Sektionstage Herbst 2023 der Deutschen Gesellschaft für Neurochirurgie

Prof. Dr. med.

Prof. Dr med.

PD Dr.

Prof. Dr.

Univ. Prof. Dr.

Prof.

Microsurgical clipping of unruptured anterior circulation aneurysms – A global multicenter investigation of surgery related complications

Abstract-Text Background and Objectives: Microsurgical aneurysm repair via clipping continues to be highly important despite increasing endovascular treatment options, especially due to inferior occlusion rates. This study aimed to present current global microsurgical treatment practices and to identify risk factors for complications and neurological deterioration after clipping of unruptured anterior circulation aneurysms. Methods: Fifteen centers from four continents participated in this retrospective cohort study. Consecutive patients who underwent elective microsurgical clipping of untreated unruptured intracranial aneurysm between January 2016 and December 2020 were included. Posterior circulation aneurysms were excluded. Outcome parameters were postsurgical complications and neurological deterioration (defined as decline on the modified Rankin Scale) at discharge and during follow-up. Multivariate regression analyses were performed adjusting for all described patient characteristics. Results: Among a total of 2192 patients with anterior circulation aneurysm, complete occlusion of the treated aneurysm was achieved in 2089 (95.3%) patients at discharge. The occlusion rate remained stable (94.7%) during follow-up. Regression analysis identified age, hypertension (p = 0.02), aneurysm diameter (p &lt; 0.001), neck diameter (p &lt; 0.05), calcification (p &lt; 0.01), and morphology (p = 0.002) as pre-existing risk factors for postsurgical complications and neurological deterioration at discharge. Furthermore, intraoperative aneurysm rupture (OR 2.863 (CI 1.606 – 5.104); p &lt; 0.01) and simultaneous clipping of more than one aneurysm (OR 1.738 (CI 1.186 – 2.545); p &lt; 0.01) were shown to be associated with an increased risk of postsurgical complications. Yet, none of the surgical-related parameters had an impact on neurological deterioration. Analyzing volume-outcome relationship revealed comparable complication rates (p = 0.61) among all 15 participating centers. Conclusion: Our international, multicenter analysis presents current microsurgical treatment practices in patients with anterior circulation aneurysms and identifies pre-existing and surgery-related risk factors for postoperative complications and neurological deterioration. These findings may assist in decision-making for the optimal therapeutic regimen of unruptured anterior circulation aneurysms.

Subarachnoidalblutung / Aneurysmen

Abstractvortrag

PD Dr. med.

Volumetric analysis of the Sylvian Fissure: Importance and considerations in vascular neurosurgery

Abstract-Text Objective. The Sylvian fissure has crucial implications for neurosurgical procedures, particularly in treating aneurysms involving major cerebral arteries. Existing classification systems of Sylvian fissure variations are primarily descriptive observations and lack consideration of dynamic changes influenced by age-related atrophy and brain volume. The aim of this study is to investigate the effects of the brain"s volumetric changes and atrophy patterns over time and their influence on the configuration of the Sylvian fissure. The goal is to enhance preoperative assessments and surgical approaches based on a comprehensive analysis. Methods. A cohort of 150 individuals from three age groups was included in this study. Using the Brainlab software, a negative representation of the SF was generated, enabling a comprehensive 3D visualization and volumetric measurement. A Pearson correlation analysis was conducted to investigate the relationship between age-related atrophy and SF morphology. Multiple regression analyses and t-tests were performed to examine the influence of additional variables and to compare differences in the SF volumes between different age groups. Statistical analyses were conducted using appropriate software, with all assumptions of tests checked, allowing interpretation based on findings. Results. Our study identified a notably strong correlation between the volume of the Sylvian fissure and human age, indicating a dynamic relationship between brain volumes and variations in the Sylvian fissure and underscoring the necessity of an objective classification system. Anatomical landmarks were defined, incorporating the dynamic factor, to establish a classification system. Conclusion. The presented methodology presents a novel and objective classification system for Sylvian fissure variations based on volumetric dynamics. This approach offers a deeper understanding of the fissure's morphological changes over time and their correlation with specific brain volumes. This refined classification could enhance preoperative assessments, guiding neurosurgeons toward more effective surgical strategies. Various pathologies such as hemorrhages can impact brain volume and consequently influence Sylvian fissure variations. By considering the influence of volumetric changes on the configurations of the Sylvian fissure, we now anticipate improved outcomes in neurosurgical interventions.

Intrazerebrale Blutungen

Overcoming barriers in neurosurgical traning: Development and assessment of a novel perfused cerebral aneurysm clipping simulator

Abstract-Text Objective. Neurosurgery stands out as an intricate and highly specialized field within medicine. The acquisition of technical skills, particularly in vascular neurosurgery, is often directly linked to the number of cases available. Influenced by the ISAT and subsequent research, there has been a decline in the number of aneurysms treated microsurgically. The medical community has recognized the value of training simulators, but their recurrent use can be prohibitive in terms of cost. Our aim was to develop a cost-effective, perfused, patient-tailored microsurgical aneurysm training simulator (MATS) to elevate the standards and reach of neurosurgical training and education. Methods. Digital 3D models of patient"s MCA aneurysms were reconstructed from DSA and CTA scan using freeware. After digital refinement, molds were created using a boolean function and 3D printed with water-soluble PVA filament. These PVA molds were filled with wax and subsequently dissolved in water. The resulting wax models were coated with a silicon layer, after which the wax was removed. Additionally, skull and brain models were generated from a single patient's MRI and CT data and partitioned into reusable and replaceable components to enhance cost-efficiency and sustainability. A silicon-based negative brain mold was used to cast tactilely realistic brain models using candle gel. The custom-designed perfusion system comprised a roller pump, a stepper motor, and a control unit. The MATS was trialed and assessed by 6 neurosurgeons (Group A) and 12 medical students (Group B) twice, with a one-week interval. Subjective face and content validities were evaluated based on a 5-point Likert scale. Objective construct and predictive validities were gauged using the standardized Objective Structured Assessment of Aneurysm Clipping Skills (OSAACS). Results. The simulator reflected the abilities of experienced and inexperienced participants, demonstrating a high constructive validity. Inexperienced students showed immediate and significant progress in all categories, highlighting the efficacy of the simulator. Furthermore, the MATS was found highly cost-effective by all participants of A and B. The MATS was deemed superior to traditional training methods by both groups. Conclusion. Our results demonstrate that developing and implementing a high-fidelity patient specific microsurgical aneurysm training simulator into a neurosurgical curriculum is possible at low cost and in a timely manner.

Comparative evaluation of the lateral supraorbital and pterional approaches for clipping middle cerebral artery bifurcation aneurysms: Insights from a phantom model study

Abstract-Text Objective. The pterional approach has traditionally been employed for managing middle cerebral artery aneurysms. With potential benefits like reduced surgical morbidity and improved postoperative recovery, the lateral supraorbital approach (LSO) should be considered individually based on aneurysm morphology, size and patient-specific variations of the middle cerebral artery anatomy. However, choosing and executing the correct approach requires considerable expertise and skills traditionally acquired through years of experience. This study aims to develop and utilize a novel phantom model to accelerate the learning curve and decision making in the microsurgical management of unruptured middle cerebral artery (MCA) bifurcation aneurysms. Methods. A meticulously designed phantom model of the skull, brain, and MCA, inclusive of varying lengths of the M1-segment and bifurcation aneurysms, was created for this comparison. Six medical students and six neurosurgey residents and attendings (n = 12) tested the model and compared both surgical approaches. Participants rated the model"s general usability and usefulness derived from a 5-point Likert scale. Participants" performances were measured using an objective structured assessment scale for cerebral aneurysm clipping skills. Results. The simulator overwhelmingly received positive ratings in face and content validity, with mean scores of 4.9 out of 5, respectively. Objective evaluation demonstrated a high construct validity and efficiency of the model, especially among novice students. The results highlighted the potential benefits of the LSO approach such as decreased surgical time, improved precision in aneurysm clipping, potential for reduced surgical morbidity and improved postoperative recovery in cases where M1 was shorter than 12 mm. Conclusion. The phantom model proved to be an effective training and assessment tool showcasing the potential benefits of phantom models in patient-specific surgical planning.

Simulation in neurosurgery: Life-like reconstruction of the Sylvian Fissure for practical neurovascular simulation training

Abstract-Text Objective. The correct microsurgical dissection of the Sylvian fissure is an important technique in neurosurgeryrequiring considerable expertise and technical skills acquired through years of experience and rigorous training. The rapidly evolving landscape of neurosurgery necessitates the development of efficient training methodologies with the aim to accelerate the learning curve. Synthetic models can provide the freedom of focused, hands-on training in a more controlled environment. However, the incorporation of simulators into the neurosurgical curriculum remains a challenge due to their lack of realism, high acquisition costs or complex and time-consuming production processes. The aim of this work is to develop and evaluate a highly realistic yet cost-effective and easily producible synthetic model of the Sylvian fissure with a focus on middle cerebral artery aneurysm clipping. Methods. Segmentation and high-detail reconstruction of the skull, brain and cerebral arteries from CT and MRI datasets were achieved using freeware. The models were sliced into replaceable, adjustable parts and printed using a desktop 3D-Printer. Based on the expertise of experienced neurosurgeons and rheological tissue characterizations, high-detailed models of the sylvian fissure with emphasis on mimicking the tactile properties of the living brain were produced including life-like reconstructions of the brain meninges, vessels and aneurysms using readily available und inexpensive materials. Six medical students, four neurosurgery residents, and two experienced neurosurgeons tested and evaluated the model"s face and content validity. Construct and predictive validity were assessed using an objective assessment scale for the dissection of the Sylvian fissure. Results. The simulator overwhelmingly received positive ratings in face and content validity, with mean scores of 4.8 and 4.7 out of 5, respectively. Construct validity was demonstrated by significant differences in performance scores between the three groups (p &lt; 0.05). Predictive validity was supported by significant improvement in performance scores among novice participants. Conclusions. We were able to demonstrate that developing and implementing a high-fidelity simulator for one the most challenging neurosurgical procedures into neurosurgical training curriculum is achievable in a timely manner and without extensive investments.

Introducing the frontobasis-dome-angle: A comparative analysis of interhemispheric vs. pterional approach for anterior communicating artery aneurysms with emphasis on aneurysm angulation

Abstract-Text Objective: The surgical treatment of Anterior communicating artery aneurysms (AcomA) is intricate due to their deep midline position and proximity to multiple vessels, increasing the risk of ischemic events. This study aims to compare the widely-used pterional craniotomy with the interhemispheric approach, emphasizing AcomA angulation relative to the frontobasis. Methods: A total of 584 saccular intracranial aneurysms (IAs) were analyzed, selecting 50 AcomA cases that underwent microsurgical clipping through either the pterional or interhemispheric approach. All selected cases had available CT-angiography with sagittal imaging slices and conventional angiography. Using an interactive tool, we matched 14 cases of AcomA treated via interhemispheric approach with 14 pterionally approached cases based on clinical and morphological parameters, placing special emphasis on IA dome angulation relative to the frontobasis. Outcomes considered included IA occlusion, patient functionality, incidence of temporary clipping, intraoperative rupture, postoperative strokes, hemorrhages, hydrocephalus, and vasospasm. Results: The matched cohorts revealed consistent demographics. Both surgical approaches resulted in similar IA occlusion rates. However, the interhemispheric approach led to improved clinical outcomes, with a significant reduction in the modified Rankin Scale at discharge (p=0.027). Additionally, the interhemispheric method indicated a decreased incidence of hydrocephalus and diminished requirement for permanent ventriculoperitoneal shunt placement. Vasospasms and postoperative infarctions were comparable between the groups. Conclusion: For AcomA surgery, our data from a small cohort suggests a slight advantage of the interhemispheric approach based on the selected parameters. Yet, surgical choices should be tailored to individual patient characteristics and the expertise of the surgeon.

Vaskuläre Neurochirurgie
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Vaskuläre NeurochirurgieVaskulär / Ausbildung

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Vaskuläre Neurochirurgie
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