Early surgery for superficial supratentorial spontaneous intracerebral hemorrhage: a Finnish Intensive Care Consortium study

Acta Neurochirurgica (2020) 162:3153–3160

The benefits of early surgery in cases of superficial supratentorial spontaneous intracerebral hemorrhage (ICH) are unclear. This study aimed to assess the association between early ICH surgery and outcome, as well as the cost-effectiveness of early ICH surgery.

Methods We conducted a retrospective, register-based multicenter study that included all patients who had been treated for supratentorial spontaneous ICH in four tertiary intensive care units in Finland between 2003 and 2013. To be included, patients needed to have experienced supratentorial ICHs that were 10–100 cm3 and located within 10 mm of the cortex. We used a multivariable analysis, adjusting for the severity of the illness and the probability of surgical treatment, to assess the independent association between early ICH surgery (≤ 1 day), 12-month mortality rates, and the probability of survival without permanent disability. In addition, we assessed the cost-effectiveness of ICH surgery by examining the effective cost per 1-year survivor (ECPS) and per independent survivor (ECPIS).

Results Of 254 patients, 27%were in the early surgery group. Overall 12-monthmortality was 39%, while 29%survived without a permanent disability. According to our multivariable analysis, early ICH surgery was associated with lower 12-month mortality rates (odds ratio [OR] 0.22, 95% confidence intervals [CI] 0.10–0.51), but not with a higher probability of survival without permanent disability (OR 1.23, 95% CI 0.59–2.56). For the early surgical group, the ECPS and ECPIS were €111,409 and €334,227, respectively. For the non-surgical cohort, the ECPS and ECPIS were €76,074 and €141,471, respectively.

Conclusions Early surgery for superficial ICH is associated with a lower 12-month mortality risk but not with a higher probability of survival without a permanent disability. Further, costs were higher and cost-effectiveness was, thus, worse for the early surgical cohort.

Early postmarket results with PulseRider for treatment of wide-necked intracranial aneurysms: a multicenter experience

J Neurosurg 133:1756–1765, 2020

Traditionally, stent-assisted coiling and balloon remodeling have been the primary endovascular treatments for wide-necked intracranial aneurysms with complex morphologies. PulseRider is an aneurysm neck reconstruction device that provides parent vessel protection for aneurysm coiling. The objective of this study was to report early postmarket results with the PulseRider device.

METHODS This study was a prospective registry of patients treated with PulseRider at 13 American neurointerventional centers following FDA approval of this device. Data collected included clinical presentation, aneurysm characteristics, treatment details, and perioperative events. Follow-up data included degree of aneurysm occlusion and delayed (> 30 days after the procedure) complications.

RESULTS A total of 54 aneurysms were treated, with the same number of PulseRider devices, across 13 centers. Fourteen cases were in off-label locations (7 anterior communicating artery, 6 middle cerebral artery, and 1 A1 segment anterior cerebral artery aneurysms). The average dome/neck ratio was 1.2. Technical success was achieved in 52 cases (96.2%). Major complications included the following: 3 procedure-related posterior cerebral artery strokes, a devicerelated intraoperative aneurysm rupture, and a delayed device thrombosis. Immediately postoperative Raymond-Roy occlusion classification (RROC) class 1 was achieved in 21 cases (40.3%), class 2 in 15 (28.8%), and class 3 in 16 cases (30.7%). Additional devices were used in 3 aneurysms. For those patients with 3- or 6-month angiographic follow-up (28 patients), 18 aneurysms (64.2%) were RROC class 1 and 8 (28.5%) were RROC class 2.

CONCLUSIONS PulseRider is being used in both on- and off-label cases following FDA approval. The clinical and radiographic outcomes are comparable in real-world experience to the outcomes observed in earlier studies. Further experience is needed with the device to determine its role in the neurointerventionalist’s armamentarium, especially with regard to its off-label use.

Intraoperative CT and cone-beam CT imaging for minimally invasive evacuation of spontaneous intracerebral hemorrhage

Acta Neurochirurgica (2020) 162:3167–3177

Minimally invasive surgery (MIS) for evacuation of spontaneous intracerebral hemorrhage (ICH) has shown promise but there remains a need for intraoperative performance assessment considering the wide range of evacuation effectiveness. In this feasibility study, we analyzed the benefit of intraoperative 3-dimensional imaging during navigated endoscopyassisted ICH evacuation by mechanical clot fragmentation and aspiration.

Methods 18 patients with superficial or deep supratentorial ICH underwent MIS for clot evacuation followed by intraoperative computerized tomography (iCT) or cone-beamCT (CBCT) imaging. Eligibility for MIS required (a) availability of intraoperative iCT or CBCT, (b) spontaneous lobar or deep ICH without vascular pathology, (c) a stable ICH volume (20–90 ml), (d) a reduced level of consciousness (GCS 5–14), and (e) a premorbid mRS ≤ 1. Demographic, clinical, and radiographic patient data were analyzed by two independent observers.

Results Nine female and 9 male patients with a median age of 76 years (42–85) presented with an ICH score of 3 (1–4), GCS of 10 (5–14) and ICH volume of 54 ± 26 ml. Clot fragmentation and aspiration was feasible in all cases and intraoperative imaging determined an overall evacuation rate of 80 ± 19% (residual hematoma volume: 13 ± 17 ml; p < 0.0001 vs. Pre-OP).Based on the intraoperative imaging results, 1/3rd of all patients underwent an immediate re-aspiration attempt. No patient experienced hemorrhagic complications or required conversion to open craniotomy. However, routine postoperative CT imaging revealed early hematoma re-expansion with an adjusted evacuation rate of 59 ± 30% (residual hematoma volume: 26 ± 37 ml; p < 0.001 vs. Pre-OP).

Conclusions Routine utilization of iCTor CBCT imaging in MIS for ICH permits direct surgical performance assessment and the chance for immediate re-aspiration, which may optimize targeting of an ideal residual hematoma volume and reduce secondary revision rates.

PulseRider for treatment of wide-necked intracranial aneurysms: a multicenter experience

J Neurosurg 133:1756–1765, 2020

Traditionally, stent-assisted coiling and balloon remodeling have been the primary endovascular treatments for wide-necked intracranial aneurysms with complex morphologies. PulseRider is an aneurysm neck reconstruction device that provides parent vessel protection for aneurysm coiling. The objective of this study was to report early postmarket results with the PulseRider device.

METHODS This study was a prospective registry of patients treated with PulseRider at 13 American neurointerventional centers following FDA approval of this device. Data collected included clinical presentation, aneurysm characteristics, treatment details, and perioperative events. Follow-up data included degree of aneurysm occlusion and delayed (> 30 days after the procedure) complications.

RESULTS A total of 54 aneurysms were treated, with the same number of PulseRider devices, across 13 centers. Fourteen cases were in off-label locations (7 anterior communicating artery, 6 middle cerebral artery, and 1 A1 segment anterior cerebral artery aneurysms). The average dome/neck ratio was 1.2. Technical success was achieved in 52 cases (96.2%). Major complications included the following: 3 procedure-related posterior cerebral artery strokes, a devicerelated intraoperative aneurysm rupture, and a delayed device thrombosis. Immediately postoperative Raymond-Roy occlusion classification (RROC) class 1 was achieved in 21 cases (40.3%), class 2 in 15 (28.8%), and class 3 in 16 cases (30.7%). Additional devices were used in 3 aneurysms. For those patients with 3- or 6-month angiographic follow-up (28 patients), 18 aneurysms (64.2%) were RROC class 1 and 8 (28.5%) were RROC class 2.

CONCLUSIONS PulseRider is being used in both on- and off-label cases following FDA approval. The clinical and radiographic outcomes are comparable in real-world experience to the outcomes observed in earlier studies. Further experience is needed with the device to determine its role in the neurointerventionalist’s armamentarium, especially with regard to its off-label use.

Lateral supra-cerebellar infra-tentorial approach for P2-P3 junction cerebral aneurysms

Acta Neurochirurgica (2020) 162:2767–2772

P2-P3 junction aneurysms are challenging to treat surgically because of their frequent complex morphology and their location deep in close proximity to the midbrain. The sub-temporal route requires significant retraction of the temporal lobe in addition to potential injury to the vein of Labbe.

We describe the technique for treating such aneurysms via a lateral supra-cerebellar infratentorial (LSCIT) approach, which eliminates manipulation of the temporal lobe.

Method Cadaveric dissection provided comprehensive understanding of relevant anatomy. Intraoperative video shows clipping of the aneurysm using a LSCIT approach.

Conclusion LSCIT approach allows safe clipping of P2-P3 aneurysms with minimal brain manipulation.

Diagnostic reliability of the Berlin classification for complex MCA aneurysms—usability in a series of only giant aneurysms

Acta Neurochirurgica (2020) 162:2753–2758

The main challenge of bypass surgery of complex MCA aneurysms is not the selection of the bypass type but the initial decision-making of how to exclude the affected vessel segment from circulation. To this end, we have previously proposed a classification for complexMCA aneurysms based on the preoperative angiography. The current study aimed to validate this new classification and assess its diagnostic reliability using the giant aneurysm registry as an independent data set.

Methods We reviewed the pretreatment neuroimaging of 51 patients with giant (> 2.5 cm) MCA aneurysms from 18 centers, prospectively entered into the international giant aneurysm registry. We classified the aneurysms according to our previously proposed Berlin classification for complex MCA aneurysms. To test for interrater diagnostic reliability, the data set was reviewed by four independent observers.

Results We were able to classify all 51 aneurysms according to the Berlin classification for complex MCA aneurysms. Eight percent of the aneurysm were classified as type 1a, 14% as type 1b, 14% as type 2a, 24% as type 2b, 33% as type 2c, and 8% as type 3. The interrater reliability was moderate with Fleiss’s Kappa of 0.419.

Conclusion The recently published Berlin classification for complex MCA aneurysms showed diagnostic reliability, independent of the observer when applied to the MCA aneurysms of the international giant aneurysm registry.

A Simple Flow Classification Parameter Can Discriminate Rupture Status in Intracranial Aneurysms

Neurosurgery 2020 DOI:10.1093/neuros/nyaa189

A simple dimensionless aneurysm number (An), which depends on geometry and flow pulsatility, was previously shown to distinguish the flow mode in intracranial aneurysms (IA): vortex mode with a dynamic vortex formation/evolution if An > 1, and cavity mode with a steady shear layer if An < 1.

OBJECTIVE: To hypothesize that An > 1 can distinguish rupture status because vortex mode is associated with high oscillatory shear index, which, in turn, is statistically associated with rupture.

METHODS: The above hypothesis is tested on a retrospective, consecutively collected database of 204 patient-specific IAs. The first 119 cases are assigned to training and the remainder to testing dataset. An is calculated based on the pulsatility index (PI) approximated either from the literature or solving an optimization problem (denoted as PI). Student’s t-test and logistic regression (LR) are used for hypothesis testing and data fitting, respectively.

RESULTS: An can significantly discriminate ruptured and unruptured status with 95% confidence level (P<.0001). An (using PI) and An (usingPI) significantly predict the ruptured IAs (for training dataset An: AUC = 0.85, An: AUC = 0.90, and for testing dataset An: sensitivity = 94%, specificity = 33%,An: sensitivity = 93.1%, specificity = 52.85%).

CONCLUSION: An > 1 predicts ruptured status. Unlike traditional hemodynamic parameters such as wall shear stress and oscillatory shear index, An has a physical threshold of one (does not depend on statistical analysis) and does not require time-consuming flow simulations. Therefore, An is a simple, practical discriminator of IA rupture status.

Aspirin associated with decreased rate of intracranial aneurysm growth

J Neurosurg 133:1478–1485, 2020

Aspirin has emerged as a potential agent in the prevention of rupture of intracranial aneurysms (IAs). In this study, the authors’ goal was to test if aspirin is protective against aneurysm growth in patients harboring multiple IAs ≤ 5 mm.

METHODS The authors performed a retrospective review of a prospectively maintained database covering the period July 2009 through January 2019. Patients’ data were included if the following criteria were met: 1) the patient harbored multiple IAs; 2) designated primary aneurysms were treated by surgical/endovascular means; 3) the remaining aneurysms were observed for growth; and 4) a follow-up period of at least 5 years after the initial treatment was available. Demographics, earlier medical history, the rupture status of designated primary aneurysms, aneurysms’ angiographic features, and treatment modalities were gathered.

RESULTS The authors identified 146 patients harboring a total of 375 IAs. At the initial encounter, 146 aneurysms were treated and the remaining 229 aneurysms (2–5 mm) were observed. During the follow-up period, 24 (10.48%) of 229 aneurysms grew. All aneurysms observed to grow later underwent treatment. None of the observed aneurysms ruptured. Multivariate analysis showed that aspirin was significantly associated with a decreased rate of growth (odds ratio [OR] 0.19, 95% confidence interval [CI] 0.05–0.63). Variables associated with an increased rate of growth included hypertension (OR 14.38, 95% CI 3.83–53.94), drug abuse (OR 11.26, 95% CI 1.21–104.65), history of polycystic kidney disease (OR 9.48, 95% CI 1.51–59.35), and subarachnoid hemorrhage at presentation (OR 5.91, 95% CI 1.83–19.09).

CONCLUSIONS In patients with multiple IAs, aspirin significantly decreased the rate of aneurysm growth over time. Additional prospective interventional studies are needed to validate these findings.

Assessment of drainage techniques for evacuation of chronic subdural hematoma

J Neurosurg 133:1113–1119, 2017

Surgery for chronic subdural hematoma (CSDH) is one of the most common neurosurgical procedures. The benefit of postoperative passive subdural drainage compared with no drains has been established, but other drainage techniques are common, and their effectiveness compared with passive subdural drains remains unknown.

METHODS In Scandinavian population-based cohorts the authors conducted a consecutive, parallel cohort study to compare different drainage techniques. The techniques used were continuous irrigation and drainage (CID cohort, n = 166), passive subdural drainage (PD cohort, n = 330), and active subgaleal drainage (AD cohort, n = 764). The primary end point was recurrence in need of reoperation within 6 months of index surgery. Secondary end points were complications, perioperative mortality, and overall survival. The analyses were based on direct regional comparison (i.e., surgical strategy).

RESULTS Recurrence in need of surgery was observed in 18 patients (10.8%) in the CID cohort, in 66 patients (20.0%) in the PD cohort, and in 85 patients (11.1%) in the AD cohort (p < 0.001). Complications were more common in the CID cohort (14.5%) compared with the PD (7.3%) and AD (8.1%) cohorts (p = 0.019). Perioperative mortality rates were similar between cohorts (p = 0.621). There were some differences in baseline and treatment characteristics possibly interfering with the above-mentioned results. However, after adjusting for differences in baseline and treatment characteristics in a regression model, the drainage techniques were still significantly associated with clinical outcome (p < 0.001 for recurrence, p = 0.017 for complications).

CONCLUSIONS Compared with the AD cohort, more recurrences were observed in the PD cohort and more complications in the CID cohort, also after adjustment for differences at baseline. Although the authors cannot exclude unmeasured confounding factors when comparing centers, AD appears superior to the more common PD.

Neurosurgical simulator for training aneurysm microsurgery

Acta Neurochirurgica (2020) 162:2313–2321

Due to its complexity and to existing treatment alternatives, exposure to intracranial aneurysm microsurgery at the time of neurosurgical residency is limited. The current state of the art includes training methods like assisting in surgeries, operating under supervision, and video training. These approaches are labor-intensive and difficult to fit into a timetable limited by the new work regulations. Existing virtual reality (VR)–based training modules lack patient-specific exercises and haptic properties and are thus inferior to hands-on training sessions and exposure to real surgical procedures.

Materials and methods We developed a physical simulator able to reproduce the experience of clipping an intracranial aneurysm based on a patient-specific 3D-printed model of the skull, brain, and arteries. The simulator is made of materials that not only imitate tissue properties including arterial wall patency, thickness, and elasticity but also able to recreate a pulsatile blood flow. A sample group of 25 neurosurgeons and residents (n = 16: early residency with less than 4 years of neurosurgical exposure; n = 9: late residency and board-certified neurosurgeons, 4–15 years of neurosurgical exposure) took part to the study. Participants evaluated the simulator and were asked to answer questions about surgical simulation anatomy, realism, haptics, tactility, and general usage, scored on a 5-point Likert scale. In order to evaluate the feasibility of a future validation study on the role of the simulator in neurosurgical postgraduate training, an expert neurosurgeon assessed participants’ clipping performance and a comparison between groups was done.

Results The proposed simulator is reliable and potentially useful for training neurosurgical residents and board-certified neurosurgeons. A large majority of participants (84%) found it a better alternative than conventional neurosurgical training methods.

Conclusion The integration of a new surgical simulator including blood circulation and pulsatility should be considered as part of the future armamentarium of postgraduate education aimed to ensure high training standards for current and future generations of neurosurgeons involved in intracranial aneurysm surgery. Resident training ,Surgical simulation,Surgical education ,Microsurgery , Intracranial aneurysm , Neurosurgery

Predictors of Complications, Functional Outcome, and Morbidity in a Large Cohort TreatedWith Flow Diversion

Neurosurgery DOI:10.1093/neuros/nyz508

A dramatic improvement in obliteration rates of large, wide-necked aneurysms has been observed after the FDA approved the Pipeline Embolization Device (PED) in 2011.

OBJECTIVE: To assess the predictors of complications, morbidity, and unfavorable outcomes in a large cohort of patients with aneurysms treated with PED.

METHODS: A retrospective chart review of a prospectively maintained database for subjects treated with flow diversion from 2010 to 2019.

RESULTS: A total of 598 aneurysms were treated during a period extending from 2010 to 2019 (84.28% females, mean age 55.5 yr, average aneurysm size 8.49 mm). Morbidity occurred at a rate of 5.8% and mortality at a rate of 2.2%. Ischemic stroke occurred at a rate of 3%, delayed aneurysmal rupture (DAR) at 1.2%, and distal intraparenchymal hemorrhage (DIPH) at 1.5%. On multivariate analysis, the predictor of stroke was aneurysm size>15 mm. Predictors of DAR were previous subarachnoid hemorrhage (SAH), increasing aneurysm size, and posterior circulation aneurysm. Predictors of DIPH were using more than 1 PED and baseline P2Y12 value. Predictors of in-stent stenosis were the increasing year of treatment and balloon angioplasty, whereas increasing age and previous treatment were negatively associated with in-stent stenosis. Predictors of morbidity were posterior circulation aneurysms, increasing aneurysm size, and hypertension, and incidental aneurysm diagnosis was protective for morbidity.

CONCLUSION: Flow diversion is a safe and effective treatment option for aneurysms. A better understanding of predictive factors of complications, morbidity, and functional outcomes is of high importance for a more accurate risk assessment.

Craniectomy size for subdural haematomas and the impact on brain shift and outcomes

Acta Neurochirurgica (2020) 162:2019–2027

Midline shift in trauma relates to the severity of head injury. Large craniectomies are thought to help resolve brain shift but can be associated with higher rates of morbidity. This study explores the relationship between craniectomy size and subtemporal decompression for acute subdural haematomas with the resolution of brain compression and outcomes. No systematic study correlating these measures has been reported.

Method A retrospective study of all adult cases of acute subdural haematomas that presented to a Major Trauma Centre and underwent a primary decompressive craniectomy between June 2008 and August 2013. Data collection included patient demographics and presentation, imaging findings and outcomes. All imaging metrics were measured by two independent trained assessors. Compression was measured as midline shift, brainstem shift and cisternal effacement.

Results Thirty-six patients with mean age of 36.1 ± 12.5 (range 16–62) were included, with a median follow-up of 23.5 months (range 2.2–109.6). The median craniectomy size was 88.7 cm2 and the median subtemporal decompression was 15.0 mm. There was significant post-operative resolution of shift as measured by midline shift, brainstem shift and cisternal effacement score (all p < .00001). There was no mortality, and the majority of patients made a good recovery with 82.8% having a Modified Rankin Score of 2 or less. There was no association between craniectomy size or subtemporal decompression and any markers of brain shift or outcome (all R2 < 0.05).

Conclusions This study suggests that there is no clear relationship between craniectomy size or extent of subtemporal decompression and resolution of brain shift or outcome. Further studies are needed to assess the relative efficacy of large craniectomies and the role of subtemporal decompression.

Four-Dimensional Magnetic Resonance Imaging Assessment of Intracranial Aneurysms

Neurosurgery DOI:10.1093/neuros/nyaa021

Treatment of unruptured intracranial aneurysms can reduce the risk of subarachnoid hemorrhage and its associated morbidity and mortality. However, current methods to predict the risk of rupture and optimize treatment strategies for intracranial aneurysms are limited. Assessment of intra-aneurysmal flow using 4-dimensional magnetic resonance imaging (4D MRI) is a novel tool that could be used to guide therapy.

A systematic search of the literature was performed to provide a state-of-the-art review on 4DMRI assessment of unruptured intracranial aneurysms.

A total of 18 studies were available for review. Eccentric flow on 4D MRI is associated with a greater aspect ratio and peak wall shear stress (WSS). WSS, vorticity, and peak velocity are greater in saccular than fusiform aneurysms. Unstable aneurysms are associated with greater WSS, peak wall stress, and flow jet angle and may exhibit wall enhancement. In comparison to computational fluid dynamics (CFD), 4D MRI has a lower spatial resolution and reports lower WSS and velocity magnitudes, but these parameters equalize when spatial resolution is matched.

4D MRI demonstrates the intra-aneurysmal hemodynamic changes associated with flow diversion, including significantly decreased flow velocity. Thus, 4D MRI is a novel, noninvasive imaging tool used for the evaluation of hemodynamics within intracranial aneurysms. Hemodynamic indices derived from 4D MRI appear to correlate well with the simulated (CFD) values and may be used to measure the success of endovascular therapies and risk factors for aneurysm growth and rupture.

Design and Physical Properties of 3-Dimensional Printed Models Used for Neurointervention

Neurosurgery DOI:10.1093/neuros/nyaa134

Three-dimensional (3D) printing has revolutionized training, education, and device testing. Understanding the design and physical properties of 3D-printed models is important.

OBJECTIVE: To systematically review the design, physical properties, accuracy, and experimental outcomes of 3D-printed vascular models used in neurointervention.

METHODS: We conducted a systematic review of the literature between January 1, 2000 and September 30, 2018. Public/Publisher MEDLINE (PubMed), Web of Science, Compendex, Cochrane, and Inspec databases were searched using Medical Subject Heading terms for design and physical attributes of 3D-printed models for neurointervention. Information on design and physical properties like compliance, lubricity, flow system, accuracy, and outcome measures were collected.

RESULTS: A total of 23 articles were included. Nine studies described 3D-printed models for stroke intervention. Tango Plus (Stratasys) was the most common material used to develop these models. Four studies described a population-representative geometry model. All other studies reported patient-specific vascular geometry. Eight studies reported complete reconstruction of the circle of Willis, anterior, and posterior circulation. Four studies reported a model with extracranial vasculature. One prototype study reported compliance and lubricity. Reported circulation systems included manual flushing, programmable pistons, peristaltic, and pulsatile pumps. Outcomes included thrombolysis in cerebral infarction, post-thrombectomy flow restoration, surgical performance, and qualitative feedback.

CONCLUSION: Variations exist in the material, design, and extent of reconstruction of vasculature of 3D-printed models. There is a need for objective characterization of 3D-printed vascular models. We propose the development of population representative 3D-printed models for skill improvement or device testing.

Is 3 years adequate for tracking completely occluded coiled aneurysms?

J Neurosurg 133:758–764, 2020

The authors conducted a study to ascertain the long-term durability of coiled aneurysms completely occluded at 36 months’ follow-up given the potential for delayed recanalization.

METHODS In this retrospective review, the authors examined 299 patients with 339 aneurysms, all shown to be completely occluded at 36 months on follow-up images obtained between 2011 and 2013. Medical records and radiological data acquired during the extended monitoring period (mean 74.3 ± 22.5 months) were retrieved, and the authors analyzed the incidence of (including mean annual risk) and risk factors for delayed recanalization.

RESULTS A total of 5 coiled aneurysms (1.5%) occluded completely at 36 months showed recanalization (0.46% per aneurysm-year) during the long-term surveillance period (1081.9 aneurysm-years), 2 surfacing within 60 months and 3 developing thereafter. Four showed minor recanalization, with only one instance of major recanalization. The latter involved the posterior communicating artery as an apparent de novo lesion, arising at the neck of a firmly coiled sac, and was unrelated to coil compaction or growth. Additional embolization was undertaken. In a multivariate analysis, a second embolization for a recurrent aneurysm (HR = 22.088, p = 0.003) independently correlated with delayed recanalization.

CONCLUSIONS Almost all coiled aneurysms (98.5%) showing complete occlusion at 36 months postembolization proved to be stable during extended observation. However, recurrent aneurysms were predisposed to delayed recanalization. Given the low probability yet seriousness of delayed recanalization and the possibility of de novo aneurysm formation, careful monitoring may be still considered in this setting but at less frequent intervals beyond 36 months.

The Danish Chronic Subdural Hematoma Study—comparison of hematoma age to the radiological appearance at time of diagnosis

Acta Neurochirurgica (2020) 162:2007–2013

Chronic subdural hematomas (CSDH) show different radiological characteristics on CT scans at the time of diagnosis. The reason for this is largely unknown. We hypothesize that the imaging characteristics reflect a time-linked pathophysiological evolution. We therefore conducted a retrospective study to examine a possible relation between the hematoma age and the radiological subtype of a CSDH.

Methods Demographic data on patients with CSDH were retrieved from a Danish national cohort from 2010 to 2012. CT scans obtained on admission to a neurosurgical department were categorized as homogenous, separated, mixed, or membranous hematoma subtypes. The time from a known date of head injury to time of diagnostic CT was defined as hematoma age. The hematoma age was correlated to radiological hematoma subtype at the time of diagnosis by analysis of variance testing.

Results In total, 543 patients were analyzed for hematoma age and classified in the following hematoma subtypes: 231 homogenous, 44 separated, 119 mixed, and 149 membranous. Patients with homogenous, separated, mixed, and membranous hematoma subtypes had a median interval of 37, 36, 40, and 60 days from head injury to diagnostic CT. We found that membranous hematoma is significantly older than other subtypes. Comparison between the other radiological subtypes showed no statistical hematoma age difference. The distribution of radiological subtypes in 590 patients without a known head injury was similar to that of patients with a known head injury. Additionally, we found that hematoma age was significantly younger for patients on antiplatelet medication.

Conclusion In this large national cohort, patients with membranous CSDH had a significantly longer interval between head injury and diagnosis compared to other radiological subtypes. This indicates that the radiological appearance of CSDH evolves over time, causing an alteration from different early radiological subtypes to a radiological subtype with membranes.

Clinical trial registration number The study was approved by the Danish Data Protection Agency (journal no.30-1145).

A grading scale for surgically treated patients with spontaneous supratentorial intracerebral hemorrhage: the Surgical Swedish ICH Score

J Neurosurg 133:800–807, 2020

The authors aimed to develop the first clinical grading scale for patients with surgically treated spontaneous supratentorial intracerebral hemorrhage (ICH).

METHODS A nationwide multicenter study including 401 ICH patients surgically treated by craniotomy and evacuation of a spontaneous supratentorial ICH was conducted between January 1, 2011, and December 31, 2015. All neurosurgical centers in Sweden were included. All medical records and neuroimaging studies were retrospectively reviewed. Independent predictors of 30-day mortality were identified by logistic regression. A risk stratification scale (the Surgical Swedish ICH [SwICH] Score) was developed using weighting of independent predictors based on strength of association.

RESULTS Factors independently associated with 30-day mortality were Glasgow Coma Scale (GCS) score (p =0.00015), ICH volume ≥ 50 mL (p = 0.031), patient age ≥ 75 years (p = 0.0056), prior myocardial infarction (MI) (p =0.00081), and type 2 diabetes (p = 0.0093). The Surgical SwICH Score was the sum of individual points assigned as follows: GCS score 15–13 (0 points), 12–5 (1 point), 4–3 (2 points); age ≥ 75 years (1 point); ICH volume ≥ 50 mL (1 point); type 2 diabetes (1 point); prior MI (1 point). Each increase in the Surgical SwICH Score was associated with a progressively increased 30-day mortality (p = 0.0002). No patient with a Surgical SwICH Score of 0 died, whereas the 30-day mortality rates for patients with Surgical SwICH Scores of 1, 2, 3, and 4 were 5%, 12%, 31%, and 58%, respectively.

CONCLUSIONS The Surgical SwICH Score is a predictor of 30-day mortality in patients treated surgically for spontaneous supratentorial ICH. External validation is needed to assess the predictive value as well as the generalizability of the Surgical SwICH Score.

Ventriculostomy with subsequent ventriculoperitoneal shunt placement after subarachnoid hemorrhage: the effect of implantation site on postoperative complications

Acta Neurochirurgica (2020) 162:1831–1836

Patients suffering from aneurysmal subarachnoid hemorrhage (SAH) with shunt-dependent hydrocephalus require subsequent placement of a ventriculoperitoneal shunt (VPS) after ventriculostomy. However, in patients with previous ventriculostomy, the site for proximal VPS catheter placement is still controversial.We investigated the effect of catheter placement on postoperative complications by analyzing patients with ventriculostomy and subsequent VPS placement after SAH.

Methods From January 2004 to December 2018, 164 of 1128 patients suffering from SAH underwent subsequent VPS placement after ventriculostomy in the authors’ institution. Patients were divided into two groups according to the position of the ventriculostomy and the site of the proximal VPS catheter (“same site” group versus “contralateral site” group). VPS-related infectious and bleeding complications following VPS placement were assessed and analyzed.

Results Overall, VPS-related infections occurred in 11 of the 164 patients (7%). Furthermore, five of the 164 patients (3%) suffered from VPS-related hemorrhage. However, VPS infection rate was lower 5% (6/115) in the same site compared to 10% (5/49) in the contralateral site group, although without reaching statistical significance (OR = 0.48 (0.14, 1.67) 95% confidence interval, p = 0.3). VPS-related hemorrhage rate did not differ significantly between patients in the same site group (3.5%, 4/115) and the contralateral site group (2.0%, 1/49; OR = 1.73 (0.18, 15.9), p = 1.0).

Conclusions Our study suggests that the use of the ventriculostomy site for VPS placement does not significantly increase the risk of either VPS-related infections or VPS-related hemorrhages.

Surgical treatment of pontine cavernous malformations via subtemporal transtentorial and intradural anterior transpetrosal approaches

Neurosurgical Review (2020) 43:1179–1189

The aim of this study was to report our surgical experience on resection of the pontine cavernous malformations (CMs) via subtemporal transtentorial approach (STTA) and intradural anterior transpetrosal approach (ATPA).

Clinical data were retrospectively reviewed in 61 patients with pontine CMs that were surgically treated by the STTA and the intradural ATPA. The surgical procedures, complications, and outcomes were analyzed.

The study consists of 61 patients with a total of 61 pontine CMs. Other than 4 lesions located medially in the pons, all CMs were in the lateral pons with a left or right lateral epicenter (the left/right ratio was 22/35). Totally, 11 patients (18.0%) with lesions located in the upper pons were treated by the STTA, and 50 patients (82.0%) with lesions involving the lower pons were treated by the intradural ATPA. Postoperatively, the complete resection was achieved in 58 patients (95.1%) and incomplete resection in 3 patients (4.9%). Twenty-seven patients (44.3%) suffered from a new or worsened neurological deficit in the immediate postoperative period, and 8 patients (13.1%) encountered a non-neural complication, including rebleeding, cerebrospinal fluid leak, intracranial infection, and pulmonary infection, and 3 patients had contusion of temporal lobe. With a mean follow-up of 54.2 months, the patients’ neurological condition had improved in 43 cases (71.6%), not changed in 10 cases (16.7%), and worsened in 7 cases (11.7%), respectively. The Karnofsky Performance Scale (KPS) score evaluated at the last time for per patient was significantly better than their baseline status (t = 6.677, p < 0.001). However, 21 patients (35.0%) suffered from a new or worsened persistent postoperative deficit.

The lateral and anterolateral pons can be exposed well by the subtemporal transtentorial and intradural anterior transpetrosal approaches. Lesions of CMs located in the lateral pons, including ventrolateral and dorsolateral pons, could be totally removed by these two lateral approaches with an acceptable surgical morbidity.

Biologically effective dose and prediction of obliteration of unruptured arteriovenous malformations treated by upfront Gamma Knife radiosurgery: a series of 149 consecutive cases

https://doi.org/10.3171/2020.4.JNS201250

Arteriovenous malformations (AVMs) present no pathologic tissue, and radiation dose is confined in a clear targeted volume. The authors retrospectively evaluated the role of the biologically effective dose (BED) after Gamma Knife radiosurgery (GKRS) for brain AVMs.

METHODS A total of 149 consecutive cases of unruptured AVMs treated by upfront GKRS in Lille University Hospital, France, were included. The mean length of follow-up was 52.9 months (median 48, range 12–154 months). The primary outcome was obliteration, and the secondary outcome was complication appearance. The marginal dose was 24 Gy in a vast majority of cases (n = 115, 77.2%; range 18–25 Gy). The mean BED was 220.1 Gy2.47 (median 229.9, range 106.7–246.8 Gy2.47). The mean beam-on time was 32.3 minutes (median 30.8, range 9–138.7 minutes). In the present series, the mean radiation dose rate was 2.259 Gy/min (median 2.176, range 1.313–3.665 Gy/min). The Virginia score was 0 in 29 (19.5%), 1 in 61 (40.9%), 2 in 41 (27.5%), 3 in 18 (12.1%), and 4 in 0 (0%) patients, respectively. The mean Pollock-Flickinger score was 1.11 (median 1.52, range 0.4–2.9). Univariate (for obliteration and complication appearance) and multivariate (for obliteration only) analyses were performed.

RESULTS A total of 104 AVMs (69.8%) were obliterated at the last follow-up. The strongest predictor for obliteration was BED (p = 0.03). A radiosurgical obliteration score is proposed, derived from a fitted multivariable model: (0.018 × BED) + (1.58 × V12) + (−0.013689 × beam-on time) + (0.021 × age) − 4.38. The area under the receiver operating characteristic curve was 0.7438; after internal validation using bootstrap methods, it was 0.7088. No statistically significant relationship between radiation dose rate and obliteration was found (p = 0.29). Twenty-eight (18.8%) patients developed complications after GKRS; 20 (13.4%) of these patients had transient adverse radiological effects (perilesional edema developed). Predictors for complication appearance were higher prescription isodose volume (p = 0.005) and 12-Gy isodose line volume (V12; p = 0.001), higher Pollock-Flickinger (p = 0.02) and Virginia scores (p = 0.003), and lower beam-on time (p = 0.03).

CONCLUSIONS The BED was the strongest predictor of obliteration of unruptured AVMs after upfront GKRS. A radiosurgical score comprising the BED is proposed. The V12 appears as a predictor for both efficacy and toxicity. Beam-on time was illustrated as statistically significant for both obliteration and complication appearance. The radiation dose rate did not influence obliteration in the current analysis. The exact BED threshold remains to be established by further studies.