Facial nerve dysfunction after parotidectomy: the role of local factors

OBJECTIVES/HYPOTHESIS: The objective was to analyze the incidence and factors associated with facial nerve dysfunction after conservative parotidectomy with facial nerve dissection. STUDY DESIGN: A retrospective unicentric study in a tertiary care center with prospective record of studied factors. METHODS: Over a 10-year period, 131 patients with normal facial nerve function underwent a superficial or total conservative parotidectomy with nerve dissection performed by one surgeon for primary benign or malignant tumors. Facial nerve function was assessed on the first postoperative day and at 1 month and 6 months after the parotidectomy. Extent of surgery, histopathological findings, tumor size, close contact of tumor with facial nerve, and sex and age of the patient were reviewed. These variables were studied in a chi2 statistical univariate and stratified analysis to determine their association with postoperative facial nerve dysfunction. RESULTS: Incidence of postoperative facial nerve dysfunction was 42.7% on the first postoperative day, 30.7% at 1 month after the parotidectomy, and 0% at 6 months after the parotidectomy. The most common dysfunction was paresis in a single nerve branch (48.2%), in particular, the marginal mandibular branch. Total parotidectomy was associated with a significantly higher incidence of facial nerve dysfunction during the first postoperative period (60.5% at day 1 and 44.7% at month 1) than superficial parotidectomy (18.2% at day 1 and 10.9% at month 1) (P < .001). In patients with total parotidectomy, close contact of the tumor with the facial nerve was found to have statistical causal relation with facial nerve weakness. In patients with superficial parotidectomy, inflammatory conditions were found as factors that increased postoperative facial nerve dysfunction. CONCLUSION: In the study series of conservative parotidectomies with facial nerve dissection, only extent of surgery and particular local conditions of nerve dissection, especially the close contact of tumor with facial nerve and inflammatory conditions, were found to be associated with postoperative facial nerve dysfunction.     

The efficacy of corticosteroids in postparotidectomy facial nerve paresis

OBJECTIVE: To determine whether the administration of perioperative corticosteroids is effective in ameliorating facial nerve paresis after parotidectomy. STUDY DESIGN: Prospective, randomized, double-blinded, placebo-controlled clinical trial at a university medical center. METHODS: Patients scheduled for parotidectomy and who met inclusion criteria were invited to enroll in the protocol. They were stratified according to the anticipated surgery (superficial or total parotidectomy) and then received one of two doses of dexamethasone (0.51 or 1.41 mg/kg divided into three doses) or placebo solution immediately preoperatively and then every 8 hours for 16 hours postoperatively. The facial nerve was graded for proportion (percentage) of function at each of the four major regions (frontal, orbital, midface and upper lip, and lower lip). The early postoperative function and rate of return of function were compared among the treatment groups. RESULTS: Forty-nine patients were enrolled and evaluated (18 in the control group, 16 receiving low-dose dexamethasone, and 15 receiving high-dose dexamethasone). No therapeutic advantage of dexamethasone treatment could be appreciated with respect to the degree of early postoperative nerve function (81.3% for control patients vs. 69.5% for dexamethasone-treated patients [ =.239]). Similarly, the median time to recovery of complete facial nerve function was 60 days in the control group and was 150 days in the dexamethasone-treated patients. CONCLUSIONS: Dexamethasone administration in patients undergoing parotidectomy is not justified. Despite the relatively modest risk profile of dexamethasone, we were unable to demonstrate any benefit in patients who were treated with either low-dose or high-dose steroids compared with placebo-treated patients in a randomized, controlled trial.     

Risk of facial palsy and severe Frey's syndrome after conservative parotidectomy for benign disease: analysis of 610 operations

Conclusions: Advanced age, long operation time and large specimen volume were significant risk factors for transient facial palsy after conservative parotidectomy. Revision operation was the only risk factor for development of a permanent palsy. Risk factors for Frey's syndrome were not found. The incidence of Frey's syndrome was not altered by the use of a sternocleidomastoid muscle flap or other implantation material. Objectives: The results of studies identifying risk factors for facial palsy and Frey's syndrome after parotidectomy are contradictory. This study attempted to identify these risk factors by performing a retrospective review of a large series of patients. Patients and methods: A total of 610 standardized conservative parotidectomies for benign diseases performed between 1989 and 2004 were studied retrospectively. The risk factors for facial palsy and Frey's syndrome were determined by univariate and if possible by multivariate analysis of variables related to patient demographics and operation characteristics. Results: The rates of transient facial palsies, permanent facial palsies and Frey's syndrome were 18%, 4%, and 4%, respectively. Significant univariate and multivariate risk factors for development of a transient facial palsy were age >70 years, operation time >260 min, and a specimen volume >70 cm³. The only significant risk factor for the development of a permanent palsy was prior surgery. A significant risk factor for the development of Frey's syndrome could not be estimated.     

Great auricular nerve conservation and parotidectomy for tumor

ObjectiveTo describe the key technical points for preserving the great auricular nerve during parotidectomy for tumor, and to discuss the literature regarding the benefits, limitations and indications for nerve-sparing surgery. Data suggested that great auricular nerve preservation should be discussed in the preoperative consultation, attempted intraoperatively and mentioned in the operative report once parotidectomy completed.     

Postparotidectomy facial nerve paralysis: possible etiologic factors and results with routine facial nerve monitoring.

OBJECTIVE: Analyze the incidence and factors responsible for postparotidectomy facial nerve paralysis when the surgery is performed with the routine use of facial nerve monitoring. STUDY DESIGN: A prospective, nonrandomized study. METHODS: Seventy consecutive patients underwent parotidectomy with intraoperative facial nerve monitoring. Two devices were used: a custom mechanical transducer and a commercial electromyograph-based apparatus. All patients were analyzed, including those with cancer and those with deliberate or accidental sectioning of facial nerve branches. The outcome variables were the motor facial nerve function according to the House-Brackmann grading scale (HB) at 1 week (temporary paralysis) and 6 to 12 months (definitive paralysis). Facial nerve grading was performed blindly from reviewing videotapes. RESULTS: The overall incidence of facial paralysis (HB>1) was 27% for temporary and 4% for permanent deficits. Most of the deficits were partial, most often concerning the marginal mandibular branch. Temporary deficits with HB scores of greater than 2 were only present in patients with parotid cancer or infection. Permanent deficits were present in three patients, including one patient with facial nerve sacrifice. Factors significantly associated with an increased incidence of temporary facial paralysis include the extent of parotidectomy, the intraoperative sectioning of facial nerve branches, the histopathology and the size of the lesion, and the duration of the operation. CONCLUSIONS: Despite a stringent accounting of postoperative facial nerve deficits, these data compare favorably to the literature with or without the use of monitoring. An overall incidence of 27% for temporary facial paralysis and 4% for permanent facial paralysis was found. Although the lack of a control group precludes definitive conclusions on the role of electromyograph-based facial nerve monitoring in routine parotidectomy, the authors found its use very helpful.     

Actinomycosis of the temporal bone with labyrinthine and facial nerve involvement

OBJECTIVES: To demonstrate the clinical, radiologic, and pathologic findings of actinomycosis of the temporal bone. STUDY DESIGN: Case report and literature review. METHODS: Analysis of a case through medical records and literature review. RESULTS: Actinomycosis is a rare cause of subacute-chronic suppurative infection of the temporal bone. We present an 11-year-old male with a history of ciliary dyskinesia presenting with a 6-week history of right-sided otorrhea, otalgia, and a 1-week history of progressive facial weakness. Final histopathology revealed a diagnosis of actinomycosis. A review of the literature showed 25 cases of temporal bone actinomycosis. This is the first reported case of actinomycosis causing facial nerve palsy and labyrinthine invasion. Effective treatment includes aggressive surgical debridement followed by long-term administration of appropriate antibiotic. CONCLUSIONS: Actinomycosis can be a cause for bone erosive lesions of the temporal bone and can result in significant morbidities. Prompt tissue diagnosis with suspicion for nonmalignant causes of bone erosive disease can help in implementing appropriate treatment.     

Continuous intraoperative facial nerve monitoring in predicting postoperative injury during parotidectomy

OBJECTIVES/HYPOTHESIS: To assess whether the use of continuous intraoperative facial nerve monitoring correlates to postoperative facial nerve injury during parotidectomy. STUDY DESIGN: A retrospective analysis. METHODS: Forty-five consecutive parotidectomies were performed using an electromyograph (EMG)-based intraoperative facial nerve monitor. Of those, 37 had complete data for analysis. Intraoperative findings and final interpretation of the EMGs were analyzed by a senior neurologist and neurophysiologist. All patients were analyzed, including those with preoperative weakness and facial nerve sacrifice. RESULTS: The overall incidence of facial paralysis (House-Brackmann scale > 1) was 43% for temporary and 22% for permanent deficits. This includes an 11% incidence of preoperative weakness and 14% with intraoperative sacrifice. An abnormal EMG occurred in only 16% of cases and was not significantly associated with permanent or temporary facial nerve paralysis (chi, P < 1.0; Fisher's exact P < .68). Of the eight patients with permanent paralysis, only two had abnormalities on the facial nerve monitor. Also, only one of five patients with intraoperative sacrifice of the facial nerve had an abnormal EMG. Factors significantly associated with the incidence of facial paralysis include malignancy, advanced age, extent of parotidectomy, and dissection beyond the parotid gland (chi and Fisher's, P < .05). CONCLUSIONS: The results suggest that abnormalities on the intraoperative continuous facial nerve monitor during parotidectomy do not predict facial nerve injury. The incidence of permanent and temporary facial nerve paralysis compare favorably with the literature given that this study includes patients with revision surgery, intraoperative sacrifice, and preoperative paralysis. Standard of care implications will be discussed.     

Facial nerve paralysis following cochlear implant surgery

OBJECTIVES: Facial nerve paralysis is a rare but devastating complication of cochlear implant surgery. The aims of the study were to define the incidence of facial nerve paralysis in our series and understand possible mechanisms of injury. STUDY DESIGN: Retrospective chart review and case reports. METHODS: Charts were reviewed of all 705 patients implanted between 1980 and 2002 at the authors' institutions to identify those with postoperative facial nerve weakness and determine incidence. For patients with facial nerve weakness, onset, degree, and timing of paralysis were noted; clinical findings were correlated to operative report findings. The method of treatment was noted, and the final facial nerve function outcome was recorded. RESULTS: Five patients (one child and four adults) were found to have postoperative facial nerve weakness, for an incidence of 0.71%. This complication was delayed in all cases, ranging from 18 hours to 19 days postoperatively. All patients were treated with steroids or steroids combined with antiviral medication, and all ultimately recovered normal facial function. CONCLUSIONS: In the study series, the incidence of facial nerve paralysis following cochlear implant surgery was 0.71%. Possible mechanisms of injury included heating injury and viral reactivation. All patients presented with a delayed facial nerve paralysis and did recover normal facial nerve function.     

The impact of malignant disease on facial nerve function after parotidectomy

OBJECTIVES/HYPOTHESIS: Studies of immediate postoperative facial nerve function following parotidectomy focus on benign disease. The purpose of the study was to compare facial nerve function with regard to benign or malignant disease in patients undergoing superficial parotidectomy. STUDY DESIGN: Retrospective cohort study of consecutive patients undergoing parotidectomy between 1995 to 2002. METHODS: House-Brackmann (HB) grade was recorded or assigned at the first postoperative visit. For patients with HB grade of III or greater, final resolution of facial nerve function was recorded. A chi2 analysis for independence was conducted between patients with HB grade of II or less and those with HB grade of III or greater and final pathological finding (benign vs. malignant disease). Mean and median times to resolution were determined for patients with HB grade of III or greater. Times to resolution for benign and malignant disease for those with HB grade of III or greater were compared (Kaplan-Meier method). RESULTS: Sixty-seven patients with benign disease and 52 with malignant disease were included. Ninety-four percent of patients with benign disease had HB grade of II or less at first postoperative visit (mean period, 11.6 d) compared with 76.9% of patients with malignant disease (mean period, 12.4 d). A chi2 analysis found this difference significant (chi2 = 7.36, P =.0067). Time to resolution for HB grade of III or greater was 253.8 days (+/-168.2 d) with median time of 229.5 days for benign disease and 182.4 days (+/-134.6 d) with median time of 138 days for malignant disease. Kaplan-Meier comparison found no significant differences in time to final resolution (P =.83). Three patients in the group with malignant disease had unresolved dysfunction (one patient for >2 y). CONCLUSIONS: Patients with benign disease have a greater chance of having HB grade of II or less immediately following surgery; however, whether the disease is benign or malignant, long-term final facial nerve function is the same.     

Temporary facial nerve dysfunction after parotidectomy correlates with tumor location

Objective

To investigate the clinical factors associated with temporary facial nerve dysfunction (TFND) following surgery for benign parotid gland tumors.

Methods

We reviewed the records of 175 patients with benign parotid gland tumors who underwent partial parotidectomy at Yokohama City University Medical Center in Japan. TFND was found in 33 patients (18.9%). We used two hypothetical lines in magnetic resonance imaging (MRI) images to define the tumor location (upper/lower or anterior/posterior) in the parotid gland. We then studied the associations of TFND with the following clinical factors: patient age, tumor size, histopathological diagnosis, and the location of the tumor within the parotid gland (superficial lobe/deep lobe; upper part/lower part; and anterior part/posterior part).

Results

Tumors located in the upper parts, anterior parts or the deep lobes of the parotid gland had statistically higher incidences of TFND compared with tumors located in the lower parts, posterior parts or the superficial lobe (P < 0.001, <0.001, <0.01, respectively). The odds ratio for the risk of TFND was significantly high if tumors were located in the upper parts, the anterior parts or the deep lobes with stepwise multivariate regression analysis. The other factors, including patient's age, tumor size, histopathology of the tumor, and inadequate surgeon's experience, were not apparent risks for TFND.

Conclusions

Parotid gland tumors located in the upper parts, the anterior parts or the deep lobes had a higher risk of TFND. The two hypothetical lines we used were shown to be useful to define the tumor location, eventually the risk of TFND.