Dural Venous Sinus Thrombosis after Vestibular Schwannoma Surgery: The Anticoagulation Dilemma.

Introduction Dural venous sinus thrombosis (DVST) is a relatively understudied complication of vestibular schwannoma (VS) surgery. Several studies have examined this topic; however, there is limited data on the incidence, clinical progression, and proper management of this patient population. Methods A retrospective review was performed for patients undergoing surgery for VS at a single institution. All postoperative imaging was reviewed for incidence of DVST. Demographic data were collected including tumor and surgical characteristics along with postoperative course. Results A total of 63 patients underwent resection of their VS. The incidence of DVST was 34.9%. The operative time was greater in the dural venous sinus thrombosis (DSVT) group, at an average of 6.69 hours versus 4.87 in the no DSVT cohort ( p = 0.04). Tumor size was correlationally significant ( p = 0.051) at 2.75 versus 2.12 cm greatest diameter. The translabyrinthine approach was most prevalent (68.2%). The side of the thrombosis was ipsilateral to the tumor and surgery in all patients. The sigmoid sinus was most commonly involved (95.5%). Of them, 85% patients had a codominant or thrombus contralateral to the dominant sinus. All patients were asymptomatic. No patients were treated with anticoagulation. Resolution of thrombus was seen in five (22.7%) of the patients on last follow-up imaging. There were no hemorrhagic complications. Conclusion The overall incidence of DVST was (34.9%) of 63 patients who underwent VS surgery. All patients were asymptomatic and none were treated with anticoagulation. In our study, continuing to observe asymptomatic patients did not lead to any adverse events.

Petrous Apex Cephaloceles: Radiology Features and Surgical Management of a Rare Entity.

OBJECTIVE: To characterize the radiologic findings of petrous apex cephalocele (PAC) in a patient cohort, and report the surgical management for three symptomatic PAC patients and cerebrospinal fluid (CSF) leak via the middle cranial fossa approach. STUDY DESIGN: Retrospective case series. SETTING: Academic center. PATIENTS: Thirty-five patients with PAC were identified by review of the imaging archive between 2008 and 2019 (29 females; mean, 55 yrs; range, 4-86 yrs). All patients underwent magnetic resonance imaging of the skull base and/or computed tomography examination. INTERVENTIONS: Surgical repair of PAC. MAIN OUTCOME MEASURES: Radiologic features of PAC. RESULTS: Radiological features of PAC: 25.7% bilateral; partial or expanded empty sella in 82.9%; arachnoid pits in 14.2%; and enlarged CSF space of optic nerve sheath in 20.0%. Coexisting pathology included temporal, sphenoid, and bilateral jugular foramen meningocele; as well as cribriform, middle crania fossa, and right temporal defect. Three case studies describing the surgical course of spontaneous CSF leak secondary to PAC were managed with the middle cranial fossa approach. CONCLUSIONS: PAC is an exceedingly unusual cause for CSF leak in the adult and pediatric population. A middle fossa approach may be used to treat CSF leak as a result of PAC. Typically, CSF otorrhea originates from an encephalocele that extends via a bony defect in the tegmen tympani or tegmen mastoideum. However, on occasion the source of the CSF otorrhea is not via the tegmen, instead defects in the middle fossa floor, medial to the ridge for the gasserian ganglion (tubercle of Princeteau), need to be considered.

Structural and Functional Imaging in Glioma Management.

The goal of glioma surgery is maximal safe resection in order to provide optimal tumor control and survival benefit to the patient. There are multiple imaging modalities beyond traditional contrast-enhanced magnetic resonance imaging (MRI) that have been incorporated into the preoperative workup of patients presenting with gliomas. The aim of these imaging modalities is to identify cortical and subcortical areas of eloquence, and their relationship to the lesion. In this article, multiple modalities are described with an emphasis on the underlying technology, clinical utilization, advantages, and disadvantages of each. functional MRI and its role in identifying hemispheric dominance and areas of language and motor are discussed. The nuances of magnetoencephalography and transcranial magnetic stimulation in localization of eloquent cortex are examined, as well as the role of diffusion tensor imaging in defining normal white matter tracts in glioma surgery. Lastly, we highlight the role of stimulated Raman spectroscopy in intraoperative histopathological diagnosis of tissue to guide tumor resection. Tumors may shift the normal arrangement of functional anatomy in the brain; thus, utilization of multiple modalities may be helpful in operative planning and patient counseling for successful surgery.

Responsive Neurostimulation of the Mesial Temporal White Matter in Bilateral Temporal Lobe Epilepsy.

BACKGROUND: Responsive neuromodulation (RNS) is a treatment option for patients with medically refractory bilateral mesial temporal lobe epilepsy (MTLE). A paucity of data exists on the feasibility and clinical outcome of hippocampal-sparing bilateral RNS depth lead placements within the parahippocampal white matter or temporal stem. OBJECTIVE: To evaluate seizure reduction outcomes with at least a 1-yr follow-up in individuals with bilateral MTLE undergoing hippocampus-sparing implantation of RNS depth leads. METHODS: A retrospective analysis of prospectively collected data was performed on patients at our institution with bilateral MTLE who were implanted with RNS depth leads along the longitudinal extent of bitemporal parahippocampal white matter or temporal stem. Baseline and postoperative seizure frequency, previous surgical interventions, and postimplantation electrocorticography and stimulation data were analyzed. RESULTS: Ten patients were included in the study (7 male, 3 female). Overall seizure frequency declined by a median 44.25% at 3.13 yr (standard deviation 3.31) postimplantation. Four patients (40%) achieved 50% responder rate at latest follow-up. Two of four patients with focal onset bilateral tonic-clonic seizures became completely seizure-free. Forty percent of patients were previously implanted with a vagus nerve stimulator, and 20% underwent a prior temporal lobectomy. All depth lead placements were confirmed as radiographically located in the parahippocampal white matter or temporal stem without hippocampus violation. There were no cases of lead malposition. CONCLUSION: Extrahippocampal or temporal stem white matter targeting during RNS surgery for bitemporal MTLE is feasible and allows for electrographic seizure detection. Larger controlled studies with longer follow-up are needed to validate these preliminary findings.

Posterior atlantoaxial fusion: a comprehensive review of surgical techniques and relevant vascular anomalies.

Posterior atlantoaxial fusion is an important surgical technique frequently used to treat various pathologies involving the cervical 1-2 joint. Since the beginning of the 20th century, various fusion techniques have been developed with improved safety profile, higher fusion rates, and superior clinical outcome. Despite the advancement of technology and surgical techniques, posterior C1-2 fusion is still a technically challenging procedure given the complex bony and neurovascular anatomy in the craniovertebral junction (CVJ). In addition, vascular anomalies in this region are not uncommon and can lead to devastating neurovascular complications if unrecognized. Thus, it is important for spine surgeons to be familiar with various posterior atlantoaxial fusion techniques along with a thorough knowledge of various vascular anomalies in the CVJ. Intimate knowledge of the various surgical techniques in combination with an appreciation for anatomical variances, allows the surgeon develop a customized surgical plan tailored to each patient's particular pathology and individual anatomy. In this article, we aim to provide a comprehensive review of existing posterior C1-2 fusion techniques along with a review of common vascular anomalies in the CVJ.

Combined Transarterial and Transvenous Onyx Embolization of Jugular Foramen Paragangliomas.

OBJECTIVE: Jugular foramen paragangliomas are highly vascular tumors known to have significant venous hemorrhage during resection even after conventional transarterial embolization. The authors report a novel technique to the endovascular embolization of jugular foramen paragangliomas using a combined transarterial and transvenous access for better intraoperative control of blood loss and visualization. METHODS: This is a retrospective data collection of 2 patients diagnosed with jugular foramen paragangliomas with novel embolization technique and surgical resection. RESULTS: Two patients underwent embolization of jugular foramen paragangliomas through combined transarterial and transvenous routes using 2 double-lumen balloon microcatheters. In both cases, single arterial vessel embolization was performed through the occipital artery in Case 1 and the tympanic branch of the ascending pharyngeal artery in Case 2. Simultaneously, balloon microcatheter occlusion in the sigmoid sinus and single venous outflow vessel embolization was performed. Near-complete occlusion was established, with angiographic disappearance of tumor blush. Surgical resection was performed in both cases. Estimated blood loss BL was 600 mL in Case 1 and 200 mL in Case 2. No blood transfusions were required, intraoperatively or postoperatively. There were no cranial nerve deficits post embolization. One patient had a persistent House Brackman 2 facial nerve palsy after resection. CONCLUSIONS: The initial experience with simultaneous transvenous and transarterial paraganglioma embolization demonstrated the safety of the technique and superior embolic agent penetration. This was supported by our observations during embolization and intraoperatively during tumor resection. Additional patients need to be treated with this technique for better assessment of long-term efficacy and incidence of embolization-related cranial neuropathies.

Resection of vestibular schwannomas after stereotactic radiosurgery: a systematic review.

OBJECTIVE: Multiple short series have evaluated the efficacy of salvage microsurgery (MS) after stereotactic radiosurgery (SRS) for treatment of vestibular schwannomas (VSs); however, there is a lack of a large volume of patient data available for interpretation and clinical adaptation. The goal of this study was to provide a comprehensive review of tumor characteristics, management, and surgical outcomes of salvage of MS after SRS for VS. METHODS: The Medline/PubMed, Scopus, CINAHL, Cochrane Library, and Google Scholar databases were queried according to PRISMA guidelines. All English-language and translated publications were included. Studies lacking adequate study characteristics and outcomes were excluded. Cases involving neurofibromatosis type 2, previous MS, or malignant transformation were excluded when possible. RESULTS: Twenty studies containing 297 cases met inclusion criteria. Three additional cases from Rush University Medical Center were added for 300 total cases. Tumor growth with or without symptoms was the primary indication for salvage surgery (92.3% of cases), followed by worsening of symptoms without growth (4.6%) and cystic enlargement (3.1%). The average time to MS after SRS was 39.4 months. The average size and volume of tumor at surgery were 2.44 cm and 5.92 cm3, respectively. The surgical approach was retrosigmoid (42.8%) and translabyrinthine (57.2%); 59.5% of patients had a House-Brackmann (HB) grade of I or II. The facial nerve was preserved in 91.5% of cases. Facial nerve preservation and HB grades were lower for the translabyrinthine versus retrosigmoid approach (p = 0.31 and p = 0.18, respectively); however, fewer complications were noted in the translabyrinthine approach (p = 0.29). Gross-total resection (GTR) was completed in 55.7% of surgeries. Studies that predominantly used subtotal resection (STR) were associated with a lower rate of facial nerve injury (5.3% vs 11.3%, p = 0.07) and higher rate of HB grade I or II (72.9% vs 48.0%, p = 0.00003) versus those using predominantly GTR. However, majority STR was associated with a recurrence rate of 3.6% as compared to 1.4% for majority GTR (p = 0.29). CONCLUSIONS: This study showed that the leading cause of MS after SRS was tumor growth at an average of 39.4 months after radiation. There were no significant differences in outcomes of facial nerve preservation, postoperative HB grade, or complication rate based on surgical approach. Patients who underwent STR showed statistically significant better HB outcomes compared with GTR. MS after SRS was considered by most authors to be more difficult than primary MS. These data support the notion that the surgical goals of salvage surgery are debulking of tumor mass, decreasing compression of the brainstem, and not necessarily pursuing GTR.

Transvenous arteriovenous malformation embolization.

Transvenous embolization of arteriovenous malformations has emerged as a safe and effective intervention. In carefully selected patients the transvenous approach has shown efficacy similar to that of conventional transarterial routes. The optimal lesions amenable to the transvenous approach have not been robustly delineated; however, the approach is reserved for small, deep seeded, single venous drainage lesions with poorly amenable arterial vascular supply. In this video we demonstrate a case of transvernous Onyx embolization of a Spetzler-Martin grade 3 (SM3) left hemispheric, ruptured arteriovenous malformation. The patient underwent successful, single session, complete embolization of the arteriovenous malformation through a venous route without further complications or repeat treatment.

Perioperative complications with multilevel anterior and posterior cervical decompression and fusion.

OBJECTIVE: Cervical spondylotic myelopathy (CSM) is a progressive degenerative pathology that frequently affects older individuals and causes spinal cord compression with symptoms of neck pain, radiculopathy, and weakness. Anterior decompression and fusion is the primary intervention to prevent neurological deterioration; however, in severe cases, circumferential decompression and fusion is necessary. Published data regarding perioperative morbidity associated with these complex operations are scarce. In this study, the authors sought to add to this important body of literature by documenting a large single-surgeon experience of single-session circumferential cervical decompression and fusion. METHODS: A retrospective analysis was performed to identify intended single-stage anterior-posterior or posterior-anterior-posterior cervical spine decompression and fusion surgeries performed by the primary surgeon (V.C.T.) at Rush University Medical Center between 2009 and 2016. Cases in which true anterior-posterior cervical decompression and fusion was not performed (i.e., those involving anterior-only, posterior-only, or delayed circumferential fusion) were excluded from analysis. Data including standard patient demographic information, comorbidities, previous surgeries, and intraoperative course, along with postoperative outcomes and complications, were collected and analyzed. Perioperative morbidity was recorded during the 90 days following surgery. RESULTS: Seventy-two patients (29 male and 43 female, mean age 57.6 years) were included in the study. Fourteen patients (19.4%) were active smokers, and 56.9% had hypertension, the most common comorbidity. The most common clinical presentation was neck pain in 57 patients (79.2%). Twenty-three patients (31.9%) had myelopathy, and 32 patients (44.4%) had undergone prior cervical spine surgery. Average blood loss was 613 ml. Injury to the vertebral artery was encountered in 1 patient (1.4%). Recurrent laryngeal nerve palsy was observed in 2 patients (2.8%). Two patients (2.8%) had transient unilateral hand grip weakness. There were no permanent neurological deficits. Dysphagia was encountered in 45 patients (62.5%) postoperatively, with 23 (32%) requiring nasogastric parenteral nutrition and 9 (12.5%) patients ultimately undergoing percutaneous endoscopic gastrostomy (PEG) placement. Nine of the 72 patients required a tracheostomy. The incidence of pneumonia was 6.9% (5 patients) overall, and 2 of these patients were in the tracheostomy group. Superficial wound infections occurred in 4 patients (5.6%). Perioperative death occurred in 1 patient. Reoperation was necessary in 10 patients (13.9%). Major perioperative complications (permanent neurological deficit, vascular injury, tracheostomy, PEG tube, stroke, or death) occurred in 30.6% of patients. The risk of minor perioperative complications (temporary deficit, dysphagia, deep vein thrombosis, pulmonary embolism, urinary tract infection, pneumonia, or wound infection) was 80.6%. CONCLUSIONS: Single-session anterior-posterior cervical decompression and fusion is an inherently morbid operation required in select patients with cervical spondylotic myelopathy. In this large single-surgeon series, there was a major perioperative complication risk of 30.6% and minor perioperative complication risk of 80.6%. This overall elevated risk for postoperative complications must be carefully considered and discussed with the patient preoperatively. In some situations, shared decision making may lead to the conclusion that a procedure of lesser magnitude may be more appropriate.