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.

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.

Snake-Eye Myelopathy and Surgical Prognosis: Case Series and Systematic Literature Review.

The prognostic value of "snake-eyes" sign in spinal cord magnetic resonance imaging (MRI) is unclear and the correlation with different pathological conditions has not been completely elucidated. In addition, its influence on surgical outcome has not been investigated in depth. A literature review according to PRISMA (Preferred reporting items for systematic review and meta-analysis protocols) guidelines on the prognostic significance of "snake-eyes" sign in operated patients was performed. Clinical, neuroradiological, and surgical data of three institutional patients, were also retrospectively collected. The three patients, with radiological evidence of "snake-eyes" myelopathy, underwent appropriate surgical treatment for their condition, with no new post-operative neurological deficits and good outcome at follow-up. The literature review, however, reported conflicting results: the presence of "snake-eyes" sign seems a poor prognostic factor in degenerative cervical myelopathy, even if some cases can improve after surgery. "Snake-eyes" myelopathy represents a rare form of myelopathy; pathophysiology is still unclear. The frequency of this myelopathy may be greater than previously thought and according to our literature review it is mostly a negative prognostic factor. However, from our experience, prognosis might not be so dire, especially when tailored surgical intervention is performed; therefore, surgery should always be considered and based on the complete clinical, neurophysiological, and radiological data.

Filling the gap between the OR and virtual simulation: a European study on a basic neurosurgical procedure.

BACKGROUND: Currently available simulators are supposed to allow young neurosurgeons to hone their technical skills in a safe environment, without causing any unnecessary harm to their patients caused by their inexperience. For this training method to be largely accepted in neurosurgery, it is necessary to prove simulation efficacy by means of large-scale clinical validation studies. METHODS: We correlated and analysed the performance at a simulator and the actual operative skills of different neurosurgeons (construct validity). We conducted a study involving 92 residents and attending neurosurgeons from different European Centres; each participant had to perform a virtual task, namely the placement of an external ventricular drain (EVD) at a neurosurgical simulator (ImmersiveTouch). The number of attempts needed to reach the ventricles and the accuracy in positioning the catheter were assessed. RESULTS: Data suggests a positive correlation between subjects who placed more EVDs in the previous year and those who get better scores at the simulator (p = .008) (fewer attempts and better surgical accuracy). The number of attempts to reach the ventricle was also analysed; senior residents needed fewer attempts (mean = 2.26; SD = 1.11) than junior residents (mean = 3.12; SD = 1.05) (p = .007) and staff neurosurgeons (mean = 2.89, SD = 1.23). Scoring results were compared by using the Fisher's test, for the analysis of the variances, and the Student's T test. Surprisingly, having a wider surgical experience overall does not correlate with the best performance at the simulator. CONCLUSION: The performance of an EVD placement on a simulator correlates with the density of the neurosurgical experience for that specific task performed in the OR, suggesting that simulators are able to differentiate neurosurgeons according to their surgical ability. Namely this suggests that the simulation performance reflects the surgeons' consistency in placing EVDs in the last year.