and disadvantages of KTP laser tonsillectomy compared with those of the conventional method. Methods: Eighteen adult patients (ten male and eight female, ranging in age from 14 to 44 years) underwent KTP-532 laser tonsillectomy on one side and standard dissection surgery on the other side under general anesthesia. Results: By KTP laser tonsillectomy, there was a reduction in intraoperative blood loss and average time for removing one tonsil. On the second day of tonsillectomy, subjective pain on the KTP laser surgery side was less than that on the conventional surgery side. By the days 5–8, however, this effect disappeared and many patients indicated the laser side was more painful. There was no postoperative bleeding after KTP laser tonsillectomy. Laser surgery appeared to lead to slow wound healing during the whole post-operative course with significant difference compared with the conventional method. Disadvantages of postoperative pain and the possibility of secondary infection due to slow wound healing could be prevented by application of antibiotics and an anodyne. Conclusion: Considering safety and reliability during surgery, KTP laser was considered useful for adult tonsillectomy.     

Function-saving microsurgery in suboccipital removal of large acoustic neuromas

Various successful approaches are available for acoustic neurinoma surgery, permitting total tumor removal and preservation of cranial nerve function. In smaller and medium sized tumors excellent results can be achieved with respect to facial and cochlear nerve function using the transtemporal approach. For larger tumors similar results can be achieved by the suboccipital approach. The results of 45 completely removed large acoustic neurinomas all operated upon via the suboccipito-lateral approach with microsurgical techniques and neurophysiological monitoring are presented. The average tumor size, excluding the portion within the internal auditory canal was 3 cm. Anatomical preservation of the VIIth cranial nerve was achieved in nearly all cases. Satisfactory to excellent facial nerve function was preserved in 70% of all cases. Initial hearing was preserved in 29%. However delayed postoperative hearing loss was encountered in 13%. Therefore definite hearing preservation was achieved in 16% of the cases. Intraoperative monitoring, especially of auditory evoked potentials, was very helpful in achieving these functional results.     

Water-jet dissection in parotid surgery--initial clinical results

INTRODUCTION: The most frequent complication following parotidectomies is postoperative facial nerve dysfunction. In animal experiment we successfully studied the technique of water-jet-dissection for safe and functional preservation in facial nerve dissection in parotid gland surgery. The aim of the present study was to evaluate our animal experiments clinically. METHODS: Until November '99 ten patients with benign parotid gland tumors (4 female, 6 male, age 32-77 years) underwent lateral or latero-segmental parotidectomies using water-jet-dissection ("Hydro-Jet", Andreas Pein Medizintechnik GmbH, Schwerin, Germany). All operations were performed under permanent intraoperative facial nerve monitoring ("Neurosign 100", Fa. Inomed, Tenningen, Germany). The postoperative facial nerve function was measured daily by the House-Brackmann and Stennert-Paresis-Index for at least one week. RESULTS: A quick parotid gland and safe facial nerve dissection could be performed in all operations using the 120 microns-nozzle with effective working pressures from 30-50 bar. In addition strong connective tissue fibers were transected with scissors. Intraoperative facial nerve lesions did not occur and cardiopulmonary complications due to eventual cutting-fluid-resorption were not seen. After surgery all patients had a normal facial nerve function. DISCUSSION: The results of our studies showed that the technique of water-jet-dissection provides safe facial nerve dissection and preservation during parotid gland surgery. CONCLUSIONS: The tissue selective cutting qualities of the new surgical method are an excellent alternative compared to standard dissection methods in parotid surgery.     

Results of KTP-532 laser and tendon preservation stapedotomy in otosclerosis-a preliminary report

Tendon preservation stapedotomy with or without KTP-532 laser has been performed on 25 rases Jrom November 1998 to February 2000. A study of the symptoms, demographic profile, audiological impairment, surgical treatment and the resultant hearing improvement after 3 weeks and 6 weeks was done. KTP-532 laser assisted cruratamy and stapedotomy was found to be easier than the conventional method. Insertion of the prosthesis was also found to be much easier because of tendon preservation.     

CO2 and KTP-532 laser cordectomy for bilateral vocal fold paralysis

Laryngeal obstruction due to bilateral vocal fold paralysis has been treated in many different ways. The CO2 laser or KTP-532 laser endoscopic cordectomy described in this report is a slight modification of the posterior partial cordectomy proposed by Dennis and Kashima. This technique was used in 18 patients (14 with the CO2 and four with the KTP-532 laser). Prophylactic tracheostomy was performed pre-operatively. Post-operative results were excellent in nine cases, good in seven cases and poor in two cases who had to remain with a permanent tracheostomy tube with a speaking valve. The main complications noted were the formation of a granuloma (seven cases) and arytenoid oedema (six cases). Revision surgery was performed in the seven cases with granuloma formation and in the two with persistent oedema. The results and the post-operative findings from the use of the two lasers were similar.     

Preservation of the marginal mandibular branch of the facial nerve using a plexus block nerve stimulator

Preserving the marginal mandibular branch of the facial nerve is essential in submandibular neck dissection to avert disfiguring complications. Despite the high incidence of postoperative palsy, old-fashioned techniques of nerve identification remain widespread. The use of disposable plexus block nerve stimulators as a safe and accurate method to localize the nerve intraoperatively is suggested herein. Such devices are significantly more affordable and user-friendly than larger facial nerve monitoring devices, which are rather favored for those procedures more extensively jeopardizing the branches of the facial nerve. In this report, disposable stimulators led to successful identification of the nerve in 100% of 25 patients between 2003 and 2005, with no postoperative paralysis. In addition, stimulation devices are constantly gaining in reliability and safety, and the number of surgical fields supporting their use is expanding. Therefore, their routine use for surgery on the submandibular area is recommended by the authors.     

Facial nerve monitoring in otologic surgery: clinical indications and intraoperative technique

While identification of the intratemporal portion of the facial nerve is mandatory in most otologic surgical procedures, inadvertent instrumentation, traction, or thermal injury may still result from inaccurate delineation, purposeful avoidance, or false protection of this critical structure. Improved functional preservation of the facial nerve has been achieved in acoustic neuroma surgery through the monitoring of evoked facial electromyographic activity. This technique may also be used during otologic procedures in which facial nerve manipulation is anticipated in the management of recurrent cholesteatoma, temporal bone trauma, congenital deformity, or purposeful access for cochlear implantation. Potential indications for using facial nerve monitoring in contemporary otologic surgery are detailed through illustrative case presentations, and necessary instrumentation and techniques are briefly reviewed. Intraoperative monitoring can assist the surgeon in isolating the facial nerve when chronic inflammation, traumatic injury, or anomalous development has resulted in distortion or absence of microanatomic landmarks.     

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。     

A systematic approach to the surgical management of acoustic neuroma

Contemporary otomicrosurgical techniques have made total removal of acoustic tumor with preservation of the seventh and sometimes the eighth cranial nerves possible. The four approaches currently used in acoustic tumor surgery are the middle cranial fossa, the translabyrinthine, the suboccipital, and the combined translabyrinthine-suboccipital. This review examines the surgical results in the removal of more than 600 acoustic tumors and outlines a rationale for the choice of approach. Tumor size on computed tomographic scan and auditory reserve establish the parameters used in planning the surgical procedure. The translabyrinthine exposure is used most frequently followed by the combined translabyrinthine-suboccipital. The middle fossa and suboccipital approaches are used when preservation of hearing is attempted. Total removal of tumor was accomplished in more than 99% of patients with a mortality rate of less than 1%. Anatomic preservation of the facial nerve, which is directly related to tumor size, was achieved in more than 80% of patients. Preservation of hearing is unlikely when the tumor is larger than 2 cm; anatomic preservation of the cochlear nerve was successful in 73% of hearing preservation procedures.     

Skull base surgery for removal of temporal bone tumors

CONCLUSION: When selecting the appropriate surgical approach the pathological type of tumor, the physiological status as well as the functional aspects should be considered. Understanding the strengths and weaknesses of each surgical technique and knowledge of the particular tumor biology facilitates selection of the most appropriate surgical approach and a successful outcome. OBJECTIVES: The purpose of this study was to review cases that underwent skull base surgery for a variety of tumors that involved the temporal bone. We reviewed a single center's 25-year experience for epidemiologic characteristics, symptoms, treatment type and outcomes. PATIENTS AND METHODS: The medical records and radiological images of 91 patients, who underwent skull base surgery, were retrospectively reviewed. RESULTS: Among the 91 patients, 61 cases had benign disease and 30 had malignancies. A facial nerve schwannoma was the most common benign intratemporal tumor and a squamous cell carcinoma was the most common malignant tumor. With the facial nerve schwannoma, facial nerve paralysis and hearing loss were the most common presenting complaints; otalgia was the most common presenting symptom for temporal bone cancer. For patients with a glomus tumor, there was a characteristic pulsating tinnitus. A majority of the facial nerve schwannomas were resectable through the transmastoid approach. The infratemporal fossa approach type A was usually required for lower cranial nerve schwannomas and glomus jugulare tumors. However, the fallopian bridge technique with hypotympanectomy was another surgical option. Partial temporal bone resection and subtotal temporal bone resections were performed in cases with temporal bone cancer. The disease free 5-year survival of the temporal bone cancers was 42% and for the squamous cell carcinomas, it was 44%.     

Primary tumor of the facial nerve: Diagnosis and management

Benign primary tumors of facial nerve are rare, difficult to diagnose due to their subtle and variable clinical manifestations and these are usually misdiagnosed as idiopathic facial nerve paralysis. A case of facial nerve sehwannoma in internal auditory meatus presenting as a tumor indistinguishable from acoustic neuroma clinically is presented here. Difficalties in patient assessment, inadequacy of diagnostic techniques presently available and surgical technique of the removal of the tumor will be discussed.     

腮腺肿瘤手术57例临床体会

目的探讨腮腺肿瘤手术方式、手术范围与治疗效果的关系。方法对1997～2003年间面神经解剖行腮腺肿瘤切除术57例(腮腺浅叶切除术51例，全腮腺切除术6例，1例行功能性颈淋巴结清扫术，术后加放疗4例)的临床随访资料进行分析。结果腮腺浅叶切除术51例中，并发暂时性面瘫5例，持续性面瘫1例，全腮腺切除6例中，并发暂时性面瘫2例，持续性面瘫2例，无腮腺瘘及Frey综合征，随访6月～7年无复发。结论腮腺良性肿瘤应施行解剖面神经的腮腺浅叶及肿瘤切除，恶性肿瘤在面神经尚未累及时行保留面神经的腮腺广泛切除，术后辅以放疗，可以减少肿瘤复发和面瘫等并发症的发生。     

Transoral carbon-dioxide laser resection of hypopharyngeal carcinoma

In hypopharyngeal carcinoma, open partial resection is rarely feasible because of the high rate of chronic aspiration. Transoral laser surgery, however, is not associated with major swallowing problems. Between 1991 and 1995, a total of 29 patients with cancer of the hypopharynx were treated using laser surgical resection. In 25 patients, a neck dissection was performed, and 26 patients were radiated postoperatively. The 5-year overall survival was 48% and tumor-related survival 58%. The outcome was significantly ( P<0.048) dependent on the preoperative lymph node status (N(0)=74%, N(+)=34% overall survival). Accordingly, the 5-year survival in stage I and stage II tumors was 71% and in stage III and IV tumors 47%. The highest local control rate was achieved in patients with carcinoma of the hypopharyngeal walls. A major advantage of laser surgery is that resurfacing of the wounds takes place per secundam. No reconstructions with free vascularized grafts have to be performed.There were no functional deficits regarding speech and swallowing in 94%, 100% and 100% of the surviving patients without local recurrence after 3, 4 and 5 years, respectively. No patient had to have a tracheostomy intraoperatively. Laser surgical treatment in combination with neck dissection and postoperative radiotherapy of selected patients with early cancer of the hypopharynx shows comparable results with open surgical procedures and is superior to radiotherapy alone. Given the low postoperative morbidity, transoral laser surgery with the goal of preserving the larynx should gain more importance in the future.     

Results of surgery by the modified extended middle cranial fossa approach in 100 patients with acoustic neuroma

The results of surgery by the middle cranial fossa (MCF) approach or the modified extended MCF approach in 100 patients with acoustic neuroma are reported. The rates of facial nerve preservation, tumor removal, and hearing preservation were reported and discussed. This surgical procedure can be applied to tumors of any size, from tumors confined to the internal auditory canal to those extending into the posterior fossa.     

Fluorescent retrograde axonal tracing of the facial nerve

OBJECTIVE: The objective of this study was to investigate retrograde fluorescent axonal labeling of motor nerves as an aid to surgical dissection in otolaryngology-head and neck surgery. METHODS: Cholera toxin B subunit conjugated to a fluorescent dye was injected into the facial musculature of New Zealand white rabbits. At variable time points after injection, the facial nerves were harvested and analyzed for fluorescence in the peripheral axon. RESULTS: All injected animals demonstrated axonal fluorescence. No animal demonstrated facial weakness. Fluorescence was detected a maximum of 20 mm from the distal end of the nerve. Time periods greater than 48 hours did not substantially increase transport distance. CONCLUSIONS: Cholera toxin B subunit fluorescent conjugates, when administered intramuscularly, reliably label the distal portion of the facial nerve. In vivo labeling of a motor nerve may have significant potential for identifying a nerve in surgery. This work represents a preliminary investigation into the adaptation of in vivo fluorescence techniques as an aid to surgical dissection. Further research to refine this technique should be supported.     

Trigeminal Neuralgia: Retrolabyrinthine Selective Posterior Root Section

Selective section of the posterior root of the trigeminal nerve was performed 42 times on 41 patients over the past 5 years. Twenty-eight retrolabyrinthine procedures for the selective section of the posterior root of the trigeminal nerve were performed for typical tic douloureux with complete lasting relief in 25; 1 was relieved with the addition of aspirin; and 2 were relieved by Tegratol, even though it was ineffective before surgery. Of 8 patients with atypical trigeminal neuralgia, 5 required subsequent surgery for treatment of geniculate neuralgia before relief was obtained. Two patients with atypical pain continued their discomfort despite surgery. Selective Vth nerve section was accomplished during translabyrinthine approach in 5 cases with acoustic neuroma and 1 during VIIIth nerve section and facial nerve decompression. There were no deaths and no serious complications. None had facial paralysis or anesthesia dolorosa resulting from the nerve section. The retrolabyrinthine approach to the posterior root of the trigeminal nerve is ideally suited for those patients with refractory tic douloureux or patients with facial pain secondary to other causes such as tumor. Because of its effectiveness and low morbidity this procedure offers advantages over other surgical techniques.