Objective: We aimed to identify unfavorable prognostic factors for the development of cerebral ischemic complications of surgical treatment in patients with moyamoya disease. Methods: We analyzed 80 patients with moyamoya disease, who underwent 134 surgical revascularizations. Persistent complications (ischemic strokes) developed in seven cases (5.3
INTRODUCTION:Intracranial aneurysms (IAs) are critical vascular defects potentially leading to subarachnoid hemorrhage. A Bayesian framework assists clinicians in assessing IA risks by evaluating multiple factors, including sex, due to its higher prevalence in women. METHODS:This study adopted the Bayesian theorem to quantify IA prevalence and the incidence of subsequent hemorrhage, examining sex as a pivotal risk factor for IA rupture stratification. RESULTS:The Bayesian analysis revealed a greater incidence of IAs among women yet indicated that sex does not have a significant impact on the rupture risk in diagnosed patients. This finding suggests the necessity of considering other cofactors in risk evaluation. CONCLUSIONS:Bayesian approaches provide clinicians with refined tools for IA risk assessment, emphasizing the complex interplay of various risk factors beyond sex. Acknowledging the limited influence of sex on rupture probability is crucial in guiding IA management. Continuous research is warranted to advance Bayesian methods, improving their clinical applicability and enhancing patient treatment outcomes.
Purpose: The analysis of the microstructure of dural arteriovenous fistulas (DAVFs) plays a crucial role in achieving the successful embolization of DAVFs associated with complex microanatomy. Recent advancements in high-resolution cone-beam computed tomography (CBCT) enable detailed visualizations of the microstructure of the shunt point. In this study, we retrospectively evaluated the efficacy of this imaging modality in terms of the clinical and angiographic outcomes of the endovascular approach. Methods: We retrospectively analyzed a total of 83 cases of dural arteriovenous fistulas (AVFs), including spinal lesions. High-resolution CBCT images with an 8-inch field of view and 1024 × 1024 pixel matrix detector at 80 kV were acquired. The anatomical variation and configuration of DAVFs were analyzed and compared with superselective angiography findings. Results: The sensitivity of the shunt location was over 96.3
Perfusion MRI via arterial spin labeling (ASL) could not precisely estimate cerebral ischemia severity in patients with occlusive cerebrovascular disease (CVD), because the delayed arrival of arterial blood spins (AB spins) in the affected vascular territories could not be corrected v single post-labeling delay (PLD) setting. In this study, new hemodynamic parameters for cerebral ischemia using dual ASL perfusion imaging under double PLD setting will be proposed. In 67 patients with moyamoya disease (MMD) and 22 patients with large artery atherosclerosis (LAA), hemodynamic parameters were investigated by using dual ASL perfusion imaging via 3.0 T MRI. PLD was fixed to 1525 ms (early image) and 2525 ms (late image). In early images, early slow-in of AB spins into cerebral tissue, and the early stagnation of AB spins within cortical arteries were investigated. In late images, late filling up (complete or incomplete) and both late stagnation and overstagnation were estimated. Early slow-in (65/67 = 97
Flow-augmentation bypass aims to enhance blood flow to hypoperfused brain regions in patients with cerebrovascular steno-occlusive diseases. This surgical procedure is indicated for ischemic and hemorrhagic moyamoya vasculopathy and for selected patients with chronic steno-occlusive disease and acute ischemic stroke. Flow-augmentation bypass has been rigorously evaluated in randomized clinical trials, including the EC-IC Bypass Trial, the Carotid Occlusion Surgery Study (COSS), the Japanese Adult Moyamoya (JAM) trial, and the recent Carotid and Middle Cerebral Artery Occlusion Surgery Study (CMOSS). In this article, we examine the current indications and outline the diagnostic and therapeutic decision-making processes for patients with steno-occlusive disease who are candidates for flow-augmentation bypass surgery.
Training microsurgical and neurosurgical techniques by using multimodal simulators in the lab is a fundamental component of neurosurgical residency nowadays. The authors of this chapter describe a training curriculum for residents in neurosurgery implemented at the Zurich Microsurgery Lab, one that integrates different simulators to ensure a seamless and effective progression in microneurosurgical skill acquisition. Neurosurgical residents at all levels of training can benefit from this training scheme, profiting from the realistic replication of surgical scenarios and conditions. Next-generation silicon tubes are used as the initial tools and provide exposure to basic microsurgical skills. Placental simulators have become a milestone at our lab for training microsurgical techniques such as vessel dissection and microanastomoses. Craniotomy sessions are performed using hyper-realistic three-dimensional (3D) skull models. Mixed reality allows for teaching surgical anatomy with 3D interactive reconstructions of the most relevant anatomical structures. Cadaver models offer a realistic anatomical setting for advanced specialistic training.
Moyamoya disease (MMD) is considered to run a progressive course, but little is known about its long-term outcomes. We conducted a structured phone interview to assess outcomes in a mixed cohort of conservatively and surgically treated patients a median of 9 years and up to 27 years after a diagnosis of MMD. We found that 60
PurposeThe purpose of this chapter is to present our initial results of the use of a hybrid operating room (OR) in cerebrovascular procedures.MethodsIn this retrospective study, 152 patients who suffered from cerebrovascular pathology and were treated at the hybrid OR at the Department of Neurosurgery at Kepler University Hospital from April 2020 to October 2022 were included. Vascular pathologies and hybrid interventions were analyzed. Additionally, the number of residual aneurysms and vessel stenosis/occlusions was assessed.ResultsSpecifically, 106 patients were treated because of a cerebral aneurysm. In six cases, a residual aneurysm was identified. In another three cases, a stenosis/occlusion was found, and in three patients, a hybrid intervention was performed. These results indicate that about 10% of the patients might benefit from the treatment in a hybrid OR. Furthermore, 49 patients were treated for carotid stenosis/occlusion and 12 had an arteriovenous malformation or fistula.ConclusionNo procedure-related complications occurred in the observed cohort. The hybrid OR provided readily available, high-quality intraoperative imaging. Hybrid procedures increase the quality of care and patient safety. Furthermore, they might contribute to the reduction of intraoperative complications.
Purpose: Although endovascular treatment (EVT) is often the treatment of choice for intracranial dural arteriovenous fistula (dAVF), direct surgery is an efficient option for many types of dAVFs. Herein, we present a relatively large case series of direct surgical patients to discuss the role and efficacy of direct surgery in managing intracranial dAVFs. Methods: 43 consecutive patients with dAVFs (ethmoid, n = 11; middle fossa, n = 1; convexity, n = 2; tentorium, n = 11; superior sagittal sinus, n = 2; transverse-sigmoid sinus, n = 11; and cranio-vertebral junction [CVJ], n = 5) treated with direct surgery were retrospectively assessed. Here, 21 (48.8
Purpose: To investigate the role of magnetic resonance tractography (MRT) for the evaluation of motor function in surgery for brain arteriovenous malformations (AVMs). Methods: Of 112 patients with brain AVMs operated on by the senior author (K.K.) between 2000 and 2022, 22 consecutive patients with frontal, parietal, temporal, sylvian, and insular AVMs underwent an evaluation of neural tracts via 3-tesla (3 T) MRT before and after surgery. There were 12 men and 10 women (mean age 29.0 ± 13.6 years). Here, 14 patients presented with hemorrhage, five with epilepsy, and three with ischemic symptoms. Spetzler–Martin grade (SMG) assessments were I in six patients, II in nine, III in six, and IV in one. The microsurgical resection of the AVMs achieved total removal in all 22 patients. Results: The presence of preoperative motor dysfunction and the minimal distance between an AVM and the corticospinal tract (MDACST) was significantly related to transient motor deterioration. The presence of preoperative motor dysfunction, a tract injury on postoperative MRT, the presence of transient motor dysfunction, and the MDACST were significantly related to permanent motor dysfunction. Multivariate analysis also suggested that the MDACST was one of the most predictive factors of transient motor deterioration and permanent motor dysfunction. The cutoff value at the receiver operating characteristic analysis indicated that MDACST less than 16 mm and MDACST less than 8 mm could highly predict transient motor deterioration and permanent motor dysfunction, respectively. Conclusions: Surgery on an AVM with MDCT less than 16 mm would probably induce transient motor deterioration, and less than 8 mm would probably cause permanent motor dysfunction.
Cerebral cavernous malformations (CCMs) are vascular anomalies affecting the central nervous system in up to 0.5% of the population. These lesions are characterised by thin-walled, dilated blood vessels that are susceptible to haemorrhage. They can cause several symptoms, such as epileptic seizures, haemorrhagic strokes, and focal neurological deficits. Clinical studies have revealed the epidemiology and natural history of CCMs. Human genetic studies have identified CCM1, CCM2, and CCM3 as established driver genes, and more recently, PIK3CA and MAP3K3 have been identified as additional potential driver genes. Moreover, on the basis of genetic information, animal studies have developed model organisms, including murine models, that highly recapitulate human CCMs, facilitating the elucidation of molecular mechanisms. This article provides a brief overview of the epidemiology and aetiology of CCMs.
Introduction: We aimed to classify different degrees of cerebrovascular insufficiency (CVI) in patients with moyamoya disease (MMD) by measuring cerebral blood flow (CBF) and distinguishing arterial transit artifacts (ATAs) on arterial spin labeling (ASL) magnetic resonance imaging (MRI). Methods: The study included 121 images of patients with MMD who underwent ASL-MRI before and after surgical treatment (242 hemispheres). On ASL-CBF maps, regions of interest (ROIs) were manually drawn in each hemisphere in seven zones. Quantitative and qualitative patterns of arterial transit artifacts (ATA) were studied. Analysis of variance (ANOVA) was used for group comparisons. Results: Distinguished patterns were divided into four statistically significant degrees on the basis of CBF values and the presence of ATA: degree 0 with normal CBF values and without ATAs (n = 59) (CBF 60.37–68.64 mL/100gxmin); degree 1 with moderate decreased CBF and with ATAs (n = 97) (CBF 55.82–62.16); degree 2 with significantly decreased CBF and with ATAs (n = 64) (CBF 25.64–28.96); and degree 3 with very low CBF and without ATAs (n = 22) (CBF 15.58–19.97). All groups exhibited significant differences between the value of CBF in all cortical territories (p < 0.01). Distinguished patterns had high correlations between Suzuki stage, the severity of ischemic disease, and neurologic deficit. Conclusion: The revealed ASL-MRI patterns correspond to the degree of CVI, the stage of the disease, and the clinical symptoms and can be used for assessment in the patients with moyamoya disease.
Background: Brain arteriovenous malformations (AVMs) can cause cerebral haemorrhage, associated morbidity, and mortality if left untreated. Therefore, prophylactic interventions are essential to manage these lesions. The purpose of this study was to describe our experience of incorporating new technologies into gamma knife radiosurgery (GKRS) for AVMs, aiming to improve its effectiveness and safety. Methods: We conducted a retrospective observational study that included 1032 patients with AVMs who underwent GKRS at our institution from 1990 to 2022. We reviewed the detailed treatment techniques and updates on GKRS, including tractography-guided identification of critical white matter fibres for eloquent AVMs, GKRS with minimal targeting embolisation for high-haemorrhage risk AVMs, and rotational angiography based GKRS for all AVMs. We evaluated the GKRS outcomes for AVM obliteration, post-GKRS haemorrhage, survival, post-GKRS signal changes, and neurological preservation. Results: We collected data from 90 patients by using the most advanced techniques. The cumulative obliteration rates were 61.0
Objective: Revascularization surgery such as superficial temporal artery–middle cerebral artery (STA-MCA) bypass is a standard management choice for symptomatic moyamoya disease (MMD) patients, with either ischemic or hemorrhagic presentation. We sought to clarify the efficacy and safety of institutional standardized revascularization procedures for MMD. Materials and methods: The present study includes 37 consecutive patients with MMD (2–60 years old, 42.0 on average) undergoing revascularization surgery on 42 affected hemispheres. Direct-indirect combined revascularization surgery was performed on most hemispheres (41/42, 97.6
Having a paraspinal arteriovenous shunt located in the paraspinal region outside the spinal canal is rare. Germline phosphatase and tensin homolog gene (PTEN) mutations have been noted in cases with a specific paraspinal arteriovenous shunt. We report a patient with a paraspinal arteriovenous shunt with multiple primary cancers and report a germline mutation diagnosed with PTEN hamartoma syndrome. PTEN hamartoma syndrome can manifest as various cancers. Early diagnosis of PTEN hamartoma syndrome is essential for improving patient prognosis and life expectancy. The coexistence of multiple primary cancers and vascular malformations can be considered red flags for PTEN hamartoma syndrome.
Purpose: Exoscopes have been used as a reliable surgical tool in the neurosurgical field. They could improve surgical field visibility with 4K three-dimensional (4K-3D) monitors and provide alleviation for the physical strain by allowing surgeons to maintain a neutral posture. In this study, we report our initial experience with exoscopic superficial temporal artery (STA)–middle cerebral artery (MCA) bypass compared to the conventional microscope at our institution. Methods: This study included 58 patients with ischemic status, including internal carotid artery (ICA) stenosis, ICA occlusion, MCA stenosis, MCA occlusion, and moyamoya disease with ischemic onset, who underwent STA-MCA bypass between January 2021 and August 2022. The baseline characteristics, setup time, operative time, duration of MCA occlusion, surgical complications, and clinical outcomes were retrospectively analyzed. Additionally, a total of 19 neurosurgeons evaluated the effects of exoscope on the cerebrovascular procedure by using a questionnaire. Results: 36 patients (62.0
PURPOSE:Intravenous and intra-arterial milrinone as a rescue measure for delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) has been adopted by several groups, but so far, evidence for the clinical benefit is unclear and the effect on brain perfusion is contradictory. We recently published our experience with intravenous milrinone as a rescue strategy for DCI. The aim of the actual analysis was to contextualize our experience with the currently available evidence from clinical trials on the effect of intravenous milrinone in preventing or treating DCI following aneurysmal SAH. METHODS:PubMed was searched for clinical studies using intravenous milrinone for the prevention or treatment of DCI after aneurysmal subarachnoid hemorrhage. RESULTS:In our series, using intravenous milrinone as a rescue strategy together with using norepinephrine to elevate blood pressure, improvements in cerebral perfusion as measured by perfusion computed tomography (CT) and in clinical symptoms were seen after the induction of rescue therapy. At long-term follow-up, patients suffering DCI had only modestly worse outcomes than patients not suffering DCI. The PubMed search provided four comparative clinical studies. In a preventive setup, Soliman et al. compared intravenous milrinone with magnesium. The incidence of cerebral vasospasm was significantly lower and patients' neurological condition in terms of the Glasgow Coma Scale (GCS) better with magnesium compared to milrinone. Milrinone was associated with hypotension and the need for dopamine and norepinephrine. Rouanet et al. compared milrinone with norepinephrine as a rescue strategy. They found that transcranial Doppler (TCD) flow velocities decreased after milrinone therapy only, not after norepinephrine, whereas clinical improvement was achieved with both treatment strategies. Labeyrie et al. compared balloon angioplasty plus intravenous milrinone with induced hypertension alone. They did not find any significant differences regarding the outcomes. Finally, Lakhal and coauthors compared intravenous milrinone plus induced hypertension as a rescue strategy, where a historical control group received induced hypertension alone. Milrinone was associated with a lower rate of additional endovascular angioplasty and a positive impact on long-term neurological and radiological outcomes. CONCLUSION:Our study showed that cerebral perfusion in the setting of secondary cerebral ischemia following SAH is measurably improved via intravenous milrinone and norepinephrine-based hyperdynamic therapy. In the context of the available literature, when used as a rescue strategy, milrinone appears to be beneficial if additional norepinephrine is given to maintain adequate arterial pressure.
PURPOSE:The three-dimensional (3D) exoscope has been reported to have better image quality, ergonomics, and educational outcomes than a microscope. However, whether the exoscope can improve communication between the main surgeon and the mentor remains unclear. This chapter introduces our experience with using an exoscope and an annotation system for surgical education during a left middle cerebral aneurysm surgery in a 63-year-old woman. METHODS:We used an annotation system integrated with a 3D exoscope during aneurysm surgery. The mentor provided instruction by using the annotation system to write information on the surgical monitor. RESULTS:The aneurysmal neck was broad and required two clips to achieve complete clipping. On a monitor, the mentor drew instructions for inserting the clips. The surgeon successfully accomplished the clipping as instructed. Intraoperative indocyanine green angiography revealed the complete occlusion of the aneurysm. The patient had no postoperative neurological deficit. CONCLUSION:A new system using an annotation system integrated with an exoscope for surgical education was introduced and applied to an aneurysm clipping surgery. This system is expected to improve communication between surgeons and mentors and improve surgical safety.
Background: The increasing adoption of artificial intelligence (AI) and augmented reality (AR) within vascular neurosurgery has become a prominent trend. The primary challenge before us is seamlessly integrating these advanced concepts and developing them further to improve patient outcomes. Methods: We combined peer-reviewed publications of our research group over the past 5 years with current research projects to form the basis of a narrative discussion, aiming to better understand drawbacks, challenges, and the developmental steps to be followed. Results: Four developmental phases were identified: (1) the integration of AI and AR to create adequate three-dimensional (3D) segmentations; (2) adding flow and pulsatility data to create 5D segmentations; (3) treatment planning in these models; and (4) treatment guidance using these models. The main drawback described was the limited added value in the microscopic phase of neurovascular surgery due to view obstructions and a lack of accuracy. The main challenge described was the current limitation in computational and graphical processing capabilities. Conclusion: Although drawbacks and challenges still exist, AI and AR are rapidly developing topics within vascular neurosurgery. The research in this field could lay the groundwork for fully automatized treatment strategies in the future.
The endovascular approach, as a less invasive method, has been used to deliver direct surgery for the treatment of cerebral aneurysms. With the rapid and evolutional improvement in imaging technology, devices, treatment skills, and perioperative managements, the success rates of endovascular treatments have been increasing annually. Particularly, endovascular treatments are highly expected for surgically difficult aneurysms, such as large aneurysms, or for those similar to tiny blood blisters. The flow diverter, one of the breakthrough devices, has improved the clinical results of these aneurysms. As another challenge, robotics may resolve the problems of radiation exposure for the operator by allowing remote telesurgery. Such a recent challenge with novel devices and technologies is introduced here, along with our own experiences.
