Long-term Facial Nerve Outcome Research Articles

Safety and Facial Nerve Outcomes of Intracisternal Papaverine Irrigation for Vestibular Schwannoma Resection

Papaverine, a vasodilator approved for use by the U.S. Food and Drug Administration, has shown efficacy in treating vasospasm in cardiology, urology, and nephrology. The vasodilatory effect of papaverine is also hoped to protect the facial nerve from ischemic damage and nerve manipulation during vestibular schwannoma surgery. Our institution uses intracisternal papaverine irrigation during vestibular schwannoma resection to protect the facial nerve in patients with neuromonitoring changes. Our objective was to investigate the safety and facial nerve outcomes of intracisternal papaverine irrigation during vestibular schwannoma resection. We retrospectively reviewed patients who underwent resection of vestibular schwannoma at our institution between 2008 and 2021. Patients received papaverine if the intraoperative facial nerve stimulation threshold increased above 0.05 mA. Postoperative outcomes were compared with control patients who did not receive papaverine. A total of 283 cases were included in our analysis. Patients who received papaverine (n= 60) had lower immediate postoperative House-Brackmann (HB) grades than did control individuals (mean, 1.54 vs. 1.95; P= 0.029) and a lower likelihood of immediate postoperative HB grade >1 (odds ratio, 0.514; P= 0.039). At long-term follow-up, there was no significant difference in HB grade. Papaverine use was not associated with increased rates of perioperative complications (P= 0.24). The off-label use of intracisternal papaverine irrigation during vestibular schwannoma resection can certainly be used safely for select cases. It is associated with improved immediate postoperative facial nerve outcomes, similar long-term facial nerve outcomes, and no significant increase in complications.

Long-Term Facial Nerve Outcome in Primary Parotid Cancer Surgery: A Population-Based Analysis.

To determine immediate postoperative and long-term facial nerve dysfunction after parotid cancer surgery, risk factors, and the role of facial reanimation surgery. Population-based long-term analysis for all new primary parotid carcinoma cases in Thuringia from 1996 to 2019. Data of the cancer registries of Thuringia, a federal state in Germany, were analyzed in combination with hospital-based data on facial function. About 477 patients (42.3% women; median age: 68 years) were included. It was observed that 6.7% had a preoperative facial nerve dysfunction, 11.7% received a radical parotidectomy, that is, that 5% had a normal preoperative facial function but needed radical surgery because of intraoperative detection of tumor infiltration into the facial nerve. About 10.2% received facial nerve reconstruction surgery. Immediate postoperative facial nerve dysfunction in the other patients was observed in 34.4% of the patients. Advanced T classification (odds ratio [OR]=2.140; confidence interval [CI]=1.268-3.611; P= .004) and neck dissection (OR=2.012; CI=1.027-3.940; P= .041) were independent risk factors for immediate postoperative facial nerve dysfunction. In addition, 22.0% showed no recovery during follow-up. Advanced T classification (OR=2.177; CI=1.147-4.133; P= .017) and postoperative radiotherapy (OR=2.695; CI=1.244-5.841; P= .012) were independent risk factors for permanent postoperative facial nerve dysfunction. Patients with primary parotid cancer are at high risk for long-term facial nerve dysfunction. It seems that the possibilities of facial reanimation surgery needs to be utilized even more effectively. 3 Laryngoscope, 131:2694-2700, 2021.

Delayed Facial Palsy After Resection of Vestibular Schwannoma: An Analysis of Long-term Facial Nerve Outcomes.

1) Identify clinical factors associated with delayed facial palsy (DFP) after microsurgical resection of vestibular schwannoma. 2) Determine whether DFP predicts worse facial nerve (FN) outcomes. Adult patients (≥18 yrs) who underwent vestibular schwannoma resection between February 2008 and December 2017 were retrospectively reviewed. Postoperative House-Brackmann (HB) FN function was assessed on the day of surgery, daily during patients' inpatient admissions, and at postoperative clinic visits. Follow-up exceeded ≥12 months for all patients. DFP was defined as a decline (≥1 HB grade) in FN function (relative to the preoperative state) occurring between postoperative days 1 and 30. Two hundred ninety-one patients were analyzed. Mean age was 51.5 years (±12.3) and mean tumor size 20.6 mm (±10.8). Immediate FP occurred in 61 (21%) patients, and DFP occurred in 112 (38%) patients. Tumor size was largest in patients with immediate FP (p < 0.0001). On univariate analysis, DFP was associated with better final FN outcomes (OR 0.447, p = 0.0101) compared with immediate FP. Multivariate analysis, however, showed that timing of FP was no longer significant, whereas larger tumor size and preoperative HB2 function predicted worse FN outcomes (OR 2.718, p < 0.0001 and OR 9.196, p = 0.0039, respectively). In patients with DFP, longer time to onset of palsy predicted more favorable FN outcomes. When accounting for tumor size, the timing of onset of postoperative facial palsy does not predict final FN outcomes. In patients who develop DFP, the longer the interval between surgery and onset of weakness, the better the chances of good long-term FN function.

Predicting Long-Term Facial Nerve Outcomes After Resection of Vestibular Schwannoma

1) Describe the effect of tumor size on facial nerve (FN) outcomes after microsurgical resection of vestibular schwannoma (VS).2) Describe the effect of surgical approach, preoperative radiation, and early postoperative facial function on long-term FN outcomes. Retrospective analysis. Tertiary referral center. Adult (≥18 yr) patients underwent translabyrinthine or retrosigmoid VS resection by a single neurotologist and single neurosurgeon between February 2008 and December 2017. Long-term FN outcomes (≥12 mo) according to House-Brackmann (HB) grade. During the study period, 350 patients underwent VS resection, of whom 290 met inclusion criteria. Translabyrinthine surgery was performed in 54% (n = 158) and retrosigmoid in 45% (n = 131). One patient underwent a combined approach. Among patients who underwent retrosigmoid approach, none had a tumor more than 30 mm. Gross total resection was achieved in 98% (n = 283). Long-term HB1-2 function was achieved in 90% (n = 261). On univariate analysis, tumor size (per cm increase), history of preoperative radiation, and worse HB score at discharge predicted worse FN function. Multivariate analysis showed that tumor size (per cm increase) and history of radiation were independent predictors of FN function. For patients with tumors less than 30 mm, multivariate analysis of tumor size and surgical approach was performed; tumor size remained predictive of worse FN function (odds ratio [OR] 2.362, p = 0.0035), whereas surgical approach was not significantly predictive (p = 0.7569). Tumor size and history of radiation predict long-term FN function after VS resection. When accounting for tumor size, the translabyrinthine and retrosigmoid approaches yield equivalent FN results.

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on Intraoperative Cranial Nerve Monitoring in Vestibular Schwannoma Surgery.

Does intraoperative facial nerve monitoring during vestibular schwannoma surgery lead to better long-term facial nerve function? This recommendation applies to adult patients undergoing vestibular schwannoma surgery regardless of tumor characteristics. Level 3: It is recommended that intraoperative facial nerve monitoring be routinely utilized during vestibular schwannoma surgery to improve long-term facial nerve function. Can intraoperative facial nerve monitoring be used to accurately predict favorable long-term facial nerve function after vestibular schwannoma surgery? This recommendation applies to adult patients undergoing vestibular schwannoma surgery. Level 3: Intraoperative facial nerve can be used to accurately predict favorable long-term facial nerve function after vestibular schwannoma surgery. Specifically, the presence of favorable testing reliably portends a good long-term facial nerve outcome. However, the absence of favorable testing in the setting of an anatomically intact facial nerve does not reliably predict poor long-term function and therefore cannot be used to direct decision-making regarding the need for early reinnervation procedures. Does an anatomically intact facial nerve with poor electromyogram (EMG) electrical responses during intraoperative testing reliably predict poor long-term facial nerve function? This recommendation applies to adult patients undergoing vestibular schwannoma surgery. Level 3: Poor intraoperative EMG electrical response of the facial nerve should not be used as a reliable predictor of poor long-term facial nerve function. Should intraoperative eighth cranial nerve monitoring be used during vestibular schwannoma surgery? This recommendation applies to adult patients undergoing vestibular schwannoma surgery with measurable preoperative hearing levels and tumors smaller than 1.5 cm. Level 3: Intraoperative eighth cranial nerve monitoring should be used during vestibular schwannoma surgery when hearing preservation is attempted. Is direct monitoring of the eighth cranial nerve superior to the use of far-field auditory brain stem responses? This recommendation applies to adult patients undergoing vestibular schwannoma surgery with measurable preoperative hearing levels and tumors smaller than 1.5 cm. Level 3: There is insufficient evidence to make a definitive recommendation. The full guideline can be found at: https://www.cns.org/guidelines/guidelines-manage-ment-patients-vestibular-schwannoma/chapter_4.

Long-Term Facial Nerve Outcomes after Microsurgical Resection of Vestibular Schwannomas in Patients with Preoperative Facial Nerve Palsy

Objectives This study aimed at evaluating facial nerve outcomes in vestibular schwannoma patients presenting with preoperative facial nerve palsy. Design A retrospective review. Setting Single-institution cohort. Participants Overall, 368 consecutive patients underwent vestibular schwannoma resection. Patients with prior microsurgery or radiosurgery were excluded. Main Outcome Measures Incidence, House-Brackmann grade. Results Of 368 patients, 9 had confirmed preoperative facial nerve dysfunction not caused by prior treatment, for an estimated incidence of 2.4%. Seven of these nine patients had Koos grade 4 tumors. Mean tumor diameter was 3.0 cm (range: 2.1-4.4 cm), and seven of nine tumors were subtotally resected. All nine patients were followed up clinically for ≥ 6 months. Of the six patients with a preoperative House-Brackmann grade of II, two improved to grade I, three were stable, and one patient worsened to grade III. Of the three patients with grade III or worse, all remained stable at last follow-up. Conclusions Preoperative facial nerve palsy is rare in patients with vestibular schwannoma; it tends to occur in patients with relatively large lesions. Detailed long-term outcomes of facial nerve function after microsurgical resection for these patients have not been reported previously. We followed nine patients and found that eight (89%) of the nine patients had either stable or improved facial nerve outcomes after treatment. Management strategies varied for these patients, including rates of subtotal versus gross-total resection and the use of stereotactic radiosurgery in patients with residual tumor. These results can be used to help counsel patients preoperatively on expected outcomes of facial nerve function after treatment.

Long-Term Facial Nerve Outcomes Following Microsurgical Resection of Vestibular Schwannomas in Patients with Preoperative Facial Nerve Palsy

Long-Term Facial Nerve Outcomes Following Microsurgical Resection of Vestibular Schwannomas in Patients with Preoperative Facial Nerve Palsy

Management of Facial Nerve in Surgical Treatment of Previously Untreated Fisch Class C Tympanojugular Paragangliomas: Long-Term Results

The aim of this study was to evaluate the long-term facial nerve outcome according to management of the facial nerve in patients undergoing surgery for Fisch class C tympanojugular paragangliomas. The study population consisted of 122 patients. The infratemporal type A approach was the most common surgical procedure. The facial nerve was left in place in 2 (1.6%) of the 122 patients, anteriorly rerouted in 97 (79.5%), anteriorly rerouted with segmental resection of the epineurium in 7 (5.7%), and sacrificed and reconstructed in 15 (12.3%). One patient underwent cross-face nerve grafting. At last follow-up, House-Brackmann grade I to II was achieved in 51.5% of patients who underwent anterior rerouting and in 28.5% of those who underwent anterior rerouting with resection of the epineurium. A House-Brackmann grade III was achieved in 73.3% of patients who underwent cable nerve graft interposition. The two patients in whom the facial nerve was left in place experienced grade I and grade III, respectively. The patient who underwent cross-face nerve grafting had grade III. Gross total resection was achieved in 105 cases (86%). Management of the facial nerve in tympanojugular paraganglioma surgery can be expected to ensure satisfactory facial function long-term outcome.

Facial nerve prognostication in vestibular schwannoma surgery: The concept of percent maximum and its predictability

To evaluate percent maximum as an intraoperative facial nerve measurement for the long-term prognostication of vestibular schwannoma surgery. Prospective cohort study. Evoked amplitude responses to varying levels of stimulus intensity at the nerve root were compared to their supramaximal responses (Mmax) as a percentage, that is, percent maximum. Response charts were constructed for each of the levels of stimulus intensity between 0.05 to 0.3 mA, vis-à-vis facial nerve outcome at 1 year, to establish sensitivities, specificities, and positive predictive values. Logistic regression analyses were used to determine the impact of sex, age, tumor size, and historically defined response parameter on outcomes. Seventy-eight patients who underwent vestibular schwannoma surgeries between 2005 and 2010 were studied. The positive predictive value (PPV) of a good facial nerve outcome, defined as House-Brackmann (HB) I-II, increases with percent maximum responses. A 90% PPV could be established when the response amplitude was 50% or greater compared to Mmax. Long-term prognostication appeared best at a higher stimulus level of 0.3 mA. Age and sex did not have an impact on outcome, but tumor size did; with each centimeter increase in tumor size, patients were 105% more likely to have a poor outcome (HB III-VI). If the response parameter "≥240 μV at 0.05 mA" was not present, there was a trend toward poor outcome. Percent maximum is a valid intraoperative monitoring measure to prognosticate long-term facial nerve outcome. It should be considered a complementary method of monitoring when evoked responses do not conform to conventional predictors. 4.

Facial Nerve Outcome after Vestibular Schwannoma Surgery: Our Experience

In this study we evaluate the postoperative facial nerve function after vestibular schwannoma (VS) surgery and analyze the factors that cause it. We included 97 consecutive patients undergoing surgical excision of sporadic unilateral VS. Patient and tumor characteristics, surgical approaches, facial nerve function, extent of tumor removal, perioperative complications are all analyzed through standardized systems. Four different surgical approaches are used: translabyrinthine, retrolabyrinthine, retrosigmoid, and middle cranial fossa. Anatomic preservation of the facial nerve is achieved in 97% of patients. The incidence of postoperative facial palsy is found to be statistically correlated to tumor size, but not to the surgical approach used and to extent of tumor penetration in the internal auditory canal. A significant improvement of the short-term facial nerve outcome is detected in patients undergone simultaneous intraoperative electromyography (EMG) and pneumatic facial nerve monitoring. Complete tumor excision is achieved in 94% of cases. Complication rates are excellent and no deaths are reported. Short- and long-term facial nerve outcome is good and comparable with those of other series reported in literature. In VS surgery both EMG and pneumatic facial nerve monitors should be simultaneously used. Further investigations are desirable to improve the facial outcome respecting the oncological radicality.

The value of intraoperative facial nerve electromyography in predicting facial nerve function after vestibular schwannoma surgery

The prognostic significance of intraoperative facial nerve electromyography (EMG) changes is not well-established in vestibular schwannoma (VS) surgery. We studied facial nerve EMG with a threshold >0.05 mA and performed subgroup analyses based on tumor size, resection approach, and extent of resection, for prediction of long-term facial nerve outcome. A total of 477 surgically treated VS patients were included. Elevated stimulation threshold exceeding >0.05 mA is a highly specific (90%), but very insensitive (29%) finding in this cohort. The positive predictive value and negative predictive values (NPV) of facial nerve EMG for detection of permanent facial palsy are 68% and 63%, respectively. The NPV decreased with increasing tumor size (72% versus [ vs.] 64% vs. 53%) due to the increasing prevalence of post-operative facial nerve palsy in these patients. In conclusion, while facial nerve EMG is a critical adjunct for locating the facial nerve intraoperatively, its predictive value for facial nerve function remains to be determined.

Cystic Vestibular Schwannoma

Review of postoperative morbidity and facial nerve outcomes of cystic vestibular schwannoma (CVS) patients compared with solid vestibular schwannoma (SVS) patients and a proposal for a new CVS classification system. Retrospective review. Tertiary care facility. Ninety-six patients with surgically treated CVS (1998-2008). Outcomes were assessed in a subpopulation of 57 patients with greater than or equal to 1-year follow-up compared with 57 SVS patients. Fifty-six CVS patients underwent the enlarged translabyrinthine approach with transapical extension (Type I), and 1 patient underwent a transcochlear/transzygomatic approach. Preoperative and postoperative (at least 1 yr) House-Brackmann facial nerve (HBFN) grade evaluation. Favorable HBFN grades (I-III) were observed in 46 (81%) CVS patients, and unfavorable HBFN grades (IV-VI) were seen in 11 (19%) CVS patients. Comparison of tumor size and 1-year HBFN grades showed significant, moderate to strong, Pearson correlation (0.38). Comparison of long-term facial nerve outcomes with a sample of 57 matched SVS patients showed no significant difference (p = 0.74). When the tumor was adherent to the facial nerve and a dissection plane could not be developed between the cyst wall and the nerve, only subtotal resection could offer the CVS patients a normal facial nerve outcome. In most CVS cases, complete resection should be foreseen. Central and thick-walled tumors can be removed in almost all cases. However, when peripheral thin-walled, adherent, cystic tumors are confronted and the cysts are medially or anteriorly located, we recommend subtotal resection, leaving portions of the cyst walls on neurovascular structures and on the facial nerve. This surgical strategy allows us to improve facial nerve outcomes and to reduce complications.

Prediction of Long-Term Facial Nerve Outcomes with Intraoperative Nerve Monitoring

Evaluate the utility of a statistical equation using two independent intraoperative monitoring parameters in predicting long-term facial nerve function. Retrospective case review. Tertiary care hospital. Sixty patients undergoing resection of vestibular schwannomas with intraoperative facial nerve monitoring at a single institution. All patients underwent microsurgical resection of vestibular schwannomas with the use of intraoperative cranial nerve monitoring. Final facial nerve outcome measured using the House-Brackmann scale at least 6 months after microsurgical resection. Five out of 60 (8.3%) patients demonstrated significant long-term weakness (i.e., House-Brackmann grade III or worse). Intraoperative monitoring parameters (proximal stimulation threshold, proximal-to-distal response amplitude ratio) were accurate in predicting increased risk of long-term facial nerve dysfunction when used in a logistic regression model. A Student's t test confirmed the equation result was statistically significant in differentiating long-term facial nerve outcomes. Patients with immediate weakness are at higher risk of having long-term poor facial nerve function. The use of intraoperative monitoring parameters was reliable in predicting facial nerve outcomes. Patients with permanent facial nerve dysfunction often require rehabilitative procedures. The ability to predict facial nerve outcomes with intraoperative monitoring may allow early rehabilitative procedures to improve quality of life and prevent ocular complications.

Intraoperative monitoring and facial nerve outcomes after vestibular schwannoma resection.

To determine the predictive value of proximal facial nerve electrical threshold and proximal-to-distal facial muscle compound action potential amplitude ratio on facial nerve outcomes after resection of vestibular schwannomas. Retrospective case review. Tertiary care hospital. Two hundred twenty-nine patients undergoing resection of vestibular schwannomas with intraoperative facial nerve monitoring at a single institution. All patients underwent resection of vestibular schwannomas with the use of intraoperative monitoring. Facial nerve function was classified according to the House-Brackmann scale at the patient's last office follow-up. Last follow-up was at least 6 months after surgery. Good facial nerve function (House-Brackmann Grade I or II) was observed in 87% of the patients at their last office follow-up. Proximal-to-distal amplitude ratio and proximal electric threshold were statistically significant in predicting facial nerve outcome. A mathematical model predicting the probability of good outcome on the basis of the intraoperative parameters is presented. Intraoperative monitoring has significantly decreased facial nerve morbidity in vestibular schwannoma surgery. Despite the advances in surgery and monitoring, a group of patients still have poor facial nerve outcomes. The use of intraoperative nerve monitoring may be able to predict poor long-term facial nerve outcomes and thus modify the timing of rehabilitation.

Predictive factors of long-term facial nerve function after vestibular schwannoma surgery.

To assess predictive factors of long-term facial nerve function in a series of patients undergoing vestibular schwannoma surgery and to evaluate the reproducibility of the relevant parameters. Prospective. Three tertiary referral neurotology units in two separate countries. A total of 67 patients, with normal preoperative facial function and an anatomically intact facial nerve postoperatively, undergoing vestibular schwannoma surgery during a sequential 18-month period. Recording of intraoperative stimulus amplitudes (minimum intensity medial to the tumor after excision) and postoperative facial nerve function up to 2 years after surgery. Long-term facial nerve function related to tumor size, early postoperative facial nerve function, and intraoperative electrophysiologic intensities. Multivariate logistic regression model identified tumor size and the minimum intensity required to provoke a stimulus threshold event medial to the tumor after excision as independent predictors of a favorable initial outcome. Immediate facial nerve function was the only independent predictor of long-term normal function. The sensitivity of this predictor was 95% (95% confidence interval [CI], 89-100%); specificity, 83% (95% CI, 62-100%); positive predictive accuracy, 96% (95% CI, 91-100%); and negative predictive accuracy, 77% (95% CI, 54-100%). The combination of electrophysiologic intensities and tumor size are reproducible and better predictors of initial facial nerve function than any individual parameter, but long-term facial nerve function is more likely to have a better outcome if the nerve is left intact and a per-operative graft repair is not performed. The study suggests that although the best available predictor of overall long-term facial nerve outcome is the level of early postoperative function, this factor is not useful in surgical rehabilitation decision making.

Facial Nerve Outcome after Acoustic Neuroma Surgery: A Study from the Era of Cranial Nerve Monitoring

The introduction of intraoperative cranial nerve monitoring in posterior fossa surgery has greatly aided the surgeon in identification and anatomic preservation of cranial nerves. As a result, the long-term function of the facial nerve continues to improve after removal of acoustic neuroma. Herein, we report our long-term (1 year or greater) facial nerve outcome in 129 patients who underwent surgical removal of their acoustic neuromas with the aid of intraoperative neurophysiologic monitoring between 1986 and 1990. The facial nerve was anatomically preserved in 99.2% of the patients, and 90% of all the patients had grade 1 or 2 facial nerve function 1 year after surgery. Long-term facial function was inversely correlated with the size of tumor (chi-squared, p < 0.02) and was not related to the side of tumor, the age and sex of the patient, or the surgical approach. In a comparison among tumor groups matched for size, no statistically significant difference in facial nerve outcome between the translabyrinthine and retrosigmoid approaches was detected. The proximal facial nerve stimulation threshold at the end of surgical removal was predictive of long-term facial nerve function (analysis of variance, p < 0.02). At 1 year, 98% (87 of 89) of the patients with electrical thresholds of 0.2 V or less had grade 1 or 2 facial nerve function compared with only 50% (8 of 16) of those with thresholds between 0.21 and 0.6 V. In the era of cranial nerve monitoring, patients can be better advised about long-term facial nerve outcome after surgical intervention. Preoperatively, the size of the tumor is the most critical factor in predicting long-term facial function. Postoperatively, the proximal seventh nerve stimulation threshold at the end of the surgical procedure can be used as one prognostic measure of long-term facial nerve function.