The internal carotid artery and the atlas: anatomical relationship and implications for C1 lateral mass fixation.

PURPOSE: The internal carotid artery (ICA) is potentially at risk during posterior fixation of C1. In this study, we performed a CT-based anatomical analysis of the relationship between the internal carotid artery and the lateral mass of the atlas. METHODS: We analysed 30 CT angiography of the cervical spine, and we measured on both sides the distance of the carotid artery from the midline, distance of the ICA from the anterior cortex of C1 and from the ideal C1 screw entry point. We measured the angle between the sagittal plane passing through the entry point and the tangent line of the vessel. Separated statistical analysis between left and right sides, between male and female patients, and differentiation by age were also performed. RESULTS: Sixty ICAs were studied. The mean distance of the ICA from the midline was 23.3 ± 4.3 mm, with a minimum of 15 mm. The distance between the ICA and the anterior cortical layer of C1 was 4.8 ± 2.7 mm, with a minimum of 1.1 mm. The distance between the screw entry point and the arterial wall was 22.6 ± 2.8 mm, with a minimum of 17.5 mm. The mean angle was 10.4°, with a minimum of 11°. CONCLUSIONS: Although rare, intraoperative lesion of the ICA is reported and the spine surgeon must be aware of this risk. Careful preoperative planning is mandatory and the position of the ICA in relation to C1 must be assessed. The anatomical parameters presented in this paper can be useful to reduce the risk of ICA injury.

Spheno-Orbital Meningiomas: When the Endoscopic Approach Is Better.

Spheno-orbital meningiomas were historically treated by traditional craniotomies. However, in the past few years new endoscopic treatments have been successfully performed. In this study, we analyzed different indications for craniotomy and endoscopy, and the advantages and disadvantages of these procedures.Thirty patients with spheno-orbital meningiomas were operated on over 2 years, between 2013 and 2014. Computed tomography (CT) and magnetic resonance imaging (MRI) were performed in all patients preoperatively. Navigated surgical removal and histological confirmation, as well as follow-up examinations, including CT scan at 24 h and MRI at 3, 6, and 12 months after surgery, were performed. Twenty-three patients were treated by traditional fronto-temporal, fronto-temporo-orbital, and supraorbital craniotomies; in six cases the tumor was removed via endoscopic endonasal and lateral transorbital resection. Only one case required a combined supraorbital and endoscopic endonasal approach.We analyzed the results of the different surgical techniques, in particular those of the endoscopic approaches.In selected cases, the endoscopic approach to spheno-orbital meningiomas, compared with traditional approaches, may be more effective in removing tumors completely. The surgical technique is easy and the rate of complications is low.

Intraoperative Ultrasonography for the Surgical Treatment of Grisel Syndrome of the Adult: Management of A Rare Condition.

STUDY DESIGN: This is a narrative review and case report. OBJECTIVE: To review the literature concerning Grisel syndrome physiopathology, diagnosis, and surgical reports, highlighting the decision-making for treatment and its timing. We describe the role of intraoperative US in the management of 2 cases of GS of the adult. SUMMARY OF BACKGROUND DATA: GS is a rare nontraumatic post inflammatory C1-C2 rotatory instability usually affecting children; adult cases are even rarer, and the role of surgical treatment is not well defined. CASE DISCUSSION: Case 1: A 72-year-old man with upper cervical pain and no neurological deficit; radiologic examination revealed C1-C2 spondylitis and epidural abscess. After antibiotic therapy, the patient developed cervical instability. Hence, surgical decompression and C1-C2 stabilization were performed. Case 2: An 82-year-old woman with progressive right hemiparesis. CT and MRI showed C1-C2 spondylitis with retro-odontoid epidural abscess. Atlanto-axial rotatory instability was evident so surgery was achieved. In both cases, intraoperative US was useful for localizing retro-odontoid abscess and allowing safe puncture of the collection, leading to its remarkable radiologic reduction. CONCLUSION: GS in adults remains a challenge: Patients should be closely monitored concerning neurological and inflammatory status. We describe the successful use of intraoperative US for draining retro-odontoid abscess for the first time, with satisfactory postoperative outcome without need of circumferential approach.

Right gyrus cinguli low-grade astrocytoma recurrence removed through a contralateral transfalcine approach with a 4K-3D exoscope.

BACKGROUND: Brain tumor surgery has been using operative microscope for years. Recently, thanks to developments in surgical technology with procedures performed on head-up displays, exoscopes have been introduced as an alternative to microscopic vision. CASE PRESENTATION: We present a case of a 46-year-old patient with a low-grade glioma recurrence of the right gyrus cinguli removed with a contralateral transfalcine approach using an exoscope (ORBEYE 4K-three-dimensional (3D) exoscope, Sony Olympus Medical Solutions Inc., Tokyo, Japan). The operating room setup for this approach is illustrated. During the procedure, the surgeon was seated with head and back in an upright position, while the camera was aligned with the surgical corridor. The exoscope provided detailed, high-quality 4K-3D images of the anatomical structures and optimal depth perception, making surgery accurate and precise. At the end of the resection, an intraoperative MRI scan showed complete removal of the lesion. The patient was discharged on postoperative day 4 with an excellent performance on neuropsychological examination. CONCLUSIONS: In this clinical case the contralateral approach was favorable because the glioma was located close to the midline and because it offered a straight path to the tumor, minimizing retraction on the brain. The exoscope provided the surgeon with important advantages in terms of anatomical visualization and ergonomics during the entire procedure.

High definition 4K-three-dimensional exoscope for removal of a C1-C2 meningioma: Technical case report.

In recent years, the exoscope has been proposed as an alternative to the microscope when a magnified view of the surgical field is required in spinal surgery. We present a case of a 52-year-old patient in which a meningioma in the upper cervical spine (C1-C2) was removed using a 4K-three-dimensional (3D) exoscope. The advantages of surgical removal of an intradural spinal tumor using an exoscope are illustrated, focusing mainly on vision quality and ergonomics. In addition, some technical details regarding the operating room setup are provided. Based on this experience, a 4K-3D exoscope can be useful for spinal tumor surgery when high magnification of anatomical details is required, allowing the surgeon to operate in a comfortable position throughout the surgical procedure.

Use of a neuro-evacuation device for the endoscopic removal of third ventricle colloid cysts.

Background: Colloid cysts are benign tumors usually located at the level of the foramen of Monro and account for approximately 1% of all intracranial tumors. Endoscopic surgical treatment represents the approach of choice for removal of these tumors and is usually preferred over transcortical or transcallosal microsurgical approaches. Our purpose is to demonstrate the feasibility of endoscopic removal of colloid cysts using a novel aspiration and fragmentation system, currently designed for evacuation of cerebral hematomas. Methods: We performed an evaluation of the results obtained in patients with symptomatic colloid cysts of the third ventricle operated on using an endoscopic neuroevacuation system (Artemis Neuro Evacuation Device, Penumbra, Alameda, California, USA) between April 2020 and April 2022. Instrumentation and surgical technique are described in detail. All patients underwent postoperative MRI to assess the extent of cyst removal. Results: Five patients were included in our study. The predominant symptom at onset was headache. No intraoperative complications related to the technology in use occurred. The surgical time for the cyst removal was significantly shorter than removal via a standard endoscopic technique (80 vs. 120 min). Removal was complete, both content and capsule of the cyst, in all patients. In all cases there was a complete regression of the previously complained symptoms. Conclusion: The Artemis Neuro Evacuation Device has proved to be effective and safe in removal of colloid cysts of the third ventricle and may be proposed as a possible alternative or as a complement of the standard instruments routinely used in neuroendoscopy.

Spinal navigation for small thoracic intradural tumors: The challenge between minimally invasive and exoscopic magnification.

Background: Spinal navigation offers significant benefits in the surgical treatment of small thoracic intradural tumors. It enables precise tumor localization without subjecting the patient to high radiation doses. In addition, it allows for a smaller skin incision, reduced muscle stripping, and limited bone removal, thereby minimizing the risk of iatrogenic instability, blood loss, postoperative pain, and enabling shorter hospital stays. Case Description: This video presents two cases demonstrating the application of spinal navigation technique for thoracic intradural tumors measuring <20 mm. In the first case, which involves a small calcified tumor, navigation can be performed using 3D fluoroscopy or computed tomography images obtained intraoperatively. Notably, as illustrated in the second case, the merging of preoperative magnetic resonance imaging images with intraoperative 3D fluoroscopy enables navigation in the context of soft intradural lesions as well. The setup of the operating room for these procedures is also depicted. Conclusion: In these procedures, the use of an exoscope, in addition to the well-known advantages in terms of magnification and ergonomics, provides a large space of movement around the surgical field, with greater ease in the use of navigation devices and ultrasound. The minimal invasiveness of the surgical approach is in no way a hindrance to exoscopic visualization and surgical dissection.

Case Report: High-Definition 4K-3D Exoscope for Removal of an Orbital Cavernous Hemangioma Using a Transpalpebral Approach.

Background: Cavernous hemangioma, also known as cavernous vascular malformation (CVM), is the most common primary lesion of the orbit in adults. The management of these lesions is challenging and is strongly dependent on their location, as well as the patient's symptoms and expectations. The trans-palpebral approach is currently used in surgery for orbital tumors, anterior skull base tumors, and even more, orbital reconstruction, because of its well-demonstrated esthetic advantages. Similarly, the use of magnification can be provided by surgical loupes, microscope, or more recently, endoscope, which is well-documented for its advantages in terms of minimal invasiveness and safety. In the last years, the use of exoscopes in microsurgery has been proposed due to their greater and sharper intraoperative magnification, but never for the removal of orbital tumors. Clinical Presentation: We describe a case of a 38-year-old woman with a right orbital intraconic CVM removed using an inferior transpalpebral approach performed under 4K-3-dimensional (4K-3D) exoscopic vision. Navigation and ultrasound were also used, with the former allowing better identification of the lesion within the orbit and the second overcoming the limitations of navigation, in terms of the retraction on the ocular globe before or just after periorbital incision. Conclusion: The use of a 4K-3D exoscope allowed us to perform the surgery safely, thanks to the high magnification and definition of anatomical details, with the surgeon operating in an upright, comfortable position. The CVM was completely removed with excellent results from both functional and esthetic points of view.

Spinal navigation applied to the anterior approach for the resection of thoracic disc herniation: patient series.

BACKGROUND: Thoracic disc herniation (TDH) represents a challenge for spine surgeons. The goal of this study is to report the surgical technique and clinical results concerning the application of navigation to anterior transthoracic approaches. OBSERVATIONS: Between 2017 and 2019, 8 patients with TDH were operated in the lateral decubitus by means of mini-open thoracotomy. An adapted patient referent frame was secured to the iliac wing. The high-speed drill was also navigated. Intraoperative three-dimensional scans were used for level identification, optimized drilling trajectory, and assessment of complete resection. At 12 months follow up, all patients were ambulatory. Seven out of 8 patients (87%) experienced a postoperative neurological improvement. We observed 2 postoperative complications: 1 case of pleural effusion and 1 case of abdominal wall weakness. LESSONS: In order to increase the safety of anterior transthoracic discectomy, the authors applied the concepts of spinal navigation to the thoracotomy setting. The advantages of this technique include decrease in wrong-level procedure, continuous matching of intraoperative and navigation anatomical findings, better exposure of the TDH, optimized vertebral body drilling, and minimized risk of neurological damage. In conclusion, the authors consider spinal navigation as an important resource for the surgical treatment of patients with TDH.

The positive effects of surgery on symptomatic stereotactic radiation-induced peritumoral brain edema: A report of three cases.

BACKGROUND: Peritumoral brain edema is an uncommon but life-threatening side effect of brain tumors radiosurgery. Medical therapy usually alleviates symptoms until edema spontaneously disappears. However, when peritumoral brain edema endangers the patient's life or medical therapy fails to guarantee an acceptable quality of life, surgery might be considered. CASE DESCRIPTION: Our report focuses on three patients who developed extensive peritumoral brain edema after radiosurgery. Two were affected by vestibular schwannomas and one by a skull-base meningioma. Peritumoral brain edema worsened despite maximal medical therapy in all cases; therefore, surgical removal of the radiated lesion was carried out. In the first patient, surgery was overdue and resulted in a fatal outcome. On the other hand, in the latter two cases surgery was quickly effective. In all three cases, an unmanageable brain swelling was not found at surgery. CONCLUSION: Surgical removal of brain tumors previously treated with radiosurgery was safe and effective in resolving shortly peritumoral brain edema. This solution should be considered in patients who do not respond to medical therapy and before worsening of clinical conditions. Interestingly, the expected brain swelling was not confirmed intraoperatively. In our experience, this magnetic resonance finding should not be considered a criterion to delay surgery.

Ruptured dissecting cerebral aneurysms in young people: report of three cases.

Intracranial arterial aneurysms in the pediatric population are rare. Among these, dissecting aneurysms are the most frequent, followed by saccular, infectious, and posttraumatic. It is widely known that aneurysmal rupture is uncommon in the first two decades of life. Spontaneous dissecting aneurysms (SDAs) of the middle cerebral artery (MCA) affecting young individuals most frequently present as occlusive syndrome with ischemia, although bleeding and subarachnoid hemorrhage can also occur. Between March 2006 and January 2008, three young patients (20 months, 8 and 20 years old) were surgically treated for MCA SDA in the Neurosurgical Department of "12 de Octubre" Hospital of Madrid. These patients showed hemorrhage as primary radiological finding, and all of them underwent surgical operation. Aneurysms were always treated by trapping, with aneurysmectomy in one case, but no distal extra-intracranial (EC-IC) bypass was performed. In two cases, the histological examination of the aneurysm's wall evidenced signs of subintimal dissection with widespread disruption of the internal elastic lamina and media with neointima formation and intramural hemorrhage. Although bleeding is an uncommon presenting sign of SDAs, they should be suspected in young people showing hemorrhage at CT scan. Early surgical treatment and, if possible, preoperative neuroimaging evaluation of intracranial vessels should be performed to reduce the mortality in these patients despite a higher postoperative morbidity. From a technical point of view, surgical trapping of the aneurysm seems to be a reasonable treatment strategy especially in an emergency basis. However, whenever possible, an EC-IC bypass could help diminish the ischemic morbidity associated with these aneurysms.

Real-time navigation in spinal surgery: what has changed in surgical practice?

BACKGROUND: The authors have carried out a retrospective study to assess the advantages of real-time spinal navigation with 3D-fluoro images (O-arm® and StealthStation® navigation systems, Medtronic, Minneapolis, MN, USA) versus fluoroscopy in spinal surgery. The aim of the study is to ascertain whether this technology has affected surgical indications and clinical practice. METHODS: From January 2009 to December 2013, 421 patients underwent image-guided spinal surgery procedures in our department. They were divided into two main groups: group 1: operated on with C-arm fluoroscopic control; group 2: operated on with real-time navigation with 3D-fluoro images. All patients with vertebral osteosynthesis underwent a postoperative CT scan to check the final position of the screws. RESULTS: The screw misplacement proved to be 5.8% in group 1 and 1.5% in group 2. The odds ratio was 4.2 (95% confidence interval 2.3-7.5) with statistical significance (P<0.0001). The results clearly show an increased number of percutaneous procedures in group 2, as well as longer open osteosynthesis. CONCLUSIONS: Navigation with 3D-fluoro images reduces screw misplacement, facilitates osteosynthesis in the most difficult vertebral segments and allows broader use of percutaneous techniques, when indicated.

Intraoperative Spinal Navigation for the Removal of Intradural Tumors: Technical Notes.

BACKGROUND: In recent years, spinal surgery has incorporated the many advantages of navigation techniques to facilitate the placement of pedicle screws during osteosynthesis, mainly for degenerative diseases. However, spinal intradural tumors are not clearly visible by intraoperative fluoroscopy or computed tomography scans, thereby making navigation necessary. OBJECTIVE: To evaluate the use of spinal navigation for the removal of intradural and spinal cord tumors using spinal magnetic resonance imaging (MRI) merged with intraoperative 3-dimensional (3-D) fluoro images. METHODS: After fixing the patient reference frame on the spinous process, the 3-D fluoro images were obtained in the surgical room. Using this image as the reference, the preoperative volumetric MRI images and intraoperative 3-D fluoro images were merged using automated software or manually. RESULTS: From January to July 2016, we performed 10 navigated procedures for intradural spinal tumors by merging MRI and 3-D fluoro images. Nine patients had an intradural extramedullary tumor, 6 had neurinomas, and 3 had meningiomas; 1 patient had an intramedullary spinal cord metastasis. CONCLUSION: The surgically demonstrated benefits of spinal navigation for the removal of intradural tumors include the decreased risk of surgery at the wrong spinal level, a minimal length of skin incision and muscle strip, and a reduction in bone removal extension. Furthermore, this technique offers the advantage of opening the dura as much as is necessary and, in the case of intrinsic spinal cord tumors, it allows the tumor to be centered. Otherwise, this would not be visible, thus enabling the precise level and the posterior midline sulcus to be determined when performing a mielotomy.

Recurrent Pituicytoma with Pseudoaneurysm: Report of a Challenging Case.

BACKGROUND: Pituicytoma is a rare tumor originating from glial cells of the adult neurohypophysis and infundibulum. Surgical removal is the treatment of choice for this neoplasm. In recent years the endoscopic endonasal approach has proven to be a viable and effective alternative to standard craniotomy. CASE DESCRIPTION: We report a case of a patient submitted to surgical treatment for a recurrence of pituicytoma, which was operated on transcranially at another hospital approximately 5 years previously. After transcranial surgery, the patient developed a symptomatic recurrence and an undisclosed intrasellar pseudoaneurysm that were treated with an endoscopic endonasal approach, but still required an intracranial approach to complete the resection. CONCLUSIONS: An intrasellar pseudoaneurysm can endanger the endoscopic removal of the pituicytoma, forcing the surgeon to reevaluate a microscopic transcranial approach or to consider a staged procedure.

High definition 4K-three-dimensional exoscope for removal of a C1-C2 meningioma: Technical case report / Meningioma espinal C1-C2 extirpado con un exoscopio tridimensional y resolución 4K: reporte técnico de caso clínico

In recent years, the exoscope has been proposed as an alternative to the microscope when a magnified view of the surgical field is required in spinal surgery. We present a case of a 52-year-old patient in which a meningioma in the upper cervical spine (C1-C2) was removed using a 4K-three-dimensional (3D) exoscope. The advantages of surgical removal of an intradural spinal tumor using an exoscope are illustrated, focusing mainly on vision quality and ergonomics. In addition, some technical details regarding the operating room setup are provided. Based on this experience, a 4K-3D exoscope can be useful for spinal tumor surgery when high magnification of anatomical details is required, allowing the surgeon to operate in a comfortable position throughout the surgical procedure. (AU)

En los últimos años, el exoscopio se ha propuesto como alternativa al microscopio cuando se requiere una visión ampliada del campo quirúrgico, incluso en la cirugía de la columna vertebral. Presentamos un caso clínico de un paciente de 52 años en el que se extirpó un meningioma en la columna cervical superior (C1-C2) utilizando un exoscopio tridimensional con resolución 4K (4K-3D). Se ilustran las ventajas de la extirpación quirúrgica de un tumor espinal intradural con exoscopio, centrándose principalmente en la calidad de la visión y en la ergonomía. Además, se ofrecen algunos detalles técnicos sobre la configuración del quirófano. Nuestra experiencia sugiere que un exoscopio 4K-3D puede ser muy útil para la cirugía de tumores espinales cuando se requiere una gran ampliación de los detalles anatómicos, permitiendo también al cirujano operar en una posición cómoda durante todo el procedimiento quirúrgico. (AU)