Facial Preservation Research Articles

Outcome of Surgery of Vestibular Schwannomas in a Tertiary Care Hospital in Bangladesh

Background: Presenting symptoms, treatment considerations, and outcome are strongly related to the extension of vestibular schwannomas (VS). The aim of the current retrospective study was to analyze the clinical features, microsurgical treatment, and outcome of VS with brainstem compression. Methods: Seventy patients presented with VS who had undergone operative procedures performed in our unit from 2017 to 2019. The facial nerve function and hearing assessment was done according to House-Brackmann [HB] grading and pure tone audiometry (PTA) respectively. All patients were operated by retro-mastoid suboccipital approach. Results: Most patients had large tumors and had no useful hearing (85%), had disabling cerebellar ataxia (92.86%) and presented with features of raised intracranial pressure (48.57%). Large sized tumors were in 32.86% and giant sized tumors were in 57.14% cases. Complete tumor excision was carried out 92.86% and anatomical preservation of facial nerve was achieved in 73.85% cases. Hearing preservation was achieved in 4 patients. Cerebrospinal fluid leak with or without meningitis and transient lower cranial nerve paresis were common complications. The mortality rate was 7.14%. Conclusions: Complete tumor excision with good facial nerve preservation can be achieved in large vestibular schwannomas. Hearing preservation is difficult in larger tumors. Primary microsurgical resection is an appropriate management option for large VS. In our experience, this goal can be achieved safely and successfully by using the retrosigmoid approach. Bang. J Neurosurgery 2021; 10(2): 175-181

Hearing preservation/rehabilitation surgery for small vestibular schwannoma: preliminary experience with the presigmoid retrolabyrinthine approach

Background The presigmoid retrolabyrinthine approach (PRA) for small vestibular schwannoma (VS) has unique advantages. Combination with partial labyrinthectomy further makes up its defect of high demand for anatomy. Objective Aimed to describe our use of the PRA with partial labyrinthectomy in VS surgery. Methods We retrospectively analyzed 10 patients diagnosed with VS who underwent PRA between September 2017 and November 2020. Their perioperative data were analyzed. Results Six tumors were on the left and three were on the right. One case was due to neurofibromatosis type 2 with bilateral involvement and underwent internal auditory canal decompression by PRA without tumor removal; all other patients underwent total tumor resection. Four patients underwent cochlear implantation simultaneously because of hearing loss that was detected during surgery. Three patients underwent partial labyrinthectomy. Five patients achieved hearing preservation, and one experienced hearing improvement. One of the three patients who underwent partial labyrinthectomy maintained hearing. All patients’ pre- and postoperative facial nerve functions were House-Brackmann grade I. After a median follow-up time of 13 months, no tumors recurred. Conclusions PRA for small VS is a safe and effective surgery that can achieve facial nerve and hearing preservation. Combination with partial labyrinthectomy can also preserve hearing.

766 Endoscopic Surgery for Sporadic Vestibular Schwannoma Resection: A Systematic Review of Surgical Outcomes

Abstract Introduction Vestibular schwannomas (VS) are benign intracranial tumours originating from the vestibular division of the eighth cranial nerve. The mainstay of their surgical management is microsurgery, other options are radiotherapy or radiological monitoring. Endoscopy (ES) is becoming widely used in neurosurgery and may have a role in improving visualisation and outcomes by enhancing extent of resection, facial nerve, and hearing preservation in VS resection and describe the postoperative outcomes. Method The review was conducted according to the PRISMA guidelines and yielded 31 studies for inclusion. Systematic searches of literature databases were done for studies where endoscopic-assisted and/or endoscopic resection of VS were reported. Results ES facial nerve preservation rates (median 91.3%, range 39.0 - 100%) were comparable to microsurgical treatment. Hearing outcomes were more variable in ES series and were under-reported. A median gross total resection rate of 97.4% (61.0 - 100%) was achieved in the ES series. Conclusions Current data suggest that ES-assisted resection of sporadic VS is not inferior to microsurgical resection with respect to facial nerve outcomes and extent of resection. However, some ES series report poor hearing outcomes, which are under-reported in the literature.

Complications of Parotid surgery: A study in 60 cases

Objective: To evaluate the common complications following parotid surgery.
 Material & methods: A retrospective study was done from January 2011 to December 2019 in the Department of ENT & Head Neck Surgery, Enam Medical College & hospital, Savar. Sixty (60) patients with both benign & malignant parotid disease underwent surgical treatment was selected for this study. All cases were diagnosed preoperatively by Fine Needle Aspiration Cytology (FNAC). Patients with preoperative facial nerve palsy were excluded from this study. Patients were followed up for six months and per operative & postoperative complications were evaluated.
 Results: Out of 60 patients, superficial parotidectomy was done in52 (86.67%) patients and total conservative parotidectomy was done in 08 (13.33%) patients. In this study 56 cases were benign and 04 cases were malignant. Among this 41 (68.33%) pleomorphic adenoma, 05 (8.33%) warthin’s tumour, 03 (5%) benign lymphoepithelial cyst, 03(5%) haemangioma, 02(3.33) sialocele, 01(1.67) dermoid and 01 (1.67%) had salivary fistula. All 04(6.67%) malignant cases were diagnosed as mucoepidermoid carcinoma. Majority of pleomorphic adenomas (92.68%) involved the superficial lobe of the gland. Most commonly observed post operative complication was facial nerve paresis (05%), but only 1.67% developed permanent palsy. Others complication includes Hypoesthesia of the greater auricular nerve (05%), Frey’s syndrome (3.33%) & wound infection (3.33%).
 Conclusion: Facial nerve palsy is the frequent complication after parotid surgery in this study. Surgeons have to pay attention to minimize the risk of complication during parotidectomy. However, this operation continues to be a challenge on account of the wide range of tumours encountered and the variations in size and location and the facial nerve preservation.
 Bangladesh J Otorhinolaryngol; April 2021; 27(1): 59-65

Tufts Medical Center Experience With Long-Term Follow-Up of Vestibular Schwannoma Treated With Gamma Knife Stereotactic Radiosurgery: Novel Finding of Delayed Pseudoprogression

PurposeOur purpose was to evaluate the long-term outcomes of patients with vestibular schwannoma (VS) treated with Gamma Knife stereotactic radiosurgery (GKSRS) with modern techniques, with attention to posttreatment tumor growth dynamics, dosimetric predictors, and late toxicities. Methods and MaterialsOne hundred twelve patients with VS were treated with GKSRS with a median dose of 12.5 Gy to the 50% isodose line treated between 2004 and 2015, with patients followed up to 15 years. Target and organ-at-risk doses were recorded, and tumor diameter/volume, audiologic decline, and trigeminal/facial nerve preservation were tracked from treatment onward. ResultsGKSRS yielded local control of 5, 10, and 15 years at 96.9%, 90.0%, and 87.1% respectively. Pseudoprogression was found in 45%, with a novel pattern detected with peak swelling at 31 months. Pseudoprogression was associated with smaller tumor diameter at treatment and fewer treatment isocenters, but not with the development of any toxicity, nor was it predicted by any dosimetric factor. Median time to hearing loss was 3.4 years with actuarial hearing preservation at 2, 5, and 10 years of 66.5%, 43.1%, and 37.6%, with rate of hearing loss correlating with maximum cochlea and modiolus doses. Trigeminal and facial nerve preservation rates were 92.7% and 97.6%, respectively. Increasing maximum tumor dose was associated with facial paresthesia. ConclusionsModern GKSRS is a safe and effective treatment for VS on long-term follow-up, with high levels of facial and trigeminal nerve preservation. A novel pattern of pseudoprogression has been identified suggesting longer imaging follow-up may be needed before initiating salvage in those without symptomatic progression. Several tumor and dosimetric predictors have been suggested for the development of different toxicities, requiring further evaluation.

Deep Lobe Parotid Tumors: A Systematic Review and Meta-analysis.

We performed a systematic review and meta-analysis of deep lobe parotid tumors to evaluate their unique characteristics. PubMed/Medline, Embase, Web of Sciences, and Cochrane Library databases were queried for relevant literature. Studies were individually assessed by 2 independent reviewers. Risk of bias was assessed with the Cochrane bias tool, GRADE criteria, and MINORS criteria. Results were reported according to the PRISMA guidelines. Statistical analysis was performed by comparing rates of malignancy between deep and superficial lobe tumors. In total, 8 studies including 379 deep lobe parotid tumors met inclusion criteria. Mean age at diagnosis was 44.9 years. Computed tomography scan was the most common imaging modality. Preoperative diagnostic fine-needle aspiration was utilized in 39.4% of patients and demonstrated high sensitivity for malignant disease. The most common approach was subtotal parotidectomy with facial nerve preservation (58.9%). The rate of malignancy was 26.6%, which was significantly higher than that of the superficial lobe tumors in this study (risk ratio, 1.25; 95% CI, 1.01-1.56). The rate of temporary postoperative facial nerve weakness between deep and superficial lobe tumors was 32.5% and 11.7%, respectively. Deep lobe parotid tumors had a 26.6% rate of malignancy. On meta-analysis, deep lobe tumors appeared to have higher rates of malignancy than superficial lobe tumors. Surgical excision of deep lobe tumors showed increased rates of temporary facial nerve paresis as compared with superficial lobe tumors. Computed tomography scan was the most common imaging modality. There were limited data regarding the utility of fine-needle aspiration.

THE RESULTS OF SURGICAL TREATMENT OF ACOUSTIC NEUROMA BY DRILLING THE POSTERIOR WALL OF THE INTERNAL AUDITORY CANAL VIA THE RETROSIGMOID SUBOCCIPITAL APPROACH

Objective: To assess of surgical results of acoustic neuroma by the retrosigmoid suboccipial approach with drilling the posterior wall of the internal auditory canal. Patients and methods: A prospective study with 26 patients who were diagnosed with acoustic neuroma and surgically treated by drilling the posterior wall of the internal auditory canal via retrosigmoid suboccipital approach at Viet-Duc Hospital from January 2019 to October 2020. Results: Mean age: 42.74±14.95; male: female ratio was 1; tinnitus was the most common symptom (76.92%), after that hearing loss (69.23%). There was no predominant in the side of the tumor. There was a significant difference between KOOS classification’s tumor before and after surgery, as well as the facial nerve function 3-month post-operation versus discharge time. Conclusion: The retrosigmoid suboccipital approach with drilling the posterior wall of the internal auditory canal was useful for treating acoustic neuroma both the tumor removing capacity and facial nerve preservation.

Facial Nerve Function Outcome and Risk Factors in Resection of Large Cystic Vestibular Schwannomas.

Objective Cystic vestibular schwannomas (VS) in contrast to solid VS tend to have accelerated growth, larger volume, rapid/atypical presentation, lobulated/adherent surface, and unpredictable course of the cranial nerves. Cystic VS are surgically challenging, with worse clinical outcomes and higher rate of subtotal resection (STR). Methods We retrospectively analyzed postoperative outcomes of 125 patients with cystic VS, operated between years 2005 and 2019 in our center. We confronted the extent of the resection and House-Brackmann (HB) grade of facial palsy with the results of comparable cohort of patients with solid VS operated in our center and literature review by Thakur et al. 1 Results Translabyrinthine approach was preferred for resection of large, cystic VS (97.6%). Gross-total resection (GTR) was achieved in 78 patients (62.4%), near-total resection (NTR) with remnant (<4 × 4 × 2 mm) in 43 patients (34.4%), and STR in 4 patients (3.2%). NTR/STR were significantly associated with higher age, tumor volume >5 cm 3 , retrosigmoid approach, high-riding jugular bulb, tumor adherence to the brain stem, and facial nerve ( p = 0.016; 0.003; 0.005; 0.025; 0.001; and <0.00001, respectively). One year after the surgery, 76% of patients had HB grades 1 to 2, 16% had HB grades 3 to 4, and 8% had HB grades 5 to 6 palsy. Worse outcome (HB grades 3 to 6) was associated with preoperative facial palsy, tumor volume >25 cm 3 , and cyst over the brain stem ( p = 0.045; 0.014; and 0.05, respectively). Comparable solid VS operated in our center had significantly higher HB grades 1 to 2 rate than our cystic VS (94% versus 76%; p = 0.03). Comparing our results with literature review, our HB grades 1 to 2 rate was significantly higher (76% versus 39%; p = 0.0001). Tumor control rate 5 years after surgery was 95.8%. Conclusion Our study confirmed that microsurgery of cystic VS has worse outcomes of facial nerve preservation and extent of resection compared with solid VS. Greater attention should be paid to the above-mentioned risk factors.

Optimal Volume of the Residual Tumor to Predict Long-term Tumor Control Using Stereotactic Radiosurgery after Facial Nerve-preserving Surgery for Vestibular Schwannomas.

BackgroundIntended subtotal resection (STR) followed by adjuvant gamma knife radiosurgery (GKRS) has emerged as an effective treatment option for facial nerve (FN) preservation in vestibular schwannomas (VSs). This study aimed to identify the optimal cut-off volume of residual VS to predict favorable outcomes in terms of both tumor control and FN preservation.MethodsThis retrospective study assessed the patients who underwent adjuvant GKRS for residual VS after microsurgery. A total of 68 patients who had been followed up for ≥ 24 months after GKRS were included. Tumor progression was defined as an increase in tumor volume (TV) of ≥ 20%. House-Brackmann grades I and II were considered to indicate good FN function.ResultsThe median residual TV was 2.5 cm3 (range: 0.3–27.4). The median follow-up period after the first adjuvant GKRS was 64 months (range: 25.7–152.4). Eight (12%) patients showed tumor progression. In multivariate analyses, residual TV was associated with tumor progression (P = 0.003; hazard ratio [HR], 1.229; 95% confidence interval [CI], 1.075–1.405). A residual TV of 6.4 cm3 was identified as the cut-off volume for showing the greatest difference in progression-free survival (PFS). The 5-year PFS rates in the group with residual TVs of < 6.4 cm3 (54 patients) and that with residual TVs of ≥ 6.4 cm3 (14 patients) were 93.3% and 69.3%, respectively (P = 0.014). A good FN outcome was achieved in 57 (84%) patients. Residual TV was not associated with good FN function during the immediate postoperative period (P = 0.695; odds ratio [OR], 1.024; 95% CI, 0.908–1.156) or at the last follow-up (P = 0.755; OR, 0.980; 95% CI, 0.866–1.110).ConclusionIn this study, residual TV was associated with tumor progression in VS after adjuvant GKRS following STR. As preservation of FN function is not correlated with the extent of resection, optimal volume reduction is imperative to achieve long-term tumor control. Our findings will help surgeons predict the prognosis of residual VS after FN-preserving surgery.

Predictive Ability of Direct Electrical Stimulation on Facial Nerve Function Following Vestibular Schwannoma Surgery: A Systematic Review and Meta-analysis.

Facial nerve preservation is critical in vestibular schwannoma (VS) surgery. Direct electrical stimulation (DES) is a widely used method for intraoperative localization of the facial nerve and assessment of nerve integrity. We sought to assess the predictive ability of DES parameters on facial nerve function post-VS surgery. A systematic literature search of English-language studies published from 1946 to 2019 was undertaken using EMBASE, MedLine/PubMed, and the Cochrane Central Register of Controlled Trials. Included studies involved patients undergoing VS surgery and assessed predictive ability of any DES parameter on postoperative facial function. Two authors independently reviewed studies and extracted data. Meta-analysis of diagnostic accuracy of DES parameters was used to calculate pooled sensitivities and specificities of common cutoffs. For DES parameters reported by less than four studies, outcomes were reported descriptively. A MST cutoff of 0.10 mA had sensitivity of 0.76 (95% CI 0.53-0.90) and specificity 0.68 (95% CI 0.42-0.87) for facial function in the long term, and MST 0.05 mA had sensitivity 0.73 (95% CI 0.58-0.84) and specificity 0.74 (95% CI 0.59-0.85). CMAP amplitude < 500 μV had sensitivity of 0.87 (95% CI 0.78-0.93) for poor short-term facial function. A CMAP amplitude response < 500 μV is sensitive for poor short-term facial function, whereas MST values of 0.05 mA and 0.10 mA are both sensitive and specific in the long term. Other DES parameters may be able to accurately predict both short- and long-term postoperative facial function, but have been less studied.

Parotid Gland Metastasis From Breast Cancer: A Case Report

Introduction: Breast cancer metastasis at the parotid gland is uncommon. There were only 21 cases reported until the recent year, and none of them came from Indonesia. The reports showed that breast cancer metastasis is more often found at the liver, lung, bone, and brain. Therefore, any masses found on the parotid are usually considered as a double primer.Case Presentation: We report a case of a woman, firstly diagnosed with luminal A stage IIA breast cancer at 39 years old. The patient had undergone breast-conserving therapy (BCT), followed by adjuvant hormonal therapy before being diagnosed with bone metastasis four years later. She also complained about a painful mass on her left upper neck. Ultrasonography and CT-scan resulted in insignificant abnormality. After a year with increasing painful mass, we performed FNAB. The result showed metastatic adenocarcinoma with a suspicious breast cancer origin. We did total parotidectomy with facial nerve preservation to alleviate the pain. Pathology results showed a confirmed diagnosis of breast cancer metastasis. The patient was given radiotherapy as local control and was scheduled to receive chemotherapy as systemic therapy.Conclusions: Parotid mass with a clinical symptom in the patient with the history of breast cancer should be evaluated firstly by imaging and may be followed by cytology or pathology evaluation to confirm whether it is primary or secondary malignancy. If the parotid metastasis from breast cancer is confirmed, we should consider adding systemic therapy after completing the local control.

First branchial cleft fistula: a case report

&lt;p class="abstract"&gt;First branchial cleft anomalies (BCA) are a rare finding in head and neck with incidence nearly- incidence of nearly 1 million per year which are distributed below external auditory canal, above the hyoid bone, anterior to sternocleidomastoid and posterior to submandibular triangle. First branchial cleft cysts are frequently misdiagnosed as they are rare and pose unfamiliar clinical signs and symptoms. Here we are reporting a case of surgical management of 1st branchial cleft fistula in a 5 years old male child from AIIMS, Raipur, Chhattisgarh, India as it’s a rare entity. Child presented with discharge from right upper part of neck. There was a swelling in right upper lateral part of neck with an opening also in floor of right external auditory canal (EAC). Contrast enhanced computed tomography of neck showed a 4.8 cm long obliquely oriented fistulous tract opening at junction of middle and upper one third of sternocleidomastoid with opening in right EAC. Surgical excision of the fistulous tract was done with preservation of facial nerve. Histopathology examination confirmed the presence of fistula. Common clinical presentation of BCAs is pre-auricular swelling (24%), parotid swelling (36%) or cervical region swelling (41%). In our case, it was a fistulous opening that presented as discharging tract in upper neck. Management include early diagnosis, control of infection and complete excision with facial nerve preservation Surgical approach should be based on the clinical examination, imaging and clinical course; and there is a need to safely identify and preserve facial nerve in almost all cases.&lt;/p&gt;

FASCIAL NERVE PRESERVATION IN CEREBELLOPONTINE ANGLE TUMORS SURGERIES

Background: Impairment of the facial nerve functions, after cerebellopontine angle surgery is a common complication that limits the quality of life. Appropriate preoperative planning with a visualization of the facial nerve is a vital tool for the proper management of this disease. Objective: To discuss retrospectively and introspectively, the different modalities helping in preservation the facial nerve during cerebellopontine angle surgeries, and to evaluate the outcome of the usage of these modalities. Patients and Methods: A total of 30 cases with cerebellopontine angle lesions, who had surgical excision of these lesions, performed by different surgical procedure, with preservation of facial nerve function. They were operated upon in Neurosurgery Department at Al-Azhar University Hospitals and Nasser Institute Hospital, during the period between November 2017 and November 2019. Results: One patient had a CSF leak that was temporarily, one patient had postoperative hydrocephalus that was treated with external ventricular drain, and one patient had small sized intracranial hemorrhage resolved spontaneously and did not need any intervention. The remaining 27 patients have improvement of symptoms and signs at follow up periods of 3, 6, 12 months. Conclusion: Preservation of the facial nerve, during cerebellopontine angle surgeries, can be done altogether with total removal of the tumor in one session, by usage of microscopic surgical procedures altogether with intraoperative neurophysiological monitoring. Facial nerve preservation is a safe procedure.

Benign Intracranial Lesions - Radiotherapy: An Overview of Treatment Options, Indications and Therapeutic Results.

Radiation Therapy (RT) is an established treatment option for benign intracranial lesions. The aim of this study is to display an update on the role of RT concerning the most frequent benign brain lesions and tumors. Published articles about RT and meningiomas, Vestibular Schwannomas (VSs), Pituitary Adenomas (PAs), Arteriovenous Malformations (AVMs) and craniopharyngiomas were reviewed and extracted data were used. In meningiomas RT is applied as an adjuvant therapy, in case of patientrefusing surgery or in unresectable tumors. The available techniques are External Beam RT (EBRT) and stereotactic ones such as Stereotactic Radiosurgery (SRS), Fractionated Stereotactic RT (FSRT), Intensity Modulated RT (IMRT) and proton-beam therapy. The same indications are considered in PAs, in which SRS and FSRT achieve excellent tumor control rate (92-100%), acceptable hormone remission rates (>50%) and decreased Adverse Radiation Effects (AREs). Upon tumor growth or neurological deterioration, RT emerges as alone or adjuvant treatment against VSs, with SRS, FSRT, EBRT or protonbeam therapy presenting excellent tumor control growth (>90%), facial nerve (84-100%), trigeminal nerve (74-99%) and hearing (>50%) preservation. SRS poses an effective treatment modality of certain AVMs, demonstrating a 3-year obliteration rate of 80%. Lastly, a combination of microsurgery and RT presents equal local control and 5-year survival rate (>90%) but improved toxicity profile compared to total resection in case of craniopharyngiomas. RT comprises an effective treatment modality of benign brain and intracranial lesions. By minimizing its AREs with optimal use, RT projects as a potent tool against such diseases.

Middle Fossa Approach for Facial Nerve Schwannoma Aiming for Functional Improvement: 2-Dimensional Operative Video.

The treatment paradigm of skull base surgery has been changed from radical tumor resection to maximal tumor removal while giving priority to functional preservation. Facial nerve schwannoma is one of the representative disorders of this type of paradigm shift.1 This video demonstrates facial nerve schwannoma surgery through the middle fossa approach, aiming for improvement of facial function. A 33-yr-old woman presented with gradually worsening facial palsy (House-Brackmann grade IV), dizziness, and nausea. Neuroimaging revealed a growing tumor involving the geniculate ganglion, and extending to the middle fossa, internal acoustic meatus, and cerebellopontine angle. The nerve-sparing surgery through the left middle fossa approach was performed under detailed neuromonitoring including the evoked facial electromyograms and auditory brainstem response. The facial nerve fibers were involved within the tumor mass and the plane between the tumor and facial nerve could not be identified as seen in most cases of such large facial nerve schwannomas. But sufficient tumor removal with facial nerve preservation was achieved owing to continuous facial monitoring.2 The patient had no new neurological deficits. Her facial palsy has been gradually improving, now at grade III, without any signs of tumor regrowth during the 10 mo of follow up after the operation. Careful follow up is being continued to survey the possible tumor recurrence. The video was reproduced after informed consent of the patient.

The role of facial nerve motor evoked potentials in predicting facial nerve function in vestibular schwannoma surgery

Objective: To analyze the role of facial nerve motor evoked potentials in predicting facial nerve function in vestibular schwannoma surgery. Methods: In a retrospective clinical study of 226 patients with acoustic neuroma, admitted to our hospital from January 2016 to May 2019, were investigated by facial nerve motor evoked potentials (FNMEP) elicited by multi-pulse transcranial electrical motor cortex stimulation from. For recording the same electrode set-up was used as for continuous EMG monitoring of the orbicularis oculi,oris muscles and mentalis. Pre-surgical (opening dural), intraoperative and post-surgical (closing dural) FNMEP amplitudes and latencies were recorded. End (closing dura) to start (opening dura) amplitude ratios were compared to early-term(3 day after surgery) facial nerve function by House-Brackmann(HB) Grading. Results: 201 patients(88.9%) get a total tumor resection, 15 patients (6.6%) were a subtotal resection, 10 patients(4.4%) were a partial resection. 100 percent of patients had a integrated anatomical preservation of facial nerves, there were four (1.8%) death cases in this group. Reliable FNMEPs were obtained in all patients. The ratio of end-operative to start-operative FNMEP-amplitude showed a negative correlation with early facial nerve function. Correlation was especially close with early function: an amplitude preservation rate of 85.3% led to HB Ⅰ or Ⅱ in 190(84.1%) patients, of 45.6% to HB Ⅲ in 17(7.5%) patients, of 23.1% to HB Ⅳ in 13(5.8%) patients and of 6.7% to HB Ⅴor Ⅵ in 6(2.7%) patients. There was a negative correlation between FNMEP amplitude ratio and post-surgical early HB grading(r=-0.895, P=0.000). Conclusion: FNMEP was highly reliable in predicting early postoperative facial function of the resection of vestibular schwannoma, was a valid protection technique of facial nerve.

Postoperative Functional Preservation of Facial Nerve in Cystic Vestibular Schwannoma

To retrospectively analyze clinical and surgical data of a consecutive series of 26 patients with unilateral cystic vestibular schwannomas. Tumors were classified as type A (central cyst) and type B (peripheral cyst) and as small (tumor diameter <3 cm) and large (tumor diameter >3 cm). All patients underwent microsurgical removal via retrosigmoid approach. The course of the facial nerve (FN) was classified as anterior, anterior-inferior, anterior-superior, and dorsal to the tumor's surface. Mean patient age was 53.5 years. Mean tumor size was 3.2 cm. There were 22 cases classified as type A and only 4 as type B. Total or near-total resection (>95%) was achieved in 16 cases (61.5%), subtotal removal (90%-95%) was achieved in 9 cases (34.6%), and partial removal (<90%) was achieved in 1 case (3.9%). Position pattern of FN was anterior-inferior in 10 cases (38.4%), anterior-superior in 10 cases (38.4%), anterior in 23.2% of 6 cases. At hospital discharge, FN function was House-Brackmann grade I-V in 9 (36%), 10 (38%), 3 (12%), 3 (12%), and 1 (4%) patients; at final follow-up, House-Brackmann grades I, II, III, and IV accounted for 18 (72%), 6 (24%), 1, and 1 cases. During follow-up ranging from 6 months to 10 years, reoperation for growing of residue was never necessary. According to the literature and the results of our series, microneurosurgery of cystic vestibular schwannomas is associated with good outcomes in terms of extent of resection and FN function. In particular, long-term FN function is much more satisfactory than short-term function. In most cases, microsurgery represents the treatment of choice of cystic vestibular schwannomas.

TcMEP threshold change is superior to A-train detection when predicting facial nerve outcome in CPA tumour surgery

ObjectSurgery of tumours in the cerebellopontine angle (CPA) can lead to loss of facial nerve function. Different methods of intra-operative nerve monitoring (IOM) (including free-running EMG, direct nerve stimulation and transcranial motor evoked potentials (TcMEP)) have been used to predict facial nerve outcome during surgery. Recent research has shown TcMEP threshold increase and the occurrence of A-trains on the EMG to have great potential in doing so. This study compares these two methods and correlates them to House-Brackmann (HB) scores post-op in patients with tumours in the cerebellopontine angle.MethodForty-three patients (one was operated twice) with large CPA tumours treated surgically in the Radboud University Medical Center between 2015 and 2019 were included in this study. During surgery, TcMEP threshold increases and A-train activity were measured. Because our treatment paradigm aims at facial nerve preservation (accepting residual tumour), TcMEP threshold increase of over 20 mA or occurrence of A-trains were considered as warning signs and used as a guide for terminating surgery. HB scores were measured post-op, at 6 weeks, 6 months and 1 year after surgery. Spearman’s correlation was calculated between the IOM-values and the HB scores for a homogeneous subgroup of 30 patients with vestibular schwannoma (VS) without neurofibromatosis type II (NF-II) and all patients collectively.ResultsTcMEP threshold was successfully measured in 39 (90.7%) procedures. In the homogeneous VS non-NFII group, we found a statistically significant moderate-to-strong correlation between TcMEP threshold increase and House Brackmann score immediately post-op, at 6 weeks, 6 months and 1 year after surgery (Spearman’s rho of 0.79 (p < 0.001), 0.74 (p < 0.001), 0.64 (p < 0.001) and 0.58 (p = 0.002), respectively). For A-trains, no correlation was found. Similar results were found when including all patients with CPA tumours. A threshold increase of < 20 mA was a predictor of good facial nerve outcome.ConclusionThese results show that TcMEP threshold increases are strongly correlated to post-operative HB scores, while A-trains are not. This suggests TcMEP threshold increases can be a valuable predictor for facial nerve outcome in patients with large tumours when facial nerve preservation is prioritized over total resection. In this study, we found no use for A-trains to prevent facial nerve deficits.

Facial Nerve Preservation During Temporal Exposure- Search for an Optimal Strategy.

Facial Nerve Preservation During Temporal Exposure- Search for an Optimal Strategy.

Facial Nerve Preservation for Supraorbital Approaches: Anatomical Mapping Based on Consistent Landmarks.

The supraorbital keyhole approach (SOKA) provides a safe and advantageous access to the anterior cranial fossa. The implemented skin incision varies depending on surgeon's preferences and requirements. Facial nerve (FN) injury might appear in up to 5.6% of patients. There is a lack of validated tenets for avoiding FN injury. To define a safety area for FN preservation during a SOKA. Ten dried skulls and 5 injected cadaveric heads (10 sides) were used. A Cartesian frame was created with its horizontal axis at the level of the supraorbital notch and the vertical axis just lateral to the frontozygomatic junction (FZj). FNs were dissected and points along their course were registered and transferred to the Cartesian frame. Ten microscopic dissections of the FN were performed preserving all branches. A safety area could be defined 8 mm superior and 10 mm inferior to the FZj extending medially to the supraorbital notch and beyond. A 20 mm2 area superior and lateral to the FZj provided low probability (≤10%) of injuring the FN. Similarly, starting 4 mm inferior to the FZj, a lateral safety area was also found. A probabilistic colored heat map was built to represent the results. We provide a "safety zone" for a SOKA incision in which the probability to encounter the FN is low. Clinical studies following our method may validate our findings and add evidence to the tenets for minimizing morbidity related to the SOKA incision.