Predictors of hearing functional outcome following surgery for cerebellopontine angle meningioma.

OBJECTIVE: Cerebellopontine angle (CPA) meningiomas can affect hearing function and require expeditious treatment to prevent permanent hearing loss. The authors sought to determine the factors associated with functional hearing outcome in CPA meningioma patients treated with surgery and/or radiation therapy in the form of either stereotactic radiosurgery or stereotactic radiation therapy. METHODS: Consecutive patients with CPA meningiomas who had presented at our hospital from 2008 to 2018 were identified through retrospective chart review. Hearing function (as defined by pure tone average (PTA) and speech discrimination score (SDS) on Audiogram) was assessed before and after surgery for CPA meningioma. Audiograms with PTA > 50 dB and SDS < 69% were defined as poor hearing functional outcome. Multivariable Cox Proportional Hazards Regression Model was used to assess the associations between pre-operative hearing functional assessment and post-operative hearing functional outcomes. RESULTS: The study cohort included 31 patients (80.6% females, with a mean age of 61.3 ± 15.2 years) with a median clinical follow-up of 5 months (range: 1 week-98 months). The mean pre-operative PTA and SDS were 23.8 ± 11.2 dB and 64.4 ± 22.2% respectively. At the last visit, there was significant hearing recovery, with an improvement of 29.7 ± 18.0 dB (p < 0.001) and 87.6 ± 17.8% (p < 0.001) in PTA and SDS respectively. After adjusting for age, gender, tumor volume, location, and tumor classification, Multivariable Cox Proportional Hazards Regression Model was conducted which revealed that patients undergoing surgery through retro sigmoid approach [Hazards Ratio (HR): 32.1, 95% Confidence Interval (CI): 2.11-491.0, p = 0.01] and gross total resection (GTR) (HR: 2.99, 95% CI: 1.09-9.32, p = 0.05) had significantly higher risk of poor hearing functional outcome compared to petrosal approach and near/subtotal resection. Moreover, patients with poor preoperative hearing had 85% higher chance of poor hearing functional outcome postoperatively (HR: 0.15, 95%CI: 0.03-0.59, p = 0.007). CONCLUSION: Postoperative improvement in hearing is a reasonable expectation following surgery for CPA meningioma. Preoperative hearing, surgical approach and extent of surgical resection are predictive factors of postoperative hearing function outcome and can therefore aid in identification of patients at higher risk of hearing loss.

Segmental spinal neurofibromatosis 1: a novel phenotype.

INTRODUCTION: Segmental neurofibromatosis (SNF) is a rare subtype of neurofibromatosis (NF). The disease is characterized by features circumscribed to one or more body cutaneous and/or subcutaneous segments. This is a classic example of somatic mosaicism which occurs by postzygotic mut ation of the NF1 gene late in the course of embryonic development affecting localized neural crest lines in the fetus. Spinal neurofibromatosis, on the other hand, is characterized by histologically proven bilateral neurofibromas of the spinal roots. METHODS: Hereby we describe a novel manifestation of spinal SNF. RESULTS: Our case report demonstrated one patient who had segmental spinal expression of the disease classified as true mosaic/segmental NF1 along with its management plan treated at one of the largest NF1 centers to exist. CONCLUSION: This will aid in understanding the rare clinical presentation and treatment options for this novel phenotype.

Options and strategies for hearing restoration in pediatric neurofibromatosis type 2.

PURPOSE: In this article, we will review the mechanisms and natural history of hearing loss in neurofibromatosis type 2 (NF2) and discuss the hearing outcomes with different rehabilitation options. METHODS: Review of the published literature. RESULTS: NF2 is a rare autosomal dominant syndrome characterized by vestibular schwannomas and other intracranial and spinal tumors. Bilateral vestibular schwannomas are the hallmark of the disease which occur in 90 to 95% of the patients. As a result, hearing loss will eventually occur in almost all NF2 patients. Deafness can occur from tumor progression or from treatment of vestibular schwannomas and is among the most debilitating aspects of NF2. A number of surgical and non-surgical rehabilitation options are available for these patients including cochlear and auditory brainstem implants. The audiologic outcomes with surgical rehabilitation options have been variable but most patients are able to achieve sound awareness and benefit from auditory cues in lip reading. CONCLUSION: Early identification and treatment of NF2 patients can help in achieving better hearing outcomes in the pediatric population. An increasing number of NF2 patients are receiving open set word understanding with refinement in surgical techniques.

Use of a flexible hollow-core carbon dioxide laser for microsurgical resection of vestibular schwannomas.

OBJECTIVE The CO2 laser has been used on an intermittent basis in the microsurgical resection of brain tumors for decades. These lasers were typically cumbersome to use due to the need for a large, bulky design since infrared light cannot be transmitted via fiber-optic cables. Development of the OmniGuide cable, which is hollow and lined with an omnidirectional dielectric mirror, has facilitated the reintroduction of the CO2 laser in surgical use in a number of fields. This device allows for handheld use of the CO2 laser in a much more ergonomically favorable configuration, holding promise for microneurosurgical applications. This device was introduced into the authors' practice for use in the microsurgical resection of skull base tumors, including vestibular schwannomas. METHODS The authors reviewed the initial 41 vestibular schwannomas that were treated using the OmniGuide CO2 laser during an 8-month period from March 2010 to October 2010. The laser was used for all large tumors, and select medium-sized tumors were treated via both the translabyrinthine and retrosigmoid approaches. The estimated time of tumor resection and estimated blood loss were obtained from operating room records. Data regarding complications, facial nerve and hearing outcomes, and further treatment were collected from hospital and clinic records, MRI reports, and direct review of MR images. Time of resection and blood loss were compared to a control group (n = 18) who underwent surgery just prior to use of the laser. RESULTS A total of 41 patients with vestibular schwannomas were surgically treated. The median estimated time of tumor resection was 150 minutes, and the median estimated blood loss was 300 ml. The only operative complication was 1 CSF leak. Thirty-eight patients had normal facial nerve function at late follow-up. The median MRI follow-up was 52 months, and, during that time, only 1 patient required further treatment for regrowth of a residual tumor. CONCLUSIONS The OmniGuide CO2 laser is a useful adjunct in the resection of large vestibular schwannomas. This device was used primarily as a cutting tool rather than for tumor vaporization, and it was found to be of most use for very large and/or firm tumors. There were no laser-associated complications, and the results compared favorably to earlier reports of vestibular schwannoma resection.

Endoscope-assisted middle fossa craniotomy for resection of inferior vestibular nerve schwannoma extending lateral to transverse crest.

OBJECTIVE The authors describe their results using an endoscope as an adjunct to microsurgical resection of inferior vestibular schwannomas (VSs) with extension into the fundus of the internal auditory canal below the transverse crest. METHODS All patients who had undergone middle fossa craniotomy for VSs performed by the senior author between September 2014 and August 2016 were prospectively enrolled in accordance with IRB policies, and the charts of patients undergoing surgery for inferior vestibular nerve tumors, as determined either on preoperative imaging or as intraoperative findings, were retrospectively reviewed. Age prior to surgery, side of surgery, tumor size, preoperative and postoperative pure-tone average, and speech discrimination scores were recorded. The presence of early and late facial paralysis, nerve of tumor origin, and extent of resection were also recorded. RESULTS Six patients (all women; age range 40-65 years, mean age 57 years) met these criteria during the study period. Five of the 6 patients underwent gross-total resection; 1 patient underwent a near-total resection because of a small amount of tumor that adhered to the facial nerve. Gross-total resection was facilitated using the operative endoscope in 2 patients (33%) who were found to have additional tumor visible only through the endoscope. All patients had a House-Brackmann facial nerve grade of II or better in the immediate postoperative period. Serviceable hearing (American Academy of Otolaryngology-Head and Neck Surgery class A or B) was preserved in 3 of the 6 patients. CONCLUSIONS Endoscope-assisted middle fossa craniotomy for resection of inferior vestibular nerve schwannomas with extension beyond the transverse crest is safe, and hearing preservation is feasible.

Growth hormone-secreting pituitary macroadenoma presenting concurrently with non-Hodgkin's lymphoma and responding to doxorubicin treatment: case report and review of the literature.

We present a case report of a patient who presented with nausea and vomiting, as well as acromegalic features. Following testing, a pituitary adenoma and mediastinal non-Hodgkin's lymphoma were diagnosed. Following two cycles of R-CHOP chemotherapy, imaging showed significant decrease in size of the sellar tumor. Following resection of tumor, both frozen and permanent section revealed only necrotic material. Further research into the potential utility of doxorubicin for the treatment of recurrent or refractory pituitary adenomas may be warranted.

Translabyrinthine resection of neurofibromatosis type 2 associated vestibular and facial schwannomas, repair of facial nerve, and placement of auditory brainstem implant.

We present video of gross-total resection of a large cerebellopontine angle tumor consisting of both vestibular and facial schwannoma components via the translabyrinthine route in a patient with neurofibromatosis type 2. The facial nerve is reconstructed using a greater auricular nerve graft, and an auditory brainstem implant is placed. Prior to surgery the patient had no facial nerve function on the operative side and had lost useful hearing. He also had usable vision only on the ipsilateral side and had contralateral vocal cord paralysis. The video can be found here: http://youtu.be/IOkEND-0vhI .

Arachnoid Cyst of the Cerebellopontine Angle: A Systematic Literature Review.

OBJECTIVE: The role of surgical management of arachnoid cyst (AC) of the cerebellopontine angle (CPA) is uncertain. This topic has remained controversial with varying contradictory recommendations in the literature, which is limited to mostly case reports. We aimed to provide a comprehensive summary and analysis of symptoms, operative techniques, outcomes, and recurrence of all available surgical cases of AC of the CPA to date. METHODS: A systematic literature search was performed in May 2022 querying several scientific databases. Inclusion criteria specified all studies and case reports of patients with AC located at the CPA for which any relevant surgical procedures were performed. RESULTS: A total of 55 patients from the literature and 5 treated at our institution were included. Mean patient age was 29 years (range, 0.08-79 years), with nearly twice (1.7×) as many female as male patients (37 female, 22 male). Headaches (35%), hearing loss (30%), vertigo (22%), and ataxia (22%) were the most common presentations. Following surgery, 95% experienced symptom improvement, with complete resolution in 64%. Of patients with hearing loss, 44% reported a return to normal. The rate of mortality was 1.69%, and 10% of tumors recurred (mean follow-up 2.3 years [range, 0-15 years]. CONCLUSIONS: Symptomatic AC of the CPA is rare. It exhibits a proclivity for females and commonly manifests with headache, hearing loss, vertigo, and ataxia. While careful selection for surgical candidacy is needed and intervention should be reserved for patients with severe symptoms, surgical decompression is an effective tool for symptom alleviation and recovery.

The endaural subtemporal keyhole: a novel minimally invasive approach to the middle cranial fossa.

OBJECTIVE: The goal of this study was to evaluate the feasibility of a minimally invasive approach to the middle cranial fossa using a novel endaural keyhole. METHODS: The charts of all patients who underwent this novel minimally invasive approach to the middle cranial fossa were retrospectively reviewed. In addition, cadaveric dissection was performed to demonstrate the feasibility of the endaural keyhole to the middle cranial fossa. RESULTS: Six patients (5 female and 1 male; age range 47-77 years) who underwent craniotomy for CSF leak (n = 3), intracerebral hematoma evacuation (n = 2), and tumor resection (n = 1) via the endaural subtemporal approach were identified. There were no approach-related complications noted. Representative imaging from cadaveric dissection is provided with a stepwise discussion of the procedure. CONCLUSIONS: The endaural subtemporal keyhole craniotomy provides a novel approach to middle fossa skull base pathology, as well as a minimally invasive approach to intra-axial pathology of the temporal lobe and basal ganglia. Further research is needed to establish the limitations and potential complications of this novel approach.

Facial Nerve Schwannoma Treatment with Stereotactic Radiosurgery (SRS) versus Resection followed by SRS: Outcomes and a Management Protocol.

Background Stereotactic radiosurgery (SRS) and resection are treatment options for patients with facial nerve schwannomas without mass effect. Objective This article evaluates outcomes of patients treated with SRS versus resection + SRS. Method We retrospectively compared 43 patients treated with SRS to 12 patients treated with resection + SRS. The primary study outcome was unfavorable combined endpoint, defined as worsening or new clinical symptoms, and/or tumor radiological progression. SRS (38.81 ± 5.3) and resection + SRS (67.14 ± 11.8) groups had similar clinical follow-ups. Results At the time of SRS, the tumor volumes of SRS (mean ± standard error; 1.83 ± 0.35 mL) and resection + SRS (2.51 ± 0.75 mL) groups were similar. SRS (12.15 ± 0.08 Gy) and resection + SRS (12.16 ± 0.14 Gy) groups received similar radiation doses. SRS group (42/43, 98%) had better local tumor control than the resection + SRS group (10/12, 83%, p = 0.04). Most of SRS (32/43, 74%) and resection + SRS (10/12, 83%) group patients reached a favorable combined endpoint following SRS ( p = 0.52). Considering surgical associated side effects, only 2/10 patients of the resection + SRS group reached a favorable endpoint ( p < 0.001). Patients of SRS group, who are > 34 years old ( p = 0.02), have larger tumors (> 4 mL, 0.04), internal auditory canal (IAC) segment tumor involvement ( p = 0.01) were more likely to reach an unfavorable endpoint. Resection + SRS group patients did not show such a difference. Conclusion While resection is still needed for larger tumors, SRS offers better clinical and radiological outcomes compared to resection followed by SRS for facial schwannomas. Younger age, smaller tumors, and non-IAC situated tumors are factors that portend a favorable outcome.

Atypical tumors of the facial nerve: case series and review of the literature.

OBJECT: The authors present a series of 4 patients with rare facial nerve tumors. The relevant literature is reviewed and is discussed regarding diagnostic features, the role of operative management, and surgical approach. METHODS: A retrospective chart review was conducted for patients with tumors of the facial nerve that were treated between 2008 and 2011. Patients undergoing observation with serial MRI and those who were treated with up-front radiosurgery and for whom tissue diagnosis was not available were excluded. In addition, patients with suspected vestibular schwannoma, facial nerve schwannoma, neurofibromatosis Type 2, and metastatic disease were also excluded. The charts of 4 patients (2 men and 2 women) with "atypical" tumors were reviewed and analyzed. RESULTS: A total of 12 patients with tumors of the facial nerve were identified during the study period. Patient characteristics, preoperative imaging, operative approach, tumor histology, and outcomes are described. CONCLUSIONS: Atypical facial nerve tumors must be distinguished from the more common facial nerve schwannoma. How the authors of this study treat rare facial nerve tumors is based on their experience with the more common facial nerve schwannomas, characterized by a slow progression of symptoms and growth. Less is known about the rare lesions, and thus a conservative approach may be warranted. Open questions include the role of radiosurgery, facial nerve decompression, and indications for resection of tumor and cable grafting for these rare lesions.

Multi-Disciplinary Approach to Skull Base Paragangliomas.

The treatment of skull base paragangliomas has moved towards the use of cranial nerve preservation strategies, using radiation therapy and subtotal resection in instances when aiming for gross total resection would be expected to cause increased morbidity compared to the natural history of the tumor itself. The goal of this study was to analyze the role of surgery in patients with skull base paragangliomas treated with CyberKnife stereotactic radiosurgery (SRS) for definitive tumor control. A retrospective review identified 22 patients (median age 65.5 years, 50% female) treated with SRS from 2010-2022. Fourteen patients (63.6%) underwent microsurgical resection. Gross total resection was performed in four patients for tympanic paraganglioma (n = 2), contralateral paraganglioma (n = 1), and intracranial tumor with multiple cranial neuropathies (n = 1). Partial/subtotal resection was performed for the treatment of pulsatile tinnitus and conductive hearing loss (n = 6), chronic otitis and otorrhea (n = 2), intracranial extension (n = 1), or episodic vertigo due to perilymphatic fistula (n = 1). Eighteen patients had clinical and imaging follow-up for a mean (SD) of 4.5 (3.4) years after SRS, with all patients having clinical and radiological tumor control and no mortalities. Surgery remains an important component in the multidisciplinary treatment of skull base paraganglioma when considering other outcomes besides local tumor control.

Comparison of Surgeons' Assessment of the Extent of Vestibular Schwannoma Resection with Immediate Post Operative and Follow-Up Volumetric MRI Analysis.

(1) Background: Incomplete excision of vestibular schwannomas (VSs) is sometimes preferable for facial nerve preservation. On the other hand, subtotal resection may be associated with higher tumor recurrence. We evaluated the correlation between intra-operative assessment of residual tumor and early and follow-up imaging. (2) Methods: The charts of all patients undergoing primary surgery for sporadic vestibular schwannoma during the study period were retrospectively reviewed. Data regarding surgeons' assessments of the extent of resection, and the residual size of the tumor on post-operative day (POD) one and follow-up MRI were extracted. (3) Results: Of 109 vestibular schwannomas meeting inclusion criteria, gross-total resection (GTR) was achieved in eighty-four, near-total (NTR) and sub-total resection (STR) in twenty-two and three patients, respectively. On follow up imaging, volumetric analysis revealed that of twenty-two NTRs, eight were radiographic GTR and nine were radiographic STR (mean volume ratio 11.9%), while five remained NTR (mean volume ratio 1.8%). Of the three STRs, two were radiographic GTR while one remained STR. Therefore, of eighteen patients with available later follow up MRIs, radiographic classification of the degree of resection changed in six. (4) Conclusions: An early MRI (POD#1) establishes a baseline for the residual tumor that may be more accurate than the surgeon's intraoperative assessment and may provide a beneficial point of comparison for long-term surveillance.

Tandem cranial and spinal cerebrospinal fluid leaks presenting with otogenic tension pneumocephalus: illustrative case.

BACKGROUND: Cranial and spinal cerebrospinal fluid (CSF) leaks are associated with opposite CSF fluid dynamics. The differing pathophysiology between spontaneous cranial and spinal CSF leaks are, therefore, mutually exclusive in theory. OBSERVATIONS: A 66-year-old female presented with tension pneumocephalus. The patient underwent computed tomography (CT) scanning, which demonstrated left-sided tension pneumocephalus, with an expanding volume of air directly above a bony defect of the tegmen tympani and mastoideum. The patient underwent a left middle fossa craniotomy for repair of the tegmen CSF leak. In the week after discharge, she developed a recurrence of positional headaches and underwent head CT. Further magnetic resonance imaging of the brain and thoracic spine showed bilateral subdural hematomas and multiple meningeal diverticula. LESSONS: Cranial CSF leaks are caused by intracranial hypertension and are not associated with subdural hematomas. Clinicians should maintain a high index of suspicion for intracranial hypotension due to spinal CSF leak whenever "otogenic" pneumocephalus is found. Close postoperative follow-up and clinical monitoring for symptoms of intracranial hypotension in any patients who undergo repair of a tegmen defect for otogenic pneumocephalus is recommended.

The approach to the patient with incidentally diagnosed vestibular schwannoma.

With the increasing prevalence and decreasing cost of MRI scans, incidental discovery of vestibular schwannoma (VS) has become more common. Scarce literature exists regarding management of the tumors in those patients with incidentally discovered VSs, and clear guidelines for management do not exist. In this review, the authors examine the available literature for insights into management of incidentally diagnosed VS and provide an algorithm for their management.

Intraoperative Fluorescence With Second Window Indocyanine Green Enhances Visualization During Vestibular Schwannoma Surgery.

OBJECTIVE: To investigate the utility of the so-called "second window" of indocyanine green (ICG) as a near-infrared fluorescent dye for intraoperative visualization. PATIENTS: Three patients who underwent surgical resection of vestibular schwannoma (two retrosigmoid and one middle fossa approach). INTERVENTIONS: Patients underwent intravenous infusion of ICG at a mean dose of 4.8 mg/kg at a mean of 15.3 hours before surgical incision. Once tumor dissection began, near-infrared fluorescence was used alongside conventional operative microscopy to visualize tumor tissue. MAIN OUTCOME MEASURES: Ability to distinguish tumor tissue from adjacent nerves. RESULTS: Intraoperative fluorescence allowed for enhanced visualization of the tumor-nerve plane in all patients. However, the effect varied among patients, and the effect faded with increasing surgical time. CONCLUSIONS: ICG, a well-tolerated cyanine dye, demonstrates late fluorescence hours after administration secondary to diffusion into tumor as well as normal tissues (the so-called "second window" of fluorescence). Its fluorescence in the near-infrared spectrum is a promising adjunct for enhancing visualization of tumor planes during vestibular schwannoma surgery.

Endoscopic closure of the Eustachian tube orifice for refractory lateral skull base cerebrospinal fluid leak using autologous fat graft: illustrative case.

BACKGROUND: Rhinorrhea due to lateral skull base cerebrospinal fluid (CSF) leaks can be a challenge to manage. Multiple strategies exist for treating CSF leaks in this region including direct repair, posterior Eustachian tube packing, and CSF diversion. Endonasal closure of the Eustachian tube has been reported using cerclage and mucosal flaps. OBSERVATIONS: We present the first reported case of endoscopic autologous fat packing of the Eustachian tube orifice to repair a CSF leak. In this case a 42-year-old woman who underwent middle fossa meningioma resection 20 years ago presented with refractory CSF rhinorrhea despite blind sac closure of the ear canal. This persisted after CSF diversion and only resolved after endoscopic endonasal Eustachian tube closure described herein. LESSONS: This technique is simple to perform with minimal risk of morbidity. Eustachian tube orifice fat packing may be particularly useful for patients with refractory CSF rhinorrhea with low CSF pressure.

Safety of 3 Tesla Magnetic Resonance Imaging in Patients With Auditory Brainstem Implants.

OBJECTIVE: To evaluate the safety of 3 Tesla (T) magnetic resonance imaging (MRI) in patients with auditory brainstem implants (ABI) with the magnet removed at implantation and report incidence of complications. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary neurotology ambulatory practice. PATIENTS: Patients with diagnosis of Neurofibromatosis, type 2 (NF2) with functional ABIs. INTERVENTIONS: Observational recordings. MAIN OUTCOME MEASURES: Of the 89 patients meeting inclusion criteria, 7 patients underwent 3T MRI, with a total of 39 scans done. Three patients had 1 scan each, one patient had 4 scans, one patient had 5 scans, one patient had 6 scans, and one patient had 21 scans. The mean time between ABI placement and first 3 T scan was 118 ±â€Š73 months. The most common indication for imaging was surveillance of NF2 lesions. The most frequent scans were MRI brain (25.6%), followed by MRI of cervical (15%), thoracic (15%) and lumbar (15%) spine, and MRI IAC (8%). There were no reported complications for any of the scans. No scans were interrupted due to patient discomfort. There were no device malfunctions. CONCLUSIONS: 3 T MRIs are safe in patients with ABIs as long as the magnet is removed. It is recommended that the magnet be removed at the time of implantation in all NF2 patients, who require frequent surveillance.

Malignant progression of cerebellopontine angle solitary fibrous tumors following radiation: illustrative case.

BACKGROUND: Intracranial solitary fibrous tumors (ISFTs) are rare mesenchymal tumors originating in the meninges and constitute a heterogeneous group of clinical and biological behavior. Benign histotypes, such as hemangiopericytomas are now considered as a cellular phenotypic variant of this heterogenous group of rare spindle-cell tumors. IFSTs are poorly recognized and remain a diagnostic challenge due to rarity and resemblance to other brain tumors. Previously, IFSTs were thought to pursue a slow, indolent, and nonaggressive course, however, a growing body of literature based on longer follow-up demonstrates an unpredictable clinical course and an uncertain diagnosis. OBSERVATIONS: A rare case report of malignant transformation of IFST following radiation therapy is reported. In this case a 60-year-old female who underwent gross total resection of the cerebellopontine angle tumor with histopathology consistent with solitary fibrous tumor followed by salvage stereotactic radiosurgery, presented with another recurrence after 2 years of surgery. The authors performed complete removal of the tumor with pathology now consistent with malignant solitary fibrous tumor. A recent follow-up magnetic resonance imaging did not show any recurrence or residual tumor, and the patient reports a generalized well-being. LESSONS: This report will help to understand the natural history and unusual clinical behavior of these intracranial tumors.

The Role of Intra-Operative Duplex Ultrasonography Following Translabyrinthine Approach for Vestibular Schwannoma.

Objective: Sigmoid sinus (SS) stenosis is a complication of translabyrinthine approach. Velocity changes in the SS measured by intra-operative doppler ultrasound may help in identifying patients at risk for sinus occlusion. Patients: SS velocity was measured using doppler ultrasound prior to opening dura and again prior to placement of the abdominal fat graft. Intervention: Data collected included: patient age, surgical side, sinus dominance, tumor volume, intra-operative doppler ultrasound measurements, post-operative venous sinus imaging, anticoagulation, and morbidities and mortalities. Main Outcome Measure: SS patency and velocity. Results: Eight patients were included in the analysis (22 to 69 years). Four had left-sided and four had right-sided craniotomies. Sigmoid sinuses were either right-side dominant or co-dominant. The mean velocity ± standard deviation (SD) prior to dura opening and abdominal fat packing was 23.2 ± 11.3 and 25.5 ± 13.9 cm/s, respectively, p = 0.575. Post-operative Magnetic Resonance Venography (MRV) imaging showed four sigmoid sinus occlusions; seven patients showed sigmoid sinus stenosis, and one internal jugular vein occlusion. One patient had post-operative Computed Tomography Venography (CTV) only. Of the four patients with MRV occlusions, CTVs were performed with three showing occlusion and all four-showing stenosis. One patient with internal jugular vein occlusion on MRV received warfarin anticoagulation. There was one cerebrospinal fluid leak requiring ear closure, one small cerebellar infarct, and one with facial nerve palsy (House-Brackman Grade 3). Conclusion: SS velocity changes before and after tumor resection were not predictive of sinus occlusion. We hypothesize that sinus occlusion may be caused by related factors other than thrombosis, such as external compression of the sinus secondary to abdominal fat grafting.