Endoscopic-assisted resection of vestibular schwannomas in high-riding jugular bulb

The present surgical video demonstrates safe opening of the internal auditory canal (IAC) during vestibular schwannoma surgery via a retrosigmoid approach in the sitting position. Resection of the intrameatal portion of a tumor is important for progression-free survival. Preoperative thin-sliced CT revealed a high-riding jugular bulb obscuring the trajectory. After dural opening, the IAC was approached anteriorly and superiorly. The posterior margin of IAC drilling was above the Tubingen line. Drilling was performed under continuous jugular compression. The vein was pushed down to augment visibility. An angled endoscope was helpful. IAC can be drilled safely in a high-riding jugular bulb with the technique mentioned in the video. The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID2198

Diamond-Shaped Mini-Craniotomy: A New Concept in Neurosurgery

Background We describe, step by step, a modified, less invasive, diamond-shaped mini-craniotomy that optimizes dural opening and can be performed in elderly patients affected by acute subdural or intracerebral hematomas, in therapy with antiplatelets or anticoagulants. Methods We retrospectively analyzed the clinical records of 67 patients (mean age of 78.5 years) treated in our institution, during a period of 10 years, with this novel diamond-shaped craniotomy. Seventeen patients were treated for intracerebral hemorrhage and 50 patients for acute subdural hematomas. All the patients were in therapy with antiplatelets or anticoagulants. Results Approach-related complications were not detected. Ten of 67 patients (14.9%) presented temporal muscle atrophy; there was no scar deformity, paresthesia, hyperalgesia, or ramus frontalis palsy around the scalp incision. Thirty-day mortality was 22%. The mean follow-up was 1.3 years. One-month postoperative brain computed tomography scans showed a satisfactory hematoma evacuation in 57 of 67 patients (85%). Conclusions The diamond-shaped mini-craniotomy for acute subdural and intracerebral hematomas is safe and effective, and it should be considered as an alternative to traditional approaches, particularly in elderly patients.

Comparison of 1.0 g/kg of 20% mannitol initiated at different time points and effects on brain relaxation in patients with midline shift undergoing supratentorial tumor resection: a randomized controlled trial

OBJECTIVE Previous studies have suggested the use of 1.0 g/kg of 20% mannitol at the time of skin incision during neurosurgery in order to improve brain relaxation. However, the incidence of brain swelling upon dural opening is still high with this dose. In the present study, the authors sought to determine a better timing for mannitol infusion. METHODS One hundred patients with midline shift who were undergoing elective supratentorial tumor resection were randomly assigned to receive early (immediately after anesthesia induction) or routine (at the time of skin incision) administration of 1.0 g/kg body weight of 20% mannitol. The primary outcome was the 4-point brain relaxation score (BRS) immediately after dural opening (1, perfectly relaxed; 2, satisfactorily relaxed; 3, firm brain; and 4, bulging brain). The secondary outcomes included subdural intracranial pressure (ICP) measured immediately before dural opening; serum osmolality and osmole gap (OG) measured immediately before mannitol infusion (T0) and at the time of dural opening (TD); changes in serum electrolytes, lactate, and hemodynamic parameters at T0 and 30, 60, 90, and 120 minutes thereafter; and fluid balance at TD. RESULTS The time from the start of mannitol administration to dural opening was significantly longer in the early administration group than in the routine administration group (median 66 [IQR 55–75] vs 40 [IQR 38–45] minutes, p < 0.001). The BRS (score 1/2/3/4, n = 14/26/9/1 vs 3/25/18/4, p = 0.001) was better and the subdural ICP (median 5 [IQR 3–6] vs 7 [IQR 5–10] mm Hg, p < 0.001) was significantly lower in the early administration group than in the routine administration group. Serum osmolality and OG increased significantly at TD compared to levels at T0 in both groups (all p < 0.001). Intergroup comparison showed that serum osmolality and OG at TD were significantly higher in the routine administration group (p < 0.001 and = 0.002, respectively). Patients who had received early administration of mannitol had more urine output (p = 0.001) and less positive fluid balance (p < 0.001) at TD. Hemodynamic parameters, serum lactate concentrations, and incidences of electrolyte disturbances were comparable between the two groups. CONCLUSIONS Prolonging the time interval between the start of mannitol infusion and dural incision from approximately 40 to 66 minutes can improve brain relaxation and decrease subdural ICP in elective supratentorial tumor resection.

Subdural false twins: concomitant appearance of subdural haematoma and spontaneous subdural empyema

A 55-year-old man was taken to the emergency department due to right arm weakness for the past 3 days and fever (39.5°C). There was no impaired consciousness, no history of trauma and meningeal signs were absent on physical examination. Blood analysis and inflammatory markers were not evocative of a systemic infection. A cranial CT scan was requested, revealing hypodense bilateral hemispheric subdural collections, suggestive of chronic subdural haematomas. He was submitted to surgical drainage by burr holes, which confirmed the chronic subdural collection on the left side. Unexpectedly, after dural opening on the right side, a subdural purulent collection was found, which was later confirmed as an empyema due to Escherichia coli infection. A second surgical drainage was performed by craniotomy due to recurrence of the right subdural collection. Spontaneously appearing subdural empyemas due to E. coli are extremely rare and their treatment is not always straightforward. The reported case is an example of an apparently straightforward and frequent pathology that turned out to be a challenging case, requiring a multidisciplinary approach.

Thoracic spine schwannoma presenting with traumatic spinal cord injury: A case report

Background: The presentation of a thoracic spinal tumor due to high-impact trauma is quite rare and we found no other case reported. Case Description: This is a case report and literature review. A patient presented with severe paraparesis on day 4 after trauma. Thoracic MRI showed an oval image centered to T4-T5 suggestive of hemorrhage. The patient underwent a bilateral T4 and T5 laminectomy and microsurgically assisted intradural exploration. After laminectomy, we found no extradural lesions, so we proceeded to dural opening, after which we found a large extramedullary lesion which was completely removed. Pathology revealed a schwannoma. The patient had a very good recovery after surgery and motor rehabilitation. At 6 months after surgery, inferior limbs muscle strength was completely normal. We found no other case reported. Conclusion: Thoracic spine schwannomas are difficult to early diagnose unless there is a clinical suspicion. Initial presentation as bleeding after trauma was not described before. This presentation should be kept in the differential diagnosis of any patient with an acute neurological deficit without trauma signs on admission imaging.

Posterior Transdural Approach for a Calcified Thoracic Intradural Disc Herniation Using a 3-Dimensional Exoscope: 2-Dimensional Operative Video

This video depicts the removal of an intradural thoracic disc herniation through a purely transdural approach. Thoracic disc herniations are rare, and less than 5% are intradural. Though thoracic disc herniations are removed through a posterolateral or transthoracic corridor, there is literature to support a transdural approach for central herniations.1-3 Although the transdural approach has been selectively adopted for central soft herniations, calcified herniations have been regarded as less suitable.1,2 Intradural thoracic herniations have not been specifically addressed by a transdural approach in the limited literature, though it has been utilized in conjunction with a larger transthoracic approach.4 Our case features a 72-yr-old female presenting with worsening left leg weakness. Computed tomography (CT) identified a multilobulated ventral calcified mass at T11-12. Magnetic resonance imaging was not possible because of an incompatible pacemaker. Our impression was that this likely represented an intradural meningioma though a calcified intradural disc herniation was considered. Given the apparent intradural location, we opted for a transdural approach only via T11-12 laminectomy and a midline dural opening. Dentate ligament sectioning allowed a clear corridor to the now apparent disc material. Postoperative CT confirmed near complete resection, and the patient showed neurological improvement. Ultimately, the transdural approach alone led to complete discectomy while avoiding the morbidity of an invasive transthoracic approach and instrumented fusion. To our knowledge, this is the first video documenting a purely transdural approach for resection of an intradural disc herniation. The patient consented to the surgical procedure and to the use of intraoperative video for education purposes.

Utility of Intraoperative Ultrasound in Neurosurgery

Objective The purpose of the present study is to demonstrate the usefulness of intraoperative ultrasound guidance as a technique for the assessment, in real time, of tumor resection and as a navigation aid during intra-axial brain lesion removal on patients admitted in the Neurosurgical Department at the Hospital Universitario de Caracas, Caracas, Venezuela, in 2018. Methods A total of 10 patients were enrolled, each with intra-axial brain lesions with no previous neurosurgical procedures and a mean age of 49 years old, ranging from 29 to 59 years old. Results A male predominance was observed with 7 cases (70%) over 3 female cases (30%). Six patients had lesions in the dominant hemisphere. The frontal lobe was the most commonly affected, with 5 cases, followed by the parietal lobe, with 4 cases. After craniotomy, ultrasound evaluation was performed previously to dural opening, during tumor resection and after tumor removal. The mean tumor size in axial, coronal and sagittal views was 3.72 cm, 3.08 cm and 3.00 cm, respectively, previously to dural opening with intraoperative ultrasound. The average tumor depth was 1.73 cm from the cerebral cortex. The location and removal duration from the beginning of the approach (ultrasound usage time) was 83.60 minutes, and the average surgery duration was 201 minutes. Navigation with intraoperative ultrasound served to resect intra-axial tumors more precisely and safely. There was no postoperative complication associated with the surgery in this series of cases. Conclusions Intraoperative ultrasound guidance for intra-axial subcortical tumor resection is a technique that serves as a surgical and anatomical orientation tool.

Combined Petrosal Approach for Resection of a Large Trigeminal Schwannoma With Meckel's Cave Involvement—Part II: Microsurgical Approach and Tumor Resection: 2-Dimensional Operative Video

This video is the second part of a 2-part video presentation demonstrating the microsurgical technique of a combined petrosal approach for resection of a large trigeminal schwannoma in a 54-yr-old woman involving multiple cranial fossae extending anteriorly into Meckel's cave. The patient presented with long-standing worsening headache and facial tingling and numbness. After discussing the benefits and risks of the surgery as well as the alternative management strategies, the patient decided to proceed with surgery and informed consent was obtained. The surgery was performed in a single stage. The technical nuances of anterior and posterior (retrolabyrinthine) petrosectomy are demonstrated and discussed. Microsurgical resection of the tumor is also demonstrated emphasizing the important steps of dural opening, arachnoid dissection, identification and preservation of cranial nerves, and exploration of Meckel's cave. Use of endoscopic-assistance for visualization of the cerebellopontine angle and neurovascular structures is also demonstrated. Table in video reprinted by permission from Copyright Clearance Center: Springer Nature, Acta Neurochirurgica, Frontotemporal epidural approach to trigeminal neurinomas, Dolenc VV, Copyright 1994.