Operative Neurosurgery最新文献

Background and objectives: The efficacy of deep brain stimulation (DBS) relies on accurate electrode placement. Unfortunately, electrode deviation poses a persistent problem, with most electrodes demonstrating some degree of bending. Although such bending does not always result in target deviation, an estimated 3% to 8% of patients still require revision surgery to address suboptimal electrode placement. DBS electrode deviation may occur at mechanical tissue interfaces, with denser internal capsule (IC) fibers being the most likely factor. Based on basic principles of physics, we hypothesized that the angle of a planned trajectory relative to tissue interfaces created by the IC induces deviation.

Methods: Ten patients with Parkinson disease scheduled for DBS surgery underwent preoperative 3T magnetic resonance elastography (MRE) using synchronized external vibrations to measure brain tissue stiffness. The IC stiffness interface (ICSI) was defined as the transition between the corona radiata and IC on MRE. The rate of transition was calculated as the change in stiffness across the ICSI. Postoperative computed tomography was used to measure target deviation. The angle of approach was calculated as the angle between the planned trajectory and the normal vector to the ICSI. Pearson correlations and t-tests were performed to evaluate associations between the angle of approach and target deviation.

Results: Twenty-one electrode trajectories were analyzed. The mean electrode deviation was 1.27 ± 0.63 mm. A significant correlation (r = 0.57, 95% CI [0.18, 0.80], P = .007) was found between angle of approach and target deviation, with larger angles associated with greater deviations. The rate of transition did not correlate with deviation (P = .874).

Conclusion: MRE effectively quantifies in vivo brain tissue stiffness in Parkinson disease. The angle between the planned trajectory and the ICSI correlates with target deviation, supporting the hypothesis that tissue mechanics influence electrode bending. MRE has potential to quantify the likelihood of DBS electrode deviation, which could reduce revision surgeries and enhance clinical outcomes.

Background and objectives: External ventricular drain (EVD) placement is a critical, lifesaving procedure in cranial neurosurgery, often performed manually using anatomical landmarks that vary between individuals. This study evaluates the efficacy of a 3-dimensional (3D)-printed EVD training model designed to improve the accuracy of this procedure.

Methods: Computed tomography scans from 3 patients were used to create 3D-printed head models with narrow, wide, and normal ventricles. Twenty-five neurosurgeons participated in a three-round training protocol: pre-training, training with neuronavigation and a standardized protocol, and post-training. The accuracy of EVD placement was measured using an optical navigation system, and participants' confidence levels were assessed through questionnaires.

Results: Training significantly enhanced EVD placement accuracy. Pre-training, only 55.3% of placements were intraventricular (Kakarla grade 1), which increased to 84.0% post-training (P < .001). The distance to the ideal entry point improved from 5.8 mm (SD, ±3.7 mm) to 4.1 mm (SD, ±1.5 mm), and the distance to the target point improved from 12.6 mm (SD, ±5.8 mm) to 8.3 mm (SD, ±4.0 mm) (P < .001 for both). The time to identify entry points and puncture the ventricles also improved significantly. Left-sided EVDs were more frequently misplaced. In addition, right-handed participants (n = 24) performed better when placing left-sided EVDs with their right hand. Participants with more than 6 years of experience were more likely to misplace the EVD and overestimate their placement accuracy compared with less experienced participants. Post-training, both experienced and less experienced neurosurgeons achieved similar success rates. Confidence in EVD placement and puncture direction significantly increased post-training.

Conclusion: A standardized training protocol using a 3D-printed model significantly improves the accuracy and confidence of neurosurgeons in EVD placement. Regular training is recommended to maintain high clinical performance, emphasizing the need for standardized procedures and the use of neuronavigation for complex cases.

Background and objectives: The medial parietooccipital and peritrigonal areas present challenges for neurosurgical procedures. Adjacency to the eloquent cortex-postcentral gyrus and cuneus, as well as crucial white matter tracts, such as optic radiation-makes the surgical approaches difficult. This study aims to describe the surgical technique and outcomes of treating lesions using the contralateral approach.

Methods: This study is a retrospective analysis of 19 surgical cases treated in the Department of Neurosurgery and Neurooncology, Copernicus Memorial Hospital, in Łódź between April 2021 and May 2024.

Results: Nineteen cases were treated with the contralateral posterior interhemispheric transfalcine transprecuneus approach. Six cases were vascular (all arteriovenous malformation) and 13 tumors (5 glioblastomas, 4 meningiomas, 4 metastasis, and 1 pilocytic astrocytoma). Twelve of them were in precuneus, 3 in the peritrigonal part of lateral ventricle, 2 in falx, and 2 in pulvinar. The mean surgery time was 4 hours 15 minutes ± 2 hours 21 minutes. The superior sagittal sinus was injured and managed using suture and hemostatic material in 2 cases. In 2 cases, a small anastomotic vein was sacrificed, and in none of cases, a venous infarction related to anastomotic veins was observed. A new neurologic deficit was present in 8 cases post-surgery improving after a few days. The mean hospitalization time was 11 ± 8.7 days.

Conclusion: The contralateral interhemispheric transfalcine approach is a valuable surgical technique for managing medial parietooccipital and peritrigonal lesions.

Background and objectives: Managing dolichoectatic vertebrobasilar artery aneurysms requires a multifaceted approach. Revascularization of the posterior circulation with a high-flow bypass is part of the flow reversal paradigm. Performing a robust high-flow bypass and addressing the aneurysm through the same approach smooths the operative intervention. This study assessed the anatomic feasibility of accessing the basilar trunk and aneurysm simultaneously to revascularize the posterior circulation using a petrous internal carotid artery (pICA)-posterior cerebral artery (PCA) interpositional bypass through a complete petrosectomy.

Methods: Six embalmed cadaveric heads (12 sides) underwent a combined extended transcochlear-subtemporal approach to expose the pICA and P2 PCA. A pICA (side-to-end) graft (end-to-side) PCA bypass was attempted. The lengths of the vessels relevant to the bypass and the graft length were measured.

Results: The bypass was successfully completed in all specimens. The mean exposed lengths of the pICA and PCA were 21.3 and 20.0 mm, respectively. The mean length of the perforator-free zone on PCA was 11.2 mm. The mean length of the interposition graft was 36.6 mm.

Conclusion: The transcochlear approach can be used to expose the pICA as a donor for a high-flow bypass to the PCA as part of the treatment paradigm for dolichoectatic vertebrobasilar artery aneurysms. Careful patient selection and extensive knowledge of skull base anatomy are mandatory for this strategy.

Background and objectives: Despite growing interest in neuroendoscopy, endoscopic resection of intraventricular and paraventricular brain tumors is still hindered by a lack of appropriate instrumentation. The Söring ultrasonic aspirator holds significant promise but is limited because of its original design allowing sole use with the GAAB® endoscope.

Methods: A simple modification of the ultrasonic aspirator which allows use down multiple endoscopes is described along with surgical outcomes in the context of the largest reported case series of 58 procedures in 52 patients, thus further expanding its applications and versatility.

Results: Our modification enabled the use of the Söring ultrasonic aspirator with the MINOP® InVent neuroendoscope, facilitating tumor resection in 58 procedures of 52 patients between July 2015 and June 2022. Near-total to gross-total resection was achieved in 30.8% of cases, with no permanent neurological deficits observed. The modified aspirator proved effective and safe, with no adverse events related to its use.

Conclusion: The Söring ultrasonic aspirator represents a significant landmark in neuroendoscopic surgery. Our modification allowed greater versatility and compatibility with multiple endoscopes. This safe and effective modification will broaden its use and with time will have a considerable impact in the field of minimally invasive neurosurgery.

Background and objectives: The coexistence of complete carotico-clinoid bridge (CCB), an ossification between the anterior (ACP) and the middle clinoid (MCP), and an interclinoidal osseous bridge (ICB), between the ACP and the posterior clinoid (PCP), represents an uncommonly reported anatomic variant. If not adequately recognized, osseous bridges may complicate open or endoscopic surgery, along with the pneumatization of the ACP, especially when performing anterior or middle clinoidectomies.

Methods: According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews guidelines, a systematic scoping review was conducted up to June 5, 2023. PubMed, Scopus, Web of Science databases, and additional citations were searched. Two hundred high-resolution noncontrast computed tomography (CT) scans (400 sides) and 41 dry skulls (82 sides) were analyzed to identify the different morphology of sellar bridges, focusing on the coexistence of complete CCF and ICB. Two embalmed latex-injected heads with coexisting CCF and ICB were dissected step-by-step to show the anatomic relationship with the surrounding structures from an endoscopic and microscopic perspective.

Results: A total of 19 articles were included. The review identified a complete CCF and ICB rate ranging from 4.92% to 6.3%. The analysis of 200 CT scans revealed a rate of coexistence in 4% of the cases, all encountered in White women. Two different types of interclinoid bridges were identified based on the degree of bone mineralization. Both endoscopic and macroscopic step-by-step dissections highlighted variability in morphology and consistency of the sellar bridges and the close relationship with the cavernous sinus neurovascular structures.

Conclusion: The coexistence of CCF and ICB is an anatomic variation found in 4% of cases. Preoperative knowledge of the degree of mineralization and its relationship with surrounding structures is essential to performing safe surgery and minimizing cranial nerve and vascular injuries. Preoperative high-resolution CT scans can adequately identify these anatomic variations.