Postoperative Facial Palsy Research Articles

The importance of simultaneous oculoplastic surgery in quality of life related to vision in surgical resection of large vestibular schwannomas.

Facial nerve palsy is one of the most important complications of vestibular schwannoma resection. When VII cranial nerve is damaged, ocular complications might appear, impacting patient´s quality of life. Therefore, standardized eye care must be a priority. This involves three key treatments: topical treatment, rehabilitation and oculoplastic surgery. The aim of this work is to review the results of oculoplastic surgery performed simultaneously with vestibular schwannoma resection in terms of vision-related quality of life, compared to deferred surgery. The study involved 177 patients who underwent vestibular schwannoma resection between 2015 and 2022. The incidence of facial palsy was registered. Of those patients who had the palsy, we selected 35 who also had oculoplastic surgery. 5 of them declined participating in the study. The final sample (n = 30) was divided in two groups depending on the timing of oculoplastic surgery: simultaneously- first group (n = 15) and deferred-second group (n = 15). The vision-related quality of life was measured using the NEI VFQ-25 test. 26.56% patients developed an immediate postoperative facial dysfunction, decreasing to 18.08% after one year of follow-up. Timing of oculoplastic surgery was associated with better results in quality of life; the first group of patients had a better quality of life (70.27/100) compared to the second group (53.73/100; p = 0.006). Moreover, worse results in quality of life were also associated with long-term postoperative facial palsy (p = 0.042). Current criteria for selecting patients were reliable, proving adequacy as we found worse long-term facial functions in patients who underwent simultaneous surgery (p = 0.01). Our current criteria for selecting candidates for simultaneous oculoplastic surgery are effective. When long-term facial nerve dysfunction is expected during vestibular schwannoma resection, oculoplastic surgery should be performed simultaneously to preserve the q vision-related quality of life. Long-term severe facial palsy is associated with poor vision-related quality of life.

Functional Outcomes and Self-Reported Quality of Life in Patients with Facial Nerve Impairment Following Vestibular Schwannoma Surgery.

The aim of this observational retrospective study was to report quality of life (QoL) in patients with postoperative facial nerve (FN) palsy after vestibular schwannoma (VS) surgery, investigating clinical factors related to functional outcomes. Forty-eight consecutive patients (M:F 25:23; median age: 52.5 years) with facial palsy following surgery for sporadic VS were considered retrospectively. FN palsy was graded by using the Sunnybrook facial grading system (SBFGS), while postoperative QoL and subjective functional aspects were assessed by using the Penn Acoustic Neuroma Quality of Life (PANQOL) Scale, the Synkinesis Assessment Questionnaire, and questions on eating and drinking. A significant correlation emerged between all Sunnybrook scores and median PANQOL domain regarding facial function. Increasing overall SBFGS scores were associated with reduced risk of slow chewing on the affected side (p = 0.004), lack of masticatory strength (p = 0.025), masticatory fatigue (p < 0.001), accumulation of food in the oral vestibule (p < 0.001), difficulty in drinking from a glass (p = 0.019), and fluid spillage while drinking (p = 0.016). This study suggests that the clinical evaluation of patients with FN palsy after VS surgery should be integrated with patient reports about functional outcomes and perceived QoL to help clinicians guide rehabilitation choices.

Clinical Outcomes and Complications of Parotidectomy for Pleomorphic Adenoma Tumour

Objective: To evaluate the clinical and surgical outcomes in patients treated for pleomorphic adenoma (PA) of the parotid gland. Methods: This retrospective study covered 100 PA cases from 2000 to 2018, all confirmed by histopathology and with at least 24 months of follow-up. Statistical analysis was performed using Student’s t-test, Pearson’s Chi-square test, and Fisher’s exact test, with a significance level of 0.05. Results: The average patient age was 42±12 years, with an even sex ratio. Parotid swelling was the main symptom (94%), with an average tumor size of 2.5cm. Most tumors were in the superficial lobe (94 cases), and there were 3 bilateral cases. Surgical approaches included superficial exofacial parotidectomy (55 cases), total parotidectomy (25 cases), partial exofacial parotidectomy (14 cases), and enucleation (6 cases). Complications occurred in 49 patients, with postoperative facial paralysis (FP) being the most common (20%). Total parotidectomy had a higher transient FP rate (24%) compared to exofacial parotidectomy (11%). Four recurrences were noted, mainly after enucleation or exofacial parotidectomy. Statistical analysis showed significant associations: exofacial parotidectomy had the highest complication rate (47%) and was linked to permanent FP (p=0.02). Total parotidectomy was associated with Frey’s syndrome (p=0.01), partial exofacial parotidectomy with salivary fistula (p&lt;0.001), and enucleation with tumor recurrence (p&lt;0.001). Conclusions: Superficial exofacial parotidectomy is common but associated with complications. Total parotidectomy is linked to Frey’s syndrome, while partial exofacial parotidectomy and enucleation have specific risks of salivary fistula and recurrence. Careful selection of surgical technique is crucial to minimize complications and recurrence.

LATEST ADVANCES IN FACIAL NERVE INTRAOPERATIVE MONITORING FOR VESTIBULAR SCHWANNOMA - UP TO DATE 2024

Introduction: Vestibular schwannoma, a benign tumor of the eighth cranial nerve, can be treated with radiosurgery, microsurgery, or observation. This study aims to present advances in intraoperative monitoring techniques for preserving facial nerve function during acoustic neuroma surgeries. By sharing the latest evidence, we hope to influence clinical practices for the benefit of patients. Methodology: Thus, we conducted a comprehensive literature review using the Scopus database, we searched for articles published from 2018 to 2023 using the keywords "facial paralysis," "acoustic neuroma," and "intraoperative monitoring." Results: The use of electromyographic parameters in the pre, intra, and post-resection monitoring of vestibular schwannoma provides valuable indicators of both the functional state of the facial nerve and the tumor adherence. This information plays a crucial role in making safe decisions regarding the extent of tumor resection while minimizing the risk of facial nerve damage during surgery. Supramaximal stimulation of the facial nerve in proximity to the tumor is of utmost importance to preserve facial function. However, the presence of a separate intermediate nerve poses challenges in accurately detecting false positives. Therefore, monitoring the facial nerve during surgery becomes essential to prevent potential injuries and to predict both short- and long-term outcomes. Conclusion: Intraoperative electrophysiological facial nerve monitoring is a crucial strategy to reduce postoperative facial paralysis. While the best technique is still under debate, several options exist to enhance monitoring efficacy and patient safety. By staying informed, clinicians can make better decisions to improve patient outcomes.

Masseteric-facial anastomosis and hypoglossal-facial anastomosis after lateral skull base and middle ear surgery.

Lateral skull base (LSB) and middle ear pathologies often involve the facial nerve (FN), and their treatment may require FN sacrifice. Cases with unidentifiable proximal stump or intact FN with complete FN palsy, necessitate FN anastomosis with another motor nerve in order to restore innervation to the mimicking musculature. The results of hypoglossal-to-facial nerve anastomosis (HFA) and masseteric-facial nerve anastomosis in patients with facial paralysis after middle ear and LSB surgeries, are presented and compared. Adult patients with total definitive facial paralysis after middle ear or LSB surgery undergoing facial nerve reanimation through hypoglossal or masseteric transfer anastomosis were enrolled. The facial nerve function was graded according to the House Brackmann grading system (HB). The facial function results at 3months, 6months, 12months, 18months and at the last follow up (more than 18months) are compared. 153 cases of LSB and middle ear surgery presented postoperative facial palsy and underwent facial nerve reanimation surgery with HF in 85 patients (55.5%) and MF in 68 patients (44.5%). The duration of the FN palsy before reconstructive surgery was inversely associated to better FN results, in particular with having a grade III HB (p = 0.003). Both techniques had significantly lower HB scores when an interval between palsy onset and reanimation surgery was 6months or less (MF p = 0.0401; HF p = 0.0022). Patients who underwent a MF presented significant improvement of the FN function at 3months from surgery (p = 0.0078). At the last follow-up, 63.6% recovered to a grade III HB and 22.7% to a grade IV. On the other hand, the first significant results obtained in the HF group were at 6months from surgery (p < 0.0001). 67.8% of patients had a grade III HB after a HF at the last follow-up, 28.8% a grade IV. FN grading at 6months from surgery was significantly lower in the MF group compared to the HF (p = 0.0351). The two techniques had statistically similar results at later follow-up evaluations. MF was associated to initial superior results, presenting significant facial recovery at 3months, and significantly better functional outcomes at 6months from surgery compared to HF. Although later results were not significantly different in this study, earlier results have an important role in order to limit the duration of risk of corneal exposure.

Clinical features and management strategies concerning auditory canal duplication anomalies in children with congenital first branchial cleft anomalies.

This study aimed to summarise the clinical features and management strategies concerning auditory canal duplication anomalies in children with congenital first branchial cleft anomalies (CFBCAs), and to provide guidance for precise treatment. We retrospectively analysed 84 children with CFBCAs who had complete data, diagnosed between December 2018 and February 2024. All the lesions identified were located around the external auditory canal or near the mandibular angle, manifested as pinhead-sized perforations in 10 cases, painless masses in 18 cases, recurrent swelling and pain with purulent discharge in 52 cases, and otorrhea in 4 cases. Otoscopy examinations revealed external auditory canal swelling in seven children, fistulas within the auditory canal in four children, and a myringa web in three children. Fifty-six children had a preoperative history of infection. Using Work's classification system, Work I and II in 70 (87.5%) and 14 (12.5%) children, respectively. Intraoperatively, 80 (95.2%) children had auditory canal duplication anomalies at the base of the lesion, closely associated with the cartilage of the inferior wall of external auditory canal(EAC), We then classified auditory canal duplication anomalies into three types: Type A (duplication anomalies of epithelial tissue structure between the skin of the EAC and the cartilage of the inferior wall, n = 16 children), Type B (duplication anomalies of the epithelial and/or skin tissue structure, sharing a wall with the cartilage of the inferior wall, n = 40), and Type C (duplication anomalies of the skin and cartilage tissue structure, connected to the cartilage of the inferior wall of EAC, n = 24). Sixty-eight children had lesions superficial to the facial nerve, 12 had lesions deep to the facial nerve, and four had lesions between branches. There were two cases of transient postoperative facial paralysis, three cases of CFBCA recurrence, and two cases of transient auditory canal stenosis. Auditory canal duplication anomalies are an important feature of first branchial cleft anomalies in children. Precise staging and accurate identification of the base of the lesion facilitate complete removal, thereby increasing the cure rate.

Cystic vestibular schwannoma – a subgroup analysis from a comparative study between radiosurgery and microsurgery

Some vestibular schwannoma (VS) show cystic morphology. It is known that these cystic VS bear different risk profiles compared to solid VS in surgical treatment. Still, there has not been a direct comparative study comparing both SRS and SURGERY effectiveness in cystic VS. This retrospective bi-center cohort study aims to analyze the management of cystic VS compared to solid VS in a dual center study with both microsurgery (SURGERY) and stereotactic radiosurgery (SRS). Cystic morphology was defined as presence of any T2-hyperintense and Gadolinium-contrast-negative cyst of any size in the pre-interventional MRI. A matched subgroup analysis was carried out by determining a subgroup of matched SURGERY-treated solid VS and SRS-treated solid VS. Functional status, and post-interventional tumor volume size was then compared. From 2005 to 2011, N = 901 patients with primary and solitary VS were treated in both study sites. Of these, 6% showed cystic morphology. The incidence of cystic VS increased with tumor size: 1.75% in Koos I, 4.07% in Koos II, 4.84% in Koos III, and the highest incidence with 15.43% in Koos IV. Shunt-Dependency was significantly more often in cystic VS compared to solid VS (p = 0.024) and patients with cystic VS presented with significantly worse Charlson Comorbidity Index (CCI) compared to solid VS (p < 0.001). The rate of GTR was 87% in cystic VS and therefore significantly lower, compared to 96% in solid VS (p = 0.037). The incidence of dynamic volume change (decrease and increase) after SRS was significantly more common in cystic VS compared to the matched solid VS (p = 0.042). The incidence of tumor progression with SRS in cystic VS was 25%. When comparing EOR in the SURGERY-treated cystic to solid VS, the rate for tumor recurrence was significantly lower in GTR with 4% compared to STR with 50% (p = 0.042). Tumor control in cystic VS is superior in SURGERY, when treated with a high extent of resection grade, compared to SRS. Therapeutic response of SRS was worse in cystic compared to solid VS. However, when cystic VS was treated surgically, the rate of GTR is lower compared to the overall, and solid VS cohort. The significantly higher number of patients with relevant post-operative facial palsy in cystic VS is accredited to the increased tumor size not its sole cystic morphology. Cystic VS should be surgically treated in specialized centers.

Patterns and timing of recovery from facial nerve palsy after nerve-sparing parotid surgery: the role of neuromuscular retraining

ObjectivesAmong the complications of parotid surgery, facial palsy is frequent and burdened by high functional and social impact for the patient. There are few data on the efficacy of facial neuromuscular retraining (FNR) in patients with facial palsy after parotid surgery, and no data exist on its impact in timing and extent of recovery.Material and methodsA retrospective study was conducted on patients undergoing FN sparing parotid surgery and suffering from postoperative facial palsy. Among 400 patients undergoing surgery between July 2016 and May 2023, those with the preservation of the FN and onset of facial palsy were selected. Nerve function was evaluated during 2 years follow up using the House-Brackman (H&Bs) and Sunnybrook scales (SBs).ResultsA total of 46 patients undergoing partial or total parotidectomy were included. At discharge 18 patients (39,1%) had IV to VI grade paralysis according to the H&Bs and the mean SBs value was 54. At 2 and 6 months after surgery, the average value of Sunnybrook increased to 76.5 and 95.4 respectively. After 12 months no patients with IV to VI grade paralysis were represent in our cohort. Two years after surgery, only five patients (10.9%) had persistent grade II paralysis according to HBs.ConclusionsOur study supports the efficacy of FNR in the rehabilitation of facial paralysis after nerve-sparing parotidectomy. The greater functional improvement is achieved within the first 6 months of rehabilitation. A significant improvement is detected still after 18 months, supporting the importance of long rehabilitation for patients without complete recovery after the first year.

An updated protocol for mandibular reconstruction in nongrowing patients with craniofacial microsomia with temporomandibular joint total prosthesis

The authors aim to present an updated protocol for mandibular reconstruction in nongrowing patients with Pruzansky/Kaban type IIb/III congenital craniofacial microsomia with customized temporomandibular joint (TMJ) prosthesis to reduce facial nerve (FN) damage and improve surgical accuracy. This is illustrated (using 3 cases) and is based on preoperative mapping of the FN using MRI for better virtual surgical planning of custom-made TMJ prosthesis. Intraoperative FN mapping and monitoring, as well as verification of the final result with intraoperative cone-beam computed tomography (CBCT) and 3D-reconstructed images is also achieved. All 3 patients presented mild transient postoperative facial palsy due to surgical soft tissue stretching which resolved within 2 months of surgery. All patients presented proper occlusion and mouth opening without pain, with an average incisal opening of 38.8 mm (range 35.5–42 mm) at two months of follow-up. Moreover, superposition of intraoperative and preoperative 3D reconstruction images ensured surgical accuracy and avoided the need for a potential reintervention. In conclusion, the proposed surgical protocol for mandibular reconstruction with customized alloplastic TMJ prosthesis in nongrowing patients with type IIb/III Pruzansky-Kaban congenital mandibular hypoplasia may reduce FN morbidity, improve surgical accuracy and final outcomes.

Application of Crus of Helix Incision Through the Posterior Parotid Gland Approach in the Mid-Level or High-Level Mandibular Condylar Fractures.

This study is to explore the clinical effect of crus of helix incision through the posterior parotid gland approach in the treatment of Mid-or High-Level mandibular condylar fractures. From September 2020 to June 2023, we performed incision reduction internal fixation of 23 patients with mid-level or high-level fractures of the mandibular condylar through the approach of the posterior parotid gland, and observed the effect of the operation. After a follow-up period of 6 to 12 months, all patients showed no signs of postoperative facial paralysis or salivary gland fistula. In addition, satisfactory scars were observed in the operation area, and the occlusion function had recovered well. The approach of using a crus of helix incision through the posterior parotid gland proved to be an effective method for treating mid-level or high-level fractures of the condylar fractures. This technique offers several advantages, including adequate exposure, minimal facial nerve injury, ease of incision and reduction, inconspicuous scarring, and a more concealed incision.

Bilateral Simultaneous Magnetic Resonance-Guided Focused Ultrasound Pallidotomy for Life-Threatening Status Dystonicus.

Invasive treatments like radiofrequency stereotactic lesioning or deep brain stimulation of the globus pallidus internus can resolve drug-resistant status dystonicus (SD). However, these open procedures are not always feasible in patients with SD. The aim was to report the safety and efficacy of simultaneous asleep bilateral transcranial magnetic resonance-guided focused ultrasound (MRgFUS) pallidotomy for life-threatening SD. We performed bilateral simultaneous MRgFUS pallidotomy under general anesthesia in 2 young patients with pantothenate kinase-associated neurodegeneration and GNAO1 encephalopathy. Both patients had medically refractory SD and severe comorbidities contraindicating open surgery. SD resolved at 4 and 12 days after MRgFUS, respectively. Adverse events (intraoperative hypothermia and postoperative facial paralysis) were mild and transient. Bilateral simultaneous MRgFUS pallidotomy under general anesthesia is safe and may be a valid alternative therapeutic option for fragile patients. Further studies are needed to assess long-term efficacy of the procedure.

Impact of Surgeon's Experience and Tumor's Nature in the Use of Intraoperative Facial Nerve Monitoring in Superficial Parotidectomy. Preliminary Results from a Single-Center Retrospective Analysis.

To assess the effectiveness of intraoperative facial nerve monitoring (IFNM) compared to non-monitoring in the prevention of post-operative facial nerve palsy during superficial parotidectomy. Patients treated with curative intent for parotid gland tumors between January 2020 and January 2022 were included. The study population has been divided in 2 groups, based on IFNM: the group A included patients operated with IFNM, whilst group B was the non-monitoring group. A further classification focused on the pathologies and the surgeons' experience. The study group included 58 patients, 27 female and 31 male. The mean age was 45.7yr (range 36-78). No statistical difference has been found in post-operative HB grade between group A and B. The analysis of patients affected by pleomorphic surface lobe adenomas of the parotid did not show a statistical difference in HB outcome (p > 0.05). The analysis of the effect of surgeons' experience in IFNM advantage did not show statistical difference for superficial parotid tumors. The results of the present study suggest that the use of IFNM during parotid surgery is not mandatory to preserve the VII nerve function, both in case of primary tumor and in case of recurrence, and even when surgery is performed by less experienced surgeon compared to those cases treated by a more experienced surgeon.

The risk of facial nerve palsy after benign parotidectomy. A quality project

Background Facial nerve palsy is a potential complication of parotidectomy for benign salivary gland tumours, necessitating a comprehensive understanding of its incidence and associated risk factors for improved patient counselling and preoperative planning. Aim/objectives This single-centre retrospective study aimed to assess the rate of facial nerve palsy following benign parotidectomy at a University Teaching Hospital. Material and methods Over a 3-year period, 160 patients undergoing parotid surgery for benign tumours were included. Data, encompassing sex, age, operation technique, tumour pathology, facial nerve function, and follow-up duration, were collected from medical records. Exclusion criteria comprised patients with prior parotid gland surgery or preoperative facial nerve palsy. Results The study revealed a 3.75% incidence of facial nerve palsy with no total paralysis post-parotidectomy for benign disease. Pleomorphic adenoma (50.6%) and Warthin’s tumour (44.4%) were the predominant tumour types. No significant differences were noted between groups with and without postoperative facial palsy based on obtained covariates. Conclusion and significance Our findings endorse partial superficial parotidectomy and extracapsular dissection as low-risk treatments for benign parotid tumours. However, prospective studies are warranted to elucidate recovery rates and long-term consequences of facial nerve palsy, contributing to refined surgical approaches and patient care in parotid surgery.

Modified radical mastoidectomy in chronic otitis media: year outcome post-surgery

Background: Cholesteatoma is defined as erosive process, eroding ossicular chain, scutum, otic-capsule, fallopian canal and tegmun. Surgical management of cholesteatoma includes mastoidectomy. The aim of the study was to focuss on MRM: indications and outcomes of procedure. Methods: This study aims at knowing the indications and outcome of MRM after 1 year in terms of success rate, efficacy and patient’s satisfaction. It involves study over 42 patients who underwent surgery and were followed over a period of one year post surgery. Results: After 1 year of MRM 64.27% showed hearing improvement, 95.2% had dry and settled cavity, and there was no post-operative facial palsy, and SNHL. Conclusions: MRM is a procedure of choice for COM with extensive disease of mastoid. A meticulous and skilled MRM gives a well fashioned mastoid cavity with minimum or no recurrence/post-operative complications with a satisfactory hearing outcome.

Predictive value of facial motor–evoked potential and electromyography for facial motor function in vestibular schwannoma surgery

PurposeIntraoperative neuromonitoring (IONM) aims to preserve facial nerve (FN) function during vestibular schwannoma (VS) surgery. However, current techniques such as facial nerve motor evoked potentials (FNMEP) or electromyography (fEMG) alone are limited in predicting postoperative facial palsy (FP). The objective of this study was to analyze a compound fEMG/FNMEP approach.MethodsIntraoperative FNMEP amplitude and the occurrence of fEMG-based A-trains were prospectively determined for the orbicularis oris (ORI) and oculi (OCU) muscle in 322 VS patients. Sensitivity and specificity of techniques to predict postoperative FN function were calculated. Confounding factors as tumor size, volume of intracranial air, or IONM duration were analyzed.ResultsA relevant immediate postoperative FP was captured in 105/322 patients with a significant higher risk in large VS. While fEMG demonstrated a high sensitivity (77% and 86% immediately and 15 month postoperative, respectively) for identifying relevant FP, specificity was low. In contrast, FNMEP have a significantly higher specificity of 80.8% for predicting postoperative FP, whereas the sensitivity is low. A retrospective combination of techniques demonstrated still an incorrect prediction of FP in ~ 1/3 of patients.ConclusionsFNMEP and fEMG differ in sensitivity and specificity to predict postoperative FP. Although a combination of IONM techniques during VS surgery may improve prediction of FN function, current techniques are still inaccurate. Further development is necessary to improve IONM approaches for FP prediction.

Combined microscope–endoscopy resection of petrous bone cholesteatoma with temporary facial nerve transposition versus nontransposition

PurposeThe narrow supralabyrinthine space affects surgical procedures. To study the effect of temporary transposition of geniculate ganglion of facial nerve versus nontransposition on lesion recurrence and facial nerve function in patients with petrous bone cholesteatoma.MethodsA total of 18 patients with petrous bone cholesteatoma involving the facial nerve were treated in our hospital from November 2016 to March 2023. The main surgical method is the extended supralabyrinthine approach assisted by a microscope and an endoscope. We collected and retrospectively analyzed their medical records.ResultsTemporary facial nerve transposition was performed in five patients, and nontransposition was performed in 13 patients. Cholesteatoma recurred in three patients with facial nerve nontransposition, whereas none in patients with facial nerve transposition. In this study, except for one case with a second operation, postoperative facial paralysis in other cases was improved to varying degrees, and there was no significant difference between the two groups.ConclusionTemporary transposition of geniculate ganglion of facial nerve will not affect the postoperative nerve function of patients and can reduce the possibility of cholesteatoma recurrence of the petrous bone.

Effect of Conventional Physiotherapeutic Techniques on Post-Operative Facial Palsy: A Case Study

This case study highlights the benefits of combining multiple conventional physiotherapeutic methods for post-operative facial palsy with an evidence-based treatment plan using the International Classification of Functioning Disability and Health ICF. A middle-aged female reported with a primary complaint of facial weakness experienced post the surgical removal of parotid gland due to pleomorphic adenomatous growth. Treatment was offered at the out-patient physiotherapy department and each session lasted for 45 minutes with exercises like proprioceptive training facial neuromuscular rehabilitation mime therapy and sensory re-education incorporated as a part of the patients dose-based physical treatment. With outcome measurements Sunnybrook Facial Grading System indicating improvement by 27 points and Facial Disability Index showing improvement by 41 points and a noticeably higher level of confidence the patient demonstrated a considerable reduction in discomfort and improvement of mobility prior to discharge. The case study focuses on how an evidence-based plan of conventional treatment strategies ensures better prognosis for a patient with post-operative facial palsy.

Preemptive strategies and lessons learned from complications encountered with microvascular decompression for hemifacial spasm.

Microvascular decompression (MVD) is the only curative treatment modality for hemifacial spasm (HFS). Although generally considered to be safe, this surgical procedure is surrounded by many risks and possible complications. The authors present the spectrum of complications that they met in their case series, the possible causes, and the strategies recommended to minimize them. The authors reviewed a prospectively maintained database for MVDs performed from 2005 until 2021 and extracted relevant data including patient demographics, offending vessel(s), operative technique, outcome, and different complications. Descriptive statistics with uni- and multivariable analyses for the factors that may influence the seventh, eighth, and lower cranial nerves were performed. Data from 420 patients were obtained. Three hundred seventeen of 344 patients (92.2%) with a minimum follow-up of 12 months had a favorable outcome. The mean follow-up (standard deviation) was 51.3 ± 38.7 months. Immediate complications reached 18.8% (79/420). Complications persisted in only 7.14% of patients (30/420) including persistent hearing deficits (5.95%) and residual facial palsy (0.95%). Temporary complications included CSF leakage (3.10%), lower cranial nerve deficits (3.57%), meningitis (0.71%), and brainstem ischemia (0.24%). One patient died because of herpes encephalitis. Statistical analyses showed that the immediate postoperative disappearance of spasms and male gender are correlated with postoperative facial palsy, whereas combined vessel compressions involving the vertebral artery (VA) and anterior inferior cerebellar artery can predict postoperative hearing deterioration. VA compressions could predict postoperative lower cranial nerve deficits. MVD is safe and effective for treating HFS with a low rate of permanent morbidity. Proper patient positioning, sharp arachnoid dissection, and endoscopic visualization under facial and auditory neurophysiological monitoring are the key points to minimize the rate of complications in MVD for HFS.

Subclassification of Koos grade 4 vestibular schwannoma: insights into tumor morphology for predicting postoperative facial nerve function.

Koos grade 4 vestibular schwannoma (KG4VS) is a large tumor that causes brainstem displacement and is generally considered a candidate for surgery. Few studies have examined the relationship between morphological differences in KG4VS other than tumor size and postoperative facial nerve function. The authors have developed a landmark-based subclassification of KG4VS that provides insights into the morphology of this tumor and can predict the risk of facial nerve injury during microsurgery. The aims of this study were to morphologically verify the validity of this subclassification and to clarify the relationship of the position of the center of the vestibular schwannoma within the cerebellopontine angle (CPA) cistern on preoperative MR images to postoperative facial nerve function in patients who underwent microsurgical resection of a vestibular schwannoma. In this paper, the authors classified KG4VSs into two subtypes according to the position of the center of the KG4VS within the CPA cistern relative to the perpendicular bisector of the porus acusticus internus, which was the landmark for the subclassification. KG4VSs with ventral centers to the landmark were classified as type 4V, and those with dorsal centers as type 4D. The clinical impact of this subclassification on short- and long-term postoperative facial nerve function was analyzed. In this study, the authors retrospectively reviewed patients with vestibular schwannoma who were treated surgically via a retrosigmoid approach between January 2010 and March 2020. Of the 107 patients with KG4VS who met the inclusion criteria, 45 (42.1%) were classified as having type 4V (KG4VSs with centers ventral to the perpendicular bisector of the porous acusticus internus) and 62 (57.9%) as having type 4D (those with centers dorsal to the perpendicular bisector). Ventral extension to the perpendicular bisector of the porus acusticus internus was significantly greater in the type 4V group than in the type 4D group (p < 0.001), although there was no significant difference in the maximal ventrodorsal diameter. The rate of preservation of favorable facial nerve function (House-Brackmann grades I and II) was significantly lower in the type 4V group than in the type 4D group in terms of both short-term (46.7% vs 85.5%, p < 0.001) and long-term (82.9% vs 96.7%, p = 0.001) outcomes. Type 4V had a significantly negative impact on short-term (OR 7.67, 95% CI 2.90-20.3; p < 0.001) and long-term (OR 6.05, 95% CI 1.04-35.0; p = 0.045) facial nerve function after surgery when age, tumor size, and presence of a fundal fluid cap were taken into account. The authors have delineated two different morphological subtypes of KG4VS. This subclassification could predict short- and long-term facial nerve function after microsurgical resection of KG4VS via the retrosigmoid approach. The risk of postoperative facial palsy when attempting total resection is greater for type 4V than for type 4D. This classification into types 4V and 4D could help to predict the risk of facial nerve injury and generate more individualized surgical strategies for KG4VSs with better facial nerve outcomes.

Continuous intraoperative neuromonitoring of the facial nerve predicts postoperative facial palsy in parotid surgery: a prospective study.

Facial palsy (FP) is the most significant complication of parotidectomy. Currently, the use of intermittent intraoperative neuromonitoring (iIONM) in parotid surgery facilitates nerve detection, which is paramount to nerve protection. Continuous IONM (cIONM), as applied in thyroid surgery, enables real-time information on electrophysiological nerve status through continuous nerve stimulation, thereby allowing consequent amplitude analysis. To date, the application of cIONM in parotid surgery has not been noted in literature. We performed parotidectomies with anterograde facial nerve visualization using cIONM in 32 consecutive patients in a prospective study (German Register of clinical studies-DRKS 00011051) during the period October 2016 to January 2020. After the facial trunk had been exposed, an atraumatic stimulation electrode was placed and the nerve was stimulated at 3Hz, at a low threshold (0.62 ± 0.06mA), for the entire duration of the preparation. Selected electrophysiological parameters were collected and compared to postoperative facial nerve function, measured by the House-Brackmann grading system. In the post hoc analysis, a significant correlation between a drop in amplitude (< 50% of the "baseline" amplitude) and postoperative FP was recorded (p = 0.001). True positive prediction of FP was noted in 14 out of 16 patients and true negative in 10 out of 16. The sensitivity was 87.5% (AUC 0.75), with a high negative predictive value of 83.3%. cIONM has significant value in predicting postoperative FP in parotidectomy. Future development of an acoustic/optic warning system in IONM devices could prevent nerve injury in real time.