Endoluminal Sigmoid Sinus Occlusion During Jugular Foramen Tumor Surgery: Novel Technique, Operative Nuances, and Clinical Experience With 33 Patients.

BACKGROUND AND IMPORTANCE: Surgery of jugular foramen tumors (JFTs) often requires vascular control by means of ligating the internal jugular vein and sigmoid sinus (SS) to allow intrabulbar access. Occlusion of the SS traditionally involves presigmoid and retrosigmoid durotomies allowing introduction of ligature devices, predisposing to cerebrospinal fluid (CSF) leakage and pseudomeningoceles. We describe a simple and novel endoluminal sigmoid sinus occlusion (ESSO) technique with Gelfoam that is entirely extradural. CLINICAL PRESENTATION: An extended anterolateral infralabyrinthine approach with ESSO was performed in 33 patients with JFTs. After ligating the internal jugular vein, the SS is opened and Gelfoam is placed endoluminally into the proximal SS. Care is taken to avoid occlusion of the venous outflow of the vein of Labbe to avoid temporal lobe venous infarction. Hemostatic gelatin matrix is injected distally to stop venous backflow from the inferior petrosal sinus. The jugular venous system is isolated, and the outer jugular wall can be opened to expose the JFT for resection. There were no complications of temporal lobe venous infarction or postoperative hematoma observed. Four patients with intradural tumor extension developed pseudomeningoceles. For patients with purely extradural JFTs, none developed postoperative incisional CSF leaks and one had pseudomeningocele. CONCLUSION: This ESSO technique is fast and effective, permitting occlusion of the SS during JFT surgery. It has the advantage of being entirely extradural, avoiding durotomy which can result in postoperative CSF leak. It is important to keep the Gelfoam distal to the transverse-sigmoid junction to avoid occlusion of the vein of Labbe inlet and temporal lobe venous infarction.

Use of artificial intelligence for the diagnosis of cholesteatoma.

Objectives: Accurate diagnosis of cholesteatomas is crucial. However, cholesteatomas can easily be missed in routine otoscopic exams. Convolutional neural networks (CNNs) have performed well in medical image classification, so we evaluated their use for detecting cholesteatomas in otoscopic images. Study Design: Design and evaluation of artificial intelligence driven workflow for cholesteatoma diagnosis. Methods: Otoscopic images collected from the faculty practice of the senior author were deidentified and labeled by the senior author as cholesteatoma, abnormal non-cholesteatoma, or normal. An image classification workflow was developed to automatically differentiate cholesteatomas from other possible tympanic membrane appearances. Eight pretrained CNNs were trained on our otoscopic images, then tested on a withheld subset of images to evaluate their final performance. CNN intermediate activations were also extracted to visualize important image features. Results: A total of 834 otoscopic images were collected, further categorized into 197 cholesteatoma, 457 abnormal non-cholesteatoma, and 180 normal. Final trained CNNs demonstrated strong performance, achieving accuracies of 83.8%-98.5% for differentiating cholesteatoma from normal, 75.6%-90.1% for differentiating cholesteatoma from abnormal non-cholesteatoma, and 87.0%-90.4% for differentiating cholesteatoma from non-cholesteatoma (abnormal non-cholesteatoma + normal). DenseNet201 (100% sensitivity, 97.1% specificity), NASNetLarge (100% sensitivity, 88.2% specificity), and MobileNetV2 (94.1% sensitivity, 100% specificity) were among the best performing CNNs in distinguishing cholesteatoma versus normal. Visualization of intermediate activations showed robust detection of relevant image features by the CNNs. Conclusion: While further refinement and more training images are needed to improve performance, artificial intelligence-driven analysis of otoscopic images shows great promise as a diagnostic tool for detecting cholesteatomas. Level of Evidence: 3.

Tuberculosis of the middle ear: A systematic review.

OBJECTIVE: Tuberculous otitis media (TOM) is a rare extrapulmonary manifestation of tuberculosis (TB) and remains challenging to diagnose due to non-specific symptoms. This systematic review identifies clinical characteristics, diagnostic evaluation, and outcomes in cases of TOM. METHODS: A comprehensive literature search utilizing the PubMed, CINAHL, Scopus, and Cochrane Library databases was conducted for relevant articles published between 2000 and 2021. Cases involving adult patients with TOM were included. Non-English studies, animal studies, and reviews were excluded. RESULTS: 41 case reports and 7 case series were included, comprising data from 67 patients. The mean age was 40 years (range, 19-87 years) and the majority were female (n = 46, 68.7 %). The mean symptom duration was 12.8 months (range, 0.25-120 months). Common symptoms included otorrhea (n = 60, 89.6 %), HL (n = 58, 86.6 %), otalgia (n = 19, 28.4 %), and FP (n = 18, 26.9 %). Otoscopy revealed tympanic membrane (TM) perforation in 45 patients (67.2 %). Most patients were diagnosed with tissue biopsy (n = 53, 79.1 %). Surgical interventions were performed in 48 patients (71.6 %) and 63 patients (94.0 %) were prescribed anti-TB chemotherapy. Long-term sequelae (e.g., HL, FP, and TM perforation) were noted in 39 patients (58.2 %) at a mean follow-up of 18.8 months (range, 1-120 months). CONCLUSION: TOM should be included in the differential diagnosis of chronic suppurative otitis media. Histopathological examination is a reliable diagnostic method. Early detection and management are recommended for optimizing outcomes. LEVEL OF EVIDENCE: 3b.

Association of Patient Frailty With Vestibular Schwannoma Resection Outcomes and Machine Learning Development of a Vestibular Schwannoma Risk Stratification Score.

BACKGROUND: Patient frailty is predictive of higher neurosurgical morbidity and mortality. However, existing frailty measures are hindered by lack of specificity to neurosurgery. OBJECTIVE: To analyze the association between 3 risk stratification scores and outcomes for nationwide vestibular schwannoma (VS) resection admissions and develop a custom VS risk stratification score. METHODS: We identified all VS resection admissions in the National Inpatient Sample (2002-2017). Three risk stratification scores were analyzed: modified Frailty Index-5, modified Frailty Index-11(mFI-11), and Charlson Comorbidity Index (CCI). Survey-weighted multivariate regression evaluated associations between frailty and inpatient outcomes, adjusting for patient demographics, hospital characteristics, and disease severity. Subsequently, we used k -fold cross validation and Akaike Information Criterion-based model selection to create a custom risk stratification score. RESULTS: We analyzed 32 465 VS resection admissions. High frailty, as identified by the mFI-11 (odds ratio [OR] = 1.27, P = .021) and CCI (OR = 1.72, P < .001), predicted higher odds of perioperative complications. All 3 scores were also associated with lower routine discharge rates and elevated length of stay (LOS) and costs (all P < .05). Our custom VS-5 score ( https://skullbaseresearch.shinyapps.io/vs-5_calculator/ ) featured 5 variables (age ≥60 years, hydrocephalus, preoperative cranial nerve palsies, diabetes mellitus, and hypertension) and was predictive of higher mortality (OR = 6.40, P = .001), decreased routine hospital discharge (OR = 0.28, P < .001), and elevated complications (OR = 1.59, P < .001), LOS (+48%, P < .001), and costs (+23%, P = .001). The VS-5 outperformed the modified Frailty Index-5, mFI-11, and CCI in predicting routine discharge (all P < .001), including in a pseudoprospective cohort (2018-2019) of 3885 admissions. CONCLUSION: Patient frailty predicted poorer inpatient outcomes after VS surgery. Our custom VS-5 score outperformed earlier risk stratification scores.

Extended Anterolateral Infralabyrinthine Transjugular Approach for Microsurgical Resection of Giant Glomus Vagale Tumor: Operative Video and Technical Nuances.

Glomus vagale tumor is a paraganglioma of the vagus nerve. It is a rare type of benign tumor that occupies the head and neck and skull base regions. Patients often present with lower cranial nerve dysfunctions such as difficulty swallowing, tongue weakness, and hoarseness. Surgical treatment can be complex and difficult due to its high vascularity, frequent involvement of lower cranial nerves, and surrounding critical vascular structures. In this operative video, we demonstrate an extended anterolateral infralabyrinthine transjugular approach for microsurgical resection of a giant glomus vagale tumor in a 53-year-old male who presented with an enlarging neck mass, difficulty swallowing, right tongue weakness, and hoarseness. Imaging revealed a giant glomus vagale tumor in the right parapharyngeal space extending into the jugular foramen with occlusion of the internal jugular vein. After preoperative embolization, the patient underwent a near-total resection of the tumor with a small microscopic residual at the pars nervosa. In summary, the extended anterolateral infralabyrinthine transjugular approach is a useful strategy for removal of giant glomus vagale tumors extending into the skull base. The surgical technique and nuances are described in a step-by-step fashion in this illustrative operative video. The link to the video can be found at: https://youtu.be/L0EosQK95LE .

Association of CARD8 Activating Polymorphism With Bone Erosion in Cholesteatoma Patients.

OBJECTIVES: We compared the incidence of polymorphisms activating the NLRP3 inflammasome between controls and patients with cholesteatoma and its potential association with bone erosion in patients with cholesteatoma. METHODS: This is a case-control study assessing the mutation rates in genes of interest in patients with and without cholesteatoma. A total of 133 saliva samples from control (n = 65) and cholesteatoma (n = 68) patients were collected for DNA extraction. Caspase recruitment domain family member 8 (CARD8) (AA: homozygous wild type, AT: heterozygous, TT: homozygous mutant polymorphism) and NLRP3 (CC: homozygous wild type, CA: heterozygous, AA: homozygous mutant) polymorphisms were analyzed with TaqMan single-nucleotide polymorphism (SNP) quantitative polymerase chain reaction (ThermoFisher Scientific, Waltham, MA). Mutation status was correlated with a novel bone erosion scoring model developed as a part of this study. Summary statistics, including frequencies (%) and median (Q1, Q3) were used to describe the sample. RESULTS: The presence of CARD8 and NLRP3 homozygous wild-type polymorphisms were generally similar for the control and cholesteatoma patient groups. CARD8 homozygous TT polymorphisms were an exception, occurring more frequently in patients who developed a cholesteatoma compared to the control group (29% vs. 10%, P = .009). Those patients with CARD8 homozygous TT polymorphism had higher median scores of bone erosion as compared to subjects with nonhomozygous mutant genotypes (median [interquartile range]: 4.0 [3.0, 5.5] vs. 2.5 [1.0, 3.5], P = .0142). CONCLUSION: Cholesteatoma patients have a significant, twofold higher incidence of CARD8 homozygous TT polymorphism. Furthermore, cholesteatoma patients with this homozygous polymorphism had greater bone erosion rates than controls. These findings suggest that genetic mutations may increase host susceptibility to cholesteatomas. Specifically, the CARD8 TT polymorphism may influence the severity of cholesteatoma-induced bone erosion. LEVEL OF EVIDENCE: 3B.

Retrosigmoid approach for giant cystic vestibular schwannoma: subperineural dissection technique for facial nerve preservation.

In this illustrative video, the authors demonstrate retrosigmoid resection of a giant cystic vestibular schwannoma using the subperineural dissection technique to preserve facial nerve function. This thin layer of perineurium arising from the vestibular nerves is used as a protective buffer to shield the facial and cochlear nerves from direct microdissection trauma. A near-total resection was achieved, and the patient had an immediate postoperative House-Brackmann grade I facial nerve function. The operative nuances and pearls of technique for safe cranial nerve and brainstem dissection, as well as the intraoperative decision and technique to leave the least amount of residual adherent tumor, are demonstrated. The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID21128.

Rapid Recovery of Cranial Nerve Deficits After Anterior Petrosal (Kawase) Approach for Medically Refractory Petrous Apicitis.

BACKGROUND: The mainstay treatment for petrous apicitis (Gradenigo's syndrome) is medical management with antibiotics, steroids, and placement of pressure equalization tubes. The role for surgery is limited as second-line treatment if conservative methods have failed. CASE DESCRIPTION: We report 2 cases of medically refractory petrous apicitis presenting with progressive cranial neuropathies who underwent petrous apex resection and debridement via an anterior petrosal (Kawase) approach. Both patients had improvement of their preoperative cranial nerve deficits within 24-48 hours of surgery, that previously did not improve after 2 weeks of medical management. CONCLUSIONS: To our knowledge, the use of the Kawase approach for petrous apicitis has not been previously reported. In addition, we postulate that surgical intervention can potentially result in quicker recovery of preexisting cranial nerve deficits in medically refractory petrous apicitis. This raises the potential role of earlier surgical intervention.

Translabyrinthine Approach for Resection of Large Cystic Acoustic Neuroma: Operative Video and Technical Nuances of Subperineural Dissection for Facial Nerve Preservation.

The translabyrinthine approach is advantageous for the resection of large acoustic neuromas compressing the brainstem when hearing loss is nonserviceable. This approach provides wide access through the presigmoid corridor without prolonged cerebellar retraction. Early identification of the facial nerve at the fundus is also achieved. In this operative video atlas manuscript, the authors demonstrate a step-by-step technique for microsurgical resection of a large cystic acoustic neuroma via a translabyrinthine approach. The nuances of microsurgical and skull base technique are illustrated including performing extracapsular dissection of the tumor while maintaining a subperineural plane of dissection to preserve the facial nerve. This strategy maximizes the extent of removal while preserving facial nerve function. A microscopic remnant of tumor was left adherent to the perineurium. A near-total resection of the tumor was achieved and the facial nerve stimulated briskly at low thresholds. Other than preexisting hearing loss, the patient was neurologically intact with normal facial nerve function postoperatively. In summary, the translabyrinthine approach and the use of subperineural dissection are important strategies in the armamentarium for surgical management of large acoustic neuromas while preserving facial nerve function. The link to the video can be found at: https://youtu.be/zld2cSP8fb8 .

Retrosigmoid Transmeatal Approach for Resection of Acoustic Neuroma: Operative Video and Technical Nuances of Subperineural Dissection for Facial Nerve Preservation.

The retrosigmoid (suboccipital) approach is the workhorse for most acoustic neuromas in the cerebellopontine angle. In this operative video atlas manuscript, the authors demonstrate the nuances of the subperineural dissection technique for microsurgical resection of an acoustic neuroma via the retrosigmoid transmeatal approach. The plane is developed by separating the perineurium of the vestibular nerve away from the tumor capsule. This perineurium provides a protective layer between the tumor capsule and the facial nerve which serves as a buffer to avoid direct dissection and potential trauma to the facial nerve. Using this technique during extracapsular tumor dissection helps to maximize the extent of tumor removal while preserving facial nerve function. A gross total resection of the tumor was achieved, and the patient exhibited normal facial nerve function ( Fig. 1 ). In summary, the retrosigmoid transmeatal approach with the use of subperineural dissection are important strategies in the armamentarium for surgical management of acoustic neuromas with the goal of maximizing tumor removal and preserving facial nerve function ( Fig. 2 ). The link to the video can be found at: https://youtu.be/L3lPtSvJt60 .

The Role of Fast Imaging Employing Steady-State Acquisition (FIESTA) Magnetic Resonance Imaging for Assessment of Delayed Enhancement of Fat Graft Packing on Postoperative Imaging After Vestibular Schwannoma Surgery.

OBJECTIVE: To investigate the role and efficacy of fast imaging employing steady-state acquisition (FIESTA) imaging in distinguishing fat graft enhancement from residual or recurrent tumor after vestibular schwannoma (VS) surgery. METHODS: A retrospective study of 33 patients who underwent VS resection via the retrosigmoid or translabyrinthine approach with fat graft reconstruction was performed. Magnetic resonance imaging (MRI) was collected at different time points: preoperative, immediate postoperative (24-48 hours), delayed postoperative (3-6 months after surgery), and yearly postoperative. The image sets contained T1, T2, fat-suppressed T1-weighted with gadolinium, and FIESTA. The radiographs were analyzed for tumor recurrence by the primary neurosurgeon and an independent blinded neuroradiologist. If fat-suppressed T1-weighted images demonstrated postoperative enhancement in the resection bed, a comparison was made with FIESTA imaging. RESULTS: At 3-6 months postoperatively and at 1 year and beyond, 28 (84.8%) and 33 (100%) of patients, respectively, displayed delayed enhancement of the fat graft on postgadolinium fat-suppressed T1-weighted MRI. The enhancement seen on postgadolinium, fat-suppressed, T1-weighted MRI consistently correlated with the characteristic fat graft signal on FIESTA imaging and not tumor recurrence. FIESTA imaging was able to distinguish residual tumor from enhancing fat graft compared with postgadolinium, fat-suppressed, T1-weighted MRI (P < 0.0001) due to distinctive signaling patterns. CONCLUSIONS: FIESTA is an effective tool in discerning fat graft enhancement from residual or recurrent tumor on delayed postoperative imaging after VS resection. Fat graft used in reconstruction consistently enhances on delayed postoperative postgadolinium, fat-suppressed, T1-weighted imaging, which correlates with the fat graft signal seen on FIESTA images.

Fat graft-assisted internal auditory canal closure after retrosigmoid transmeatal resection of acoustic neuroma: Technique for prevention of cerebrospinal fluid leakage.

The retrosigmoid transmeatal approach remains an important strategy in the surgical management of acoustic neuromas. Gross total resection of acoustic neuromas requires removal of tumor within the cerebellopontine angle as well as tumor involving the internal auditory canal (IAC). Drilling into the petrous bone of the IAC can expose petrous air cells, which can potentially result in a fistulous tract to the nasopharynx manifesting as cerebrospinal fluid (CSF) rhinorrhea. We describe our method of IAC closure using autologous fat graft and assessed the rates of postoperative CSF leakage. We performed a retrospective study of 24 consecutive patients who underwent retrosigmoid transmeatal resection of acoustic neuroma who underwent our method of fat graft-assisted IAC closure. We assessed rates of postoperative CSF leak (incisional leak, rhinorrhea, or otorrhea), pseudomeningocele formation, and occurrence of meningitis. Twenty-four patients (10 males, 14 females) with a mean age of 47 years (range 18-84) underwent fat graft-assisted IAC closure. No lumbar drains were used postoperatively. There were no instances of postoperative CSF leak (incisional leak, rhinorrhea, or otorrhea), pseudomeningocele formation, or occurrence of meningitis. There were no graft site complications. Our results demonstrate that autologous fat grafts provide a safe and effective method of IAC defect closure to prevent postoperative CSF leakage after acoustic tumor removal via a retrosigmoid transmeatal approach. The surgical technique and operative nuances are described.

Gruber, Gradenigo, Dorello, and Vail: key personalities in the historical evolution and modern-day understanding of Dorello's canal.

A century ago an ambitious young anatomist in Rome, Primo Dorello, who sought to understand the cause of abducent nerve palsy that often occurred in patients with severe middle ear infections, conducted intricate studies on the intracranial course of the nerve. In his findings, he identified that the abducent nerve passes through a narrow sinus near the apex of the petrous bone, which formed an osteofibrous canal. Dorello suggested that in this enclosed region the abducent nerve may be particularly vulnerable to compression due to the vascular edema accompanying the infection. Although his work was widely appreciated, it was not well received by all. Interestingly, Giuseppe Gradenigo, one of the most prominent Italian otologists of the early 20th century, who was known for his work on a triad of symptoms (Gradenigo's syndrome) that accompanies petrous apicitis, a result of severe middle ear infections, was obstinate in his criticism of Dorello's findings. Thus a scientific duel began, with a series of correspondence between these two academics-one who was relatively new to the otological community (Dorello) and one who was well reputed in that community (Gradenigo). The disagreement ultimately ebbed in 1909, when Dorello published a report in response to Gradenigo's criticisms and convinced Gradenigo to change his views. Today Dorello's canal is widely recognized as a key landmark in skull base surgery of the petroclival region and holds clinical significance due to its relation to the abducent nerve and surrounding vascular structures. Yet, although academics such as Dorello and Gradenigo are recognized for their work on the canal, it is important not to forget the others throughout history who have contributed to the modern-day understanding of this anatomical structure. In fact, although the level of anatomical detail found in Dorello's work was previously unmatched, the first description of the canal was made by the experienced Austrian anatomist Wenzel Leopold Gruber in 1859, almost 50 years prior to Dorello's landmark publication. Another critical figure in building the understanding of Dorello's canal was Harris Holmes Vail, a young otolaryngologist from Harvard Medical School, who in 1922 became the first person to describe Dorello's canal in the English language. Vail conducted his own detailed anatomical studies on cadavers, and his publication not only reaffirmed Dorello's findings but also immortalized the eponym used today-"Dorello's canal." In this article the authors review the life and contributions of Gruber, Dorello, Gradenigo, and Vail, four men who played a critical role in the discovery of Dorello's canal and paved the way toward the current understanding of the canal as a key clinical and surgical entity.