Segmentation techniques of brain arteriovenous malformations for 3D visualization: a systematic review

BACKGROUND Visualization, analysis and characterization of the angioarchitecture of a brain arteriovenous malformation (bAVM) present crucial steps for understanding and management of these complex lesions. Three-dimensional (3D) segmentation and 3D visualization of bAVMs play hereby a significant role. We performed a systematic review regarding currently available 3D segmentation and visualization techniques for bAVMs. METHODS PubMed, Embase and Google Scholar were searched to identify studies reporting 3D segmentation techniques applied to bAVM characterization. Category of input scan, segmentation (automatic, semiautomatic, manual), time needed for segmentation and 3D visualization techniques were noted. RESULTS Thirty-three studies were included. Thirteen (39%) used MRI as baseline imaging modality, 9 used DSA (27%), and 7 used CT (21%). Segmentation through automatic algorithms was used in 20 (61%), semiautomatic segmentation in 6 (18%), and manual segmentation in 7 (21%) studies. Median automatic segmentation time was 10 min (IQR 33), semiautomatic 25 min (IQR 73). Manual segmentation time was reported in only one study, with the mean of 5-10 min. Thirty-two (97%) studies used screens to visualize the 3D segmentations outcomes and 1 (3%) study utilized a heads-up display (HUD). Integration with mixed reality was used in 4 studies (12%). CONCLUSIONS A golden standard for 3D visualization of bAVMs does not exist. This review describes a tendency over time to base segmentation on algorithms trained with machine learning. Unsupervised fuzzy-based algorithms thereby stand out as potential preferred strategy. Continued efforts will be necessary to improve algorithms, integrate complete hemodynamic assessment and find innovative tools for tridimensional visualization

Evaluation of patient STress level caused by radiological Investigations in early Postoperative phase After CRANIOtomy (IPAST-CRANIO): protocol of a Swiss prospective cohort study

INTRODUCTION Postoperative imaging after neurosurgical interventions is usually performed in the first 72 hours after surgery to provide an accurate assessment of postoperative resection status. Patient frequently report that early postoperative examination after craniotomy for tumour and vascular procedures is associated with distress, exertion, nausea and pain. Delayed postoperative imaging (between 36 and 72 hours postoperatively) may have an advantage regarding psychological and physical stress compared with early imaging. The goal of this study is to evaluate and determine the optimal time frame for postoperative imaging with MRI and CT in terms of medical and neuroradiological implications and patient's subjective stress level. METHODS AND ANALYSIS Data will be prospectively collected from all patients aged 18-80 years who receive postoperative MRI or CT imaging following a craniotomy for resection of a cerebral tumour (benign and malignant) or vascular surgery. Participants have to complete questionnaires containing visual analogue scores (VAS) for headache and nausea, Body Part Discomfort score and a single question addressing subjective preference of timing of postoperative imaging after craniotomy. The primary endpoint of the study is the difference in subjective stress due to imaging studies after craniotomy, measured just before and after postoperative MRI or CT with the above-mentioned instruments. Subjective stress is defined as a combination of the scores VAS pain, VAS nausea and 0.5* Body Part Discomfort core.This study determines whether proper timing of postoperative imaging can improve patient satisfaction and reduce pain, stress and discomfort caused by postoperative imaging. Factors causing additional postoperative stress are likely responsible for delayed recovery of neurosurgical patients. ETHICS AND DISSEMINATION The institutional review board (Kantonale Ethikkommission Zürich) approved this study on 4 August 2020 under case number BASEC 2020-01590. The authors are planning to publish the data of this study in a peer-reviewed paper. After database closure, the data will be exported to the local data repository (Zurich Open Repository and Archive) of the University of Zurich. The sponsor (LR) and the project leader (MR.G) will make the final decision on the publication of the results. The data that support the findings of this study are available on request from the corresponding author LT. The data are not publicly available due to privacy/ethical restrictions. TRIAL REGISTRATION NUMBER NCT05112575; ClinicalTrials.gov

Surgically treated intradural spinal manifestation of hereditary amyloidogenic transthyretin amyloidosis - A case report and scoping review of the literature

Introduction Hereditary transthyretin amyloidosis (ATTRv) is an autosomal-dominant disorder, where a TTR mutations lead to amyloid fibril deposits in tissues and consecutively alter organ function. ATTRv is a multisystemic disorder with a heterogeneous clinical presentation. Spinal leptomeningeal depositions are described only scarcely in the literature. Research question We present a rare case of surgically treated intradural, extra-medullary amyloidosis with respective clinical, diagnostic and surgical features to raise awareness of this rare entity. Material and methods Clinical, radiological and operative characteristics were retrieved from the electronical patient management system. Additionally, a scoping literature review on leptomeningeal spinal manifestations of ATTRv was performed. Results A 45-year-old man with a known ATTRv presented with gait disturbance and paresis of the lower extremities. He had been treated with the siRNA therapeutical Patisiran for 13 months under which his symptoms worsened. An MRI of the spine revealed spinal cord compression with myelopathy at the level of T2 with anterior dislocation of the spinal cord due to an intradural, extramedullary lesion. A laminectomy and opening of the dura with a complete resection of the lesion was performed. The histological examination of the biopsy showed amyloid deposits. At six-month follow-up the patient showed complete normalization of the paresis, gait, sensory and urinary disturbances and resumed his work. Discussion and conclusion Spinal leptomeningeal deposition of amyloid is a rare occurrence within the framework of ATTRv. Micro-neurosurgical complete resection of the lesion is feasible in patients with preoperative myelopathic symptoms and resulted in complete symptom relief in this case

Aneurysm treatment within 6 h versus 6-24 h after rupture in patients with subarachnoid hemorrhage

BACKGROUND The risk of rebleeding after aneurysmal subarachnoid hemorrhage (aSAH) is the highest during the initial hours after rupture. Emergency aneurysm treatment may decrease this risk, but is a logistic challenge and economic burden. We aimed to investigate whether aneurysm treatment <6 h after rupture is associated with a decreased risk of poor functional outcome compared to aneurysm treatment 6-24 h after rupture. METHODS We used data of patients included in the ULTRA trial (NCT02684812). All patients in ULTRA were admitted within 24 h after aneurysm rupture. For the current study, we excluded patients in whom the aneurysm was not treated <24 h after rupture. We calculated crude and adjusted risk ratios (aRR) with 95% confidence intervals using Poisson regression analyses for poor functional outcome (death or dependency, assessed by the modified Rankin Scale) after aneurysm treatment <6 h versus 6-24 h after rupture. Adjustments were made for age, sex, clinical condition on admission (WFNS scale), amount of extravasated blood (Fisher score), aneurysm location, tranexamic acid treatment, and aneurysm treatment modality. RESULTS We included 497 patients. Poor outcome occurred in 63/110 (57%) patients treated within 6 h compared to 145/387 (37%) patients treated 6-24 h after rupture (crude RR: 1.53, 95% CI: 1.24-1.88; adjusted RR: 1.36, 95% CI: 1.11-1.66). CONCLUSION Aneurysm treatment <6 h is not associated with better functional outcome than aneurysm treatment 6-24 h after rupture. Our results do not support a strategy aiming to treat every patient with a ruptured aneurysm <6 h after rupture

Screening tools for early neuropsychological impairment after aneurysmal subarachnoid hemorrhage

Background Although most aneurysmal subarachnoid hemorrhage (aSAH) patients suffer from neuropsychological disabilities, outcome estimation is commonly based only on functional disability scales such as the modified Rankin Scale (mRS). Moreover, early neuropsychological screening tools are not used routinely. Objective To study whether two simple neuropsychological screening tools identify neuropsychological deficits (NPDs), among aSAH patients categorized with favorable outcome (mRS 0-2) at discharge. Methods We reviewed 170 consecutive aSAH patients that were registered in a prospective institutional database. We included all patients graded by the mRS at discharge, and who had additionally been evaluated by a neuropsychologist and/or occupational therapist using the Montreal Cognitive Assessment (MoCA) and/or Rapid Evaluation of Cognitive Function (ERFC). The proportion of patients with scores indicative of NPDs in each test were reported, and spearman correlation tests calculated the coefficients between the both neuropsychological test results and the mRS. Results Of the 42 patients (24.7%) that were evaluated by at least one neuropsychological test, 34 (81.0%) were rated mRS 0-2 at discharge. Among these 34 patients, NPDs were identified in 14 (53.9%) according to the MoCA and 8 (66.7%) according to the ERFC. The mRS score was not correlated with the performance in the MoCA or ERFC. Conclusion The two screening tools implemented here frequently identified NPDs among aSAH patients that were categorized with favorable outcome according to the mRS. Our results suggest that MoCA or ERFC could be used to screen early NPDs in favorable outcome patients, who in turn might benefit from early neuropsychological rehabilitation.Peer reviewe

Challenges in Coagulation Management in Neurosurgical Diseases: A Scoping Review, Development, and Implementation of Coagulation Management Strategies

Bleeding and thromboembolic (TE) complications in neurosurgical diseases have a detrimental impact on clinical outcomes. The aim of this study is to provide a scoping review of the available literature and address challenges and knowledge gaps in the management of coagulation disorders in neurosurgical diseases. Additionally, we introduce a novel research project that seeks to reduce coagulation disorder-associated complications in neurosurgical patients. The risk of bleeding after elective craniotomy is about 3%, and higher (14-33%) in other indications, such as trauma and intracranial hemorrhage. In spinal surgery, the incidence of postoperative clinically relevant bleeding is approximately 0.5-1.4%. The risk for TE complications in intracranial pathologies ranges from 3 to 20%, whereas in spinal surgery it is around 7%. These findings highlight a relevant problem in neurosurgical diseases and current guidelines do not adequately address individual circumstances. The multidisciplinary COagulation MAnagement in Neurosurgical Diseases (COMAND) project has been developed to tackle this challenge by devising an individualized coagulation management strategy for patients with neurosurgical diseases. Importantly, this project is designed to ensure that these management strategies can be readily implemented into healthcare practices of different types and with sustainable integration

Blood volume measurement with indocyanine green pulse spectrophotometry: dose and site of dye administration

(1) To determine the optimal administration site and dose of indocyanine green (ICG) for blood volume measurement using pulse spectrophotometry, (2) to assess the variation in repeated blood volume measurements for patients after subarachnoid hemorrhage and (3) to evaluate the safety and efficacy of this technique in patients who were treated for an intracranial aneurysm. Four repeated measurements of blood volume (BV) were performed in random order of bolus dose (10 mg or 25 mg ICG) and venous administration site (peripheral or central) in eight patients admitted for treatment of an intracranial aneurysm. Another five patients with subarachnoid hemorrhage underwent three repeated BV measurements with 25 mg ICG at the same administration site to assess the coefficient of variation. The mean +/- SD in BV was 4.38 +/- 0.88 l (n = 25) and 4.69 +/- 1.11 l (n = 26) for 10 mg and 25 mg ICG, respectively. The mean +/- SD in BV was 4.59 +/- 1.15 l (n = 26) and 4.48 +/- 0.86 l (n = 25) for central and peripheral administration, respectively. No significant difference was found. The coefficient of variance of BV measurement with 25 mg of ICG was 7.5% (95% CI: 3-12%). There is no significant difference between intravenous administration of either 10 or 25 mg ICG, and this can be injected through either a peripheral or central venous catheter. The 7.5% coefficient of variation in BV measurements determines the detectable differences using ICG pulse spectrophotometr

Neurosurgery outcomes and complications in a monocentric 7-year patient registry

Introduction Capturing adverse events reliably is paramount for clinical practice and research alike. In the era of “big data”, prospective registries form the basis of clinical research and quality improvement. Research question To present results of long-term implementation of a prospective patient registry, and evaluate the validity of the Clavien-Dindo grade (CDG) to classify complications in neurosurgery. Materials and methods A prospective registry for cranial and spinal neurosurgical procedures was implemented in 2013. The CDG – a complication grading focused on need for unplanned therapeutic intervention – was used to grade complications. We assess construct validity of the CDG. Results Data acquisition integrated into our hospital workflow permitted to include all eligible patients into the registry. We have registered 8226 patients that were treated in 11994 surgeries and 32494 consultations up until December 2020. Similarly, we have captured 1245 complications on 6308 patient discharge forms (20%) since full operational status of the registry. The majority of complications (819/6308 ​= ​13%) were treated without invasive treatment (CDG 1 or CDG 2). At discharge, there was a clear correlation of CDG and the Karnofsky Performance Status (KPS, rho ​= ​-0.29, slope -7 KPS percentage points per increment of CDG) and the length of stay (rho ​= ​0.43, slope 3.2 days per increment of CDG)

Posterior auricular artery as an alternative donor vessel for extracranial-intracranial bypass surgery

Background: Sometimes the superficial temporal artery (STA) is not available for an extracranial-intracranial (EC-IC) bypass procedure. An alternative vessel for an EC-IC bypass is the posterior auricular artery (PAA) if it extends to the temporoparietal area with a diameter large enough. We assessed the prevalence of an appropriate PAA as an alternative donor vessel and report three illustrative cases in which the PAA was used for EC-IC bypass surgery. Methods: A literature search was performed on the use of the PAA as a donor vessel for bypass surgery. Secondly, a prospective database of bypass surgeries was reviewed to calculate the prevalence of a PAA with a diameter of at least 1 mm in the parietotemporal area. Finally, three illustrative cases are reported that describe various indications for the revascularisation procedures with their clinical, surgical and imaging features. Results: Two articles have previously described the use of the PAA for bypass surgery and their results are summarised. The prevalence of a PAA that would be appropriate for an EC-IC bypass in patients with intracranial vascular pathology is 5.7 %. The presented cases demonstrate that the PAA can be successfully used for EC-IC bypass surgery with good flow velocities and patency. Conclusions: The PAA is a rarely described as an appropriate donor vessel for an EC-IC bypass. Its prevalence is 5.7 % and it can successfully be used as an alternative donor vessel. The awareness among cerebrovascular surgeons about the presence of a PAA and knowledge about its anatomy may be valuable

Management of aneurysmal subarachnoid hemorrhage patients in the first days after hemorrhage

Patients with aneurysmal subarachnoid hemorrhage (aSAH) have a high risk to die or remain in a dependent state. The initial hemorrhage causes early brain inury (EBI) which subsequently initiates a cascade of secondary brain injuries. Above this, a recurrent hemorrhage can occur in the first few hours after the initial hemorrhage and leads to additional damage to the already vulnerable brain. These problems make this type of hemorrhage a medical emergency. The goal of physicians who are specialized in the treatment and management of aSAH patients is to prevent complications and treat the secondary brain injuries. The selection of the right patients for the right treatment is mandatory in this process and the majority of the decisionmaking is done in the first days after the initial hemorrhage. The articles presented below describe management and treatment options that can be applied to aSAH patients in the first days after hemorrhage. Article 1 investigates the risk for the development of one of the secondary brain injuries, being delayed cerebral ischemia (DCI) in a cohort of 6,713 patients. The results, existing of patient data from different continents and therefore generalizable, show that female sex is independently associated with a higher risk for DCI. The influence of sex hormones was investigated but plays probably no role in causing this difference. These results help physicians in the decision-making process regarding the risk calculation for secondary brain injuries. Article 2 shows an in-hospital mortality rate of 13.9% in 1,669 patients who were treated for a ruptured intracranial aneurysm. Independent predictors were recurrent hemorrhage, cerebral infarction attributed to DCI and aneurysm treatment, and intraventricular hemorrhage. Preventing a recurrent hemorrhage from the aneurysm at the earliest possible opportunity with the treatment option that results in the lowest risk of posttreatment infarction will have a relevant impact on the reduction of in-hospital mortality. Patients who are at highest risk to achieve an unfavorable outcome after hospital discharge, including those with a poor clinical condition at admission (World Federation of Neurosurgical Societies (WFNS) grade 4 and 5), are studied in Article 3. The results show that, despite an initial poor clinical condition, these patients are able to achieve a favorable outcome in 30-45%. Therefore, in patients with a poor neurological condition (Glasgow Coma Scale (GCS) ≤12) the treatment should not be delayed or postponed because these patients have an acceptable chance to survive without significant neurological deficits. Nevertheless, a substantial part of patients who are admitted in a poor clinical condition still die in the hospital. In Article 4 we found that 43% of patients in poor clinical condition die. The major cause of death was withdrawal of life support (WOLS; 71%) followed by brain death (15%). The data were collected from hospitals in Europe and North-America and showed differences in the major causes of death, probably due to cultural and referral differences. As WOLS is a decision of the team of physicians, future studies need to investigate the exact reason that lead to WOLS in order to improve the care of patients who are admitted in poor clinical condition. What if patients used antiplatelet agents before the hemorrhage? The management options of different hospitals are summarized in Article 5 and show a large variety regarding discontinuing the antiplatelet agent and transfusing thrombocytes. This emphasizes the importance of evidence-based guidelines for the management of prehemorrhage antiplatelet agent use. As mentioned previously, the prevention of recurrent hemorrhage might have a relevant impact on in-hospital mortality. This was proven by the results in Article 6, which compares patients who received the antifibrinolytic agent tranexamic acid (TXA) or not. Early administration of TXA resulted in a significant reduction of in-hospital mortality with an odds ratio of 0.42. Early pharmacological thromboprophylaxis (PTP) is known to reduce venous thromboembolisms. However, PTP could potentially be harmful in patients with recently treated aneurysms or absence of an aneurysm on the first digital subtraction angiography (DSA). In Article 7 we reviewed the safety profile of early administration of PTP and concluded that this can be done safely in treated aneurysms and non-aneurysmal hemorrhage