Burr-hole drainage with or without irrigation for chronic subdural haematoma (FINISH): a Finnish, nationwide, parallel-group, multicentre, randomised, controlled, non-inferiority trial.

BACKGROUND: Chronic subdural haematoma is a common surgically treated intracranial emergency. Burr-hole drainage surgery, to evacuate chronic subdural haematoma, involves three elements: creation of a burr hole for access, irrigation of the subdural space, and insertion of a subdural drain. Although the subdural drain has been established as beneficial, the therapeutic effect of subdural irrigation has not been addressed. METHODS: The FINISH trial was an investigator-initiated, pragmatic, multicentre, nationwide, randomised, controlled, parallel-group, non-inferiority trial in five neurosurgical units in Finland that enrolled adults aged 18 years or older with a chronic subdural haematoma requiring burr-hole drainage. Patients were randomly assigned (1:1) by computer-generated block randomisation with block sizes of four, six, or eight, stratified by site, to burr-hole drainage either with or without subdural irrigation. All patients and staff were masked to treatment assignment apart from the neurosurgeon and operating room staff. A burr hole was drilled at the site of maximum haematoma thickness in both groups, and the subdural space was either irrigated or not irrigated before inserting a subdural drain, which remained in place for 48 h. Reoperations, functional outcome, mortality, and adverse events were recorded for 6 months after surgery. The primary outcome was the reoperation rate within 6 months. The non-inferiority margin was set at 7·5%. Key secondary outcomes that were also required to conclude non-inferiority were the proportion of participants with unfavourable functional outcomes (ie, modified Rankin Scale score of 4-6, where 0 indicates no symptoms and 6 indicates death) and mortality rate at 6 months. The primary and key secondary analyses were done in both the intention-to-treat and per-protocol populations. The trial was registered with ClinicalTrials.gov (NCT04203550) and is completed. FINDINGS: From Jan 1, 2020, to Aug 17, 2022, we assessed 1644 patients for eligibility and 589 (36%) patients were randomly assigned to a treatment group and treated (294 assigned to drainage with irrigation and 295 assigned to drainage without irrigation; 165 [28%] women and 424 [72%] men). The 6-month follow-up period extended until Feb 14, 2023. In the intention-to-treat analysis, 54 (18·3%) of 295 participants required reoperation in the group assigned to receive no irrigation versus 37 (12·6%) of 294 in the group assigned to receive irrigation (difference of 6·0 percentage points, 95% CI 0·2-11·7; p=0·30; adjusted for study site). There were no significant between-group differences in the proportion of people with modified Rankin Scale score of 4-6 (37 [13·1%] of 283 in the no-irrigation group vs 36 [12·6%] of 285 in the irrigation group; p=0·89) or mortality rate (18 [6·1%] of 295 in the no-irrigation group vs 21 [7·1%] of 294 in the irrigation group; p=0·58). The findings of the primary intention-to-treat analysis were not materially altered in the per-protocol analysis. There were no significant between-group differences in the number of adverse events, and the most frequent severe adverse events were systemic infections (26 [8·8%] of 295 participants who did not receive irrigation vs 22 [7·5%] of 294 participants who received irrigation), intracranial haemorrhage (13 [4·4%] vs seven [2·4%]), and epileptic seizures (five [1·7%] vs nine [3·1%]). INTERPRETATION: We could not conclude non-inferiority of burr-hole drainage without irrigation. The reoperation rate was 6·0 percentage points higher after burr-hole drainage without subdural irrigation than with subdural irrigation. Considering that there were no differences in functional outcome or mortality between the groups, the trial favours the use of subdural irrigation. FUNDING: State Fund for University Level Health Research (Helsinki University Hospital), Finska Läkaresällskapet, Medicinska Understödsföreningen Liv och Hälsa, and Svenska Kulturfonden.

The Influence of Potential Organ Donors on Standardized Mortality Ratios and ICU Benchmarking.

OBJECTIVES: The standardized mortality ratio (SMR) is a common metric to benchmark ICUs. However, SMR may be artificially distorted by the admission of potential organ donors (POD), who have nearly 100% mortality, although risk prediction models may not identify them as high-risk patients. We aimed to evaluate the impact of PODs on SMR. DESIGN: Retrospective registry-based multicenter study. SETTING: Twenty ICUs in Finland, Estonia, and Switzerland in 2015-2017. PATIENTS: Sixty thousand forty-seven ICU patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We used a previously validated mortality risk model to calculate the SMRs. We investigated the impact of PODs on the overall SMR, individual ICU SMR and ICU benchmarking. Of the 60,047 patients admitted to the ICUs, 514 (0.9%) were PODs, and 477 (93%) of them died. POD deaths accounted for 7% of the total 6738 in-hospital deaths. POD admission rates varied from 0.5 to 18.3 per 1000 admissions across ICUs. The risk prediction model predicted a 39% in-hospital mortality for PODs, but the observed mortality was 93%. The ratio of the SMR of the cohort without PODs to the SMR of the cohort with PODs was 0.96 (95% CI, 0.93-0.99). Benchmarking results changed in 70% of ICUs after excluding PODs. CONCLUSIONS: Despite their relatively small overall number, PODs make up a large proportion of ICU patients who die. PODs cause bias in SMRs and in ICU benchmarking. We suggest excluding PODs when benchmarking ICUs with SMR.

Prognostic value of near-infrared spectroscopy regional oxygen saturation and cerebrovascular reactivity index in acute traumatic neural injury: a CAnadian High-Resolution Traumatic Brain Injury (CAHR-TBI) Cohort Study.

BACKGROUND: Near-infrared spectroscopy regional cerebral oxygen saturation (rSO2) has gained interest as a raw parameter and as a basis for measuring cerebrovascular reactivity (CVR) due to its noninvasive nature and high spatial resolution. However, the prognostic utility of these parameters has not yet been determined. This study aimed to identify threshold values of rSO2 and rSO2-based CVR at which outcomes worsened following traumatic brain injury (TBI). METHODS: A retrospective multi-institutional cohort study was performed. The cohort included TBI patients treated in four adult intensive care units (ICU). The cerebral oxygen indices, COx (using rSO2 and cerebral perfusion pressure) as well as COx_a (using rSO2 and arterial blood pressure) were calculated for each patient. Grand mean thresholds along with exposure-based thresholds were determined utilizing sequential chi-squared analysis and univariate logistic regression, respectively. RESULTS: In the cohort of 129 patients, there was no identifiable threshold for raw rSO2 at which outcomes were found to worsen. For both COx and COx_a, an optimal grand mean threshold value of 0.2 was identified for both survival and favorable outcomes, while percent time above - 0.05 was uniformly found to have the best discriminative value. CONCLUSIONS: In this multi-institutional cohort study, raw rSO2was found to contain no significant prognostic information. However, rSO2-based indices of CVR, COx and COx_a, were found to have a uniform grand mean threshold of 0.2 and exposure-based threshold of - 0.05, above which clinical outcomes markedly worsened. This study lays the groundwork to transition to less invasive means of continuously measuring CVR.

Critical thresholds of long-pressure reactivity index and impact of intracranial pressure monitoring methods in traumatic brain injury.

BACKGROUND: Moderate-to-severe traumatic brain injury (TBI) has a global mortality rate of about 30%, resulting in acquired life-long disabilities in many survivors. To potentially improve outcomes in this TBI population, the management of secondary injuries, particularly the failure of cerebrovascular reactivity (assessed via the pressure reactivity index; PRx, a correlation between intracranial pressure (ICP) and mean arterial blood pressure (MAP)), has gained interest in the field. However, derivation of PRx requires high-resolution data and expensive technological solutions, as calculations use a short time-window, which has resulted in it being used in only a handful of centers worldwide. As a solution to this, low resolution (longer time-windows) PRx has been suggested, known as Long-PRx or LPRx. Though LPRx has been proposed little is known about the best methodology to derive this measure, with different thresholds and time-windows proposed. Furthermore, the impact of ICP monitoring on cerebrovascular reactivity measures is poorly understood. Hence, this observational study establishes critical thresholds of LPRx associated with long-term functional outcome, comparing different time-windows for calculating LPRx as well as evaluating LPRx determined through external ventricular drains (EVD) vs intraparenchymal pressure device (IPD) ICP monitoring. METHODS: The study included a total of n = 435 TBI patients from the Karolinska University Hospital. Patients were dichotomized into alive vs. dead and favorable vs. unfavorable outcomes based on 1-year Glasgow Outcome Scale (GOS). Pearson's chi-square values were computed for incrementally increasing LPRx or ICP thresholds against outcome. The thresholds that generated the greatest chi-squared value for each LPRx or ICP parameter had the highest outcome discriminatory capacity. This methodology was also completed for the segmentation of the population based on EVD, IPD, and time of data recorded in hospital stay. RESULTS: LPRx calculated with 10-120-min windows behaved similarly, with maximal chi-square values ranging at around a LPRx of 0.25-0.35, for both survival and favorable outcome. When investigating the temporal relations of LPRx derived thresholds, the first 4 days appeared to be the most associated with outcomes. The segmentation of the data based on intracranial monitoring found limited differences between EVD and IPD, with similar LPRx values around 0.3. CONCLUSION: Our work suggests that the underlying prognostic factors causing impairment in cerebrovascular reactivity can, to some degree, be detected using lower resolution PRx metrics (similar found thresholding values) with LPRx found clinically using as low as 10 min-by-minute samples of MAP and ICP. Furthermore, EVD derived LPRx with intermittent cerebrospinal fluid draining, seems to present similar outcome capacity as IPD. This low-resolution low sample LPRx method appears to be an adequate substitute for the clinical prognostic value of PRx and may be implemented independent of ICP monitoring method when PRx is not feasible, though further research is warranted.

Cerebral physiologic insult burden in acute traumatic neural injury: a Canadian High Resolution-TBI (CAHR-TBI) descriptive analysis.

BACKGROUND: Over the recent decades, continuous multi-modal monitoring of cerebral physiology has gained increasing interest for its potential to help minimize secondary brain injury following moderate-to-severe acute traumatic neural injury (also termed traumatic brain injury; TBI). Despite this heightened interest, there has yet to be a comprehensive evaluation of the effects of derangements in multimodal cerebral physiology on global cerebral physiologic insult burden. In this study, we offer a multi-center descriptive analysis of the associations between deranged cerebral physiology and cerebral physiologic insult burden. METHODS: Using data from the Canadian High-Resolution TBI (CAHR-TBI) Research Collaborative, a total of 369 complete patient datasets were acquired for the purposes of this study. For various cerebral physiologic metrics, patients were trichotomized into low, intermediate, and high cohorts based on mean values. Jonckheere-Terpstra testing was then used to assess for directional relationships between these cerebral physiologic metrics and various measures of cerebral physiologic insult burden. Contour plots were then created to illustrate the impact of preserved vs impaired cerebrovascular reactivity on these relationships. RESULTS: It was found that elevated intracranial pressure (ICP) was associated with more time spent with cerebral perfusion pressure (CPP) < 60 mmHg and more time with impaired cerebrovascular reactivity. Low CPP was associated with more time spent with ICP > 20 or 22 mmHg and more time spent with impaired cerebrovascular reactivity. Elevated cerebrovascular reactivity indices were associated with more time spent with CPP < 60 mmHg as well as ICP > 20 or 22 mmHg. Low brain tissue oxygenation (PbtO2) only demonstrated a significant association with more time spent with CPP < 60 mmHg. Low regional oxygen saturation (rSO2) failed to produce a statistically significant association with any particular measure of cerebral physiologic insult burden. CONCLUSIONS: Mean ICP, CPP and, cerebrovascular reactivity values demonstrate statistically significant associations with global cerebral physiologic insult burden; however, it is uncertain whether measures of oxygen delivery provide any significant insight into such insult burden.

Digital exoscope versus surgical microscope in spinal dural arteriovenous fistula surgery: a comparative series.

OBJECTIVE: Surgical treatment of spinal dural arteriovenous fistulas (DAVFs) has been reported to be superior to endovascular treatment in terms of occlusion of the fistula. Despite the increased availability of digital 3D exoscopes, the potential benefits of using an exoscope in spinal DAVF surgery have not been studied. The purpose of this study was to report and compare the results of exoscope- and microscope-assisted surgery for spinal DAVFs. METHODS: All consecutive adult patients (≥ 18 years of age) treated surgically for spinal DAVFs from January 2016 to January 2023 in a tertiary neurosurgical referral center were included. All patients were operated on by one neurosurgeon. Their pre- and postoperative clinical findings, imaging studies, and intra- and postoperative events were evaluated and surgical videos from the operations were analyzed. RESULTS: Altogether, 14 patients received an operation for spinal DAVF during the study period, 10 (71%) with an exoscope and 4 (29%) with a microscope. The DAVFs were most commonly located in the lower parts of the thoracic spine in both groups. The duration of exoscopic surgeries was shorter (141 vs 151 minutes) and there was less blood loss (60 vs 100 ml) than with microscopic surgeries. No major surgical complications were observed in either group. Of the 14 patients, 10 had gait improvement postoperatively: 7 (78%) patients in the exoscope group and 3 (75%) in the microscope group. None of the patients experienced deterioration following surgery. CONCLUSIONS: Exoscope-assisted surgery for spinal DAVFs is comparable in safety and effectiveness to traditional microscopic surgery. With practice, experienced neurosurgeons can adapt to using the exoscope without major additional risks to the patient.

Long-term treatment outcomes and natural course of low-grade intracranial dural arteriovenous fistulas.

OBJECTIVE: In contrast to high-grade dural arteriovenous fistula (dAVF), low-grade dAVF is mainly associated with tinnitus and carries a low risk of morbidity and mortality. It remains unclear whether the benefits of active interventions outweigh the associated risk of complications in low-grade dAVF. METHODS: The authors conducted a retrospective single-center study that included all consecutive patients diagnosed with an intracranial low-grade dAVF (Cognard type I and IIa) during 2012-2022 with DSA. The authors analyzed symptom relief, symptomatic angiographic cure, treatment-related complications, risk for intracerebral hemorrhage (ICH), and mortality. All patients were followed up until the end of 2022. RESULTS: A total of 81 patients were diagnosed with a low-grade dAVF. Of these, 48 patients (59%) underwent treatment (all primary endovascular treatments), and 33 patients (41%) did not undergo treatment. Nine patients (19%) underwent retreatments. Angiographic follow-up was performed after median (IQR) 7.7 (6.1-24.1) months by means of DSA (mean 15.0, median 6.4 months, range 4.5-83.4 months) or MRA (mean 29.3, median 24.7 months, range 5.9-62.1 months). Symptom control was achieved in 98% of treated patients after final treatment. On final angiographic follow-up, 73% of patients had a completely occluded dAVF. There were 2 treatment-related complications resulting in 1 transient (2%) and 1 permanent (2%) neurological complication. One patient showed recurrence and progression of a completely occluded low-grade dAVF to an asymptomatic high-grade dAVF. No cases of ICH- or dAVF-related mortality were found in either treated patients (median [IQR] follow-up 5.1 [2.0-6.8] years) or untreated patients (median [IQR] follow-up 5.7 [3.2-9.0] years). CONCLUSIONS: Treatment of low-grade dAVF provides a high rate of symptom relief with small risks for complications with neurological sequela. The risks of ICH and mortality in patients with untreated low-grade dAVF are minimal. Symptoms may not reveal high-grade recurrence, and radiological follow-up may be warranted in selected patients with treated low-grade dAVF. An optimal radiographic follow-up regimen should be developed by a future prospective multicenter registry.

Incidence of surgically treated chronic subdural hematoma after head injury with normal initial computed tomography.

PURPOSE: The objective was to determine the incidence of surgically treated chronic subdural hematoma (cSDH) within six months after head trauma in a consecutive series of head injury patients with a normal initial computed tomography (CT). METHODS: A total of 1941 adult patients with head injuries who underwent head CT within 48 h after injury and were treated at the Tampere University Hospital's emergency department were retrospectively evaluated from medical records (median age = 59 years, IQR = 39-79 years, males = 58%, patients using antithrombotic medication = 26%). Patients with no signs of acute traumatic intracranial pathology or any type of subdural collection on initial head CT were regarded as CT negative (n = 1573, 81%). RESULTS: Two (n = 2) of the 1573 CT negative patients received surgical treatment for cSDH. Consequently, the incidence of surgically treated cSDH after a normal initial head CT during a six-month follow-up was 0.13%. Both patients sustained mild traumatic brain injuries initially. One of the two patients was on antithrombotic medication (warfarin) at the time of trauma, hence incidence of surgically treated cSDH among patients with antithrombotic medication in CT negative patients (n = 376, 23.9%) was 0.27%. Additionally, within CT negative patients, one subdural hygroma was operated shortly after trauma. CONCLUSION: The extremely low incidence of surgically treated cSDH after a normal initial head CT, even in patients on antithrombotic medication, supports the notion that routine follow-up imaging after an initial normal head CT is not indicated to exclude the development of cSDH. Additionally, our findings support the concept of cSDH not being a purely head trauma-related disease.

Flow diversion of ruptured intracranial aneurysms: a single-center study with a standardized antithrombotic treatment protocol.

BACKGROUND: The use of antithrombotic medication following acute flow diversion for a ruptured intracranial aneurysm (IA) is challenging with no current guidelines. We investigated the incidence of treatment-related complications and patient outcomes after flow diversion for a ruptured IA before and after the implementation of a standardized antithrombotic medication protocol. METHODS: We conducted a single-center retrospective study including consecutive patients treated for acutely ruptured IAs with flow diversion during 2015-2023. We divided the patients into two groups: those treated before the implementation of the protocol (pre-protocol) and those treated after the implementation of the protocol (post-protocol). The primary outcomes were hemorrhagic and ischemic complications. A secondary outcome was clinical outcome using the modified Ranking Scale (mRS). RESULTS: Totally 39 patients with 40 ruptured IAs were treated with flow diversion (69% pre-protocol, 31% post-protocol). The patient mean age was 55 years, 62% were female, 63% of aneurysms were in the posterior circulation, 92% of aneurysms were non-saccular, and 44% were in poor grade on admission. Treatment differences included the use of glycoprotein IIb/IIIa inhibitors (pre-group 48% vs. post-group 100%), and the use of early dual antiplatelets (pre-group 44% vs. 92% post-group). The incidence of ischemic complications was 37% and 42% and the incidence of hemorrhagic complications was 30% and 33% in the pre- and post-groups, respectively, with no between-group differences. There were three (11%) aneurysm re-ruptures in the pre-group and none in the post-group. There were no differences in mortality or mRS 0-2 between the groups at 6 months. CONCLUSION: We found no major differences in the incidence of ischemic or hemorrhagic complications after the implementation of a standardized antithrombotic protocol for acute flow diversion for ruptured IAs. There is an urgent need for more evidence-based guidelines to optimize antithrombotic treatment after flow diversion in the setting of subarachnoid hemorrhage.

Changes in treatment of intracranial aneurysms during the last decade in a large European neurovascular center.

OBJECTIVE: Treatment modality for ruptured and unruptured intracranial aneurysms has shifted during the last two decades from microsurgical treatment towards endovascular treatment. We present how this transition happened in a large European neurovascular center. METHODS: We conducted a retrospective observational study consecutive patients treated for an unruptured or ruptured intracranial aneurysm at Helsinki University Hospital during 2012-2022. We used Poisson regression analysis to report age-adjusted treatment trends by aneurysm location and rupture status. RESULTS: A total of 2491 patients with intracranial aneurysms were treated (44% ruptured, 56% unruptured): 1421 (57%) surgically and 1070 (43%) endovascularly. A general trend towards fewer treated aneurysms was noted. The proportion of patients treated surgically decreased from 90% in 2012 to 20% in 2022. The age-adjusted decrease of surgical versus endovascular treatment was 6.9%/year for all aneurysms, 6.8% for ruptured aneurysms, and 6.8% for unruptured aneurysms. The decrease of surgical treatment was most evident in unruptured vertebrobasilar aneurysms (10.8%/year), unruptured communicating artery aneurysms (10.1%/year), ruptured communicating artery aneurysms (10.0%/year), and ruptured internal carotid aneurysms (9.0%/year). There was no change in treatment modality for middle cerebral artery aneurysms, of which 85% were still surgically treated in 2022. A trend towards an increasing size for treated ruptured aneurysms was found (p = 0.033). CONCLUSION: A significant shift of the treatment modality from surgical to endovascular treatment occurred for all aneurysm locations except for middle cerebral artery aneurysms. Whether this shift has affected long-term safety and patient outcomes should be assessed in the future.

Even short-term training improves the skills of novice exoscope users: a prospective laboratory experiment.

BACKGROUND: The surgical 3D exoscopes have recently been introduced as an alternative to the surgical microscopes in microneurosurgery. Since the exoscope availability is still limited, it is relevant to know whether even a short-term exoscope training develops the skills needed for performing exoscope-assisted surgeries. METHODS: Ten participants (six consultants, four residents) performed two laboratory bypass test tasks with a 3D exoscope (Aesculap Aeos®). Six training sessions (6 h) were performed in between (interval of 2-5 weeks) on artificial models. The participants were divided into two groups: test group (n = 6) trained with the exoscope and control group (n = 4) with a surgical microscope. The test task was an artificial end-to-side microsurgical anastomosis model, using 12 interrupted 9-0 sutures and recorded on video. We compared the individual as well as group performance among the test subjects based on suturing time, anastomosis quality, and manual dexterity. RESULTS: Altogether, 20 bypass tasks were performed (baseline n = 10, follow-up n = 10). The median duration decreased by 28 min and 44% in the exoscope training group. The decrease was steeper (29 min, 45%) among the participants with less than 6 years of microneurosurgery experience compared to the more experienced participants (13 min, 24%). After training, the participants with at least 1-year experience of using the exoscope did not improve their task duration. The training with the exoscope led to a greater time reduction than the training with the microscope (44% vs 17%). CONCLUSIONS: Even short-term training with the exoscope led to marked improvements in exoscope-assisted bypass suturing among novice microneurosurgeons. For the more experienced participants, a plateau in the initial learning curve was reached quickly. A much longer-term effort might be needed to witness further improvement in this user group.

Variation in Severity-Adjusted Resource use and Outcome for Neurosurgical Emergencies in the Intensive Care Unit.

BACKGROUND: The correlation between the standardized resource use ratio (SRUR) and standardized hospital mortality ratio (SMR) for neurosurgical emergencies is not known. We studied SRUR and SMR and the factors affecting these in patients with traumatic brain injury (TBI), nontraumatic intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH). METHODS: We extracted data of patients treated in six university hospitals in three countries (2015-2017). Resource use was measured as SRUR based on purchasing power parity-adjusted direct costs and either intensive care unit (ICU) length of stay (costSRURlength of stay) or daily Therapeutic Intervention Scoring System scores (costSRURTherapeutic Intervention Scoring System). Five a priori defined variables reflecting differences in structure and organization between the ICUs were used as explanatory variables in bivariable models, separately for the included neurosurgical diseases. RESULTS: Out of 28,363 emergency patients treated in six ICUs, 6,162 patients (22%) were admitted with a neurosurgical emergency (41% nontraumatic ICH, 23% SAH, 13% multitrauma TBI, and 23% isolated TBI). The mean costs for neurosurgical admissions were higher than for nonneurosurgical admissions, and the neurosurgical admissions corresponded to 23.6-26.0% of all direct costs related to ICU emergency admissions. A higher physician-to-bed ratio was associated with lower SMRs in the nonneurosurgical admissions but not in the neurosurgical admissions. In patients with nontraumatic ICH, lower costSRURs were associated with higher SMRs. In the bivariable models, independent organization of an ICU was associated with lower costSRURs in patients with nontraumatic ICH and isolated/multitrauma TBI but with higher SMRs in patients with nontraumatic ICH. A higher physician-to-bed ratio was associated with higher costSRURs for patients with SAH. Larger units had higher SMRs for patients with nontraumatic ICH and isolated TBI. None of the ICU-related factors were associated with costSRURs in nonneurosurgical emergency admissions. CONCLUSIONS: Neurosurgical emergencies constitute a major proportion of all emergency ICU admissions. A lower SRUR was associated with higher SMR in patients with nontraumatic ICH but not for the other diagnoses. Different organizational and structural factors seemed to affect resource use for the neurosurgical patients compared with nonneurosurgical patients. This emphasizes the importance of case-mix adjustment when benchmarking resource use and outcomes.

Temporal Changes in CSF Cell Parameters After SAH: Comparison of Ventricular and Spinal Drain Samples.

BACKGROUND: Forty percent of patients with aneurysmatic subarachnoid hemorrhage (aSAH) develop acute hydrocephalus requiring treatment with cerebrospinal fluid (CSF) drainage. CSF cell parameters are used in the diagnosis of nosocomial infections but also reflect sterile inflammation after aSAH. We aimed to study the temporal changes in CSF parameters and compare external ventricular drain (EVD)-derived and lumbar spinal drain-derived samples. METHODS: We retrospectively identified consecutive patients with aSAH treated at our neurointensive care unit between January 2014 and May 2019. We mapped the temporal changes in CSF leucocyte count, erythrocyte count, cell ratio, and cell index during the first 19 days after aSAH separately for EVD-derived and spinal drain-derived samples. We compared the sample sources using a linear mixed model, controlling for repeated sampling. RESULTS: We included 1360 CSF samples from 197 patients in the analyses. In EVD-derived samples, the CSF leucocyte count peaked at days 4-5 after aSAH, reaching a median of 225 × 106 (interquartile range [IQR] 64-618 × 106). The cell ratio and index peaked at 8-9 days (0.90% [IQR 0.35-1.98%] and 2.71 [IQR 1.25-6.73], respectively). In spinal drain-derived samples, the leucocyte count peaked at days 6-7, reaching a median of 238 × 106 (IQR 60-396 × 106). The cell ratio and index peaked at 14-15 days (4.12% [IQR 0.63-10.61%]) and 12-13 days after aSAH (8.84 [IQR 3.73-18.84]), respectively. Compared to EVD-derived samples, the leucocyte count was significantly higher in spinal drain-derived samples at days 6-17, and the cell ratio as well as the cell index was significantly higher in spinal drain-derived samples compared to EVD samples at days 10-15. CONCLUSIONS: CSF cell parameters undergo dynamic temporal changes after aSAH. CSF samples from different CSF compartments are not comparable.

The prognostic role of preoperative neutrophil-to-lymphocyte ratio in upper tract urothelial carcinoma.

Introduction: The blood-based inflammatory marker, neutrophil-to-lymphocyte ratio (NLR), is a reliable prognostic biomarker for several cancers. Although the literature supports the correlation between preoperative NLR, clinicopathological characteristics, and oncological outcomes in upper tract urothelial carcinoma (UTUC), the cutoff of NLR is still debated. This study aimed to determine the prognostic value of NLR in patients with UTUC. Methods: This was a retrospective analysis of prospectively collected data from July 2012 to December 2022 evaluating patients with UTUC who underwent radical nephroureterectomy (RNU). NLR was calculated using the neutrophil and lymphocyte counts obtained a day before the surgery and the cutoff value was set as 2.5. Kaplan-Meier and Cox's proportional hazards regression were used to analyze the association between NLR and the oncological outcomes. Results: The study included 91 patients (78 males, 13 females) in the final analysis with a median follow-up of 49 months (8-130). The mean age of the patients with NLR <2.5 and NLR ≥2.5 was 56.88 years and 56.35 years, respectively, and the pathological stage was pT1 in 48%, pT2 in 20.88%, pT3 in 27.47%, and pT4 in 3.30% of the patients. Multivariable Cox regression analysis showed that the preoperative NLR ≥2.5 was significantly associated (Hz = 7.17) with higher T stage, lymphovascular invasion, necrosis, nodal involvement, adjuvant chemotherapy, and worse overall survival (OS) (Hz = 9.87). The Kaplan-Meier analysis revealed an improved OS in patients with NLR <2.5, but a statistically significant difference in the recurrence-free survival was not found. Conclusions: Preoperative NLR is an easily available, inexpensive, and important prognostic biomarker of survival in patients with UTUC and has a potential role in risk stratification by predicting adverse clinicopathological characteristics.

How I do it: surgery for spinal arteriovenous malformations.

BACKGROUND: Spinal arteriovenous malformations (AVM) are rare lesions. They may present with intramedullary hemorrhage or edema, often inducing severe neurological deficits. Active treatment of spinal AVMs is challenging even for experienced neurosurgeons. METHOD: Anticipation of anatomy and AVM angiocharacteristics from preoperative imaging is key for successful treatment. Information gathered from MRI and DSA has to be then matched to intraoperative findings. This is a prerequisite for reasonably safe and structured lesion removal. CONCLUSION: We provide a structured approach for surgical treatment of spinal AVMs, supplemented by high-resolution video and imaging material.

Effect of antiplatelet and anticoagulant medication use on injury severity and mortality in patients with traumatic brain injury treated in the intensive care unit.

BACKGROUND: Antiplatelet and anticoagulant medication are increasingly common and can increase the risks of morbidity and mortality in traumatic brain injury (TBI) patients. Our study aimed to quantify the association of antiplatelet or anticoagulant use in intensive care unit (ICU)-treated TBI patients with 1-year mortality and head CT findings. METHOD: We conducted a retrospective, multicenter observational study using the Finnish Intensive Care Consortium database. We included adult TBI patients admitted to four university hospital ICUs during 2003-2013. The patients were followed up until the end of 2016. The national drug reimbursement database provided information on prescribed medication for our study. We used multivariable logistic regression models to assess the association between TBI severity, prescribed antiplatelet and anticoagulant medication, and their association with 1-year mortality. RESULTS: Of 3031 patients, 128 (4%) had antiplatelet and 342 (11%) anticoagulant medication before their TBI. Clopidogrel (2%) and warfarin (9%) were the most common antiplatelets and anticoagulants. Three patients had direct oral anticoagulant (DOAC) medication. The median age was higher among antiplatelet/anticoagulant users than in non-users (70 years vs. 52 years, p < 0.001), and their head CT findings were more severe (median Helsinki CT score 3 vs. 2, p < 0.05). In multivariable analysis, antiplatelets (OR 1.62, 95% CI 1.02-2.58) and anticoagulants (OR 1.43, 95% CI 1.06-1.94) were independently associated with higher odds of 1-year mortality. In a sensitivity analysis including only patients over 70, antiplatelets (OR 2.28, 95% CI 1.16-4.22) and anticoagulants (1.50, 95% CI 0.97-2.32) were associated with an increased risk of 1-year mortality. CONCLUSIONS: Both antiplatelet and anticoagulant use before TBI were risk factors in our study for 1-year mortality. Antiplatelet and anticoagulation medication users had a higher radiological intracranial injury burden than non-users defined by the Helsinki CT score. Further investigation on the effect of DOACs on mortality should be done in ICU-treated TBI patients.

Small amount of alcohol did not deteriorate microsurgical dexterity: a prospective laboratory study.

BACKGROUND: Alcohol consumption has been reported to deteriorate surgical performance both immediately after consumption as well as on the next day. We studied the early effects of alcohol consumption on microsurgical manual dexterity in a laboratory setting. METHOD: Six neurosurgeons or neurosurgical residents (all male) performed micro- and macro suturing tasks after consuming variable amounts of alcohol. Each participant drank 0-4 doses of alcohol (14 g ethanol). After a delay of 60-157 min, he performed a macrosurgical and microsurgical task (with a surgical microscope). The tasks consisted of cutting and re-attaching a circular latex flap (diameter: 50 mm macrosuturing, 4 mm microsuturing) with eight interrupted sutures (4-0 multifilament macrosutures, 9-0 monofilament microsutures). We measured the time required to complete the sutures, and the amplitude and the frequency of physiological tremor during the suturing. In addition, we used a four-point ordinal scale to rank the quality of the sutures for each task. Each participant repeated the tasks several times on separate days varying the pre-task alcohol consumption (including one sober task at the end of the data collection). RESULTS: A total of 93 surgical tasks (47 macrosurgical, 46 microsurgical) were performed. The fastest microsurgical suturing (median 11 min 49 s, [interquartile range (IQR) 654 to 761 s]) was recorded after three doses of alcohol (median blood alcohol level 0.32‰). The slowest microsurgical suturing (median 15 min 19 s, [IQR 666 to 1121 s]) was observed after one dose (median blood alcohol level 0‰). The quality of sutures was the worst (mean 0.70 [standard deviation (SD) 0.48] quality points lost) after three doses of alcohol and the best (mean 0.33 [SD 0.52] quality points lost) after four doses (median blood alcohol level 0.44‰). CONCLUSIONS: Consuming small amount of alcohol did not deteriorate microsurgical performance in our study. An observed reduction in physiological tremor may partially explain this.

Recurrence of brain arteriovenous malformations in pediatric patients: a long-term follow-up study.

BACKGROUND: Previously thought to be congenital, AVMs have shown evidence of de-novo formation and continued growth, thus shifting thoughts on their pathophysiology. Pediatric AVM patients have been reported to be more prone to develop AVM recurrence after a seemingly complete cure. Therefore, we assessed the risk of AVM treated in childhood to recur in adulthood after a long-term follow-up in our own cohort. METHODS: Control DS-angiography was arranged during 2021-2022 as part of a new protocol for all AVM patients who were under 21 years of age at the time of their treatment and in whom the treatment had occurred at least five years earlier. Angiography was offered only to patients under 50 years of age at the time of the new protocol. The complete eradication of AVM after the primary treatment had been originally confirmed with DSA in every patient. RESULTS: A total of 42 patients participated in the late DSA control, and 41 of them were included in this analysis after excluding the patient diagnosed with HHT. The median age at the time of admission for AVM treatment was 14.6 (IQR 12-19, range 7-21 years) years. The median age at the time of the late follow-up DSA was 33.8 years (IQR 29.8-38.6, range 19.4-47.9 years). Two recurrent sporadic AVMs and one recurrent AVM in a patient with hereditary hemorrhagic telangiectasia (HHT) were detected. The recurrence rate was 4.9% for sporadic AVMs and 7.1% if HHT-AVM was included. All the recurrent AVMs had originally bled and been treated microsurgically. The patients with sporadic AVM recurrence had been smoking their whole adult lives. CONCLUSIONS: Pediatric and adolescent patients are prone to develop recurrent AVMs, even after complete AVM obliteration verified by angiography. Therefore, imaging follow-up is recommended.

Acute ischemic stroke in a university hospital intensive care unit: 1-year costs and outcome.

BACKGROUND AND PURPOSE: Little is currently known about the cost-effectiveness of intensive care of acute ischemic stroke (AIS). We evaluated 1-year costs and outcome for patients with AIS treated in the intensive care unit (ICU). MATERIALS AND METHODS: A single-center retrospective study of patients admitted to an academic ICU with AIS between 2003 and 2013. True healthcare expenditure was obtained up to 1 year after admission and adjusted to consumer price index of 2019. Patient outcome was 12-month functional outcome and mortality. We used multivariate logistic regression analysis to identify independent predictors of favorable outcomes and linear regression analysis to assess factors associated with costs. We calculated the effective cost per survivor (ECPS) and effective cost per favorable outcome (ECPFO). RESULTS: The study population comprised 154 patients. Reasons for ICU admission were: decreased consciousness level (47%) and need for respiratory support (40%). There were 68 (44%) 1 year survivors, of which 27 (18%) had a favorable outcome. High age (odds ratio [OR] 0.95, 95% confidence interval [CI] 0.91-0.98) and high hospital admission National Institutes of Health Stroke Scale score (OR 0.92, 95% CI 0.87-0.97) were independent predictors of poor outcomes. Increased age had a cost ratio of 0.98 (95% CI 0.97-0.99) per added year. The ECPS and ECPFO were 115,628€ and 291,210€, respectively. CONCLUSIONS: Treatment of AIS in the ICU is resource-intense, and in an era predating mechanical thrombectomy the outcome is often poor, suggesting a need for further research into cost-efficacy of ICU care for AIS patients.

Current state of high-fidelity multimodal monitoring in traumatic brain injury.

INTRODUCTION: Multimodality monitoring of patients with severe traumatic brain injury (TBI) is primarily performed in neuro-critical care units to prevent secondary harmful brain insults and facilitate patient recovery. Several metrics are commonly monitored using both invasive and non-invasive techniques. The latest Brain Trauma Foundation guidelines from 2016 provide recommendations and thresholds for some of these. Still, high-level evidence for several metrics and thresholds is lacking. METHODS: Regarding invasive brain monitoring, intracranial pressure (ICP) forms the cornerstone, and pressures above 22 mmHg should be avoided. From ICP, cerebral perfusion pressure (CPP) (mean arterial pressure (MAP)-ICP) and pressure reactivity index (PRx) (a correlation between slow waves MAP and ICP as a surrogate for cerebrovascular reactivity) may be derived. In terms of regional monitoring, partial brain tissue oxygen pressure (PbtO2) is commonly used, and phase 3 studies are currently ongoing to determine its added effect to outcome together with ICP monitoring. Cerebral microdialysis (CMD) is another regional invasive modality to measure substances in the brain extracellular fluid. International consortiums have suggested thresholds and management strategies, in spite of lacking high-level evidence. Although invasive monitoring is generally safe, iatrogenic hemorrhages are reported in about 10% of cases, but these probably do not significantly affect long-term outcome. Non-invasive monitoring is relatively recent in the field of TBI care, and research is usually from single-center retrospective experiences. Near-infrared spectrometry (NIRS) measuring regional tissue saturation has been shown to be associated with outcome. Transcranial doppler (TCD) has several tentative utilities in TBI like measuring ICP and detecting vasospasm. Furthermore, serial sampling of biomarkers of brain injury in the blood can be used to detect secondary brain injury development. CONCLUSIONS: In multimodal monitoring, the most important aspect is data interpretation, which requires knowledge of each metric's strengths and limitations. Combinations of several modalities might make it possible to discern specific pathologic states suitable for treatment. However, the cost-benefit should be considered as the incremental benefit of adding several metrics has a low level of evidence, thus warranting additional research.